Lack of Association of Palataly Impacted Canines with Maxillary Arch Width and Lateral Incisor Anomalies

Omair Majeed                                         BDS

Tabassum Ahsan Quadeer                   BDS, FCPS

Maria Habib                                            BDS

Muhammad Faisal Fahim                     MSc

OBJECTIVE: To investigate if there is any relationship between palataly impacted canines and missing or anomalous lateral incisors as well as maxillary arch widths.
METHODOLOGY: The materials for this study comprised of orthodontic records including orthopantomographs and dental casts of patients visiting the Dental OPD of Bahria University Medical and Dental College. The sample size was 60 and was divided into 30 experimental subjects and 30 control subjects. The experimental group comprised of subjects having palatal canine impaction while the control group included subjects without palatal impactions. The presence of impacted canines was confirmed on OPG, their palatal presence was checked with horizontal parallax using an additional periapical radiograph. Dental casts were used not only to assess anomalies/ or absence of lateral incisors but also for measuring maxillary width from interpremolar and inter moalr distance. Data was analyzed using SPSS software. Co-relation between incisor anomaly or absence with impaction was checked using fisher exact test. To see the significance of intermolar and interpremolar widths (mm) between case and controls, independent sample t test was applied.
RESULT: Subjects with palatal canines had a weak Tassociation with anomalous and absent lateral incisors as 83% of experimental subjects and 93% of control subjects had normal lateral incisors. Maxillary width taken from inter-molar and inter-premolar distance, also had similar values between the experimental subjects and controls.
CONCLUSION: There was no association between palataly impacted canines with absent and anomalous incisors nor with maxillary skeletal width.
KEYWORDS: Palatal impactions, Maxillary arch width, Lateral incisor anomalies.
HOW TO CITE: Majeed O, Quadeer TA, Habib M, Fahim MF. Lack of association of palataly impacted canines with maxillary arch width and lateral incisor anomalies. j pak dent assoc 2020;29(3):110-113.
DOI: https://doi.org/10.25301/JPDA.293.110
Received: 18 November 2019, Accepted: 12 May 2020

INTRODUCTION

The most frequently impacted tooth in the dental arch after the third molars is the maxillary canine. The incidence of its impaction is between 1 and 2.5 %. Impactions of canine can be either buccal or lingual.1 Around 85% of impactions are palatal while the remaining 15% are buccal. Canine impaction occurs twice as more in the maxilla than in the mandible. In subjects with impacted maxillary canines, 8% of impactions occur bilaterally.2
The etiology of palatal canines is accepted to be multifactorial and of a complex nature. The two accepted theories for this anomaly are guidance theory and genetic theory. The guidance theory stresses on the impact of lateral incisors on the eruption of palatal canines and also states that absent, peg or anomalous lateral incisors lead to the impaction of maxillary canines. The genetic theory explains the occurrence of different dental anomalies that occur along with palataly impacted canines e.g. infraoccluded deciduous
molars and ectopic eruption of maxillary 1st molars.3,4
Maxillary width is usually decreased in patients with buccaly impacted canines5 but the relationship between width of maxilla and palatal canines is questionable. McConell
in a study implicated maxillary width deficiency as a factor for palatal canine displacement.6 On the other hand, Langberg and Peck found no statistical significant difference in the anterior and posterior maxillary arch widths in patients with palataly displaced canines.1,2,7
There is compelling evidence that palataly displaced canines are associated with agenesis of lateral incisors as well as peg shaped lateral incisors.8 Becker and Smith in their study indicated that the absence of lateral incisor could lead to palatal canine impaction.9
Al Nimri in his study found smaller mesiodistal width and short roots of lateral incisors in association with palatal canines.10 Contrary to the aforementioned evidence, there are studies that reflect a weak association between palataly impacted canines and lateral incsiors. Mossey et al in their study showed a weak support between impacted canines and absence of adjacent lateral incisors.11 Jena and Duggal in their study also found no positive association between lateral incisor anomalies and canine impaction.12
As such an association has not been checked on Pakistani population, our aim with this study was to explore a relationship between palatally impacted canines and maxillary interarch widths at the level of first premolar and first molars, and also their possible relation with anomalies of lateral incisors (agenesis/ peg laterals).

METHODOLOGY

This cross sectional study was conducted on the orthopantomograms and dental casts of the patients coming for orthodontic treatment at the Dental OPD of Bahria University Medical and Dental College between the periods of 2016 to 2019. An institutional ethical committee approved the protocol of study (letter no ERC 39/2019). The sample was selected via convenience sampling. The sample size was calculated with the OPENEPI online software. With a standard of 95% confidence interval and 5% error size, the proportion of subjects and controls was found to be 60 (30 subjects and 30 controls). The experimental group comprised subjects diagnosed with palatal canine impaction while the control group included subjects without palatal impactions.

The inclusion criteria for experimental subjects included:
a) Nonsyndromic subjects
b) Unilateral palatal canine impaction
c) Age group: 12 to 30 years
The exclusion criteria for experimental subjects are:
a) Missing 1st premolars
b) Missing 1st molars
c) Severely mesially rotated 1st molars
d) Previous orthodontic treatment

The patients were documented with OPG’s and Periapical

FIG 1

x rays (horizontal parallax technique) for the presence of palatal canine. Pretreatment dental casts of the patients were used to assess maxillary first inter-premolar and first intermolar widths. These readings would be used to determine the maxillary transverse width. The data was collected by a single examiner who was calibrated to make these measurements by placing the caliper tips into the deepest portion of the central fossae of the upper first premolars at their junctions with the most lingual aspect of the buccal
cusp. The same examiner also recorded the intermolar width by placing the caliper tips into the deepest portion of the central fossae at its junction with the most lingual aspect of
the mesio-buccal cusp. All dental cast measurements were made using a digital boley gauge.
The dental anomalies to be included in the experimental and control group included lateral incisor’s agenesis /peg laterals.

STATISTICAL ANALYSIS

Data analysis was done by using SPSS version 23. Fisher exact test was used to determine the co-relation between impacted canines and missing or anomalous lateral incisors.
To observe the correlation of impaction with intermolar and interpremolar width (mm), independent sample t test was applied. P value <0.05 was considered as statistically
significant.

RESULTS

A total of 60 patients (30 experimental and 30 controls) were examined in this study. Mean age in experimental subjects was 17.93±5.23 years, whereas in controls it was found to be 18.30±3.90 years.

The presence/ absence of lateral incisors as well as anomalies are presented in Table 1. There were 25 (83.3%) experimental subjects who had normal shaped lateral incisors, whereas in controls normal lateral incisors were present in

Table 1: Intergroup comparison of the number of lateral incisor anomalies

Table 2: Intergroup comparisons of maxillary intermolar and interpremolar widths (in mm)

28 (93.3%) cases. Peg lateral incisor, an anomaly of lateral incisors was found in only 1 (3.3%) experimental subject whereas none in controls with non-significant p-value of 0.339.
Mean Inter molar width (mm) in experimental subjects was found to be 44.03±3.29 whereas in controls it was found to be 44.46±3.82 with non-significance p-value of
0.64. Mean Inter premolar width (mm) in experimental cases was found to be 33.26±3.13 whereas in controls 33.06±2.99 was observed with non-significant p-value of 0.802. (Table 2)

DISCUSSION

Impaction of the maxillary canine is a common occurrence and is encountered frequently by orthodontists as well as general dentists. It has a prevalence of 1-2.5% and is the second only to developmental disturbance in third molars.1,13 Diagnosis of this condition at an early age along with preventive measures such as rapid maxillary expansion, extraction of deciduous canine and first molars, transpalatal arches as well as cervical headgear can aid in spontaneous eruption of these teeth. If the palatal canine is left untreated, it can result in various side effects of which the noteworthy ones include cyst formation, root resorption of adjacent teeth and development of malocclusion.9
In our study, lateral incisor hypodontia was found in only 13% out of 30 experimental cases with palatal canine impactions while in controls; only 6.7% of laterals were absent. Only one case of peg lateral incisor (3.3%) was found in experimental subjects while none was reported in controls. Even though some studies have established a correlation between impacted teeth with dental anomalies, our study showed no correlation. Our study was in accordance with the study of Garib et al who had maxillary lateral incisor agenesis (18.9%) for subjects with unilateral palatal canine impactions.14 Zilberman et al in their study showed similar results with only 5.5% lateral incisors missing in patients with palatal canines whereas the percentage of peg laterals was 13%.15 Peck and Peck in their study also found lateral incisor hypodontia to be 3.4% in cases with palatal canines.16 Leifert and Jonas found similar results to our study with 7.23% hypodontia of lateral incisors.11 From the results of our study, we found that the maxillary transverse dimension measured as first interpremolar and intermolar width was similar in experimental cases as well as in controls. We found the mean intermolar width to be 44 mm in both subjects and controls with a p value of 0.64 whilst the mean interpremolar width was 33 mm in both groups with a p value of 0.8. Our study was in accordance with the study of Gull and Mushtaq who also found the intermolar width to be 44mm and the interpremolar width to be 35 mm with no significant correlation to the impacted teeth.17 Naoumova and Alfaro in their study also found no difference between arch width at the molars in both impaction cases and controls.18 Ariza et al in their study found contrasting results and showed that the transverse dimensions of the first molar and first premolar were smaller in subjects with impacted maxillary canines when compared with subjects without impaction.19
From our study and the results of various other researches, we can confirm that dental anomalies like agenesis of lateral incisors, peg lateral incisors as well as maxillary skeletal width do not correlate positively with the presence of palatal canine impactions. Further investigation into the etiology of palataly impacted canines is needed before clinical recommendations can be made to find more factors that correlate positively with palatal canines.

CONCLUSION

Our study did not show any relationship between palataly impacted canines with anomalous and missing incisors or maxillary width.

CONFLICT OF INTEREST

None declared

REFERENCES

  1. K. Al-Nimri and T. Gharaibeh. Space conditions and dental and occlusal features in patients with palataly impacted maxillary canines: an etiological study. Europ J Orthod 27;2005:461-65. https://doi.org/10.1093/ejo/cji022
  2. Manne R, Gandikota C, Juvvadi SR, Medapati Rama H, Anche S.Impacted canines: Etiology, diagnosis, and orthodontic management.J Pharm Bioall Sci 2012;4:234-38. https://doi.org/10.4103/0975-7406.100216
  3. Saiar M, Rebellato J, and Sheats RD. Palatal displacement of canines and maxillary skeletal width. Am J Orthod Dentofacial Orthop 2006;129:511-19 https://doi.org/10.1016/j.ajodo.2005.03.021
  4. Hong W, Radfar R, Chung C. Relationship between the maxillary transverse dimension and palataly displaced canines: A cone beam computed tomographic study. Angle Orthod. 2015:85;440-445. https://doi.org/10.2319/032614-226.1
  5. Ariza NA, Schilling J, Guillen LEA, Mora GAR, Cardenas YAR, and Castillo AAD. Maxillary transverse dimensions in subjects with and without impacted canines: A comparative cone-beam computed
    tomography study. Am J Orthod Dentofacial Orthop 2018;154:495- 503 https://doi.org/10.1016/j.ajodo.2017.12.017
  6. McConell TL, Hoffman DL, Forbes DP, Janzen EK, Weintraub NH. Maxillary canine impaction in patients with transverse maxillary` deficiency. ASDC J Dent Child. 1996;63:190-95.
  7. Fattahi H, Ghaeed F, Alipour A. Association betweenmaxillary canine impaction and arch dimensions. Aust Orthod J. 2012;28:57-62
  8. Mercuria E; CassettM;Cavallini C; Vicari D; Leonardi R; Barbato E. Dental anomalies and clinical features in patients with maxillary canine impaction. A retrospective study. Angle Orthod. 2013;83:22- 28. https://doi.org/10.2319/021712-149.1
  9. Becker A, Smith P, Behar R. The incidence of anomalous lateral incisors in relation to palataly displaced cuspids. Angle Othod. 1981;51:24-9.
  10. Al-Nimri KS, Bsoul E. Maxillary palatal canine impaction displacement in subjects with congenitally missing maxillary lateral incisors. Am J OrthodDentofacialOrthop. 2011;140:81-86. https://doi.org/10.1016/j.ajodo.2009.11.016
  11. Mossey PA, Campbell HM, Luffingham JK. The palatal canine and the adjacent lateral incisor: a study of a west of Scotland population. Br J Orthod. 1994:21:169-74. https://doi.org/10.1179/bjo.21.2.169
  12. Jena AK, Duggal R. The pattern of maxillary canine impaction in relation to anomalous lateral inciosrs. 13 13 Leifert S, Jonas IE. Dental Anomalies as a Microsymptom of Palatal Canine Displacement. J Orofac Orthop 2003;64:108-20. https://doi.org/10.1007/s00056-003-0222-x
  13. Leifert S, Jonas IE. Dental Anomalies as a Microsymptom of Palatal Canine Displacement. J Orofac Orthop 2003;64:108-20. https://doi.org/10.1007/s00056-003-0222-x
  14. Garib DG, Alencar BM, Lauris JRP, Bacetti T. Agenesis of maxillary lateral incisors and associated dental anomalies. Am J Orthod Dentofacial Orthop2010;137:732.e1-732.
    https://doi.org/10.1016/j.ajodo.2009.12.024
  15. Zilberman Y, Cohen B, Becker A. Familial trends in palatal canines, anomalous lateral incisors, and related phenomena. Europ J Orthod 1990;12:135-39. https://doi.org/10.1093/ejo/12.2.135
  16. Peck S, Peck L, Kataja M. Prevalence of tooth agenesis and pegshaped maxillary lateral incisor associated with palatally displaced canine (PDC) anomaly. Am J Orthod Dentofac Orthop 1996;110:441- 43. https://doi.org/10.1016/S0889-5406(96)70048-3
  17. Gull MAB, Mushtaq M, Maqbool S. Palatal Displacement of Maxillary Canines and Maxillary Transverse Dimensions. Annals Int Med Dent Res. 2018;4:10.
    https://doi.org/10.21276/aimdr.2018.4.2.DE3
  18. Naoumova J, AlfaroGE; Peck S. Space conditions, palatal vault height, and tooth size in patients with and without palatally displaced canines:Angle Orthod 2018;88:726-32.
    https://doi.org/10.2319/120717-843.1
  19. Ariza NA, Schilling J, Guillen LEA, Mora GAR, Cardenas YAR, Castillo AAD. Maxillary transverse dimensions in subjects with and without impacted canines: A comparative cone-beam computed tomography study. Am J Orthod Dentofacial Orthop 2018;154:495-50 https://doi.org/10.1016/j.ajodo.2017.12.017

  1. Senior Lecturer, Department of Orthodontics, Bahria University Medical and Dental College.
  2. Associate Professor, Department of Orthodontics, Bahria University Medical and Dental College.
  3. Senior Lecturer, Department of Orthodontics, Bahria University Medical and Dental College. Researcher & Consultant Statistician, Department of Physical Therapy, Bahria
    University Medical and Dental College.
    Corresponding author: “Dr. Omair Majeed” < dromairis@hotmail.com >

Lack of Association of Palataly Impacted Canines with Maxillary Arch Width and Lateral Incisor Anomalies

Omair Majeed                                         BDS

Tabassum Ahsan Quadeer                   BDS, FCPS

Maria Habib                                            BDS

Muhammad Faisal Fahim                     MSc

OBJECTIVE: To investigate if there is any relationship between palataly impacted canines and missing or anomalous lateral incisors as well as maxillary arch widths.
METHODOLOGY: The materials for this study comprised of orthodontic records including orthopantomographs and dental casts of patients visiting the Dental OPD of Bahria University Medical and Dental College. The sample size was 60 and was divided into 30 experimental subjects and 30 control subjects. The experimental group comprised of subjects having palatal canine impaction while the control group included subjects without palatal impactions. The presence of impacted canines was confirmed on OPG, their palatal presence was checked with horizontal parallax using an additional periapical radiograph. Dental casts were used not only to assess anomalies/ or absence of lateral incisors but also for measuring maxillary width from interpremolar and inter moalr distance. Data was analyzed using SPSS software. Co-relation between incisor anomaly or absence with impaction was checked using fisher exact test. To see the significance of intermolar and interpremolar widths (mm) between case and controls, independent sample t test was applied.
RESULT: Subjects with palatal canines had a weak association with anomalous and absent lateral incisors as 83% of experimental subjects and 93% of control subjects had normal lateral incisors. Maxillary width taken from inter-molar and inter-premolar distance, also had similar values between the experimental subjects and controls.
CONCLUSION: There was no association between palataly impacted canines with absent and anomalous incisors nor with maxillary skeletal width.
KEYWORDS: Palatal impactions, Maxillary arch width, Lateral incisor anomalies.
HOW TO CITE: Majeed O, Quadeer TA, Habib M, Fahim MF. Lack of association of palataly impacted canines with maxillary arch width and lateral incisor anomalies. j pak dent assoc 2020;29(3):110-113.
DOI: https://doi.org/10.25301/JPDA.293.110
Received: 18 November 2019, Accepted: 12 May 2020

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Assessment of Failure of Prosthesis in Fixed Prosthodontics Among Patients Reporting To A Teaching Dental Hospital of Karachi

Asma Naz                            BDS, FCPS

Hira Musharraf                   BDS, FCPS

Atif Jawad                           BDS, FCPS

Kainat Zia                            BDS

Bharat Kumar                     BDS, FCPS

Muneeb Ahmed Lone        BDS, FCPS

OBJECTIVE: The purpose of this study was to evaluate reasons of failure for conventional crowns and fixed partial dentures in patients reporting to the Prosthodontics OPD.
METHODOLOGY: This cross sectional study was carried out in the Department of Prosthodontics at Jinnah Medical and Dental College, Karachi from December 2018 to September 2019. A total of 149 patients were enrolled in the study using nonprobability, consecutive sampling technique. The demographic data was recorded and patients were examined to assess the cause of failure of fixed dental prosthesis. SPSS version 22 was used for statistical analysis.
RESULTS: The mean age of the 149 prosthesis examined was 4.78 ± 4.37 years. Most of the failures 130 (87.2%) were due to biologic causes. Almost all of the patients (98.0%) cleaned their teeth by brushing. The mean life span of the 145 porcelain fused to metal prosthesis examined was 4.89 ± 4.38 years. Most of the failed restorations were single unit with a mean prosthesis age of 4.27 ± 4.26 years while 7 (4.7%) fixed partial dentures had greater than 5 units and had a mean life of 11.6 ± 5.45 years.
There was a statistically significant difference in the failure of prosthesis according to its position in the dental arch (p< 0.02)
CONCLUSION: Fixed dental prostheses provide one of the best treatment modalities for replacing teeth. At present the average life of prosthesis at 4 years is less than satisfactory. To improve the longevity of these restorations it is necessary to have proper patient selection, diagnosis, treatment planning, clinical and technical skills. It is also essential to educate the patient about proper oral hygiene and prosthesis maintenance so that the life span of fixed prosthesis is increased.
KEYWORDS: porcelain fused to metal restoration, fixed dental prosthesis, biologic failure
HOW TO CITE: Naz A, Musharraf H, Jawad A, Zia K, Kumar B, Lone MA. Assessment of failure of prosthesis in fixed prosthodontics among patients reporting to a teaching dental hospital of Karachi. J Pak Dent Assoc 2020;29(3):105-109.
DOI: https://doi.org/10.25301/JPDA.293.105
Received: 23 November 2019, Accepted: 12 May 2020

INTRODUCTION

Loss of teeth is a common condition affecting individuals globally.1 A systematic review on the global burden of severe tooth loss indicated that about 2.3% of the population was edentate in 2010.2
As there is such a large number of people who have missing teeth, there is a high demand to replace missing teeth to improve mastication and esthetics.3 Fixed prosthodontics allows replacement of missing teeth by restorations that are not readily removed from the mouth.4 Today, crowns and fixed partial dentures are one of the most commonly used prosthesis by dental practitioners to replace missing teeth.5
A crown is a fixed extra-coronal artificial restoration that replaces the lost tooth structure by covering the coronal portion of a natural tooth with various materials such as cast metal alloy, metal- porcelain, dental porcelain, resins or more recently zirconia. A fixed partial denture is defined as a fixed restoration which replaces one or more missing teeth and is attached to natural teeth or an implant.4

A crown provides one of the best options to restore an endodontically treated tooth. It is also used widely to restore
form and function when a substantial amount of tooth structure has been lost due to caries, trauma, or parafunctional habits. The goal of these restorations is to restore esthetics, function and comfort.6
When missing teeth are replaced by the provision of fixed partial dentures after proper treatment planning, they can provide acceptable function, esthetics, value for money and longevity.5,7 However, in case of improper treatment planning, they are more likely to fail prematurely and lead to irreversible damage to the teeth and supporting structures. In recent years, several investigators have taken great interest in investigating the life span and long-term quality of fixed dental prosthesis.8 Some of the common failures in fixed bridge prosthodontics are loose retainers, fracture of soldered joints, fracture of porcelain, fracture of the abutment teeth or voids in retainer or pontic. Failure of theses restorations may also lead to recurrent caries or loss of abutment teeth.5
To be able to prevent these failures when providing a fixed dental prosthesis, clinicians should have adequate knowledge and skills regarding diagnosis, examination, treatment planning and manual dexterity to execute the planned treatment.8,9
The purpose of this study was to evaluate the reason of the failure of conventional crowns and fixed partial dentures
in patients reporting to the Prosthodontics OPD.

METHODOLOGY

The study was carried out in the Department of Prosthodontics of Jinnah Medical and Dental College from December 2018 to September 2019. An institutional ethical committee approval (BMDC/R&D/ERC/2019-05) was taken before commencing the study. The sample size was calculated using OpenEpi software v.3.01. Taking the prevalence of failure of fixed restorations to be 13.8%, confidence interval 92% and margin of error 5%; the sample size came out to be 149 patients.10 Non-probability, consecutive sampling technique was used to include patients in the study. Patients who reported to the OPD of Jinnah Medical and Dental College in the Department of Prosthodontics with problems related to their crowns or fixed partial dentures (FPD) were selected for the study after consent was obtained from them. Any prosthesis that required replacement or repair was considered as failed. All the necessary data was entered in a structured form. This included the patients’ demographics i.e. name, gender and age. Other data recorded included the age of the prosthesis, the material of prosthesis, cleaning method and  frequency adopted by the patient, the arch along with the location of restoration in the arch, the number of units of fixed restoration and the cause of failure was noted. The examination of patients was carried out by the principal investigator.
The failures were classified as biologic, mechanical and esthetic. Biologic failures included endodontic failures, compromised periodontal conditions, gingivitis, secondary caries, mobility, poor oral hygiene, root recession, pain and swelling, bone resorption, abscess formation, food impaction and pocketing. Mechanical failures included dislodged prosthesis, improper crown preparation, and fracture of an abutment, prosthesis fracture and loss of restoration along with abutment teeth. Esthetic failures included shade mismatch and contour discrepancies.5
SPSS version 22 was used for data entry and analysis. Data was analyzed to record the frequency and percentages of failure of the fixed prosthesis according to cause of failure, the material of prosthesis, location of the prosthesis in the arch, the number of units in a prosthesis, the method and regularity of cleaning teeth used by a patient. Mean ± SD
were calculated for age distribution and life span of prosthesis. Stratification of data was done in terms of gender, age, material of prosthesis, the location of the restoration in the arch, number of units of fixed restoration and the cause of failure.

RESULTS

Out of the 149 patients examined, there were 39 (26.2%) males and 110 (73.8%) females. The mean age of the study
population was 42.4 years; ranging from 15- 81 years of age. The mean age of the prosthesis examined in the study
was 4.78 ± 4.37 years. The reasons for failure of restorations are shown in Figure 1.
Out of the 149 patients, 146 (98.0%) cleaned their teeth

Figure 1: Reasons of failure of fixed restorations

by brushing alone, while brushing plus flossing; use of
brushing and miswak and use of floss alone was performed by 1 patient each. Eighty-four (56.4%) patients cleaned their teeth once daily, 50 (33.6%) patients cleaned their teeth twice daily, 11 (7.4%) cleaned their teeth three times daily, 4 (2.7%) were found to clean their teeth occasionally. Among the 149 prosthesis analyzed 145 (97.3%) were made of\ porcelain fused to metal while 4 (2.7%) were all metal.
The mean prosthesis life according to the material of

Table 1: Failure percentage and mean prosthesis age according to material of prosthesis

Table 2: Failure percentage and mean prosthesis age according to dental arch

Table 3: Failure percentage and mean prosthesis age according to location of prosthesis

Table 4: Relationship of location of tooth with the dental arch

Table 5: Failure percentage and mean prosthesis age according to number of units

prosthesis is shown in Table 1. Seventy-four (49.7%) patients had failing restorations in maxilla while 75 (50.3%) patients presented with these restorations in mandible. The mean prosthesis life according to the dental arch is shown in Table 2. Results showed that 119 (79.9%) failed restorations were in posterior quadrants, 20(13.4%) were in anterior quadrants whereas the remaining 10 (6.7%) fixed restorations extended from the anterior till the posterior segment. The number of failing prostheses according to the position in the arch and its mean life is shown in Table 3. There was a statistically significant difference in the failure of prosthesis according to their position in the dental arch (p< 0.02) table 4. It was found that 89(59.7%) failed restorations were of a single unit, 14 (9.4%) were two units, 25 (16.8%) were 3 units, 10 (6.7%) were four units, 4 (2.7%) were five units and 7 (4.7%) fixed partial dentures had greater than 5 units.
The number of failed prostheses and their mean age according to the number of units is shown in Table 5.

DISCUSSION

Crown and bridge failures are one of the most routinely encountered problems by the dentists.8 A recent systematic
review revealed the cumulative 5-year survival rates of 93.5% for fixed partial dentures with a complication rate of 27.6%.11 Bjarni et al also reported a survival rate of 89.1% for fixed partial dentures after 10 years in service.12
Internationally, several surveys have been conducted to assess the mean age that the prosthesis lasts for.10,13,14 The mean prosthesis age in this study was found to be 4.8 years; that is comparatively less than the mean age found by Prasad et al13 i.e. 7.3 years and Walton et al14 8.3 years but longer than the mean prosthesis age found by Cheung et al i.e. 2.8 years.10
A multitude of reasons have been reported in the literature that result in the failure of crowns and bridges.5,8,11,14 In this study it was found that the most common cause of failure was due to biologic reasons (87.2%); with endodontic failures accounting for more than half of the failed restorations. Endodontic failures are likely to occur when the primary root canal treatment provided was not up to the standard principles.15,16 This can result in pain and swelling which may necessitate the removal of a prosthesis to carry outretreatment or retreatment through the already existing prosthesis; thereby resulting in failure of crowns and bridges.5
Such findings are present in the literature, which has shown that pulpal and root canal problems are a common cause of failure of fixed dental prosthesis.10
According to this study the second most common cause of failure in fixed restorations was secondary caries. This
finding is similar to a study conducted by Cheung GS et al.10 Similarly, other studies found secondary caries to be
the most common cause of prosthesis failure.13,16-18 This high rate of failure due to caries may be explained in part by the less than optimal oral hygiene practices of the participants in this study. This study showed more than half (55.6%) of the participants brushed their teeth only once daily along with no other cleaning aid. To maintain near ideal plaque control, brushing at least twice daily along with flossing is recommended.18 It is therefore important that good oral hygiene practices are reinforced in patients when they are provided with any dental prosthesis and they be reiterated at every follow up visit. Mechanical failures accounted for only one-tenth of the failures in porcelain fused to metal restorations, while no case of mechanical failure was reported in the metal crowns. Dislodgement of crowns was the most common mechanical failure reported. This can be partially explained by the fact that most of these restorations were found on posterior teeth which are subjected to higher forces of mastication; thus having a higher chance of dislodgement.19
The results of the present study reported more failure of the porcelain fused to metal restorations than the all-metal
restorations. Even though other studies have reported a similar trend, the results of this study should be seen with caution as the number of all-metal crowns examined in this study were very few.13,14 To correctly compare the failure rate of metal restorations to porcelain fused to metal restoration, a case-control study can be carried out in the future that studies an equal number of restorations in each group. Porcelain fused to metal restorations in this study lasted for 4.9 years, while metal restorations lasted for only around 11 months. Memon and Ghani also report a similar life span of porcelain fused to metalrestorations.20,21 Prasad et al13 however found that metal restorations had a much longer life span of 8.5 years as compared to porcelain fused to metal restorations, that were serviceable for 7 years.
Results of this study report an equal number of failed restorations in both the maxilla (50.3%) as well as the mandible (49.7%); with more restorations located in the posterior region. Restorations replacing tooth structure in the posterior region of the arch had a shorter life span of 4.3 years as compared to those present in the anterior region i.e. 6.4 years. Similarly, Saleem et al23 also found that 60% of failed restorations were located in the posterior segment of the arch. These findings were in contrast to a study carried out by Cheung22 who found that anterior fixed restorations had a higher failure rate.
In fixed prosthodontics single crowns and fixed partial dentures of up to 3 units are the most commonly used
restorations, hence more failures are likely to be reported in such prosthesis.5
These observations are reiterated by the results of this study which show that the more than half (59.5%) of the failed restorations examined were single-unit crowns, followed by 16% of 3 unit fixed partial dentures.
Similar findings have been published by the General Dental Council of United Kingdom which reported that the majority of the complaints received were about treatment related to crowns (196) and bridges (116).24 In general, fixed partial dentures that extend for a span of more than four units present a higher risk of failure.25 Randow26 reported similar results whereby there were increased failure rates of long span bridges, ranging from 7% for prostheses of 7-units to 23% for prostheses having 10-units. In light of this literature, to reduce the failure rate of a prosthesis and improve prosthesis longevity, long span prosthesis should be avoided. In the present study, however, no relation was found between the span of prosthesis and its life. Single unit crowns and small bridges examined in this study had a life of 4 years approximately, whereas prostheses that were of 5 units or more had a life of more than 7 years. These findings are similar to Walton14 who did not find any relation between prosthesis span and life of prosthesis.
Studies have been conducted in our part of the world to examine the reasons for the failure of fixed prosthesis.20,21,23,27
The majority of these studies only focused on the prevalence of failure concerning different variables. This study address the longevity of the fixed prosthesis along with reporting the variables related to failures of fixed prosthesis, such data is present in the western population14 but to the best of authors research, no local data was available. Other studies can also be carried out to assess the reasons for failure in fixed prosthesis other than conventional crowns and fixed – fixed partial dentures.

CONCLUSION

Fixed dental prostheses provide one of the best treatment modalities for replacing teeth. At present the average life of prosthesis at 4 years is less than satisfactory. To improve the longevity of these restorations it is necessary to have proper patient selection, diagnosis, treatment planning, clinical and technical skills. It is also essential to educate the patient about proper oral hygiene and prosthesis maintenance so that the life span of fixed prostheses is increased.

CONFLICT OF INTEREST

None declared

REFERENCES

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  2. Kassebaum NJ, Bernabé E, Dahiya M, Bhandari B, Murray CJ, Marcenes W. Global Burden of Severe Tooth Loss: A Systematic Review and Meta-analysis. J Dent Res. 2014;93:20S-28S. https://doi.org/10.1177/0022034514537828
  3. Akinboboye B, Akeredolu P, Sofola O, Ogunrinde B, Oremosu O. Utilization of teeth replacement service among the elderly attending teaching hospitals in Lagos, Nigeria. Ann Med Health Sci Res.
    2014;4:57-60. https://doi.org/10.4103/2141-9248.126613
  4. The Glossary of Prosthodontic Terms: 9th ed. J Prosthet Dent. 2017;117(5S):e1-e105. https://doi.org/10.1016/j.prosdent.2016.12.001
  5. Briggs P, Ray-Chaudhuri A, Shah K. Avoiding and managing the failure of conventional crowns and bridges. Dent Update. 2012; 39:78- 84. https://doi.org/10.12968/denu.2012.39.2.78
  6. Chandrakala V, Deepmala S, Srivatsa G. Different classification system for failures in tooth supported fixed partial denture: a systematic review. Int J Prev Clin Dent Res. 2019;6:17-20 https://doi.org/10.4103/INPC.INPC_15_19
  7. Patras M, Sykaras N. Esthetic and functional combination of fixed and removable prosthesis. Gen Dent. 2012; 60:e47-54.
  8. Manappallil JJ. Classification system for conventional crown and fixed partial denture failures. J Prosthet Dent. 2008; 99:293-98. https://doi.org/10.1016/S0022-3913(08)60064-5
  9. Simpson RL. Failures in crown and bridge prosthodontics. J Am Dent Assoc. 1953;47:154-59. https://doi.org/10.14219/jada.archive.1953.0160
  10. Cheung GS. A preliminary investigation into the longevity and causes of failure of single unit extracoronal restorations. J Dent. 1991;19:160-3. https://doi.org/10.1016/0300-5712(91)90006-K
  11. Muddugangadhar BC, Amarnath GS, Sonika R, Chheda PS, Garg A. Meta-analysis of failure and survival rate of implant-supported single crowns, fixed partial denture, and implant tooth-supported prosthesis. J Int Oral Health. 2015;7:11-7.
  12. Pjetursson BE, Tan K, Lang NP, Brägger U, Egger M, Zwahlen M. A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. Clin Oral Implants Res. 2004;15:654-66. https://doi.org/10.1111/j.1600-0501.2004.01119.x
  13. Prasad D. K, Hedge C, Desai H. A survey to assess the failures in fixed partial dentures. Int J Recent Sci Res. 2017;8:18770-3.
  14. Walton JN, Gardner FM, Agar JR. A survey of crown and fixed partial denture failures: length of service and reasons for replacement. J Prosthet Dent. 1986;56:416-21. https://doi.org/10.1016/0022-3913(86)90379-3
  15. Iqbal A. The factors responsible for endodontic treatment failure in the permanent dentitions of the patients reported to the college of Dentistry, the University of Aljouf, Kingdom of Saudi Arabia. J Clin Diagn Res. 2016;10(5):ZC146-8. https://doi.org/10.7860/JCDR/2016/14272.7884
  16. Schwartz NL, Whitsett LD, Berry TG, Stewart JL. Unserviceable crowns and fixed partial dentures: life-span and causes for loss of serviceability. J Am Dent Assoc. 1970;81:1395-401. https://doi.org/10.14219/jada.archive.1970.0398
  17. Näpänkangas R, Salonen-Kemppi MA, Raustia AM. Longevity of fixed metal ceramic bridge prosthesis: a clinical follow-up study. J Oral Rehabil. 2002;29:140-45. https://doi.org/10.1046/j.1365-2842.2002.00833.x
  18. Schüz B, Sniehotta FF, Wiedemann A, Seemann R. Adherence to a daily flossing regimen in university students: effects of planning when, where, how and what to do in the face of barriers. J Clin Periodontol. 2006; 33:612-19. https://doi.org/10.1111/j.1600-051X.2006.00967.x
  19. Gogna R, Jagadish S, Shashikala K, Keshava Prasad B. Restoration of badly broken, endodontically treated posterior teeth. J Conserv Dent. 2009; 12:123-28. https://doi.org/10.4103/0972-0707.57637
  20. Ghani F, Memon MR. Complications in metal ceramic fixed dental prosthesis among patients reporting to a teaching dental hospital. LUMHS 2010; 09:17-22.
  21. Memon MR, Ghani F. Reasons and problems in dislodged metal ceramic fixed partial dentures presented for recementation by patients. J Pak Dent Assoc 2007;16:13-9.
  22. Cheung GS, Dimmer A, Mellor R, Gale M. A clinical evaluation of conventional bridgework. J Oral Rehabil. 1990; 17:131-36 https://doi.org/10.1111/j.1365-2842.1990.tb01401.x
  23. Saleem T,Amjad F, Bhatti MUD. Complications associated with tooth supported fixed dental prosthesis amongst patients visiting University College of Dentistry Lahore. Pak Oral Dent J 2013;33:207-11.
  24. Helping you put things right. Dental Complaints Service Annual review – 2009/10
  25. Foster LV. The relationship between failure and design in conventional bridgework from general dental practice. J Oral Rehabil 1991;18:491-95. https://doi.org/10.1111/j.1365-2842.1991.tb00070.x
  26. Randow K, Glantz PO, Ziiger B: Technical failures and some related clinical complications in extensive fixed prosthodontics. Acta Odontol Scand 1986;44:241-255 https://doi.org/10.3109/00016358608997726
  27. Zafar N, Ghani F. Common Post-fitting Complications in Toothsupported Fixed-Fixed Design Metal-Ceramic Fixed Dental Prosthesis. Pak J Med Sci. 2014;30:619-25 https://doi.org/10.12669/pjms.303.5599

  1. Associate Professor, Department of Prosthodontics, Jinnah Medical & Dental College.
  2. Senior Registrar, Department of Prosthodontics, Dow Dental College.
  3. Assistant Professor, Department of Prosthodontics, Bhittai Dental and Medical College.
  4. Demonstrator, Department of Prosthodontics, Bhittai Dental and Medical College.
  5. Assistant Professor, Department of Prosthodontics, Dow Dental College.
  6. Assistant Professor, Department of Prosthodontics, Dr Irshad-ul-Ebad Khan Institute of Oral Health Sciences.
    Corresponding author: “Dr. Hira Musharraf” < hira.musharraf@duhs.edu.pk >

Assessment of Failure of Prosthesis in Fixed Prosthodontics Among Patients Reporting To A Teaching Dental Hospital of Karachi

Asma Naz                            BDS, FCPS

Hira Musharraf                   BDS, FCPS

Atif Jawad                           BDS, FCPS

Kainat Zia                            BDS

Bharat Kumar                     BDS, FCPS

Muneeb Ahmed Lone        BDS, FCPS

OBJECTIVE: The purpose of this study was to evaluate reasons of failure for conventional crowns and fixed partial dentures in patients reporting to the Prosthodontics OPD.
METHODOLOGY: This cross sectional study was carried out in the Department of Prosthodontics at Jinnah Medical and Dental College, Karachi from December 2018 to September 2019. A total of 149 patients were enrolled in the study using nonprobability, consecutive sampling technique. The demographic data was recorded and patients were examined to assess the cause of failure of fixed dental prosthesis. SPSS version 22 was used for statistical analysis.
RESULTS: The mean age of the 149 prosthesis examined was 4.78 ± 4.37 years. Most of the failures 130 (87.2%) were due to biologic causes. Almost all of the patients (98.0%) cleaned their teeth by brushing. The mean life span of the 145 porcelain fused to metal prosthesis examined was 4.89 ± 4.38 years. Most of the failed restorations were single unit with a mean prosthesis age of 4.27 ± 4.26 years while 7 (4.7%) fixed partial dentures had greater than 5 units and had a mean life of 11.6 ± 5.45 years.
There was a statistically significant difference in the failure of prosthesis according to its position in the dental arch (p< 0.02)
CONCLUSION: Fixed dental prostheses provide one of the best treatment modalities for replacing teeth. At present the average life of prosthesis at 4 years is less than satisfactory. To improve the longevity of these restorations it is necessary to have proper patient selection, diagnosis, treatment planning, clinical and technical skills. It is also essential to educate the patient about proper oral hygiene and prosthesis maintenance so that the life span of fixed prosthesis is increased.
KEYWORDS: porcelain fused to metal restoration, fixed dental prosthesis, biologic failure
HOW TO CITE: Naz A, Musharraf H, Jawad A, Zia K, Kumar B, Lone MA. Assessment of failure of prosthesis in fixed prosthodontics among patients reporting to a teaching dental hospital of Karachi. J Pak Dent Assoc 2020;29(3):105-109.
DOI: https://doi.org/10.25301/JPDA.293.105
Received: 23 November 2019, Accepted: 12 May 2020

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Community Dentistry or Dental Public Health to be Established As A Distinct Subject Specialty in Pakistan

Farhan Raza Khan                           BDS, MS, MCPS, FCPS

DOI: https://doi.org/10.25301/JPDA.293.103

College of Physicians & Surgeons of Pakistan is the primary body that oversees the post graduate training and assessment of medical and dental specialists in Pakistan.1
The dental specialties examination were established in year 1995, thus it’s acceptable to believe that the academic dentistry is in its developmental stage in the country. Although, disciplines such as Oral Maxillofacial Surgery, Orthodontics, Operative Dentistry and Prosthodontics, have been fairly established as distinct subject specialties (evidenced by over 600 specialists trained in these subjects in last 25 years) but still there are some dental specialties that have lacked behind others. These include Periodontology, Dental Public Health and Pediatric Dentistry.
Periodontology is the latest addition in the list of recognized specialties at CPSP. This specialty got recognition
as a distinct subject in year 2013.2 Slowly and gradually, this discipline is gaining its momentum. Pediatric Dentistry
and Dental Public Health (DPH) are yet to be declared as specialties by CPSP.3 Table 1 shows the comparison of Pakistani dental specialties with Indian counterparts and

Table 1: Dental Specialties in the India, Pakistan and United Kingdom

dental education and assessment system practiced in United Kingdom and Ireland.4
From teaching standpoint, there is an acute dearth of dentists trained in dental public health (DPH is also known as Community Dentistry). This makes it impossible for the dental institutions to find or retain suitable teachers in this discipline. The DPH specialists are the dentists who are expert in oral epidemiology, biostatistics, devising interventions that could improve the dental public health and overall quality of life of people. Thus, these DPH specialist could become the backbone of healthcare research in the dental institutions. Lack of competent teachers in DPH translates into poor understanding of research and lack of interest in the subject amongst dental graduates.
The subject of DPH warrants special attention. There are less than 10 major qualified dentists in this discipline in the entire country. Most of them are running MDS or MPhil programs in their respective institution. It’s high time to
bring these potential mentors into mainstream so that they could produce impact in the country’s academic scene. It’s sad to observe that in entire Karachi (seventh highly populated city in the world), there is just one DPH training center and that too has produced only a couple of graduates so far. All of this is because of DPH lacks the identity as a distinct specialty subject.
Following strategy could develop a justifiable resource of DPH teachers: First step is to document the actual count
of subject experts in DPH and then incentivize them to serve as trainer for FCPS program in this discipline. Pakistan
Association of Dental Research (PARD) should assist the CPSP to recognize DPH as a distinct post graduate specialty. Second step is to identify a few established dental faculty members (albeit of belonging to any specialty) who are already specialty-certified, research-active and presently teaching at a credible degree awarding institutions. Their research productivity should be evidenced by Medline indexed publications with an h-index 5 or more. Such faculty members should be offered an opportunity to progress their career in DPH.
If the above approach is implemented, it can be projected that within 10 years, an adequate number of DPH teachers and researchers will be generated for the dental academia.

This discipline will surely get parity with other specialties of dentistry. Not only the scarcity of DPH experts in Pakistan will be addressed but a new generation of dental investigators will be made available to the country as well.

REFERENCES

  1. https://www.cpsp.edu.pk/fcps.php
  2. Khan FR. Challenge of producing specialist practitioners in periodontology in Pakistan. J Pak dent Assoc. 2016; 25(1):3.
  3. Khan FR, Mahmud S, Rahman M. The need of paediatric dentistry specialists in Pakistan. J Coll Physicians Surg Pak. 2013;23:305-07.
  4. Khan FR. Similarities and differences in specialty training of conservative dentistry and endodontics (India), operative dentistry (Pakistan) and restorative dentistry-endodontics (United Kingdom). J Pak Med Assoc.  2019;70: 320-23. https://doi.org/10.5455/JPMA.2934

  1. Associate Professor, Operative Dentistry, Chief of Dental Services, Aga Khan University Karachi, Pakistan.
    Corresponding author: “Dr. Farhan Raza Khan” < farhan.raza@aku.edu >