Vol. 24 No. 03 Jul-Sep 2015

Dalal ALQahtani                                        BDS, MSc, M Ed

INTRODUCTION

Peripheral ameloblastoma (PA) is uncommon subtype of ameloblastoma. In fact it is the rarest variant, which accounts for about 1 to 10% of all ameloblastomas.¹ In contrast to the intraosseous locally aggressive ameloblastoma, PA is soft tissue tumor with indolent biological behavior.^2,3 It has been theorized that this tumor may arise from remnants of dental lamina beneath the oral mucosa or from the basal cells of the oral epithelium.^4,5 PA tends to occur between the 5^th and 7^th decades of life with an average reported age of 52 years.² Clinically, PA is usually a painless lesion that commonly affects the mandibular gingiva.⁶ Because PA has non-specific clinical presentation, it is mostly considered as pyogenic granuloma or fibroma⁶. We report a case of PA that was observed in a 32-year-old man presenting with a gingival swelling in the lingual mandibular premolar area.

CASE REPORT

A 32-year-old Indian heavy-smoker manpresented to the oral surgery clinic with painless gingival swelling on the left side of the mandible. The lesion was asymptomatic and had been noticed by the patient two years ago before the consultation. Intra-oral examination showed a sessile pink to red in color gingival mass and was located on the lingual gingiva between the left mandibular 2^nd premolar and 1^st molar (Fig. 1). The lesion was firm with granular

Figure 1: Intra-oral picture of gingival mass on the left mandibular premolar-molar area.

surface. Orthopantomogram (OPG) was taken and showed no remarkable changes (Fig. 2). Clinically, the diagnosis was pyogenic granuloma based on the clinical presentation.  Under local anesthesia, the lesion was surgically excised with 1 mm safe margin, formalin-fixed and sent for histopathologic examination.   Grossly, the excised specimen was a whitish-brown, firm soft tissue mass measured 1.3 cm x 0.7 cm x 0.3 cm. Microscopically, the examination showed multicentric down-growth and

Figure 2: Orthopantomogram (OPG) of the case showing no remarkable changes.

budding of the basal layer of the surface epitheliumwith some tumor cells were observed lying free in the connective tissue stroma (Fig. 3). Most of the proliferating islands exhibited peripheral rows of palisaded columnarcells that showed reverse polarization and

Figure 3: A low-power view of tumor cells arranged in islands within a fibrous stroma exhibiting multicentric connections with the surface epithelium (haematoxylin and eosin (H & E).

hyperchromatism with infrequent mitosis. The major pattern of the proliferating nests is follicular with some areas showing acanthomatous and cystic changes (Fig. 4). In the lumen of some of the cystic areas neutrophil infiltrate was seen. No cell atypia or pleomorphism was noted. The connective tissue stroma was collagenous and mildly infiltrated by chronic inflammatory cells. Additional immunohistochemical studies for CK19, Ber-Ep4 and Ki-67 were ordered. The tumor islands were partially positive for CK19 with marked reaction in their luminalareas (Fig. 5), and negative for Ber-Ep4. Ki-67 was positive in 5% of the cells, which were found mainly in the in the basal/parabasal layers of the epithelial islands (Fig. 6). Based on the clinical, histopathology and immunohistochemistry results, the lesion was finally

Figure 4: Ameloblastoma islands in follicular arrangements showing palisading nuclei of the peripheral cells (H and E, original magnification ×10).

Figure 5: Tumor cells showing positivity for CK19 (immunhistochmistery (IHC), original magnification ×4)

Figure 6: Tumor cells showing 5% positivity for Ki-67 in the in the basal/parabasal layers (IHC, original magnification ×20).

diagnosed as peripheral ameloblastoma.

DISCUSSION

Odontogenic tumors are uncommon unique lesions of the jaw bones. They comprise a heterogeneous group of lesions that is derived from epithelium or ectomesenchym, or both.⁷ Though these lesions share the common origin from the tooth-forming apparatus, they possess diverse histopathologic forms and clinical behavior. Some of these lesions represent a true neoplastic while others are a tumor-like hamartomatous lesions.⁸

PA is a rare soft tissue odontogenic tumor that was first described in the literature by Kuru in 1911.⁹ In 2005, the World Health Organization (WHO) classified PAas one of the distinctive subtypes of ameloblastoma.¹ This is because of its extraosseous location and less aggressive clinical behavior compared with the conventional ameloblastoma.¹⁰ Although PA is rare, it is the 2^nd most common peripheral odontogenic tumor (28% of cases), preceded by odontogenic fibroma.¹¹ Similar to the conventional ameloblastoma and other odontogenic tumors, the etiopathogenesis of PA is poorly understood and the origin is still unclear. Nevertheless, hypotheses have been suggested that it could originate from the epithelial rests of dental lamina or from the basal layer of the oral epithelium.^4,5 In fact, many of the reported cases of PA (one of them is our case) were described to be in connection with surface epithelium suggesting PA might be derived from the surface epithelial layer.^12,13 On the other hand, other cases were reported to be completely in the connective tissue without contact with surface epithelium suggesting that it might be to be derived from dental lamina residuals.^2,5,14 Genetically, one study reported genetic aberration in chromosome 7 (trisomy) in PAwhich may play a role in its tumorigenesis.¹⁵

PA is typically presented as slowly growing painless mass with smooth surface. It is more in males than females by ratio of 1.9:1, and frequently occurs on the middle age of life with mean age of 52 years.² In regard to the location, it is most commonly found on the mandibular premolar region with percentage of 33%.² Our reported case presented most of these clinical characteristics: A male patient with gingival swelling on the premolar-molar area. However, the patient here is 32 years old, which considered younger than the reported mean age of PA.

In PA, the step of detailed radiological investigation is essential to rule out any bone involvement and the  misdiagnosis of central ameloblastoma. In the current case, radiological exam didn’t indicate any bone

involvement, which directed the diagnosis toward peripheral lesions.

Although PA is rare extraosseous tumor, the clinical diagnosis of gingival swellings should involve PA as differential diagnosis since it resembles clinically other gingival swellings including pyogenic granuloma, traumatic fibroma, peripheral odontogenic fibroma, peripheral giant cell granuloma, and peripheral ossifying fibroma.² Those lesions could be excluded based on the histopathlogical examination.

Under microscope, PA should be differentiated fromperipheral squamous odontogenic tumor, peripheral odontogenic fibroma and oral basal cell carcinoma^1,2,16. The present case showed the typical features of ameloblastoma with islands exhibiting follicular and acanthomatous patterns. It has been shown that those two patterns are the most common in PA.² Occurrence of calcifications in PA is not common finding, although it was reported recently in one case.¹¹

Currently, the role of immunohistochemistry is limited in diagnosing odontogenic tumors as these tumor types are largely identified by their morphologic features. However, some markers can be used to help in distinguishing the odontogenictumors from nonodontogenicones.  For this purpose, it has been shown that CK19 and Ber-Ep4 can be usedto differentiate between PA and basal cell carcinoma¹⁶. Our case showed diffuse positivity for CK19 and negativity for Ber-Ep4 confirming the diagnosis of PA.In addition, the positive reaction of PA neoplastic cells to CK19 indicates that PA is most likely to originatefrom remnants of odontogenic epithlium⁵. The present case also showed low proliferating activity (Ki-67=5%) which indicates low-level ofaggressiveness of this tumor compared with intraosseous ameloblastoma that was shown to have greater expression of the

proliferative markers.^5,17 In fact, the labeling index of Ki67 has been linked to the patient’s age, the gross appearance of the excised specimen (solid, mixed, cystic), general histological patterns and the cytological pattern of the outer layer cells of ameloblastoma.¹⁷

Because of the indolent biological behavior of PA, it has been recommended that this tumor can be treated conservatively by local excision with small free margin.^2,10 Up to date, there is no reported cases of malignant transformation of PA, although some cases have been published in regard to PA with malignancy.^2,18 The recurrence rate is low, and close follow up is advised, especially for PA with atypical features.¹⁰

CONCLUSION

We have reported a case of peripheral ameloblastoma in the gingival region because of its low incidence and the need to include this lesion on the differential diagnosis of swellings affecting the gingiva.

Author Contribution: DAQ collected the clinical and histopathological data, drafted, review and finalized the paper.

Disclosure: Author declares no conflict of interest in any form.

REFERENCES

1. Barnes L, Eveson JW, Reichart P, Sidransky D, World Health Organiza- tion classification of tumours: pathology and genetics of head and neck tumours. eds. Lyon; IARC Press: 2005.
2. Philipsen HP, Reichart Pa, Nikai H, Takata T, Kudo Y. Peripheral ameloblastoma: Biological profile based on 160 cases from the literature. Oral Oncol 2001;37:1727.
3. Bhat Vadisha, Bhandary Satheesh Kumar B, Bhat Shubha P. Extraosseous Ameloblastoma of Maxillary Gingiva- A Case Report. Indian J Surg Oncol 2014;5:211-213.
4. Ide Fumio, Obara K, Mishima K, Saito I, Horie N, Shimoyama T, et al. Peripheral odontogenic tumor: A clinicopathologic study of 30 cases. General features and hamartomatous lesions. J Oral Pathol Med 2005;34:552-557.
5. Kishino M, Murakami S, Yuki M, Iida S, Ogawa Y, Kogo M, et al. A immunohistochemical study of the peripheral ameloblastoma. Oral Dis 2007;13:575-580.
6. López-Jornet Pía, Bermejo-Fenoll Ambrosio. Peripheral ameloblastoma of the gingiva: The importance of diagnosis. J Clin Periodontol 2005;32:125.
7. Neville BW, Damm DD, Allen CM Bouquot JE. Oral & maxillofacial pathology. 3rd ed. Pennsylvania; W.B. Saunders Company: 2008.
8. Tjioe Kellen Cristine, Damante José Humberto, Oliveira Denise Tostes. The Onset of a Peripheral Ameloblastoma. Case Rep Oncol Med 2012;2012(c):14.
9. Kuru. Ueber das adamantinoma. Zentralbl Allg Pathol 1911;22:291.
10. Renu Yadav, Anubha Gulati, Rahul Sharma SatyaNarain. Peripheral Ameloblastoma: Review of Literature and Case Presentation Ind J Multidisciplinary Dent 2011;1:135-139.
11. Alexandre Nelise, Sedassari Bruno Tavares, De Fábio. Peripheral Ameloblastoma with Dystrophic Calcification: An Unusual Feature in Non- Calcifying Odontogenic Tumors Braz Dent J 2014;25:253-256.
12. Ide Fumio, Mishima Kenji, Miyazaki Yuji, Saito Ichiro, Kusama Kaoru. Peripheral ameloblastoma insitu: an evidential fact of surface epithelium origin. Oral Surgery, Oral Med Oral Pathol Oral Radiol Endodontology 2009;108:763-767.
13. Ide F. Peripheral ameloblastoma of the buccalmucosa. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:653-4; author reply 654-655.
14. Vanoven Bryan J, Parker Noah P, Petruzzelli GuyJ. Peripheral ameloblastoma of the maxilla: a case report and literature review. Am J Otolaryngol – Head Neck Med Surg 2008;29:357-360.
15. Manor Esther, Delgado Bertha, Joshua Ben Zion,Brennan Peter A, Bodner Lipa. Trisomy 7 as sole aberration in peripheral ameloblastoma of the mandible. J Oral Maxillofac Surg 2013;71:1217-1219.
16. Lentini M, Simone a, Carrozza G. Peripheral ameloblastoma: Use of cytokeratin 19 and Ber-EP4 to distinguish it from basal cell carcinoma. Oral Oncol Extra 2004;40:79-80.
17. Sandra F, Mitsuyasu T, Nakamura N, ShiratsuchiY, Ohishi M. Immunohistochemical evaluation of PCNA and Ki-67 in ameloblastoma. Oral Oncol 2001;37:193198.
18. Califano L, Maremonti P, Boscaino A, De Rosa G,Giardino C. Peripheral ameloblastoma: report of a case with malignant aspect. Br J Oral Maxillofac Surg 1996;34:240-242.

1.Department of Oral Medicine and Diagnostic Sciences (DDS), College of Dentistry, King Saud University, Riyadh, Saudi Arabia

Corresponding author: “Dr Dalal ALQahtani” < dalalq@ksu.edu.sa  >

Khurram Parvez Sardar¹                         BDS, MDS

Iqra Sam Sam Ali Raza²                          BDS

Mahira Shafi³                                               BDS

INTRODUCTION

Anxiety is an unpleasant or overwhelming sense of apprehension and often marked by psychological signs (as sweating, tension, increase pulse).One of the major difficulties encountered by the clinician during dental care is anxiety which has been identified as a barrier to dental visits¹.

Dental anxiety is defined as the response to situations in which the source of the threat to the individual is indefinable, indistinct or not immediately present. Anticipatory anxiety prior to dental procedures is commonly experienced.  Dental anxiety is patient’s psychological state and response to the stressful environment of dental OPD such as dentist wearing gloves and masks, instruments, sight of needle, blood and the dental chair .It totally depends upon patient mind’s eye².

Dental anxiety is a frequent problem among patients, it is a feeling that something terrible is going to happen in relation to dental treatment, it reflects biochemical changes in the body that result in losing control, increase heart rate and perspiration³. It is a common fear; approximately 6-15% of population suffers from high dental fear and avoidance worldwide. The onset of dental anxiety is thought to begin in the childhood, highly rise in adults and decreased with age. It is ranked fourth among common fears and ninth among intense fears³. Dental anxiety is a dilemma for the dental professionals as well because it renders treatment more difficult. Oral diseases are major health concerns and they may boost up by dental anxiety among dentally apprehensive patients⁴.

Dental anxiety, a problem for many adults and children, acts as a barrier to treatment, by avoiding and/or attending treatment irregularly or for visiting a dentist for emergencies only. Patient anxiety poses major management problems for the dental team, such as additional time required for treatment, missed appointments, and raised pain thresholds that’s why the management of dentally anxious patients is a major cause of stress for clinicians^2,3.

A variety of factors associated with patients reporting of dental anxiety were previously reported.These include but are not limited to previous painful or traumatic dental experiences, fear of lack of control and type of personality to name a few^3,4. Previous regional studies on this subject lack use of a validated questionnaire to measure the anxiety of patients in a dental setting. The objective of this study was to use Modified Dental Anxiety Scale (MDAS) and Dental Fear Survey (DFS) to quantify the fear and anxiety in a dental setting.

METHODOLOGY

The cross-sectional study was conducted in Oral diagnosis department of at OJHA campus of Dow University of Health Sciencesfor a time period of 6 months. Total 100 patients were assessed. All patients of 18 years and above irrespective of gender that attended dental OPD were included in this study. The patients who were suffering from generalized anxiety disorder and who were physically disabled were excluded from the study.The sample contained two age groups which were assessed and compared. First group was (18-30 years) n=74 and second group was (>30 years) n=26.The descriptives of age and gender are presented in table no. 1.

Before oral history, examination and diagnosis, the patients were asked to self-assess their dental anxiety by answering a questionnaire containing measurements of Modified dental anxiety scale (MDAS)(appendix 1) and dental fear survey (DFS)(appendix 2)⁴. The questionnaire consisted of 20 questions asked in two different scales (Modified Dental Anxiety Scale and Dental Fear Survey)

Table 1: Descriptive statistics for age and gender

, began with a brief description of dental anxiety and the study purpose was to identify the factors that were intensifying /or alleviating dental anxiety. The respondents were specifically asked to what extent he or she experienced anxiety when visiting the dentist. A simplified 5-point-scale answering format was devised for each question ranging from not anxious to extremely anxious and measured in point from 1 to 5, respectively.

The survey also included questions in which respondents rated attributions for their anxiety such as feeling lack of control, perspiration, having heart beat and breathing rate faster and negative experience. Additional questions asked from the respondents to indicate what might enhance their anxiety in the dental OPD like stressful environment, smell in the dental OPD and so many people observing the respondents during their dental treatment.

Patients filled out the forms before their treatment in the waiting hall. Those patients who were uneducated and were unable to read and understand were helped by the facilitator.Data was analysed using SPSS version 19. Mean and standard deviation was calculated for quantitative variables where-as frequency and percentage was calculated for qualitative variables.

RESULTS

The results showed that dental anxiety level in male was 45.3% and in female was 54.64%.In younger participant i.e. (18-30 years) 79.5% and in older participants (>30years) 24.0%. Theseresults illustrate that female and the younger participants enclose high level of anxiousness than the counterpart, as shown in (Table 2).

Out of 48 male respondents 13.5% were extremely anxious, 17.6% were severely anxious, 17.6% were fairly anxious, 5.4% were slightly anxious and 10.8% were not anxious. Out of 52 female participants 28.4% were

Table 2: Incidence of dental anxiety among patients

extremely anxious, 16.2% severely anxious, 8.1% fairly anxious, 10.8% slightly anxious and 6.8% not anxious.

The highest percentage of anxiety is found with tooth pull(71.80%),however the level of anxiety get raised by the sight of injection(69.80), which is the second superior cause of anxiety. Other reasons which the dentist mostly ignores are the stressful and tensed environment of dental OPD which also rated high among respondents(63.60%). The patient also get apprehensive and maynot visit the dentist as they get influenced by the superfluous stories and bad experiences heard from their friends and relatives(62.60%). The drill i.e. the hand piece also found among the top fifth cause of anxiety, patient get panic by the sound of drill and feel more pain than the existing(60.80%).

The fear of dentist and dental treatment causes squeal of symptoms that the patient presents either during or before the procedure. In the dental fear index, most of the respondents presents with heart rate increase nearly every time during the dental treatment. Other symptoms such as nausea, aspiring foreign body, and breathlessness were less significant in our results (Graph 1).

Graph 1: Percentages of factors affecting dental anxiety in descending order

DISCUSSION

The present study confirms earlier research findings that younger persons show more dental fear than older ones and that women are more fearful than men. Study showed that female are more anxious to dental treatment than male this is because of the difference in brain chemistry of male and female, as the fright fight and flight response are more readily active in female than in male, partly as a result of action of estrogens and progesterone, female are more responsive to a particular stimulus. Another reason is that males tend to hide their fear due to their conventional gender role. One of the reasons female are more anxious about going to the dentist is due to traditional perception about ‘not going to the male dentist’ and going to the female dentist only.Secondly this study showed that showed that younger participants (18-30) scored higher dental anxiety than the older participants >30 years. The reason behind this is that the lack of experience of visiting the dentist and not knowing the procedure which is going to be performed⁵. Visiting a dentist is one of the rarest norms and it is routinely postponed until a serious symptom appears.According toa study, uneducated patients were dentally more anxious than the educated ones and patients who had no income and income less than ten thousand rupees were dentally more anxious than those who had higher income.Retired patients were dentally less anxious than the younger counter parts⁶.

The study showed highest dental anxiety was due to the fear of tooth extraction in patients attending DUHS OPD. Patients overestimate the pain they feel prior to the procedure⁷ as the root portion of the tooth is firmly locked in the socket so the dentist needs to expand the socket by applying optimum pressure. The anxiety during extraction occur due to the fact that the patient is unable to differentiate between pain and pressure because the local anaesthesia given only blocks the pain sensation but the nerve fibres that carry the pressure sensations are not blocked.

As far as fear of needle is concerned, similar proportion of male (49%) and female (52%) were found to be anxious. The needles are always the element of fear. Fear of needle includes fear of pain associated with injection, fear that the needle will slip, needle will break, and injection will not provide sufficient anaesthesia.

Stressful and tensed environment of the dental OPD affects patient before sitting in the dental chair.

Resultsrelated to stressful environment showed out of 48 male respondents 6.8% were extremely anxious, 14.9% severely anxious, 17.6% fairly anxious, 18.9% slightly anxious and 6.8% not anxious. Out of 52 female respondents 14.9% were extremely anxious, 24.3% severely anxious, 9.5% fairly anxious, 17.6% slightly anxious and 4.1% not anxious. The outcome of this stress would be either the patient walk away or returns back with the pessimistic observation.Patient perceive the tensed atmosphere of OPD, unfriendly behaviour of dentist, vision of  unnecessary instruments, sight of blood, lack of positive relationship between dentist and patient⁹.

Superfluous stories heard by relatives and friends about dental treatment render people backing off visiting the dentist¹⁰.

Some people enclose painful encounters with the dental drill; thinking of the sound of the hand piece alone will make them anxious. According to our results the sound of dental drill has following perceptions. Out of 48 male participants 6.8% were extremely anxious, 10.8% severely anxious, 21.6 fairly anxious, 14.9% slightly anxious and 10.8% not anxious. Out of 52 respondents 2.7% were extremely anxious, 12.2% severely anxious, 5.4% fairly anxious, 21.6% slightly anxious and 28.4% not anxious¹¹.

Smells are very powerful emotional triggers. This is because cells in the nose which process smell input send signals directly to the olfactory bulb, which is a part of the limbic system – an ancient part of the brain which is responsible for basic emotions like fear. Unpleasant smell in the dental office e.g. smells of eugenol, pulperyl, cresophane and others increase level of anxiety preoperatively¹². Out of 48 male respondents 6.8% were extremely anxious to smell, 9.5% severely anxious, 20.3% fairly anxious, 18.9% slightly anxious and 9.5% not anxious. Out of 52 female respondents 9.5% were extremely anxious, 20.3% severely anxious, 10.8% fairly anxious, 20.3% slightly anxious and 9.5% not anxious. Many dentists do not explain the procedure which is going to perform in the patient’s mouth thus increases anxiety¹³. Out of 48 male respondents 4.1% were extremely anxious, 13.5% severely anxious, 25.7% fairly anxious, 18.9% slightly anxiousand 2.7% not anxious. Out of 52 female respondents 5.4% were extremely anxious, 13.5% severely anxious, 20.3% fairly anxious, 21.6% slightly anxiousand 9.5% not anxious. Other questions that are asked in this scale were aboutgoing to the dentist, sitting in the waiting room and procedure of teeth cleaning which showed least anxiety and most of the participants were not anxious^14-15.

According to Dental Fear Survey out of n=48 male participants 47.9% and out of n=52 female respondents61.5% were having theirheart rate increased during dental procedure. Epinephrine used in the local anaesthesia cause sympathomimetic reactions such as apprehension, tachycardia and perspiration. Anxiety and sweating are interrelated with one another, the response that body made in danger, is a preventive response. Hyperhydrosis is common with patients having extreme anxiety. Out of n=48 male participants 50% and out of n=52 female participants 61.5% rated that they perspire during dental treatment¹⁵.

Anxiety leads to physiological and neuroendocrine changes which will affect digestive tract and one feels nauseated,out of n=48 male participants 45.8% and out of n=52 female respondents 50% reported nausea during treatment. Dental procedures involving isolation techniques such as placing rubber dam, cotton rolls, suction tips, mouth props etcmay result on unpleasant and nauseating experience.

Usually people anticipate more pain than they truly feel during the treatment which in response makes their muscle tense,breathing rate increase (hyperventilated) and become restless. Out of n=48 male participants

37.5% and out of n=52 female participants 51.9% expressed their anxiety by muscle stiffness. Out of n=48 male participants 41.6% and out of n=52 female participants

55.7% hyperventilated. Out of n=48 male participants 22.9% become restless and out of n=52 female participants 50% become restless.

The fear of dental treatment most commonly results in vasovagal syncope as quoted by many books, but according to our research the syncopal episode was minimal i.e. 8% participants from the total sample(n=100)reported faints during the treatment.But a fainting episode does not mean that he or she is anxious or feared of the dental treatment. Medical conditions such as hypotension, hypoglycaemia, cerebral ischemia, dehydration and diabetes should also be considered which may be alarming if not managed^15,16.

The extent of fear that leads to cancellation of appointment was not significantly found in the study only 17% participants out of our samples reported cancelling their appointment because of fear of dentist and treatment.

Due to small sample size and limited location of the study the results cannot be generalized, but still the study may enhance the body of knowledge regarding patient’s apprehension, fear of visiting the dentist and assessed the different anxiety level in patients attending  dental OPD (OJHA  campus)  DUHS.

Although this research assessed anxiety levels in relation to gender and age groups mainly, we recommend further studies to investigate actual causes of stress and anxiety and also develop methods to lower such untoward incidents.

CONCLUSION

Female gender, younger participants (18-30 age groups) tooth extraction were found to be related to increased level of dental anxiety.

Author Contribution:

Disclosure: None disclosed

REFERENCES

1. Eitner S, Wichmann M, Paulsen A, Holst S.. Dental anxiety and oral health. J Oral Rehab 2006;33:588-93.
2. Gili R Samorodnitzky.Self assessed dental status, oral behaviour, DMF and dental anxiety.J Dent Edu 2005; 69(12):1385-1388.
3. Appukuttan DP, Tadepalli A, Cholan PK, Subramanian S, Vinayagavel M.Prevalence of dental anxiety among patients attending a dental educational institution in Chennai, India–a questionnaire based study.Oral Health Dent Manag.2013;12(4):289-294.
4. Jaakkola S, Rautava P, Alanen P, Aromaa M, Pienihäkkinen K, Räihä H, Vahlberg T, Mattila ML, Sillanpää M. Dental Fear: One Single Clinical Question. Open Dent J 2009; 3:161-166.
5. Humphris GM, Dyer TA, Robinson PG. The modified dental anxiety scale: UK general public population norms in 2008 with further psychometrics and effects of age. BMC Oral Health 200;26:9-20.
6. Bare LC, Dundes L. Strategies for combating dental anxiety. J Dent Educ. 2004;68:1172-1177.
7. Gao X, Hamzah SH, Yiu CK, McGrath C, King NM. Dental fear and anxiety in children and adolescents: qualitative study using YouTube. J Med Internet Res. 2013 22;15:e29.
8. Tran D, Edenfield SM, Coulton K, Adams D. Anxiolytic intervention preference of dental practitioners in the Savannah, Chatham County area: a pilot study. J Dent Hyg. 2010;84:151-155.
9. Topf M. Hospital noise pollution: an environmental stress model to guide research and clinical interventions. J Adv Nurs2008;31: 520-528.
10. Heaton LJ, Carlson CR, Smith TA, Baer RA, de Leeuw R Predicting anxiety during dental treatment using patients’self-reports: less is more. J Am Dent Assoc. 2007;138:188-195.
11. Bhola R, Malhotra R. Dental Procedures, Oral Practices, and Associated Anxiety: A Study on Lateteenagers. Osong Public Health Res Perspect 2014;5: 219-232.
12. Robin O, Alaoui-Ismaïli O, Dittmar A, Vernet-Maury E.Basic Emotions Evoked by Eugenol Odor Differ According to the Dental Experience. A Neurovegetative Analysis. Chem Senses 1999;24:327-335.
13. Newton T, Asimakopoulou K, Daly B, Scambler S, Scott S. The management of dental anxiety: time for a sense of proportion. Br Dent J 2012;213:271-274.
14. Appukuttan D, Subramanian S, Tadepalli A, Damodaran LK. Dental anxiety among adults: An epidemiological study in South India. North Am J Med Sci 2015;7:13-18.
15. Milgrom P, Newton JT, Boyle C, Heaton LJ, Donaldson N.The effects of dental anxiety and irregular attendance on referral for dental treatment under sedation within the National Health Service in London.Community Dent Oral Epidemiol. 2010;38:453-459.
16. Hupp, J. R., & Tucker, M. R, eds. Contemporary oral and maxillofacial surgery 5th edition 2008.Pg 3233.

1.Assistant Professor Department of Science of Dental Materials Dr Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences.
2.House Officer DrIshrat-ul-Ebad Khan Institute of Oral Health Sciences Dow University of Health Sciences.
3.House Officer DrIshrat-ul-Ebad Khan Institute of Oral Health Sciences Dow University of Health Sciences.
Corresponding author: “Dr Khurram Parvez Sardar ” dr_khurramparvez@hotmail.com

Hafiz Taha Mehmood¹                         BDS

Imtiaz Ahmed²                                       BDS, FCPS, M.Orth

Gul-e-Erum³                                            BDS, FCPS, M.Orth

Hana Pervez⁴                                           BDS

INTRODUCTION

The esthetics of the lips and their role in providing the completeness of the face are very important as they are one of the most integral components of facial aesthetics.The lips have been compared to a frame that sets off the image of smile, encompassing teeth and gums.The plump and well defined lips are the symbol of beauty and they are unavoidable for the youth, attraction, fertility, sex appeal and femininity.¹ People having less attractive faces tend to be detached from the surroundings² and are more likely to face isolation. Upper and lower lips are important facial features and their rolein determining the facial esthetics is inevitable.³

Lip esthetics is one of the major reasons why many patients seek orthodontic treatment. Albino et al¹  proposed that 80% patients have undergone orthodontic treatment for esthetic concerns.Enhancing or correcting the shape, fullness and symmetry of your lips can make your smile seems fuller. Studies have suggested that thick, prominentand plump lips are considered to be more beautiful and youthful^5,6,7 and thin and loose lips are the signs of agedness.^8,9 Therefore youthful and plump appearance of the lips strengthens the youth and health on our face. People with less prominent lower lips often opt for lip enhancement surgeries.¹⁰ Lip esthetic surgeries, being performed, many of which produce more prominence in lips.¹¹

Improving smile esthetics, a component of orthodontic treatment, is always of great concern for orthodontists and orthodontic patients. In determining smile esthetics, vermillion height is one of the key factors.¹² Among the various lip esthetics parameters, we used vermilion height in our study anddeterminedthe orthodontists’ and patients’ perception of lip esthetics byusing images in which vermillion heights were adjusted incrementally. Vermilion height is defined as the length between superior vermillion border and inferior vermillion border.

The study was conducted in order to obtain answers for the questions: (i) among the following images which vermillion height is considered to be more attractive by orthodontist, residents and patients? (ii)Do orthodontist, orthodontic residents and patients have similar perception of lip esthetics? (iii) Is there any significant difference exist between orthodontist and residents in the perception of lip esthetics? (iv)Overall difference in male and female judgesin evaluation of lip esthetics?

METHODOLOGY

The study was conducted from March 2014 to August 2014 in multiple universities, hospitals and private clinics.

Images

To evaluate lip esthetics, anextra-oral frontal view photograph from a volunteer was taken exposing

the lower third of the face. The average vermillion heights were measuredusing vernier caliper clinically and it was found for upper lip from labralesuperius and crista philtri 8.2mm and 9.3mm respectively, and for lower lip from labraleinferius 9.2mm. Labralesuperius is the highest point of vermilion on upper lip and labraleinferius is the lowest point of vermillion in lower lip. The crista philtri is the point on each elevated margin of philtrum just above the vermillion line. The image was modified using Adobe CS5.The average vermillion height was increased and decreased 0.5mm incrementally from -2.0mm to +2.0mm. Overall 9 images were constructed and titled capital alphabetical letters and arranged at random. The images were printed and displayed on separate cards and the respondentswere shown single image at a time to limit the comparison. (Figure 1)

Visual Analogue Scale

Visual analogue scale has been used for assessment of pain intensity.^13,14 The respondentswere asked to enter their name, gender and age, prior to viewing the images on the data forms and thenrate the images using visual analogue scale.In the given scale, 0 being the minimum and 10 being the maximum esthetic score for each image. The VAS was used to allow the individual to show their personal evaluation in rating the images. VAS has already been used for evaluation of smile and lip esthetics.^15,16,17(Figure 2).

Groups Distribution

The raters are divided among three groups. Group 1 involves orthodontists from different dental universities and private clinics of Karachi, Pakistan and includes7 males and 3 females, aged 32 to 45years. Group 2 involves orthodontic residents from three universities of Karachi, Pakistan including Ishrat-ul-Ebad Khan Institute of Oral Health Sciences (Dow University of Health Sciences), Altamash Institute of Dental Medicine and Karachi Medical and Dental College (Karachi, Pakistan) and includes 10 males and 21 females, aged 25 to 35 years. Group 3 involves orthodontic patients from Ishrat-ulEbad Khan Institute of Oral Health Sciences, DUHS Karachi, Pakistan and includes 15 males and 31 females, aged 15 to 35 years.

Sample Size Calculation

Using PASS version 11.0, one-way ANOVA power analysis with 95% confidence interval, sample sizes were calculated for each group separately, depending on our pilot study. The effect size was estimated at 0.5860. For group 1 we needed7 individuals and for group 2 and 3, we needed 30 individuals.  The total sample would be 67 subjects achieved 99% power to detect differences among the means versus the alternative of equal means using an F test with a 0.05000 significance level. The size of the variation in the means is represented by their standard deviation which is 0.95. The common standard deviation within a group is assumed to be 1.615. The group allocation ratio for group 1 would be 0.25 and for group 2 and 3 would be 1.0.

Statistical Analysis

Statistical analyses were done using Statistical Package for the Social Sciences (SPSS for windows version 21). To evaluate the median of the esthetic scores given by the respondents, Kruskal-Wallis was performed for nine different images for each group separately at 95% level of significance. Mean with standard deviation were also calculated.

RESULTS

Group 1 included 10 orthodontists, group 2 composed of 31 residents and group 3 had 46 patients. The participants found images -0.5mm, 0mm and +0.5mm most attractive and the images -2mm, -1.5mm and +2mm least attractive.

The Kruskal-Wallis test showed that there were significant differences among the three groupsin the median esthetic scores. The median esthetic scores for each vermilion height are shown in figure 1.

Figure 1: The median esthetic scores for each vermillion height among the three groups.(O represents Orthodontists; OR, Orthodontic Residents and OP, orthodontic Patients)

Among orthodontists, the Kruskal-wallis test showed the significant differences (p<0.05) in the median scores for the nine vermillion heights. (Figure 1)

Figure 2: The median esthetic scores for each vermillion height in overall male judges.

Figure 3: The median esthetic scores for each vermillion height in overall female judges.

DISCUSSION

Aging is a complex procedure and many changes occur in the soft tissues with aging than in hard tissues of the face.¹⁸  The change most significant to orthodontist is the lips that sag downward relative to the teeth, with the resultant decrease in exposure of the upper incisors, and increase in exposure of the lower incisors.¹⁹ Lip thickness reaches its maximum width during adolescent period, and then gradually decreases, to an extent that some women seek treatment. So, if an adolescent patient is undergoing orthodontic treatment, then leaving the lips somewhat prominent will likely to appear ideal as a result of aging.

Due to the ongoing trend of having more prominent and thick lips²⁰, we might have expected that the respondents would find thick lip images more acceptable. The results of this study suggested that the images within or near the average ranges were found to be attractive to the respondents. According to the results of our study, from the series of nine images; orthodontist, orthodontic residents and orthodontic patients found images -0.5mm, 0mm and +0.5mm most attractive and the images -2mm, -1.5mm and +2mm least attractive.The results of this study were consistent with the findings of Hideki loi et al²¹ , the ranges of vermillion heights preferred by orthodontists and orthodontic patients were similar to our results.In our study, orthodontist and patients had similar perception as neither thick nor thin lips were preferred. We therefore propose that the results of orthodontic treatment mayliewithin the range of -0.5mm to +0.5mm vermillion heights.

The orthodontists and orthodontic residents have difference in their perception of lip esthetics. The orthodontists assigned highest esthetic score to 0mm and +0.5mmvermillion heights and orthodontic residents to -0.5mm vermillion heights. (Figure 4)

Figure 4: Line with markers showing the significant differences in the scores between the three groups. (O represents Orthodontists; OR, Orthodontic Residents and OP, orthodontic Patients)

There was gender difference in the perception of lip esthetics. Male respondents favored narrow and distinct range, while the female respondents favored relatively broader tolerancein vermillion height changes in evaluationof vermillion heights. 0mm average vermillion height was found to be attractive for overall male respondents while a range from -1mm to +0.5mm was attractive for overall female respondents.

There were some limitations in the study. The sample size for orthodontists was small, owing to the fact that there are only few orthodontists in Karachi. We tried to include all of them, but due to the unavailability at the time of research being conducted, the sample size remained small. The images were computer generated and there were some degrees of human error. The images were only one individual, and we have included only one variable for the assessment of lip esthetics, vermillion height and showed only the lower third of the face. Another limitation is that the respondents have perceived the lip esthetics, when the lips were in rest position only.

CONCLUSION

• Images with or near the average vermillion height was considered to be attractive by orthodontist, orthodontic residents and patients.
• The ranges of vermillion heights preferred by orthodontists and orthodontic patients were similar. . Majority of male preferred 0mm as more attractive while female respondents showed broad tolerance for vermillion height.

Author Contribution: IA and GE convinced the idea, HTM and HP collected the data and wrote the manuscript, IA and GE revised and gave final approval.

Disclosure: None disclosed

REFERENCES

1. Maloney BP. Cosmetic surgery of the lips. Facial Plast Surg 1996; 12: 265-278.
2. Shaw WC. The influence of children’s dentofacial appearance on their social attractiveness as judged by peers and lay adults. Am J Orthod.1981;79:399-415.
3. Chan EK, Soh J, Petocz P, Darendeliler MA. Esthetic evaluation of Asian-Chinese profiles from a white perspective. Am J Orthod Dentofacial Orthop. 2008;133:532-538.
4. Albino JE, Cunat JJ, Fox RN, Lewis EA, Slakter MJ, Tedesco LA. Variables discriminating individuals who seek orthodontic treatment. J Dent Res 1981. 60:166167.
5. Auger TA, Turley PK. The female soft tissue pro?le as presented in fashion magazines during the 1900s: a photographic analysis. Int J Adult Orthod Orthognath Surg. 1999;14:7-18.
6. Bisson M, Grobbelaar A. The Esthetic Properties of Lips: A Comparison of Models and Nonmodels. Angle Orthod. 2004;74:162-66.
7. Sforza C, Laino A, D’Alessio R, Grandi G, Tartaglia GM, Ferrario VF.Soft-tissue facial characteristics of attractive and normal adolescent boys and girls. Angle Orthod. 2008;78:799-807.
8. Penna V, Stark GB, Eisenhardt SU, Bannasch H, Iblher N.The Aging Lip: A Comparative Histological Analysis of Age-Related Changes in the Upper Lip Complex.Plast Reconstr Surg:2009;124:624-28.
9. Nabil F. Correction of Thin Lips: “Lip Lift”.Plast Reconstr Surg. 1984;74:33-41
10. Modarai F, Donaldson JC, Naini FB. The influence of lower lip position on the perceived attractiveness of chin prominence. Angle Orthod. 2013;83:795-800.
11. Ho LC. Augmentation cheiloplasty. Br J Plast Surg. 1994;47:257-62.
12. McNamara L, McNamara JA Jr, Ackerman MB, Baccetti T. Hard- and soft-tissue contributions to the esthetics of the posed smile in growing patients seeking orthodontic treatment. Am J Orthod Dentofacial Orthop. 2008;133:491-99.
13. CarlssonAM.  “Assessment of chronic pain. I. Aspects of the reliability and validity of the visual analogue scale.” Pain 16;1983: 87-101.
14. Collins SL, Moore RA, McQuay HJ.The visual analogue pain intensity scale: what is moderate pain in millimetres?. Pain. 1997;72: 95-97.
15. Krishnan V, Daniel ST, Lazar D, AsokA..”Characterization of posed smile by using visual analog scale, smile arc, buccal corridor measures, and modified smile index.”Am J Orthod Dentofac Orthop. 2008;133: 515-23.
16. Parekh SM, Fields   HW,     Beck    M, RosenstielS..Attractiveness of variations in the smile arc and buccal corridor space as judged by orthodontists and laymen.Angle Orthod. 2006;76: 557-63.
17. Chong, Hui Theng, et al. “Comparison of White and Chinese perception of esthetic Chinese lip position.” The Angle Orthodontist 84.2 (2013): 246-253.
18. Friedma O. “Changes associated with the aging face.” Facial Plast Surg Clin North Am. 2005;13:371-80.
19. Perenack J. “Treatment options to optimize display of anterior dental esthetics in the patient with the aged lip.” J Oral Maxillofacsurg 2005;63:1634-41.
20. Borelli C,Berneburg M. Beauty lies in the eye of the beholder? Aspects of beauty and attractiveness. J Dtsch Dermatol Ges. 2010;8:326-30. .
21. Ioi H, Kang S, Shimomura T, Kim SS, Park SB, Son WS, Takahashi I. Effects of vermilion height on lip esthetics in Japanese and Korean orthodontists and orthodontic patients. Angle Orthod. 2014;84:239-45.

1. Department of Orthodontic DIKIOHS, Karachi, Pakistan

2.Associate Professor, Head of Department of Orthodontic, DIKIOHS, Karachi, Pakistan.

3. Assistant Professor, Department of Orthodontic, DIKIOHS, Karachi, Pakistan.

4.Department of Orthodontic, DIKIOHS, Karachi, Pakistan.

Corresponding author: “Dr Hana Pervez” < hinaprervez951@gmail.com >

Waqas Yousuf¹                                                       BDS

Moiz Khan²                                                             BDS

Abubakar Sheikh³                                               BDS, FCPS

INTRODUCTION

Mandibular first molars are one of the most commonly treated teeth in dentistry.

Anatomical knowledge regarding this tooth is essential to produce a desirable and consistent treatment outcome. Themost common configuration of permanent mandibular first molars is having two roots¹ (mesial and distal) and three canals (mesiobuccal, mesiolingual and distal). However, many variations have been documented in different populations. One such significant variation is the presence of three rooted permanent mandibular first molar.

This variationappears to be significant in particular populations with as high as 33.33% in Taiwanese²population,14.5 % in Chinese³ population, 16% in Malay⁴ population,12.5% in Eskimo⁵ population,19.2% in Thai⁶ population,22.7% in Japanese⁷ population and 16% in American and Canadian Indian⁸ populations and relatively of low significance in other populations such as German⁹ with prevalence of 1.35%, 2.5% in southeastern Brazilian¹⁰ and 3.12% in Senegalese¹¹ populations.

These anatomical variations when not taken into consideration can lead to treatment failures.¹² Thus, knowledge of this prevalence in any particular region is of great value to local practitioners. Surprisingly, little work has been done on this topic onthe Pakistani population.

The aim of our study was to determine the prevalence of three rooted permanent mandibular first molars in southern Pakistani population. This will give us better understanding of anatomical variation of their root structure in order to achieve more predictableand successful endodontic outcomes.

METHODOLOGY

Study design: Cross Sectional

Setting: Removed by editor

Sample size: 405

Purposive Sampling:

All patients coming to the dental OPD for routine dental checkup.

Inclusion Criteria:

1. Both male and female patients
2. Age between 12 to 75 years
3. Patients with both permanent mandibular firstmolars erupted.

Exclusion Criteria:

1. Teeth with external root resorption.
2. Grossly carious teeth where root anatomy may notbe appreciable.
3. Radiograph of poor quality.

Data Collection:

After being sanctioned by theInstitutional Ethical Review Committee all patients visiting the Dental Hospital OPD who fulfill the inclusion criteria (after taking informed consent)were included in this study.Two periapical radiographs were taken of bothlower mandibular first permanent molars with a paralleling technique at 30° mesial angulation¹³ and the numbers of roots were assessed using Digora® Optime software for prevalence and symmetry. Peri-apical radiographs were assessed independently by two assistant professors in the department of Endodontics. In case of difference of opinion, the radiograph was shown to the professor in the department and his decision was taken as final.

Data Analysis:

SPSS version 21 was used for data analysis. Descriptive statistics were computed.

RESULTS

Our findings showed an overall 3.2% prevalence of three rooted mandibular permanent first molar in a sample of Southern Pakistani population. In males, it was 3.5% and in females 3.0%. Overall bilateral prevalence was 1.0%. In males, it was 1.2% and in females 0.9%. Overall prevalence of 2.7% on the right and 1.5% on the left side was found. See: tables 1- 2.

Table 1: Overall and bilateral prevalence of three rooted permanent mandibular first molar n=405.

DISCUSSION

This cross sectional study demonstrated a significant prevalence of three rooted mandibular permanent first molars in a southern Pakistani population. The overall prevalence was 3.2%. Bilateral prevalence was 1.0%. Male to female distribution was fairly even. Males showed a prevalence of 3.5% and female showed a prevalence of 3.0%. See tables 1.

In order to determine this anatomical variation various screening methods can be used such as peri-apical radiographs¹³, cone beam computerized tomography (CB-CT)¹⁴, human extracted teeth¹⁵ and OPG. Although the most reliable method is CB-CT but it is not practical in most of the developing countries

because it is costrestrictive and is not widely available. Bilateral incidence is difficult to determine using extracted teeth since cases of bilateral extraction are very rare. OPG is one of the most widely used screening methods, however it gives a flattened image which contains superimposition and therefore is not conducive in determining the exact root morphology. Peri-apical series of radiograph is the most commonly

used and economical method of screening in the developing countries with minimal radiation exposure and limited training requirements. Peri-apical radiographs have an advantage over other radiographic methods (such as OPG) as it easy to perform tube shift technique and give a better idea of three dimensional root anatomy. According to American Dental Association (ADA)revised 2012 guidelines¹⁶, individualized radiographic exam consisting of selected peri-apical view can be taken of a new patient being evaluated for oral disease. A full mouth intraoral radiographic exam is preferred when the patient has clinical evidence of generalized oral disease or a history of extensive dental treatment.

Similarly, this racial variation even exists amongst different regions within south Asia. In a study by Garg et al.13 prevalence of 5.97% was found in an Indian population. Al-Nazhan et al¹⁷ found a similar prevalence in a Saudi Arabian population. In a Sri Lankan¹⁸ population 3% of the people had a three rooted mandibular first permanent molar and a prevalence of 10% was found in a Burmese¹⁹ population.

Table 3:  Prevalence of three rooted permanent mandibular first molar worldwide

The high incidence of three rooted mandibular permanent first molar in different regions of the worldindicates that dental treatment can result in failure if this anatomical variation is overlooked.

These findings are significant from an endodontic perspective. Although the prevalence is infrequent, one should always be aware of the possibility of the third root to preclude the possibility of treatment failure and to provide the best quality of treatment.

Similarly, from a surgical standpoint, the extraction of three rooted mandibular permanent first molar can be challenging and may require modification of technique if such an anatomical variation is not taken into consideration.

Orthodontically, three rooted mandibular first permanent molar can be utilized as an advantage in providing increased anchorage due to increased surface area of an additional root. Conversely, this can also prove to be a disadvantage in achieving the desired movement of such teeth.

CONCLUSIONS

Although there is a low prevalence of three rooted mandibular first permanent molar in southern Pakistani population, but it is significant enough to warrant caution when performing endodontic procedures on these teeth.

Author Contribution: WY contributed to the design, conception, data collection, and write up and gave the final approval. MK contributed to the design, conception, and data collection, write up and gave the final approval. AS contributed to the design, conception and gave the final approval. Disclosure: None disclosed

REFERENCES

1. Ash MM, Nelson SJ. Wheeler’s Dental Anatomy, Physiology, and Occlusion: W.B. Saunders; 2003.
2. Tu MG, Huang HL, Hsue SS, Hsu JT,Chen SY, Jou MJ, Tsai CC. Detection of Permanent Three-rooted Mandibular First Molars by Cone-Beam Computed Tomography Imaging in Taiwanese Individuals. J Endod. 2009;35:503507.
3. Walker RT, Quackenbush LE: Three-rooted lower firstpermanent molars in Hong-Kong Chinese. Br Dent J 1985;159:298-299.
4. Jones AW: The incidence of the three-rooted lowerfirst permanent molar in Malay people. Singapore DentJ.1980; 5:15-17.
5. Cruzon MEJ: Three-rooted mandibular permanentmolars in the Keewatin Eskimo. Can Dent Assoc.1971; 37:71-73.
6. Reichart PA, Metah D: Three-rooted permanentmandibular first molars in flue Thai. Community Dent Oral Epidemiol 1981; 9:191-192.
7. Sousa-Freitas JA, Lopes ES, Casati-Alvares L: Anatomicvariations of lower first permanent molar roots in two ethnic groups. Oral Surg 1971;31:274-278,
8. Somogyi CW. Three-rooted mandibular first permanentmolar in Alberta Indian children. Can Dent Assoc 1971; 37:105-106.
9. Schäfer E1, Breuer D, Janzen S.The prevalence of threerooted mandibular permanent first molars in a German population.J Endod. 2009;35:202-205. doi:1016/j.joen.2008.11.010. Epub 2008 Dec 12.
10. De Deus QD: Topografia da cavidade pulpar. Contribuição ao seu estudo. Doctorate thesis, Belo horizonte, 1960
11. Sperber GH1, Moreau JL. Study of the number of roots and canals in Senegalese first permanent mandibular molars.Int EndodJ.1998;31:117-122.
12. Slowey RR. Root canal anatomy. Road map to successful endodontics. Dent Clin North Am.1979; 23:555573.
13. Garg AK, Tewari RK, Kumar A, Hashmi SH, Agrawal N, Mishra SK. Prevalence of three-rooted mandibular permanent first molars among the Indian Population. J Endod.2010; 36:1302-1306.
14. Park. JB, Kim NR,  Park. S, Youngkyung Ko.Evaluation of number of roots and root anatomy of permanent mandibular third molars in a Korean population, using cone-beam computed tomography.Eur J Dent.2013; 7: 296-301.
15. Sert. S, Aslanalp. V and Tanalp. J. Investigation of the root canal configuration of mandibular permanent teeth in Turkish population. Int Endod J. 2004; 37: 494-499.
16. American Dental Association. Dental radiographic examinations: recommendations for patient selection and limiting radiation exposure. Revised 2012
17. Al-Nazhan S. Incidence of four canals in root-canal treated mandibular first molars in a Saudi Arabian subpopulation. Int Endod J.1999; 32:49-52,
18. Peiris R, Takahashi M, Sasaki K, Kanazawa E. Root and canal morphology of permanent mandibular molars in a Sri Lankan population. Odontology.2007; 95:16-23.
19. Gulabivala K, Aung TH, Alavi A, Ng YL.Root and canal morphology of Burmese mandibular molars. Int Endod J. 2007;  34:359-370.

1. House officer at Fatima Jinnah Dental Hospital
2. Demonstrator, Department of Oral Pathology and Oral Surgery, Fatima Jinnah Dental Hospital
3. Assistant Professor, Department of endodontics, Fatima Jinnah Dental Hospital
Corresponding author: “Dr Waqas Yousuf ” < waqas.yousuf@hotmail.com >

Hira Akhtar¹                                                                           BDS

Farah Naz²                                                                             BDS, FCPS

Farzeen Shafiq Waseem³                                                 BDS, Mphil

Danish Shahnawaz³                                                           BDS, Mphil

INTRODUCTION

World Health Organization regards dental caries and periodontal disease as two most important global, oral health burdens. In most developed countries, dental caries affects 60-90% of schoolchildren and the vast majority of adults.¹ Dental caries is a multifactorial disease, its initiation, development and progression is influenced by numerous factors, such as the patient’s health, diet, presence of bacteria in the oral cavity, salivary parameters and fluoride exposure.^1-6 The distribution, severity andrisk for caries development vary significantly for different age groups, individuals, teeth and teeth surfaces. Thus, caries preventive measures should be based on sound knowledge and understanding of the predicted risk.²

Historically, caries was considered as a progressive disease which ultimately destroyed the tooth unless dentist performed surgical intervention.⁷ But with new evidencebased research leading to better understanding of caries process a paradigm shift from curative to preventive dentistry has taken precedence. Nowadays, management of caries is more directed towards identification of risk indicators, which are the existing signs that the disease process has occurred and modification of risk factors, which are the attributes or exposuresignificantly associated with the development of a disease.^{8, 9} This change of paradigm shift is in accordance with the National Institute of Healthconsensus statement¹⁰ which outlines methods for theidentification, modification and/or elimination of all associated risk indicators and factors for improved caries diagnostic, preventive and treatment strategies.

Caries risk assessment determines the probability of caries incidencei.e., the number of new cavities or incipient lesions over a given period of time.⁷ Over the past years, various caries risk assessment tools have been developed, modified and adapted toassist clinicians in determining a patient’s risk.¹¹ Numerousmodels have beendeveloped byAmerican Academy of Pediatric Dentistry¹¹, Caries management by risk assessment (CAMBRA)¹¹, Cariogram¹² and American Dental Association.¹¹

The American Dental Association (ADA)has developed two forms: one for patients 0-6 years old, and other for patients older than 6 years.¹³  ADA periodically updates these forms, on the basis of feedback regarding their usefulness by its members and advancements in science. These form measure patients at low, moderate or high risk of caries by using a scoring system.All positive responses in the low risk column carry a score of 0. Responses in the moderate risk column hold score of 1 each and responses in the high risk column carry score of 10 each. An overall score of 0 indicates patient has low risk for development of caries. A single high factor, or score of 10 or above places the patient at high risk and score in between 1 and 9 indicates the patient at moderate risk for caries development.¹⁴

Although extensive research has been conducted to assess caries risk in children; there is scarce evidence available for risk assessment on the global adult and elderly population.^7,9,15,16 Also no previous evidence is available regarding caries risk assessment involving Pakistani adult population. The presence of this research gap has led towards difficulty for the dental practitioners in the application of caries risk assessment models on the adult and elderly population.This article emphasizes on the importance of conducting of caries risk in adults as a prerequisite for appropriate caries preventive and treatment decisions.The objective of this study was to conduct caries risk assessment in the adult population.

METHODOLOGY

A cross sectional study was conducted in the diagnostic department of Operative dentistry at the dental section of Dow International Medical College. Sample size was calculatedusing 2 proportion formula¹⁷ with 99% confidence interval and 95% power of test. 19% proportion of low and very low risk patients¹⁶, 81% proportion of moderate and high risk patients¹⁶, the sample size calculated was 11 in each risk categories and the total sample size determined was 44.

For this study non- probability, purposive sampling was applied. Data was collected over a period of 01 month. Patients aged between 18 to 60 years, who were permanent residents of Pakistan, agreed to sign a consent form, completed the risk questionnaire and dental examination and previously did not have caries risk assessment done were included in the study. Whereas, patients who were not fitting within the age range, declined to sign the consent form or previously had risk assessment done and thus, received any preventive and therapeutic treatment were excluded from this study.

Total sample of 50 patients, fitting the inclusion criteria were selected. After obtaining a signed inform consent from each patient, a modified version of American Dental Association risk assessment form¹⁸(Annex I) was filled. Dental examination was conducted. The overall, caries risk of the each patient was calculated. Results were conveyed to the patient. Diet counseling and subsequent treatment plan was advised to the patient.

Statistical Package for Social Sciences (SPSS) Version 16 was used to enter and analyze data. Descriptive data analysis including frequencies, percentages and means were calculated in the study.

RESULTS

A total sample of 50 patients was recorded. The sample comprised more female (76%) than male patients (24%) [Figure1].The mean age was determined as 32.36 years. Caries risk assessment percentages were recorded as: 0% patient at low risk, 34% patients at moderate risk and 66% patients at high risk [Figure2].A vast majority of patients were recorded at high risk [Figure 2]. When risk percentages were compared on the basis of gender,

increased percentages (26%) of females were recorded at high risk whereas males had almost equal distribution among moderate and high risk categories [Figure 4]. The major contributing factors towards increased risk were: presence of three or more active carious lesions, extraction due to caries in the past 36 months and absence of a regular dental care system [Figure3].

DISCUSSION

Early detection of carious lesion along with incorporation of a preventive protocol regime is the central aim towards maintenance of a good oral health status. Caries risk assessment procedure can aid the dentist in achieving these goals. An ideal risk assessment model should be inexpensive, easy to use and time efficient with a high degree of accuracy in caries predictive value.⁸ In the present study, ADA risk assessment model was used to determine caries risk in the adult population. Thisstructured form was simple to adapt on our adult population, cost effective and the results were easily translated to the patient. Most importantly, this model was capable in correctly identifying the high risk patients in our population.

In the present study majority of the patients were recorded at high caries risk [Figure 2].When risk percentages were compared on the basis of gender, increased percentage (26%) of females were recorded at high risk whereas males had almost equal distribution among moderate and high risk categories  [Figure 4]. Giacaman ARsupports the results of our study, theyconducted caries risk assessment in Chilean adolescents and adults, 0.016%adults were recorded at low risk,21.6% at moderate risk and 59.4%adults at high caries risk.¹⁶ Caries risk assessment studies conducted in adults in China by Wei Xu¹⁹ and Turkey by Go¨kalp SG²⁰, have concluded that females had higher DMFT scores and higher prevalence of dental caries compared to males, these results are consistent with the findings in our study.

In this study the main contributing factors towards increased caries risk were the presence of three or more active caries lesion at the time of examination,teeth extracted due to caries in the past 36 months and absence of a regular dental care system [Figure 3]. Maher R conducted a national pathfinder study in all 4 provinces in Pakistan on 1146 individuals, which documented that 55% children(aged12-15years) and in 78% adults (aged 35-65 years) had active caries lesions and frequency of missing tooth in adult was recorded at 82%.²¹ Another cross sectional study conducted by Siddiqui TM established that 52.7% rural and 47.3% of urban adult population in Karachi suffers from active dental caries.²² These studies support the high prevalence of active carious lesion among adult population that was determined in our study. Haseeb M²³ determined the causes of tooth extraction at a tertiary care center in Pakistan, they reported that 63.1% of alldental extractions were due to advanced dental caries, followed by periodontitis (26.2%),restoration failure (4.6%), trauma (3.2%) and miscellaneous local pathologies (2.9%) supporting the result of the present study that caries is most common contributing factor that leads to dental extraction.

An important contributing factor determined in our study was that 0% of patients had a regular dental care system[Figure 3]. Oral diseases like caries and periodontitis are preventable but results of this study show that an increase percentage of our adult population is at high risk. This can be accredited to factors such as poor oral hygiene, change in dietary habits, low literacy rate, lack of dental awareness and a general disregard towards dental care. Majority of Pakistani population visits dentist only as a last resort; as a result of which 90% of oral diseases remain undiagnosed.²⁴ Waseem FS observed that almost 48% of Pakistani population had never visited a dentist and 51% of the population visited the dentist only when they had a complaint.²⁵ Asadi SGR reported that 8% adult Pakistani population never cleaned their teeth while only 36% cleaned their teeth every day.²⁶ To counteract these measures oral health programs should be arranged to educate and promote good oral hygiene habits and regular recall programs should be instilled in clinical practice and patients should be kept on follow ups.

Caries risk assessment of communities allows identification of high caries risk group and determines specific treatment therapies and preventive applications that need to be carried out.⁵ Cariogram is a computerized software that uses an algorithm to determine caries risk of an individual and then presents it graphically in the form of a pie chart.²⁷ It is an objective and quantitative method for predicting caries risk of a patient. In many of the researches conducted Cariogram is chosen as tool of choice, because the results can be saved, printed, easily documented and clearly explained to the patients. Reported barrier towards using this model is inclusion of chair side salivary testing with microbial cultures.²⁸ These procedures are costly, time consuming and can delay the process until the culture results are provided by the laboratory.²⁸

When determining caries risk in children the most commonly used risk assessment tool is CAMBRA. The form employs an evidence-based approach to prevent or treat the cause of dental caries at the earliest stages before irreversible damage to the tooth takes place¹¹. Application of CAMBRA allows early intervention and the establishment of a dental home that could reduce the risk of early childhood caries and improve child`s oral and overall health.²⁹ Although no particular risk assessment model has been proven to be superior compared to others, scientific evidence claims that a structured multifactorial or a computer based model provides the best clinical practice and patient care.³⁰

Limitations of this workinclude, being a cross sectional, single centre study with a small sample size but the information revealed in this research is alarming.It is our recommendation that further longitudinal studies be conducted on a larger scale in order to obtain a baseline data, as no statistical information regarding caries risk assessment is available on Pakistani population.

CONCLUSION

1. This study was performed using a modified version ofAmerican Dental Association caries risk assessment model in an effort to overcome the data insufficiency of caries risk in our population.
2. This model has successfully identified that our adultpopulation is at high caries risk.
3. Caries risk assessment can serve as an importantdiagnostic tool to identify the risk factors and therefore aid in reducing the high burden of caries in our adult population.

Paperpresented at 12thInternational and 32nd National PDA congress, held at Expo Centre Karachi, from January 23rd – 25th, 2015.

Author Contribution: HA conceived the idea and designed the study, recorded, analysed and interpreted the data and is responsible for the accuracy of the results and integrity of the research. Also wrote the manuscript and along with other authors was involved in critical review and final approval of the manuscript. FN supervised the project and along with Akhtar H was involved in the designing of the study, Critical review and final approval of the manuscript. FSW and DS along with the other authors were involved in the final approved version of the manuscript.

Disclosure: None disclosed

REFERENCES

1. Petersen PE, Bourgeois D, Ogawa H, Estupinan-Day S, Ndiaye C. The global burden of oral diseases and risks to oral health. Bull world health org. 2005;83:661-669.
2. Basavaraj P, Khuller N, Khuller RI, Sharma N. Caries risk assessment and control. J Oral Health Comm Dent. 2011;5:58-63.
3. Celik EU, Gokay N, Ates M. Efficiency of caries risk assessment in young adults using Cariogram. Eur J Dent. 2012;6:270.
4. Sheiham A, James WPT. A new understanding of the relationship between sugars, dental caries and fluoride use: implications for limits on sugars consumption. Pub Health Nutri. 2014;17:2176-2184.
5. Peker I, Mangal T, Erten H, Alp G, Avci E, Akca G. Evaluation of caries risk in a young adult population using a computer-based risk assessment model (Cariogram). J Dent Sci 2012;7:99-104.
6. Guo L, Shi W. Salivary biomarkers for caries risk assessment. J Cali Dent Assoc 2013;41:107.
7. Fontana M, Zero DT. Assessing patients’ caries risk. J Am Dent Assoc. 2006;137:1231-1239.
8. Ritter A, Eidson R, Donovan T. Dental Caries: Etiology, Clinical Characteristics, Risk Assessment and Management. In: Heymann H, Ritter A, Swift E, editors. Sturdevant’s Art and Science of Operative Dentistry. 6th ed. Canada: Mosby; 2012. p.64-70.
9. Fontana M, Gonzalez-Cabezas C. Minimal intervention dentistry: part 2. Caries risk assessment in adults. British Dental journal. 2012;213:447-451.
10. Diagnosis and Management of Dental Caries Throughout Life NIH Consensus Statement 2001 March 26-28; 18:1-24
11. Hurlbutt M. CAMBRA: Best Practices in Dental Caries Management. Academy of Dental Therapeutics and Stomatology. 2011.
12. Alian AY, McNally ME, Fure S, Birkhed D. Assessment of caries risk in elderly patients using the Cariogram model. J Can Dent Assoc. 2006;72(5):459.
13. http://www.ada.org/~/media/ADA/Science%20 and%20Research/Files/topic_caries_over6.ashx.
14. http://www.nysdental.org/img/uploads/file/topics _caries_over6.doc.
15. Asma M, Ho S, Yong J, Nor N, Yusof Z, editors. Developing A Caries Risk Assessment Model For Adults Patients Attending University Malaya Dental Clinic. List of conferences, seminars, lectures and workshops 38.
16. Giacaman RA, Miranda Reyes P, Bravo León V. Caries risk assessment in chilean adolescents and adults and its association with caries experience. Brazilian oral res. 2013;27:7-13.
17. Pocock SJ. Clinical Trials Of Practical Approach
18. http://www.ada.org/~/media/ADA/Public%20 Programs/Files/topics_caries_educational_over6.ashx.
19. Xu W, Lu H-X, Li C-R, Zeng X-L. Dental caries status and risk indicators of dental caries among middleaged adults in Shanghai, China. J Dent Sci. 2014;9:151157.
20. Gökalp S, Dogan BG, Tekçiçek M, Berberoglu A, Unlüer S. National survey of oral health status of children and adults in Turkey. Community Dent Hlth. 2010;27:1217.
21. Maher R. Dental disorders in Pakistan-A national pathfinder study. J Pak Med Assoc. 1991;41:250-252.
22. Siddiqui TM, Wali A, Siddiqui SH, Heyat U, Nadeem M, Shamim M. An Epidemiological Study of Prevalence of Dental Caries and Periodontal Disease among Adults in Deprived Areas-Karachi. J Oral Hlth Res. 2013;4:37.
23. Haseeb M, Ali K, Munir MF. Causes of tooth extraction at a tertiary care centre in Pakistan. JPMA-Journal of the Pak Med Assoc.2012;62:812.
24. Harchandani N. Oral Health Challenges In Pakistan And Approaches To These Problems Pak Oral Dent J. 2012;32(3).
25. Waseem FS, Hussain A, Maqsood A, Sultan M. Socioeconomic Status And Oral Health Care Attitudes: A Snapshot Of Karachi Based Teaching Hospital. Pak Oral Dent J. 2015;35(01).
26. Asadi SGR, Asadi ZG. Chewing sticks and the oral hygiene habits of the adult Pakistani population. International dental journal. 1997;47:275-278.
27. Ruiz Miravet A, Almerich Silla JM. Evaluation of caries risk in a young adult population. Medicina Oral, Patología Oral y Cirugía Bucal (Internet). 2007;12:412418.
28. http://www.aapd.org/assets/1/7/riskbasedtechbrief.pdf.
29. Ramos-Gomez F, Ng M-W. Into the future: keeping healthy teeth caries free: pediatric CAMBRA protocols. J Canadian Dent Assoc. 2011;39(10):723.
30. Twetman S, Fontana M, Featherstone JD. Risk assessment-can we achieve consensus? Community Dent Oral Epidemiol. 2013;41(1):e64-e70.

CONTINUING EDUCATION

1. Caries risk assessment can be defined as the probability of caries incidence over a given period of time.
   1. True
   2. False
2. The distribution, severity and risk for caries development do not vary significantly for different age groups, individuals, teeth and teeth surfaces therefore, universal preventive strategies can be applied to all individuals.
   1. True
   2. False
3. Risk indicators are not the direct causal factor of the disease but, merely the existing signs that the disease process has occurred.
   1. True
   2. False
4. The most common risk assessment tool, which is used to determine caries risk especially in children, is CAMBRA
   1. True
   2. False

Key:

1. True
2. False
3. True
4. True

1. Lecturer, Operative Dentistry, Dental section, Dow International Medical College, Dow University of Health Sciences
2. Associate Professor, Operative Dentistry, Dental section, Dow International Medical College, Dow University of Health Sciences. Consultant Dental Surgeon (part time) in Operative dentistry, Section of Dentistry, Department of Surgery, The Aga Khan University and Hospital, Karachi, Pakistan.
3. Assistant Professor, Department of Oral Biology, Dental section, Dow International Medical College, Dow University of Health Sciences
4. Lecturer, Operative Dentistry Dental section, Dow International Medical College, Dow University of Health Sciences
Corresponding author: “Dr. Hira Akhtar” < hira.akhtar@duhs.edu.pk >

Khola Ahmad Khan¹                                        BDS

Ahmad Waqas Javed²                                    BDS

Mariyah Javed³                                                 BDS

INTRODUCTION

Oral Squamous Cell Carcinoma (OSCC) is among the first eight most common cancers of the world.¹ In 2005 a cancer research survey reported that Pakistan has an increased risk for oral cancer and graded as the second most common cancer reporting country as 8.8% in both men and women.² Another global survey in 2005 on OSCC reported that more than one third of oral cancer was found in India and Pakistan.³ In 2000 Merchant and his coworkers observed that In Pakistan, females are more prone to oral cancers as compared to males.⁴

OSCC is a malignancy associated with multifactorial causative agent, combination of various factors like environmental, viral infections and genetic alteration which altogether results in a malignant lesion. Commonly OSCC occur in the presence of common premalignant conditions as Oral Leukoplakia, Oral Lichen Planus and Oral Submucous Fibrosis.¹ Other contributing factors are alcohol and tobacco usage associated with viruses like papilloma viruses, Epstein-Barr virus, herpes simplex virus.⁵

Squamous cell carcinoma (SCC), common head and neck malignancy, with reported 30,000 patients including oral and pharyngeal cancer diagnosed annually in the United States alone. Globally there are approximately 200,000 deaths annually, with minimal improvement in survival rates despite advances in surgery, radiation and chemotherapy.⁶

OSF is a chronic progressive premalignant condition and commonly reported in Taiwan, Bangladaish, Pakistan, Mainland China and India.¹ OSF is rarely seen in the United States and is seen among immigrants residing there, especially from South Asian population. Globally, OSF is found in 2.5 million people mostly from southern India and ranges from 0.2-2.3% in males and 1.2-4.57% in females.⁷ OSF has high morbidity because it causes inability to open mouth, trouble eating and eventually leading to nutritional deficits. Significant death rate since it can transform into OSCC.⁸ OSF as a precancerious condition has been proved by Pindborg and many other researchers and presented five characteristic points for its malignant tendency. Malignant transformation rate of OSF was found in the range of 7-13% depending on various studies mainly conducted in INDIA and Taiwan. The OSF geographic distribution is obvious as betal quid chewing habit (areca nut, slaked limeand others). So incidence of betal quid is directly propotional to severity of OSF that is an alarming situation in future.¹ Another main contributing factor in the incidence and progression of OSF is tobacco use and according to Brundtland study in 2000, worldwide approximately 5 million deaths have been recorded annually because of tobacco and its associated products.⁹ WHO released a report indicating these deaths would be double in next ten years since the use of tobacco products will peak 10 million yearly.¹⁰

SURVIVIN

Survivin is a recently characterized dual functioning protein that plays an important role in apoptosis suppression, cell division, blood vessel growth, immune regulation and tumor metastasis.

Survivin expression can be used to predict the prognosis of cancer, since its expression is increased in malignant neoplasms. Various pre -clinical trials have shown its resistance to anti-cancer drugs and ionizing radiations given to the patient. Survivin is weakly expressed in the areas where there is increase in apoptosis, radiations given to cancerous tissues, and sensitized neoplastic cells to chemotherapy.^11,12 Survivin expression is lowered in normal tissues and characterizes by selfrenewal and proliferation. Research revealed intense expression of survivin in solid neoplasms and blood cancers.¹³

Some studies detected the high expression of survivin protein in OSCC, which showed the important role of surviving in the progression of oral cancer.^14-16 So the main idea behind this study was to observe the expression of survivin with relation to betal quid and tobacco usage and its tendency to transform OSF condition into OSCC. Survivin expression assessed in present study described the importance of immunohistochemistry and it can be used as a tool for the detection of early carcinogenesis in OSF. Therefore finding the key molecule in OSF malignant transformation is urgent and may contribute to add on current knowledge on the prevention, diagnosis and therapy of this disease.

METHODOLOGY

Specimen Collection

All patients were evaluated as per inclusion and exclusion criteria. Tumors, OSF and healthy mucosa were taken at the time of surgical resection at Punjab Dental Hospital Lahore. Written informed consent was taken from all enrolled individuals. Proforma was provided, filled and signed by all enrolled subjects. The complete procedure was thoroughly explained to the patients. The clinical diagnosis and pathological stage of OSF is determined in terms of Pingborg criteria by the Department of Oral Pathology, Xiangya Hospital,

Central South University.^17,18 OSF was classified into three stages:

1. Stage I with mouth opening 45 mm
2. Stage II Restricted with mouth opening 20-44 mm3. Stage III – Mouth opening < 20 mm Forty diagnosed OSF cases were selected without OSCC or neoplastic disease. Punch biopsy was performed under local anesthesia, and the sample size measuring 5mm was taken from the affected buccal mucosa. Tissue Processing

Cautious resection of OSF tissue was taken from buccal mucosa and processed in an automated processor.

After 24 hours, specimens were fixed in 4% buffered formalin solution. Three sections each of 3 to 4 microns thickness were cut from each selected block using a rotary microtome. Two respective slides were made from one tissue specimen. One of them was made for Haematoxylin and Eosin staining and the other one was

Figure 1: Showing no expression of surviving in the epithelial cells.

Figure 2: Showing intense expression of surviving in the epithelial cells in which nucleus and cytoplasm showed positivity in brown and dense granules.

Figure 3: Showing Dense Underlying Connective Tissue on H&E

made for immunohistochemistry with survivin. Sections were taken on the charged slides and were processed for respective staining.²⁰

Microscopic interpretation

The prepared slides were seen under light microscope for the diagnosis of OSF and the findings noted down in proforma. Cytological findings

The findings in epithelium like presence of keratinization, thickness, dysplastic changes, inflammatory cells, pleomophishm, mitotic figures and hyperchromatism were recorded.

Apart from these the presence of fibrous tissue, hyalinization and inflammatory cells in the connective tissue was also noted and entered in the proforma. The readings were then entered onto the proforma of each subject, previously having their bio data.

Immunohistochemistry

An antibody will specifically bind to an antigen in the cells of tissue sections to produce an exclusive antibody-antigen complex that can be used for the

detection of specific molecule.²¹

Method

Immunohistochemical staining of survivin antibody was performed as follows

• The de-paraffinized tissues segments treated with heat induced epitope retrieval (HIER) earlier to immunohistochemistry staining processes. Water bath temperature was sustained at 95-99ºC and the tissue sections were placed in pre heated buffer solution for HIER.
• HIER was done for recommended 40 minutes at 95-99ºC.
• Once the sections in the buffer were cool down for 20 minutes at room temperature after the heat treatment, the slides were washed with buffer water. Salinized slides (code S3003) for better fixing of tissue sections along with target retrieving solution (code S1700) were suggested.
• Sections were cut in 3 to 4 £gm thickness and placed on poly-lysine coated slide. The slides were fixed in the oven at 58ºC to 60ºC for 50 to 60 minutes.
• The sections were brought to water (de wax in xylene) and hydration through a descending alcohol series followed by a through wash in running tap water.

Positive Control

Carcinoma of intestine and stomach were used as Positive controls for survivin and also stained as per manufactured advice. Statistical Analysis:

Statistical analysis was calculated with Statistical Package for Social Sciences (SPSS) software, version 20.00. Chi square test was applied to observe the association of age and gender with tobacco and betal nut chewing by observing the expression of survivin.

RESULTS

A total number of 40 samples from the buccal mucosa of the patients with oral submucous fibrosis were taken. Age range of the subjects was divided into two groups i.e. 18-30 years (26 patients) and 31-45 years (14 patients). Both genders were included with males (24 patients) and females (16 patients).

One sample from each subject was taken and 2 slides were prepared of a single subject with a sub total of 80 slides. Slides were stained with H&E and immunohistochemistry was done. After completing the proformas the results were compared with the variables.

Table 1: IRS ASSOCIATIONS

Table1.1: Association of survivin expression with age groups

Chi square was applied to observe the relation between survivin expression and Age groups, suggesting there is significant relation between the two variables. Results are given in the table 1. smoking daily

Table 2: Association of survivin expression with duration of smoking

Chi square test was applied to calculate level of significance with respect to duration of smoking and insignificant results were obtained, as shown in table 2.

Table 3: Association of survivin expression with frequency of smoking daily

Another comparison between survivin expression and frequency of smoking daily gave insignificant results when chi square test was applied. The results are shown in the table 3.

Table 4: Association of survivin expression with duration of betel nut (years) use

Association between survivin expression and duration of betel nut usage daily gave significant results and suggested that increasing the duration of betel nut use increases the IRS Levels i.e. both the percentage and intensity of survivin is increased. The results are shown in the table 4.

Table 5: Association of survivin expression with frequency of betel nut use daily

However no significant relation was seen between the survivin expression and the frequency of betel nut use. The results are given in the table 5.

DISCUSSION

Oral squamous cell carcinoma (OSCC) is the most dominant carcinoma, accounting for more than eighty percent of head and neck cancers.²²

In Pakistan, among all cancers, oral cancer is ranked as second prevalent cancer in females and third prevalent cancer in males.⁴

Oral premalignant lesions and OSCC are mainly treated on the basis of histological features, site involved, and stage of the disease. However, Oral health personnel should be aware of all the recent advances so the accurate, less time consuming diagnosis of oral premalignant lesions or OSCC can be made and eventually beneficial to the patient.²³

Hence OSF is considered as a pre malignant condition usually associated with betel quid chewing and tobacco intake. Microscopically it is characterized by epithelial atrophy, basal cell layer hyperplasia, excessive deposition of collagen fibers in connective tissue and surface keratinization. Malignant transformation rate of oral sub mucous fibrosis into squamous cell carcinoma is 7.6% .²⁴

Pre-cancerous conditions (33%) have a tendency to convert into OSCC. No absolute confirmation can be done histologically about their malignant transformation; therefore the need of new markers should be emphasized.¹⁶

Survivin an IAP which is expressed in tumors and also blood related malignancies.²⁵ Apoptosis has been revolutionary in cancer research and new cancer advances. It is the programmed cell death which is controlled genetically.²⁶ Survivin inhibits caspase 3 activity. Cytoplasmic survivin suppresses apoptosis whereas nuclear survivin controls cell division.²⁷

Inhibition of apoptosis results in tumour progression and expression of survivin can be related to its antiapoptotic activity induced by FAS/TNF legation, proapoptotic Bax, effector caspases, and many chemotherapeutic drugs.²⁸

L Lo Muzio in 2013, conducted a research in which the expression of survivin was seen both by IHC and western blotting in OSCC cases. A total number of 110 cases were taken for the study out of which 91 cases were strongly positive for survivin however the controlled group in which the normal oral mucosa was taken none of the case showed any positivity since survivin is expressed only in tumoral tissue and not in the normal mucosa. Tobacco used in two forms that is smoked tobacco in the form of cigarettes and smokeless tobacco which is chewed. A study was done by Merchant A in 2000 in Pakistan, in which 79 cases of OSCC were taken. Sixty eight percent were men, 22 years old (youngest) and 80 years old (eldest) with an average of 49 years. Patients having OSF were 19.1 times more expected to develop oral cancer than those with no OSF.⁴

The relationship of survivin expression with age, gender, size of tumor and involvement of nodes was insignificant.²⁹

About 20 of 40 (50%) OSF cases showed phosphorylation of survivin. Three/10 (30%) of early stage (mean score 0.231, SD 0.169) and 7/15 (46.7%) of moderately advanced stage of OSF were found to show weak survivin (mean score 0.515, SD 0.102). Out of the 15 advanced stage of OSF cases, 10 (66.7%) showed moderate survivin (mean score 1.687, SD 0.304). No statistically significant correlation was found between the survivin and the pathological stages of OSF (P>0.05).

Punch biopsy can be considered a safe, easy and valid procedure to take biopsies from oral mucosa for the diagnosis of lesions.³⁰

Chi-square test was applied to observe the relation between IRS score and Age groups, suggesting statistical significant (p=.031), however association between IRS score and gender, (p=.243) IRS and duration of smoking (p=.155), IRS and frequency of smoking daily and IRS and the frequency of betel nut use (p=.101), gave insignificant results (p=.276). IRS and duration of betel nut usage daily (p=.027).

A study conducted by Lo Muzio L in 2003, analyzed survivin expression in 10/30 cases (33%) of oral precancerous lesions without any malignant transformation, and 15/16 cases (94%) of oral precancerous lesions transformed into squamous cell carcinoma. Tumors originated from precancerous lesions, showed strong survivin positivity (100%). No significant relation was found between survivin expression and degree of dysplasia.¹⁶

In study by Ding YP in 2010, he investigated the role of survivin and caspase -3 in the development of oral cancer.¹⁷ OSCC and 28 cases of oral leukoplakia with dysplastic changes were seen. Immunohistochemical staining showed positivity with survivin in OSCC (21.89 ± 10.45) %. Caspase 3 was down regulated in dysplasia concluding survivin and caspase-3 are associated with carcinogenesis of the oral mucosa and survivin may restrain cell apoptosis by inhibiting caspase3.31

Tanaka C in 2003 conducted a study in which expression of survivin and its role in carcinogenesis was seen by immunohistochemistry .Premalignant lesions (37%) and malignancies (58%) showed strong positivity suggesting its role in the process of carcinogenesis.¹⁴

In the present study, association between Gender and history of smoking, duration of smoking, duration of betel nut use, frequency of smoking daily, frequency of betel nut use daily showed insignificant results (p>.05).

In contrast to the present study, the relationship of survivin expression with age, gender, size of tumor and involvement of nodes was also found insignificant by Millane and Ward.²⁹

The male to female ratio of oral sub mucous fibrosis may differ with area, but females have a gender predilection. A study from Durban, South Africa, a female predilection was observed, with a male-to-female ratio of 1:13.³²

It was confirmed by other studies, with a male-tofemale ratio of 1:7³³. In Pakistan, studies suggested a male-to-female ratio of 1:2.3.⁸

Patients with both OSF and OSCC were young males in a study by Chaturvedi with a history of chewing betel nut had better prognosis, less metastases to nodes and well differentiated³⁴, however in the present study no significant association was seen between gender and dysplastic changes.

Considering age, Chi-square test was applied in the present study to observe the relation between Age groups and history of smoking, duration of smoking, frequency of smoking daily, duration of betel nut usage daily and frequency of betel nut use suggesting there is statistical significant relation between the age and history (p=.043), age and duration (p=.004), age and frequency of smoking

(p=.043), age and duration (p<.001), age and frequency of betel nut (p=.002).

In a research conducted in Saipan, 8.8% of teens (16.3± 1.5 y) diagnosed with oral sub mucous fibrosis .³⁵ Most patient ages are ranged between 45-54 years with a history of betel nuts intake 5 times per day⁸ similar results showed by Santosh Patil in his study in 2014, that Betel nut was the main etiological factor with 73.3% and tobacco being the second one with 69.2% in 18-56 years old patients.³⁶

Sarode observed in his study that the malignant transformation rate of oral sub mucous fibrosis into squamous cell carcinoma is 7.6%.²⁴

A study was done by Merchant in 2000 in Pakistan, in which 79 cases of OSCC were taken.68% were men, age range 22 – 80 years with an average of 49 years. Patients with OSF were 19.1 times more prone to get squamous carcinoma than those with no OSF.⁴

CONCLUSION

The purpose of an early and more aggressive approach towards OSF is to provide good quality of life to the patient by improving oral hygiene and oral intake quality and at the same time to obtain a sufficient mouth opening. Immunoreactive (IRS) score changes assessed by our study depict the importance of immunohistochemistry and its expression can be used as a tool for the detection of early carcinogenesis in oral sub mucous fibrosis in those patients who are betal nut users or using tobacco. The individual mechanisms operating at various stages of the disease need further study in order to propose appropriate therapeutic interventions.

Author Contribution:

Disclosure: All authors contributed equally towards the final manuscript

REFERENCES

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2. Bhurgri Y. Cancer of the oral cavity – trends in KarachiSouth (1995-2002). Asian Pac J Cancer Prev. 2005;6:2226.
3. Pillai KR, Sujathan K, Madhavan J, Abraham EK.Significance of silver-stained nucleolar organizer regions in early diagnosis and prognosis of oral squamous cell carcinoma: a multivariate analysis. In Vivo. 2005;19:807812.
4. Merchant A, Husain SS, Hosain M, Fikree FF, PitiphatW, Siddiqui AR, et al. Paan without tobacco: an independent risk factor for oral cancer. Int J Cancer. 2000;86128-131.
5. Hillbertz NS, Hirsch JM, Jalouli J, Jalouli MM, SandL. Viral and molecular aspects of oral cancer. Anticancer Res. 2012;32:4201-4212.
6. Jemal A, Tiwari RC, Murray T, Ghafoor A, SamuelsA, Ward E, et al. Cancer statistics, 2004. CA Cancer J Clin. 2004;54:8-29.
7. Cox SC, Walker DM. Oral submucous fibrosis. Areview. Aust Dent J. 1996;41:294-299.
8. Aziz SR. Oral submucous fibrosis: an unusual disease.J N J Dent Assoc.1997 Spring;6817-19.
9. Brundtland GH. Achieving worldwide tobacco control.JAMA. 2000;284:750-751.
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13. Altieri DC. Survivin, versatile modulation of celldivision and apoptosis in cancer. Oncogene. 2003;22:8581-8589.
14. Tanaka C, Uzawa K, Shibahara T, Yokoe H, NomaH, Tanzawa H. Expression of an inhibitor of apoptosis, survivin, in oral carcinogenesis. J Dent Res. 2003 ;82:607611.
15. Lo Muzio L, Pannone G, Staibano S, Mignogna MD,Rubini C, Mariggio MA, et al. Survivin expression in oral squamous cell carcinoma. Br J Cancer. 2003;89:22442248.
16. Lo Muzio L, Pannone G, Leonardi R, Staibano S,Mignogna MD, De Rosa G, et al. Survivin, a potential early predictor of tumor progression in the oral mucosa. J Dent Res. 2003;82:923-928.
17. Pindborg JJ, Mehta FS, Daftary DK. Occurrence ofepithelial atypia in 51 Indian villagers with oral submucous fibrosis. Br J Cancer.1970;24:253-257.
18. Kiran Kumar K, Saraswathi TR, Ranganathan K, Uma Devi M, Elizabeth J. Oral submucous fibrosis: a clinico-histopathological study in Chennai. Indian J Dent Res. 2007;18:106-111.
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23. Epstein JB, Zhang L, Rosin M. Advances in the diagnosis of oral premalignant and malignant lesions. J Can Dent Assoc. 2002;68:617-621.
24. Sarode SC, Sarode GS. Better grade of tumordifferentiation of oral squamous cell carcinoma arising in background of oral submucous fibrosis. Med Hypotheses. 2013;81:540-543.
25. Ambrosini G, Adida C, Altieri DC. A novel antiapoptosis gene, survivin, expressed in cancer and lymphoma. Nat Med. 1997;3:917-921.
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1. Research Assistant (Oral Pathology) Department of Post Graduate Medical Institute, Lahore,Pakistan.
2. Research Assistant (Oral and Maxillofacial Surgery) Demondmerency College, Department of Maxillofacial Surgery, Lahore, Pakistan.
3.Research Assistant (Oral Pathology) Department of Oral Health Sciences, Shaikh Zayed Medical Complex, Lahore, Pakistan.
Corresponding author: “Dr. Khola Ahmad Khan ” < kholakhan_84@hotmail.com >

Salwa Omar Bajunaid ¹                                      BDS, MSc, DABP, FACP

Maha Fahmi²                                                          BDS, MSc, Phd

INTRODUCTION

Retention is a key element in removable prosthodontics. There is strong evidence that retention is of great importance for patients’ satisfaction.  Burns et al. found a strong patient preference for overdenture attachments with superior retention.¹ The lower retention of mandibular overdenture and the lower resistance against horizontal movements may lead to less denture stability during chewing and thus to a reduced masticatory performance.² Although many factors such as proper border extensions, adhesion, cohesion, neuromuscular control etc. contribute to the retention of complete dentures, mechanical attachments play a chief role in enhancing the retention of the prosthesis especially that of mandibular overdentures. Among all implant restorations; loosening of overdenture retentive mechanisms were identified as the most common (33%) prosthodontic complication³, therefore, routine maintenance is required to ensure successful long-term outcomes.⁴ Fatigue or failure of overdenture attachments adversely affects function, maintenance aspects, and patient satisfaction.⁵

The aim of the present in vitro study is to compare the retention strength of three LOCTOR Male Attachments on an implant-retained overdenture model.

METHODOLOGY

Three pairs of LOCATOR Male Attachments (Zest Anchors, Escondido, CA, USA), namely, blue, pink and clear were tested. Each pair was subjected tovertical dislodgment forces.

The Test Model:

The experimental model representing a two implantretained mandibular overdenture was fabricated as follows:

A mandibular test model was poured in clear acrylic resin. Two 3.5 x 11 mm titanium implants (Astra Osseo Speed^TM (3.5 × 11 mm, Astra Tech, Mölndal, Sweden) were impeded in the anterior area of the mandible. A cast metal cobalt-chromium framework was fabricated and used to reinforce the experimental acrylic overdenture. The framework had four withdrawal loops, two in the anterior region and two in the molar regions of the mandible to be used during pull-off testing.  Four stainless steel nuts (3 mm in diameter) were soldered to the most anterior area of the framework: two nuts soldered labial

to the implants and two nuts soldered lingual to the implants. The nuts were used to fasten and secure a lightcured acrylic resin housing (Triad, Dentsply International, Inc., York, PA) confining the two implants anteriorly (Fig 1).

The female compartments of the LOCATOR Attachment were screwed into the implants and the metal housings of the LOCATOR males were picked up in the acrylic housing with auto-polymerized acrylic resin. The different male pairs were interchanged within the metal housings.

Materials Testing:

Retentive force for each pair of the Locator males was tested using the series 5500 Instron Materials Testing Machine (Instron, Canton, MA) with a computer interface. The force was exerted at a crosshead speed of 50.8 mm/min, which has been reported to approximate the removal force of the denture from the edentulous ridge during mastication. Metallic chains with S hooks connected the framework to the universal testing machine at the withdrawal loops.

Dislodging tensile forces were applied in a vertical direction to measure the peak or maximum load- the maximum force developed before separation of the attachment components.

The one-way analysis of variance was performed for each of the four measurements. The three male compartments were compared using the .05 level of significance.

RESULTS

Results with statistical analysis are presented in Tables 1 & 2 and in Fig.2. The peak load-to-dislodgement for all retentive males ranged from 11.86 +-2.52 N to 39.11+-3.24 N.

Retention force of Locator LR white showed the greatest retention, with a peak load-to-dislodgement of 35.49+-3.24 N. The Locator LR blue took the second place with a retention force of 19.02 ± 5.32 N which is higher than that of the Locator LR pink (15.5 ± 2.52 N).

The statistical measures (Minimum,maximum, Standard deviation) for the peak load-to-dislodgement for the three colors and the Anova test results are shown in tables1 and 2:

Descriptive Statistics

ANOVA

DISCUSSION

A minimum of 20 N has been suggested for optimum overdenture retention. Chung et al compared the retention forces of different attachments. Among those was Locator white and Locator pink nylon attachments (28.95 &12.33 N; respectively).

Several studies compared the retention of locator attachments and ball attachment. Sadiq studied two models designs based on number & location of the implants.

He found that the retention force of locator attachments (31.30 +- 0.12 N)was more than that of the ball attachments. Also, Alsabeeha et al. found that Locator attachments had more retention force than ball attachments. The values of his findings for Locator white & pink were 28.95 N & 12.33, respectively. The results found in our study for Locator white and pink attachments are close to these findings (35.49 & 15.5 N; respectively). Hence, Locator white could be recommended in cases of severely resorbed mandible where other anatomical and biological factors are limited to aid in the retention of mandibular overdentures. However, our results are in disagreement with the findings of Ahmadzadeh who found that Locator pink had a retention force of 20.90 += 3.74 N which is greater than the findings of this study (15.51 +- 2.52N).

Both the white and the blue attachments have retention forces that are within the optimum retention value for overdenture retention while the pink male attachment showed a retention force that is below the required optimum value to retain a mandibular overdenture.

CONCLUSIONS

Within the limitations of this study, it was found that:

• Locator white male attachment shows the highestretention force.
• The retention force values of the Locator pink areless than that of the Locator blue attachment.
• The Locator blue retention force found to be veryclose to the value for optimum overdenture retention, which can be used, in average cases where all other biological factors are favorable.
• The Locator pink found to have a retention forcevalue that is lower than the required optimum value for overdenture retention. It can be used in cases of wellformed residual ridges with minimal bone resorption.

Author Contribution: Both MF and SOB have significant contribution in conceiving and designing the study, and recording, analysis and interpretation of data; have written or critically reviewed the manuscript, have approved the final version and have agreed to be responsible for accuracy of results and integrity of the research Potential Conflict of Interest: Authors have no potential conflict of interest, have no source of funding for the research project and have access to the study data and are responsible about integrity and accuracy of data analysis. Disclosure: None disclosed

REFERENCES

1. Burns DR, Unger JW, Elswick RK Jr, Giglio JA.Prospective clinical evaluation of mandibular implant overdentures: Part II-Patient satisfaction and preference. J Prosthet Dent 1995;73:364-369.
2. Fontijn-Tekamp FA, Slagter AP, Van Der Bilt A, Van’T Hof MA, Witter DJ, Kalk W, et al. Biting and chewing in overdentures, full dentures, and natural dentitions. J Dent Res 2000;79:1519-1524.
3. Goodacre CJ, Bernal G, Rungcharassaeng K, Kan JY.Clinical complications with implants and implant prostheses. J ProsthetDent 2003;90:121-132.
4. Chaffee NR, Felton DA, Cooper LF, Palmqvist U, Smith R. Prosthetic complications in an implant-retained mandibular overdenture population: initial analysis of a prospective study. J Prosthet Dent 2002;87:40-44.
5. Payne AG, Solomons YF. Mandibular implantsupported overdentures: a prospective evaluation of the burden of prosthodontic maintenance with 3 different attachment systems. Int J Prosthodont 2000;13:246-253.
6. Cordioli G, Majzoub Z, Castagna S. Mandibular overdentures anchored to single implants: a five-year prospective study. J Prosthet Dent 1997;78:159-165.
7. Johns RB, Jemt T, Heath MR, Hutton JE, McKenna S, McNamara DC, et al. A multicenter study of overdentures supported by Branemark implants. Int J Oral Maxillofac Implants 1992;7:513-522.
8. Walton JN, MacEntee MI. A prospective study on the maintenance of implant prostheses in private practice. Int JProsthodont 1997;10:453-458.
9. Wichmann MG, Kuntze W. Wear behavior of precision attachments. Int J Prosthodont. 1999;12:409-414.
10. Besimo CE, Guarneri A. In vitro retention force changes of prefabricated attachments for overdentures. J Oral Rehabil 2003;30:671-678.
11. Chung KH, Chung CY, Cagna DR, Cronin RJ Jr. Retention characteristics of attachment systems for implant overdentures. J Prosthodont 2004;13:221-226.
12. Rutkunas V, Mizutani. Retentive and stabilizing properties of stud and magnetic attachments retaining mandibular overdenture. An in vitro study.Stomatologija. Baltic DentalMaxillofac J 2004;6:85-90.
13. Chung KH, Chung CY, Cagna DR, Cronin RJ Jr. Retention characteristics of attachment systems for implant overdentures. J Prosthodont 2004;13:221-226.
14. Botega DM, Mesquita MF, Henriques GE, Vaz LG. Retention force and fatigue strength of overdenture attachment systems. J Oral Rehabil 2004;31:884-889.
15. Sadig W. A comparative in vitro study on the retention and stability of implant- supported overdentures. Quintessence Int 2009;40:313-319.
16. Fu CC, Hsu YT. A comparison of retention characteristics in prefabricated and custom-cast dental attachments. J Prosthodont 2009;18:388-392. 17. Lehmann KM, Arnim FV.Studies on the retention forces of snap-on attachments. Quintessence Dent Technol 1978;2:45-48.
17. Lehmann KM, Arnim FV.Studies on the retention forces of snap-on attachments. Quintessence Dent Technol 1978;2:45-48.
18. Nagaoka E, Nagayasu U,Yamashita H, Matsushiro H,Yoshihiki O. Study of retention in attachments for overdenture o-ring attachment.J Osaka Univ Dent Sch 1980;20:215-226.
19. Leung T, Preiskel HW. Retention profiles of studtype attachments.Int J Prosthodont 1991;4:175-179.
20. Petropoulos VC, Smith W, Kousvelari E. Comparison of retention and release periods of implant overdenture attachments. Int. J Oral Maxillofac. Implants 1997;12:176-185.

1.Assistant Professor, King Saud University, College of Dentistry, Department of Prosthetic Science

2.Professor, King Saud University, College of Dentistry, Department of Prosthetic Science

Corresponding author: “Dr Salwa Omar Bajunaid ”  < dr_prosth@hotmail.com  >

Umer bin Irfan ¹                                        BDS

Kashif Aslam ²                                           BDS, MSc

Rizwan Nadim ³                                        BDS, MSc

INTRODUCTION

Over the past 30 years, CAD CAM (computer aided design computer aided machine) has gained popularity and confidence of the profession and patients alike. It has provided ease, comfort, and quality of restoration to both the dentists and dental lab technician. Moreover, restorations which are being produced through cad cam these days, are more durable, more marginally adaptive, more esthetically pleasing and more faster in fabrication as compared to the conventional restorations. But despite of these advantages, cost is the major issue which has limited its use. Because of the financial constraints, in the under developed countries, dentists are still reluctant in using cad cam However, one should not overlook the benefits which CAD CAM provides. Accuracy and quality of CAD CAM in producing inlays, on lays, implant abutments, fixed partial dentures, crowns and bridges is acceptable and improving every day. This review article highlights the history and current indications of CAD CAM. It also provides information that how it works and what can be itsadvantages and disadvantages.

HISTORY OF CAD CAM

The history of dentistry is as old as human civilization in the ancient times. Hippocrates and Aristotle, have written many things about dental diseases and their treatments.¹ In the eastern world, ancient Chinese literature is available regarding silver pastes (primitive amalgam). As the civilization was getting developed, newer and newer findings kept on becoming the part of dentistry. Commercial production of porcelain teeth by Samuel Stockton, introduction of amalgam by Crawcours and origination of cohesive gold foil method by Robert Arthur all have brought revolution in the field of dentistry.¹ So revolutionization has become the habit of dentistry.

The history of cad cam itself is old. In ancient Egypt, Greece, and Rome, evidences suggest that cad cam was being practiced there even. Even Leonardo di Vinci has shown in his works, the use of modern graphics convention.² But Euclid of Alexandria, the great mathematician, can truly be regarded as the person behind the modern CAD soft ware because today’s CAD software is based on Euclid’s axioms and postulates, which laid the foundation of Euclidian geometry.^1,4 Iven Sutherland in early 1960s, developed the CAD software (sketchpad) but before that Dr. Patrick J. Hanratty, had already designed first numerically controlled CAM that was named as Pronto. So Dr Patrick is called as Father of CAD CAM.^3,4

The introduction of CAD CAM in dentistry begins with the work of Dr Duret.  He took optical impression of an abutment tooth after cutting and then with the help of that impression he fabricated a crown by using numerically control machine. He did that miracle in the field of dentistry in the year 1971.⁵ Later on Dr Duret along with his team mates, worked on  Sopha system and introduced it but due to few reasons that system was not generally accepted by the people.⁶ Mormann was the person who introduced first commercially designed CAD CAM system in the year 1985 and given the name of CEREC to that system.⁷ He fabricated an inlay from a ceramic block after taking digital impression from intra oral camera. That was bit easy as compared to take impression of a prepared abutment tooth. Now this system is being used all over the world successfully for the fabrication of crowns, inlays, onlays etc. Dr Andersson developed Procera system in the mid-1980s and worked on titanium as a substitute of nickel chromium alloys.⁸ Previously, gold alloys were being used, but due to increase in prices of gold, people had to think of substitutes. Dr Andersson came up with titanium because allergies were reported with nickel chromium.

CEREC 2 was introduced in 1994 by Siemens. This system was based on two dimensional principles and capable of producing inlay, onlay, veneers, partial & full crowns and copings. Currently 3^rd generation of CEREC is in use, which is capable of producing inlay, onlay, veneers, partial & full crowns, copings as well as virtual automatic occlusal adjustment. This system was introduced by Sirona in 2005. This system is basically the advanced form of CEREC 3 which was earlier introduced in 2000 by Sirona but that system worked on two dimensional principles and was not able to provide virtual automatic occlusal adjustments.⁹

Types of CAD CAM Production

CAD CAM restorations can be produced by three different ways.

1. Chair side production
2. Laboratory production
3. Centralized production
4. Chair side production:

It involves taking an impression chair side and then producing the restoration at the same time. It doesn’t require involvement of the laboratory and the patient/s can have their restoration at the same appointment¹⁰. Obviously it saves times but it is expensive and puts extra cost on the patient.

2.  Laboratory production

It is somewhat similar to the conventional method. The dentist takes the impression & sends it to the lab, where other works carried out by the lab technician.

3.   Centralized production

In centralized production of the restoration, an impression is taken and a master cast is digitized in the lab, then it sends to outsource laboratory through internet. In that outsource lab, the final restoration is fabricated which sends back to the dentist. The idea is right in the sense that it requires digitizer and software only to perform the initial steps and a high quality restoration.¹⁰

METHODS OF DATA ACQUISITION IN CAD CAM

There are several methods by which data can be collected for CAD.

1) Intra oral scanning

2) Contact and non – contact digitization

3) Ct scan or MRI

Fig 2

1.   Intra Oral Scanning

There are several intra oral scanners available in market namely CEREC^® – by Sirona Dental System GMBH (DE), Lava™ C.O.S. – by 3M ESPE (US), iTero – by CADENT LTD (IL) and E4D – by D4D

TECHNOLOGIES, LLC (US) etc. What these systems do, they take 3-D virtual picture of the prepared tooth/teeth and the adjacent structures, directly into the patient’s mouth Later on these images transfer to the CAD for designing of the prosthesis.¹¹ A comparison of intra oral scanning which is also called as digital impression and conventional impression is given below.

But despite of the advantages of digital impression technique, there are certain things which need to be considered while taking digital impressions. The dentist, who is taking intra oral pictures, must take care of moisture control. Soft tissue retraction and hemostasis should be considered too.¹²

2. Contact & Non – Contact Digitizing

This method involves taking an conventional impression and then after producing a model, transferring of that data into CAD through probe digitization ( contact) or laser light ( non – Contact ). In contact digitizing or scanning, a contact probe reads the anatomy of the model by following the contour of the physical structure. In non-contact scanning, apart from laser light, optics and charged -coupled devices are also used. Obviously, this technique doesn’t require any physical contact with the model, but precision in recording the details is required. It is assumed that, in comparison to contact scanning, this technique is relatively quick in gathering the data.¹³

3. Ct scan /MRI:

Computed Tomography (CT & Magnetic Resonance Imaging (MRI) are newer techniques for data acquisition for CAD Cam.By this method, individual images can be taken and then can be transferred to CAD. CT scan utilizes radiation for its data acquisition but MRI doesn’t. For soft tissue modelling, MRI data is suitable and for hard tissue (bone) modelling, CT data can be used.¹⁴

USES OF CAD CAM IN DENTISTRY

CAD CAM is being used in almost every field of dentistry these days. Following are its some of the uses in different specialties of dentistry:

1. Prosthodontics:

Whether it is removable or fixed prosthodontics, fabricating them through CAD CAM is becoming the choice of almost every leading dentist.

a) Removable Complete Dentures:

A group of Japanese investigators named Maeda et al, published a report in 1994, in which they proposed that removable complete dentures can be fabricated using CAD Cam technology.¹⁵ Since then many researches have been proposed regarding fabrication of removable complete dentures through CAD CAM but no clinical reports or trials have been published yet. Only 2 of the manufacturers claim that they manufacture RCD through CAD CAM.¹⁶

b) Removable Partial Dentures

Partial denture framework can be produced through CAD CAM by using additive prototyping technique.^17,18

c) Crowns / Bridges

Zirconia is the widely used material for the fabrication of crown and bridge through CAD CAM. However, metal & porcelain crown & bridge can also be fabricated through CAD CAM. A study suggests that zirconia exhibits acceptable clinical results.¹⁹

d) Inlay, Onlay & Veneers

These restorations are also being produced through CAD CAM.²⁰ A study says that inlays & onlays, produced through CAD CAM, have a higher survival rate.²¹

2. Orthodontics

In orthodontics, clear aligners have gained so much popularity due to esthetics. Now patients don’t have to show metallic brackets and wires. The credit goes to CAD CAM again.²²  Also lingual bracket system is in demand due to its invisibility. The wires and bracket system for the lingual bracket system is fabricated through CAD CAM.²³ Orthodontic mini implants can also be positioned using CAD CAM technology.²⁴

3. Implant Dentistry:

Implant abutments and surgical guides for the placement of implants are being produced through CAD CAM these days.²⁵

4. Maxillo-Facial Prosthetics:

A study shows the difference in between the outcome of the artificial ear prosthesis carved by hand & fabricated through CAD CAM. The latter is superior over the hand carved prosthesis.²⁶ So artificial ear²⁷, artificial nasal prosthesis²⁸ are being produced through CAD CAM. Not only this, but certain bony defects following trauma or removal of tumors are also being treated by manufacturing implants through CAD CAM.²⁹

ADVANTAGES AND DISADVANTAGES OF CAD CAM

If we compare the advantages of CAD CAM restorations over the conventional one, we will definitely place CAD CAM restorations on top. They provide us quality restorations with quick and easy fabrication. Scanning of intra oral tissues takes less time than conventional impression, and if the chair side system is available, the patients can get their restorations in one appointment.Quality of these restorations has been demonstrated in so many studies.

But despite of these advantages, cost is still a major issue. Also taking digital impression is a big challenge for the dentists, because they have to take care of soft tissue retraction, moisture control etc.

CONCLUSION

CAD CAM has no doubt changed the concept of modern world dentistry. Different specialties of dentistry are being successfully benefited by CAD CAM. Either orthodontics or prosthodontics, quality treatment is possible with accuracy and effectiveness. But cost of these treatments is still a problem for the patients and the dentists, esp. of the developing countries. We are hopeful that in the near future, CAD CAM will be started using widely in the developing countries as well.

Author Contribution: UBI conceived the idea and made the initial draft, KA revised the manuscript and RN collected the references. Disclosure: None disclosed

REFERENCES

1. ada.org/en/about-the-ada/ada-history-andpresidents-of-the-ada/ada-history-of-dentistry-timeline. Accessed 10-10-2015.
2. Zeid, Ibrahim,Cad/Cam Theory and Practice,1991, McGraw-Hill.
3. http://www.cadazz.com/cad-software-history.htm
4. ukessays.com.
5. Duret F, Preston JD. CAD CAM imaging in dentistry. Curr Opin Dent 1991;1(2):150-154.
6. T Miyazaki, Y Hotta.CAD/CAM system available for the fabrication of crown and bridge restorations.Aust Dent Jour. 2011;56:97-106.
7. Mormann WH, Brandestini M, Lutz F, Barbakow F.Chairside Computer Aided Direct Ceramic Inlays. Quintessence Int 1989;20:329-339.
8. T Miyazaki, Y Hotta, J Kunii, S Kuriyama, Y Tamaki.A review of dental CAD CAM: Current status and future perspectives from 20 years of experience.Dent Mat Jour 2009;28:44-56.
9. WH, Mormann. The evolution of the CEREC system.J Am Dent Assoc 2006;137:7S-13S.
10. Beuer, J. Schweiger, D. Edelhoff.Digital Dentistry: an overview of recent developments for CAD/CAM generated restorations. Br Dent J 2008;201:505-511.
11. A Kilpeta, M Capni, L Governu, L Blois.A comparative analysis of intra oral 3D digital scanner for restorative dentistry. The Int Jour Of Med Tech 2008;5.
12. Gary Davidowitz, Philip G. Kotick. The Use Of CAD /CAM in dentistry. Dent Clin N Am 2011;55:559570.
13. V Raja, KJ Fernandes.Reverse Engineering: An Industrial Perspective 2008. Springer.
14. L Siva Rama Krishna, Manmadhachary, P. Bal Reddy, Sriram Venkatesh.Development of optimum preplanning for maxillofacial surgery using selective laser sintering.International J Eng Sci Tech 2011;3:185-196.
15. Maeda Y, Minoura M, Tsutsumi S, Okada M, Nokubi T. A CAD CAM system for removable denture.Part 1: Fabrication of Complete denture.Int J Prosthdont 1994;7:17-21.
16. Avinash S. Bidra, Thomas D. Taylor, John R. Agar.Computer -Aided Technology For Fabricating Complete Dentures: Systematic Review Of Historical Background, Current Status And Future Perspectives.JProsth Dent 2013;109:361-366.
17. Chatham C, Spencer MH, Wood DJ, Johnson A. The introduction of digital dental technology into BDS curricula. Br Dent J. 2014:5;217:639-42.
18. Williams RJ, Bibb R, Eggbeer D, Collis J. Use of CAD/CAM technology to fabricate a removable partial denture framework. J Prosthet Dent. 2006;96:96-99.
19. Batson ER, Cooper LF, Duqum I, Mendonça G. Clinical outcomes of three different crown systems with CAD/CAM technology. J Prosthet Dent. 2014;112:770777.
20. TrushkowskyRD.Ceramic inlay fabrication with three dimensional copy milling technologyCelay.Compend Cont Edu Dent 1998;19:1077-80.
21. Otto T, De Nisco S.Computer aided direct ceramic restorations: A 10 year prospective clinical study of CEREC CAD/CAM inlays and onlays. Int J Prosthodont 2002;15:122-128.
22. Aristides BM. Advances in digital technology and orthodontics: A reference to the invisalign method.Med Sci Monit 2005;11:139-142.
23. Wiechmann D, Rummel V, Thalheim A, Simon JS, Wiechmann L.Customized Brackets And Arch wires For Lingual Orthodontic Treatment.Am J Orthod Dentofac Orthop 2003;124:593-599.
24. Liu H, Liu D, Wang G, Wang C, Zhao Z.Accuracy of surgical positioning of orthodontic mini screws with a computer-aided design and manufacturing template. Am JOrthod Dentofac Orthop 2010;137:728e1-28e10.
25. . Fuster-Torres MA, Albalat-Estela S, Alcañiz-Raya M, Peñarrocha-Diago MCAD CAM dental systems in implant dentistry:Update. Med Oral Patol Oral Cir Bucal 2009;14:E141-145.
26. Sykes LM, Parrott AM, Owen CP, Snaddon DR. Applications of rapid prototyping in maxillofacial prosthetics. Int J Prosthodont 2004;17:454-459.
27. Ciocca L, Scotti R.CAD CAM generated ear cast by means of laser scanner and rapid prototyping machine. J Prosthtic Dent 2204;92:591-5.
28. Leonardo Ciocca, Massimilliano Fantini, Francesca De Crescenzio, Franco Persiani, Roberto Scotti.New protocol for construction of eye glasses- supported provisional nasal prosthesis using CAD CAM techniques. J Rehab Res Dev 2010;47:595-604.
29. Eufinger H, Wehmoller M, Machtens E, Heuser L, Harder A, Kruse D.Reconstruction of craniofacial bone defects with individual alloplastic implants based on CAD/CAM manipulated CT data.J Maxillofac Surg 1995;23:175-181.

1 . Assistant Professor Dept. Of  Community Dentistry Dow Dental College, DUHS, Karachi.

Corresponding author: “Dr Kashif Aslam” < taimoor.links@gmail.com  >

Farhan Raza Khan                          BDS, MS, MCPS, FCPS

In last two decades, dental institutions in most part of the world have witnessed a major shift in their curriculum. From a restorative driven dental education, it has become a preventive one.¹ This has resulted in more hours of teaching reserved for oral hygiene, sealants, fluorides and preventive aspects of dentistry. Undoubtedly, the potential benefits of such education and training is pivotal in managing the burden of disease in given communities. However, the downside of prevention focused dentistry is that the skill-intensive discipline of dentistry is gradually losing its strong base. The inculcation of right procedural skills in the budding dentists somehow suffers.

The greatest victim of the aforementioned evolution is the discipline of removable prosthodontics. The factor that has made removable prosthodontics further lose its ground is the rise of dental Implantology. The predictable results offered by Implantology along with its promise of offering fixed solution for missing teeth in a variety of clinical situations has attracted both patients and clinicians alike. Exploring the situation further reveals that it’s not the complete denture prosthetics that has suffered but the cast partial dentures that have been most adversely affected. In other words, the cast partial prosthodontics is heading to become a dying disciple in the dental institutions of Pakistan.

If cast partial dentures are not properly taught in the dental schools then it’s expected that this remarkable modality of treatment will remain underutilized by the dentists in their practical life.² It’s imperative to understand that neither all patients with missing teeth are suitable candidate of fixed prosthodontics (also known as crown & bridge work) nor can they afford implant dentistry. In this backdrop, the cast partial dentures have their definite

Received: September 28 2015, Accepted: September 30 2015

place in most of the dental rehabilitation treatment plans.

With ever increasing population of Pakistan and an improving life expectancy; the need of removable prosthodontics service is expected to rise in future. Our dental academicians would agree that didactic and clinical teaching of cast partials to the future generation of dentists is essential but what are the measures that can be taken to revive cast partial prosthetics in academic dentistry? The answer to this question is lies in adopting the following measures:

1. Establishment of casting laboratories in dentalcolleges and ensure that they function.
2. Recruitment and retention of prosthodontics facultyin teaching institutions
3. Reserving adequate patient contact hours forstudents to develop skills, knowledge and judgment required for teaching and practicing removable prosthodontics.
4. Dental schools to set a minimum number of castpartial dentures made by the student as an eligibility requirement to appear in the professional examination.
5. Lastly, having competent laboratory techniciansemployed at dental schools to support prosthodontics department should not be overlooked.

It’s important for dentists in their formative years to learn the professional communication, cooperation and respect with their laboratory personals. It’s only with a team approach; a successful dental practice is made possible.

REFERENCES

1. Petropoulos VC, Rashedi B. Removable Partial DentureEducation in U.S. Dental Schools. J Prosth. 2006; 15: 62–68.
2. Institute of Medicine: Dental Education at theCrossroads: Challenges and Change. Washington, DC, National Academy, 1995.

1. Assist Prof. & Program Director Operative Dentistry Aga Khan University Karachi, 74800 Pakistan

Corresponding author: “Dr Farhan Raza Khan ”  < farhan.raza@aku.edu   >