Vol. 28 No. 02 Apr-Jun 2019

Rawan Almobarraz

Rawan Almobarraz

Knowledge of root canal anatomy is an important part of root canal treatment. Mandibular canines usually contain one root with one canal, but anatomical variation may be seen. This paper describes a non-surgical root canal retreatment of mandibular canine with two roots and two separate canals. Clinicians must be able to identify the different variations to be able to successfully diagnose and manage their cases.

KEY WORDS: Endodontics; retreatment; canine; two roots; two canals

HOW TO CITE:  Almobarraz  R.  Endodontic  retreatment  of a mandibular  canine  with two  roots  and two  canals. J Pak Dent Assoc 2019;28(2):98-100.

DOI: https://doi.org/10.25301/JPDA.282.98

Received: 20 January 2019, Accepted: 14 February 2019

INTRODUCTION

The mandibular canine is an important tooth in the dental arch. It’s long and stable root gives it an advantage of being useful in giving support in a prosthesis due to its proprioceptive properties that guides the masticatory function and its role in occlusal guidance during the eccentric movements and posterior disocclusion.1 Mandibular canine is known for its one root and single canal. Variation may occur but is uncommon. The studies of Greene, Hess and Vertucci revealed 13%, 15% and 18% of two canals in a single root of mandibular canines respectively2, but the occurrence of two roots and even more than two canals is rare, ranging from 1 to 5%.3 Pécora JD et al also studied the internal anatomy, the direction and the number of roots of the mandibular canines. The study was done on 830 mandibular canines, and the results showed that 98.3% had only one root and of these 97.2% had one canal and one opening orifice, 4.9% two canals and one orifice, 1.2% two canals and two orifices. Two canals and two roots were present in only 1.7% of the cases.4 The aim of endodontic treatment is to eliminate the infection from the root canal and to prevent the reinfection.5 Knowledge of the root canal anatomy contributes to the success of the treatment. This article reports a clinical case of nonsurgical endodontic retreatment of mandibular canine with two roots and two canals.

CASE REPORT

 A 43-year-old female patient with no relevant past medical history was referred to the clinical endodontic undergraduate course for retreatment of lower right canine. History of treatment was done 8 years ago. Past dental history showed multiple root canal treatments and restorations. Preoperative periapical radiograph of tooth number #43 showed mesial and distal caries, under filled obturation, periapical lesion, and widening of the PDL [Figure 1].

Upon clinical examination, the tooth was negative to percussion and palpation. With thermal testing, the tooth showed negative response. Tooth was diagnosed as previously treated with asymptomatic apical periodontitis. No mobility or deep pockets were found and the access cavity was closed with composite. The endodontic treatment plan was nonsurgical root canal retreatment.

From   the   periapical radiograph, a second root was suspected. To confirm this, further radiographic imaging using small field of view CBCT was taken after gutta percha removal and the tooth showed two separate roots with two separate canals

[Figure 2]. The treatment was scheduled and initiated after obtaining a written informed consent from the patient. Local anesthesia (2% Xylocaine with 1: 80, 000 epinephrine) was introduced through infiltration and the tooth was isolated with a rubber dam using Ivory 9 clamp.

Composite restoration from the previous access cavity was removed with a long shank round bur and the lingual orifice was located. To locate the buccal canal, the cavity was

extended buccally. After successfully locating both orifices, chloroform was used carefully as solvent with H-files to remove the previous gutta percha in the lingual canal. Upon negotiation the buccal canal, a size 8 K-File was fractured but was bypassed. Working length of both canals was measured using an apex locator Root ZX II (J. Morita, Tokyo, Japan), and was confirmed radiographically [Figure 3a]. Instrumentation was done using step-back technique with hand files. K-files up to size 35 were used while irrigating with 1% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Both canals were dried with paper points and master cone radiograph was taken [Figure 3b]. After the length of master apical cone was confirmed, obturation with gutta percha using cold lateral condensation and AH-Plus Sealer (Dentsply Maillefer, Ballaigues, Switzerland) was done [Figure 3c]. After the root canal treatment, the tooth was restored with composite and final radiograph was taken.

DISCUSSION

 The inability to treat all the canals is one of the causes leading to endodontic failure. In a study by Hoen and Pink, it was found that the incidence of missed canals were reported to be 42% of all the 1100 endodontically failing teeth.6 Each tooth has a range of variation as reported in the literature.

The occurrence of two roots and two separate root canals in mandibular canine is rare and literature search has revealed 5%, 1% and 1.2% cases with two roots and two root canals respectively.7 The patient seen was a female and it was found that the incidence of two canals in mandibular canine was reported in female more than the male.8

Mandibular canines with two roots are more difficult to instrument and clean than single rooted canines. The long axis of the canal meets the crown surface at the incisal edge or on its labial surface. If this is not taken into consideration, it may lead to a preparation that is deviated.9 Versiani et al reported that in all two-rooted mandibular canines, the main apical foramen tends to be located eccentrically. Therefore, the possibility of overinstrumentation is high.10 Access cavity preparation can a challenging and frustrating part of endodontic treatment, but it is the key to successful treatment. That is why the majority of the problems that occur during the root canal treatment are due to the insufficient knowledge of the anatomy of the pulp space. The factors which were found most responsible for endodontic failures were underfilled canals (33.3%) and unfilled and missed canals (17.7%),11 both which are seen in this case report. Radiography is an essential tool to successful diagnosis of odontogenic and nonodontogenic pathoses. Not only does it provide information on the morphology of the tooth including location and number of canals, but it also shows us the pulp chamber size and degree of calcification, root structure, direction and curvature, fractures, and the extent of dental caries.12 The image produced in a conventional intraoral radiograph is a two-dimensional representation of a three-dimensional object. Therefore when there is complex or unusual anatomy, it is best to take a CBCT. The most important advantage of CBCT in endodontics is that it demonstrates anatomic features in 3D that intraoral and panoramic images cannot. Another advantage is on-screen measurements are free from distortion and magnification.13 Clinicians should be able to study the anatomy in the preoperative radiograph and should be able to keep in mind the different anatomical variations seen. A good access cavity will help in detecting all the canals. These techniques combined with the use of magnification tools (magnification loupes or microscope) aid in the treatment.14 In addition, different angulated intraoral radiographs and CBCT could aid in diagnosis.

CONCLUSION

Although the presence of two roots in a mandibular canine is rare, the clinician should always keep in mind the different anatomical and morphological variations seen in canals and be able to diagnose before starting treatment for a successful outcome. With the help of CBCT, endodontic retreatment of mandibular canine with two separate roots was completed successfully.

ACKNOWLEDGMENTS

I would like to gratefully acknowledge Dr. Amal Almohaimede, our course director, not only for her guidance, support, and believing in her students, but also for her comments that greatly improved the manuscript. I would also like to thank for Dr. Raghad Basmael, my clinical instructor for this case, for her knowledge and clinical expertise.

CONFLICT OF INTEREST

 None declared

REFERENCES 

1. Abduo J, Tennant M, and Mcgeachie J, “Lateral occlusion schemes in natural and minimally restored permanent dentition: a systematic review,” J Oral Rehabil. 2013;40:788-02. https://doi.org/10.1111/joor.12095

2. Green Double canals in single roots. Oral Surg, Oral Medi, Oral Pathol. 1973;35:689-96.

https://doi.org/10.1016/0030-4220(73)90037-6

3. Wang L, Zhang R, Peng Clinical features and treatment of mandibular canines with two root canals: Two case reports. Chinese J Dent Res. 2009;12:61-2.

4. Pecora JD, Sousaneto MD, Saquy PC, Internal anatomy,direction and number of root and size of human mandibular Canines Braz Dent J. 1993;4:53–7.

5. Sjögren U, Hägglund B, Sundqvist G, Wing K. Factors affecting

the long-term results of endodontic treatment. J Endod. 1990;16:498- 504.

https://doi.org/10.1016/S0099-2399(07)80180-4

6. Hoen MM, Pink FE. Contemporary endodontic retreatments: An analysis based on clinical treatment findings. J 2002;28:834–36 https://doi.org/10.1097/00004770-200212000-00010

7. Victorino FR, Bernardes RA, Baldi JV, Moraes IG, Bernardinelli N, Garcia RB, et al. Bilateral mandibular canines with two roots and two separate canals: case Braz Dent J. 2009;20:84–6 https://doi.org/10.1590/S0103-64402009000100015

8. Kaffe I, Kaufman A, Littner MM, Lazarson Radiographic study of the root canal system of mandibular anterior teeth. Int Endod J. 1985;18:253-59.

https://doi.org/10.1111/j.1365-2591.1985.tb00452.x

9. Vipin Arora, Vineeta Nikhil, Jatin Gupta, Mandibular Canine with Two Root Canals – An Unusual Case Report, Int J of Stomatological Research. 2013;Vol. 2 No. 1, pp.1-4. https://doi.org.10.5923/j.ijsr.20130201.01

10. A. Versiani, J. D. Pécora, and M. D. Sousa-Neto, “The anatomy of two-rooted mandibular canines determined using micro-computed tomography,” Int Endod J. 2011;vol. 44, no. 7, pp. 682-87 https://doi.org/10.1111/j.1365-2591.2011.01879.x

11. Iqbal 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 Diag Res. 2016;10:ZC146-8. https://doi.org/10.7860/JCDR/2016/14272.7884

12. Walton RE. Diagnostic imaging A. endodontic radiography. In: Ingle JI, Bakland LK, Baumgartner JC, editors. Ingles’

13. Scarfe WC, Levin MD, Gane D, Farman Use of cone beam computed tomography in endodontics. Int J Dent. 2010;2009:634567.

14. Carr Microscopes in Endodontics. J Calif Dent Assoc. 1992;20:55-61.

Hina Nasim                                                                                                BDS

Sarah Ghafoor                                                                                          BDS, BSc, PhD

Hina Nasim                                                                                                BDS

Sarah Ghafoor                                                                                          BDS, BSc, PhD

Oral and ocular homeostasis is dependent upon saliva, lacrimal fluid and their protein components. The function of major protein families regulating salivary and lacrimal fluid secretion is well established. The aim of this review is to summarize the role of different proteins that regulate salivary and lacrimal fluid secretion and to discuss mysregulations in diseased conditions especially xerostomia and dry eye syndrome. This review paper provides a detailed description of the abnormal localization and function of proteins, which could be responsible for loss of saliva and lacrimal fluid secretion in xerostomia and dry eye syndrome patients.

KEY WORDS: Proteins, Salivary flow, Lacrimal flow, Xerostomia, Dry eye syndrome.

HOW TO CITE: Nasim H, Ghafoor S. Proteins regulating salivary and lacrimal flow in xerostomia and dry eye syndrome. J Pak Dent Assoc 2019;28(2):92-97.

DOI: https://doi.org/10.25301/JPDA.282.92

Received: 18 October 2018, Accepted: 08 March 2019

INTRODUCTION

Saliva is a complex fluid, secreted by salivary glands, plays an important role in health and maintenance of oral cavity through its vast array of functions including,lubrication, protection, buffering action, antimicrobial function, facilitates swallowing and taste, helps in digestion and tissue repair.1 Saliva has important diagnostic implications as it contains various biomarkers that can be helpful in detection and monitoring of various oral and systemic diseases.2 The lacrimal fluid, secreted by lacrimal glands, is essential for the maintenance of healthy eyes. It performs important functions such as protection of the eye by producing IgA and various antibacterial and fungicidal substances and molecules, the aqueous component keeps the ocular surface moist and helps in maintaining normal visual acuity. It is also important for the normal growth and maintenance of ocular tissue by producing various growth factors, for example, Epidermal growth factor, Fibroblast growth factor, Transforming growth factor-beta.3

Proper secretion of saliva and lacrimal fluid is dependent upon different proteins for example aquaporins, tight junction proteins and ion channel proteins. Defective structure and function of these proteins leads to mys-regularities in saliva and lacrimal fluid secretion, resulting in xerostomia and dry eye syndrome.

Xerostomia in Common Clinical Conditions

Salivary gland hypofunction leads to a clinical condition known as xerostomia. Xerostomia is defined as a subjective complaint of dry mouth due to insufficient secretion of saliva.4 The absence of saliva in the oral cavity can cause difficulty in swallowing, tasting and chewing, oesophagal dysfunction (chronic esophagitis), nutritional compromises, loss of oral buffering capacity, increased susceptibility to dental caries, inability to wear dental prostheses, increased susceptibility to mucosal injury, increased incidence of glossitis, candidiasis, halitosis, angular cheilitis, bacterial sialadenitis and Burning Mouth Syndrome.5

The local and systemic causes of xerostomia are given in table 1.

Xerostomia and hyposalivation have been reported as common oral manifestations of diabetes mellitus (DM). Xerostomia in DM patients can be due to a number of reasons, such as damage to the salivary gland parenchyma, alteration in the microcirculation of gland, dehydration and disturbed glycemic control, but the exact cause is still unknown.6 The salivary glands of head and neck are highly sensitive to radiation, and radiotherapy can cause temporary or permanent damage to the glands. Xerostomia is the most common presentation of glandular dysfunction in the head and neck region .7 Sjogren’s syndrome is an autoimmune disease of salivary and lacrimal glands, resulting in dry mouth and dry eyes.8 Xerostomia is common in the geriatric population. The main causes for xerostomia are attributed to different medications, long-term systemic diseases and head and neck radiotherapy.9 Ectodermal dysplasia is a

heterogeneous group of inherited disorders, which affects the development of tissues, derive from embryonic ectoderm. Decreased salivary flow has been reported in affected males and females with Ectodermal dysplasia due to defects in salivary glands development.10

Dry eyes in Common Clinical Conditions

Dry eye syndrome (DES) or keratoconjunctivitis sicca is a multifactorial disease, it is a common sequel of inadequate lacrimal fluid production, resulting in blurred vision, foreign body sensation, stinging sensation, photophobia or pain.11 There are many causes of keratoconjunctivitis sicca (Table 2).

Defective function of the lacrimal gland can occur due to  various causes, including ageing, inflammation  and

infection and results in insufficient tear production that leads to various ocular complications.12

Dry eyes are also a distinctive feature of Sjogren’s syndrome. It is characterized by chronic inflammation of salivary and lacrimal glands resulting in dry mouth and dry eyes.13 Dry eye syndrome is one of the common complications of diabetes mellitus.14 Hyperglycemia has an adverse effect on the lacrimal functional unit, leading  to decrease tear production, or excessive tear loss, resulting in dry eye syndrome.15 Dry eye syndrome is common in elderly patients; the exact cause is still unknown. However, it is suggested that DES is related to biochemical, molecular and immune system disturbances.16 Dry eyes are an unfortunate side effect of radiotherapy. Radiotheraphy causes damage to the cells that leads to necrosis and apoptosis, resulting in the release of inflammatory mediators that are responsible for dry eye syndrome. 17

Proteins Regulating Salivary and Lacrimal Flow Proteins Involved in Salivary Secretion

The major component of saliva is water which is approximately 99%, and remaining 1% consist of electrolytes and salivary proteins.18 Major proteins families that are involved in salivary secretion are mentioned in table 3.

Aquaporins:

Aquaporins (AQPs) is a family of transmembrane proteins, which serve an important role in transfer of water  and some other solutes across the cell membranes. Until now, 13 types of AQP’s have been identified (AQP 0- AQP 12) .19

Aquaporin-1 protein expression has been found on the capillary epithelium and myoepithelial cells of salivary gland, aquaporin-3 localize to basolateral membranes of acinar cells and aquaporin-5 has been found to be localized on canalicular and luminal membranes of acinar cells.20 The salivary secretion has been reported to be increased

by upregulating the expression of aquaporin-1 in xerostomia patients.21 Decreased expression of aquaporin-1 on myoepithlial cells of primary Sjogren’s syndrome patients has been reported.22

In humans, AQP-5 mRNA has been detected in submandibular gland by RT-PCR. Functionally, it is believed that AQP-5 is the aquaporin which seems to play an important role in saliva secretion. It helps in primary saliva production.23 Abnormal localization of AQP-5 has  been  reported in Sjogren’s syndrome (SS) patients as compared to non-Sjogren’s syndrome patients with xerostomia. AQP-5 was found to be present at both apical and basolateral membrane in SS patients as compared to non- SS patients in which the AQP-5 was restricted to the apical membrane of acinar cells.24 The defect in the AQP-5 trafficking in parotid glands has been reported in streptozocin-induced diabetic rats.25

Tight Junction Proteins

Tight junctions also known as occluding junctions are a multiprotein junctional complex,whose primary function is to prevent leakage of transported solute and water, thus they seal the paracellular pathway. The main tight junction proteins are occludin, claudin and junctional adhesion molecule.26 Occludin has been found on the ductal and acinar cells of human major salivary glands and endothelial cells.27 The occludin level has been reported to be downregulated in patients with Sjogren’s syndrome.28 Claudin is the most important protein of tight junctions; it controls paracellular as well as the intercellular flow of molecules.29 Claudin1 has been found on striated and intercalated duct epithelium of human salivary glands. Caludin -2 has been detected on acinar cells of human salivary glands.30 Claudin- 3 has been detected on mucus and serous acinar cells of human salivary glands and Claudin-4 has been detected both on ductal and acinar cells of human salivary glands.31 Claudin play important role in saliva secretion by maintianing cell polarity and tansepithalial gradient necessary for unidirectional flow of saliva.32

Linker Protein (Ezrin)

Ezrin is a cytoplasmic peripheral membrane protein that serves as a bridge between the plasma membrane and the actin cytoskeleton, it plays an important role in cell adhesion, organization and migration. Ezrin was reported to be colocalized with actin at apical membrane and plays an important role in microvilli organization.33 Abnormal localization of ezrin has been reported in acinar cells of Sjogren’s syndrome patients.34

Ion Channel Proteins

Ion channel proteins are found in cell membranes, through which ions and electrolytes can move in and out of the cell .35 The acinar cells of salivary glands express different types of ion channel proteins, that are  present mostly on apical or basolateral membranes, to facilitate fluid secretion .36 Cystic fibrosis transmembrane regulator (CFTR) is a protein and chloride channel that controls the fluid and electrolyte transport in epithelial cells. In human salivary gland, CFTR has been found on the luminal surfaces of striated ducts.37 Mutations or any abnormality in CFTR has been reported to be associated with altered salivary function in cystic fibrosis patients.38

Proteins Involved in Lacrimal Fluid Secretion

The lacrimal fluid comprises mainly of water, electrolytes, proteins & metabolites in smaller quantities. Major proteins that are involved in lacrimal fluid secretion are given in table 4.

Auqaporins

In eyes, the aqueous component of tear film/lacrimal fluid is regulated by aquaporins.39 The main aquaporins that have been found on the acinar and ductal cells of lacrimal glands are; AQP-1, AQP-3, AQP-4and AQP-5.40 The expression of AQP-5 has been found on the acinar and ductal cells of rat and mice.41 Aquaporin- 5 expression have also been found on the apical surface of acinar cells in human lacrimal glands. A defect in aquaporin- 5 trafficking and lacrimal fluid secretion have also been reported in Sjogren’s syndrome patients.42 The expression of aquaporin-4 and

-5 was altered in pregnant rabbits with induced autoimmune dacryoadenitis.43

Gap Junction Proteins

Gap junctions are organized clusters of protein channels present in cell membranes that permit transfer of small molecules and ions between neighbouring cells. These channels are made up of connexon proteins . The acinar cells of lacrimal glands are attached to each other by gap junctions. The main gap junction proteins present in lacrimal glands are Cx 32 and Cx 26.44 Decreased lacrimal flow has been reported in Cx 32 null mice, which suggests that gap junctions play an important role in lacrimal fluid secretion.

Serotonin Protein

Serotonin derived from amino acid tryptan, performs a multiple array of functions. In brain it functions as a neurotransmitter, while in peripheral organs it acts as a hormone or a signalling molecule.46 Recently, it has been reported that decrease level of serotinin in blood is related to lacrimal gland atrophy and autophagy leading to loss of tear production in a mice model.47

Ion Channel Proteins

CFTR is a chloride channel that plays an important role in fluid transport across epithelial cells.48 It has been reported that CFTR is present on acinar and ductal cells of rat and rabbit model. Recently, decrease in the production of lacrimal fluid has been reported in knockout mice.49

Extracellular and Cytoplasmic Proteins

In addition to above mentioned proteins, there are various extracellular and cytoplasmic proteins that are involved in the formation of tear film such as PRR4, S100A8, DMBT1 and PROL1. It has been reported that some of these proteins were differntially expressed in dry eye syndrome patients as compared to controls and the pathology of DES can be associated with decrease expression of these proteins.13

CONCLUSION

Xerostomia and dry eye syndrome occurring due to defects in salivary and lacrimal fluid secretion can result in a multifacet degradation of patients’ quality of life. Xerostomia is caused by disturbances in regulation of protiens such as aquaporins ( APQ-1 & -5), tight junction proteins (occludin, claudin), linker protein (ezrin) and ion channel proteins (CFTR). Similiarly, dry eye syndrome is caused by defective funstioning of aquaporins ( APQ-4 & -5), gap junction proteins (Cx 32 and Cx 26), ion channel proteins and extracellular and cytoplasmic proteins.

Further research can explore possibilities of these molecules as relevant biomarker for abnormal conditions associated with salivary and lacrimal fluid flow.

ACKNOWLEGMENTS

 The authors would like to thank the Higher Education Commission of Pakistan (HEC) for providing e-Library access through which published data for this manuscript was retrived.

CONFLICT OF INTREST

 The authors declare no conflict of interest.

Funding

None to declare.

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34. Pérez P, Aguilera S, Olea N, Alliende C, Molina C, Brito M, et Aberrant localization of ezrin correlates with salivary acini disorganization in Sjögren’s Syndrome. Rheumatology. 2010;49:915- 23.

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35. Gadsby Ion channels versus ion pumps: the principal difference, in principle. Nat Rev Mol Cell Biol. 2009;10:344-52. https://doi.org/10.1038/nrm2668

36. Catalán MA, Pe-a-Munzenmayer G, Melvin Ca(2+)-dependent K(+) Channels in Exocrine Salivary Glands. Cell calcium. 2014;55: 362-68.

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37. Webster P, Vanacore L, Nairn AC, Marino Subcellular localization of CFTR to endosomes in a ductal epithelium. Am J Physiol Cell Physiol. 1994;267:C340-C8. https://doi.org/10.1152/ajpcell.1994.267.2.C340

38. Livnat G, Bentur L, Kuzmisnsky E, Nagler RM. Salivary profile and oxidative stress in children and adolescents with cystic fibrosis. J Oral Pathol Med. 2010;39:16-21.

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40. Verkman AS, Ruiz-Ederra J, Levin Functions of Aquaporins in the Eye. Prog Retin Eye Res. 2008;27:420-33. https://doi.org/10.1016/j.preteyeres.2008.04.001

41. Hamann S, Zeuthen T, La Cour M, Nagelhus EA, Ottersen OP, Agre P, et Aquaporins in complex tissues: distribution of aquaporins 1-5 in human and rat eye. Am  J  Physiol Cell Physiol. 1998;274 (5 Pt 1):C1332-45. https://doi.org/10.1152/ajpcell.1998.274.5.C1332

42. Tsubota K, Hirai S, King LS, Agre P, Ishida Defective cellular trafficking of lacrimal gland aquaporin-5 in Sjögren’s syndrome. The Lancet. 2001;357(9257):688-89.

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43. Ding C, Nandoskar P, Lu M, Thomas P, Trousdale MD, Wang Changes of aquaporins in the lacrimal glands of a rabbit model of

Sjogren’s syndrome. Curr Eye Res. 2011;36:571-78.

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Yvonne YL Lai                                              BDSc DClinDent

Yvonne YL Lai                                              BDSc DClinDent

One of the areas that are most contentious in the diagnosis and management of traumatic dental injuries in children are in the approach toward luxation injuries in the primary dentition. Although the majority of injuries to the primary anterior dentition are luxations, there appears to be little definitive evidence in the dental literature for the management of luxation injuries in primary dentition; namely, intrusive luxations and lateral luxations. Some of the controversies centre on whether particular management approaches are likely to increase likelihood of further damage to the permanent successor, whilst others centre on question of whether certain approaches are likely to increase likelihood of pulpal necrosis or periapical inflammation of the injured primary tooth. There is conflicting published evidence over whether intruded or luxated primary teeth are best extracted, positioned, or monitored for spontaneous repositioning. For intrusion injuries, factors considered in the literature include the degree of intrusion, presence of multiple injuries, and orientation. Many approaches to management of primary tooth luxation focus on the degree of injury or occlusal interference, and novel approaches are described. The controversies are described herein.

KEY WORDS: dental trauma, primary tooth, luxation, intrusion, extrusion

HOW TO CITE: Lai Y YL. Traumatic dental injuries in children: the controversies of managing primary tooth luxation injuries. J Pak Dent Assoc 2019;28(2):85-91.

DOI: https://doi.org/10.25301/JPDA.282.85

Received: 28 January 2019, Accepted: 21 February 2019

INTRODUCTION

One of the topics that is most controversial in the diagnosis and management of traumatic dental injuries in children is about management of luxation injuries in the primary dentition. Although the majority of injuries to the primary anterior dentition are luxations1,2, there appears to be conflicting evidence in the dental literature for its management, particularly intrusive luxations and lateral luxations. These controversies are described in the following sections. Some of the controversies centre on whether particular management approaches are likely to increase likelihood of further damage to the permanent successor, whilst others centre on question of whether certain approaches are likely to increase likelihood of pulpal necrosis or  periapical inflammation of  the  injured primary tooth.

INTRUSION: EXTRACTION

An intrusive luxation is described as the displacement of a tooth into the alveolar bone. Extraction of the traumatised tooth is often recommended3, however, management of intrusive luxations in the primary dentition is not universally agreed upon in the dental literature. A recent study conducted

an impact analysis on the effect of trauma to primary teeth at different resorption stages, on the developing permanent tooth germ.4 The study used cross-sectional models using cone-beam tomography (CBCT) images of 3.5, 5 and 6 year old children to represent the various root resorption stages of a primary incisor. The study demonstrated that for all simulations, stress concentrations were found at the permanent tooth germ and surrounding hard and soft tissues regardless of the direction of impact and the primary tooth resorption stage, and that this increased the more the primary tooth was resorbed. More importantly, the stress concentrations were higher for incisal impact regardless of the root resorption stage of the primary tooth, and high stress concentrations were found at the root apex when there was no root resorption of the primary tooth. The study concluded that the stresses generated from impact during primary tooth trauma in the area of the dental follicle and surrounding tissues, were most significant for potential damage to the developing permanent tooth4, and this may lend support to the treatment option of extraction in intrusive luxation injuries. An older study, Selliseth (1970) proposed that leaving the primary tooth would lead to a higher chance of disturbance to the permanent successor as opposed to extracting the injured tooth at the time of injury. However, the findings in this study were limited to children older than three years of age, and the differences for other age groups was insignificant.5 However, a clinical and radiographic follow-up study by Andreasen and Ravn (1971) found that the younger the patient age, the more severe the injury was to the permanent successor.6 A study by von Arx found the highest prevalence of developmental disturbances of permanent teeth after intrusive injuries of primary teeth.7 An experimental study using an animal model demonstrated extraction of the intruded incisor results in less damage to the traumatised enamel epithelium of the permanent successors.8 The proposed explanation for these findings were that the subsequent intramedullary chronic inflammation is eliminated, thus reducing likelihood of damage to the permanent successor.9 However, it is difficult to extrapolate the findings of the histologic study to the clinical setting. The case for extraction of intruded teeth is also demonstrated in a case report which described the unforeseen sequalae of a subluxation injury to a primary tooth10, which is considered a far less traumatic injury than intrusive luxation. The permanent successor tooth subsequently exhibited grade III mobility on eruption, and exfoliated during daily activity. Thus, the case report demonstrated the significant consequences that even a relatively minor traumatic dental injury can have on the permanent successors.10 However, a recent retrospective study suggested that conservative measures may be acceptable for primary tooth intrusion.11 Analysis of dental records showed that the prevalence of primary tooth intrusions in the cohort was 9.98%, and of those injuries, partial intrusion (57.3%) was more common compared to complete intrusion, with palatal orientation of the crown (61.8%) compared to buccal orientation.11 Of these injuries, the most common management method involved conservative treatment (73.5%) as opposed to extraction. While the most common healing complication was mobility in 15.5% of cases, most cases exhibited no healing complications at three months (64.8%). In light of these findings, and notwithstanding the limitations of the follow-up period of the study, the authors supported the idea of conservative management of primary tooth intrusion if the permanent tooth germ is not clearly compromised, unless there are issues with  patient cooperation.11 The author’s suggestion appears to be consistent with the philosophies underpinning the International Association of Dental Trauma (IADT) guidelines, which advocate extraction of the intruded primary tooth if there is clinical and/or radiographic evidence of displacement into the developing permanent tooth germ.12

Should the degree of intrusion dictate whether the primary tooth is extracted?

It is also argued that the degree of intrusion should dictate management. An intrusion injury can be classified into three types depending on the magnitude of intrusion.13 According to the classification, in type I intrusion, more than 50% of the crown is exposed; type II, less than 50% of the crown is exposed and in type III, the entire crown is intruded.13 Others argue that regardless of the type of intrusion injury, the permanent successor is usually within 3mm of apex of the primary tooth and that this space may consist of connective tissue only, thus extraction should be the treatment of choice for an intrusive luxation in the primary dentition.14 This approach differs from the approach advocated by the IADT guidelines, in which management is dictated by the orientation of the primary tooth apex relative to the developing permanent tooth germ.12

INTRUSION WITH MULTIPLE INJURIES: REPOSITIONING OR EXTRACTION?

Many intrusive luxation injuries of primary incisors are associated with bone fractures.15 While leaving intruded primary teeth for re-eruption has been documented in the literature16, other approaches are discussed; the first is the repositioning of the fractured bone in the case of concomitant fracture using digital pressure and the use of a flexible splint for three to four weeks17 and to monitor any teeth in the fracture line with further splinting for another 2-3 weeks if further stability is required3 and the second is extraction of the injured tooth as an alternative to further splinting beyond the initial four weeks.3 It is noted however, that the latter recommendations for alveolar fracture in the 200118 and 20023 guidelines are absent from the latter paper by Flores and colleagues17 and the most recent IADT guidelines.12 Interestingly, one study assessing the prognosis of luxation injuries found that intrusions had a decreased risk of necrosis when repositioned.19

INTRUSION: DEPENDS ON ORIENTATION OF TOOTH

Theoretically, it is argued that apex of primary maxillary central incisors is usually curved in a labial orientation and so in most cases, intrusion results in the apex being pushed labially away from permanent successor tooth germ.20 This presents radiographically as a tooth with a foreshortened apex on maxillary occlusal film.3 An alternative method to confirm this radiographically is to expose a lateral film taped to the child’s cheek extra orally and to double the exposure time. This approach appears to be used routinely in some earlier studies by Andreasen, but more recent guidelines recommend this only if there is 100% intrusion and one cannot palpate the apex buccally through alveolar bone. In this instance, the film would be used to determine whether the apex has been pushed into  the  tooth  germ.3 One school of thought states that if the apex is displaced labially (foreshortened root on maxillary occlusal film), then the tooth should be left for spontaneous eruption.15,21 If the apex is pushed into follicle of the permanent successor, it presents as an elongated root on maxillary occlusal film and the apex is not visible. In this case, it is thought that the tooth should be extracted due to risk of damaging the permanent successor 19, and this philosophy and approach is described in the current IADT guidelines.12 This view is supported by the findings of a retrospective study by Holan and Ram (1999) involving 172 intruded primary teeth. More than 80% of these teeth were intruded with the roots orientated buccally, and most of them erupted with no complications over a 36 month follow up period.21

INTRUSION: LEAVE AND WAIT

Other studies in the literature support a “leave and wait” approach for intrusive luxation injuries in the primary dentition with no other concomitant injuries. A study conducted by Ravn involving 88 intruded teeth found that 72 of these intruded teeth re-erupted after the injury, four needed to be extracted immediately at the time of evaluation, and four were over-retained.22

Ravn also conducted another study in 1976 which reported the outcomes of 100 intruded teeth. Of these teeth, 86 teeth re-erupted with 35 demonstrating calcific degeneration. Twenty-two teeth developed peri-apical pathology, and 29 teeth showed no post-traumatic sequelae. Eight teeth were removed immediately and six never re-erupted.23

A study by Ravn and Andreasen 1971 study showed no difference in occurrence of damage to the permanent successor regardless of whether extraction or conservative management was adopted.6 Similarly, a study some years later by Thylstrup and Andreasen in 1977 found no differences in damage to the permanent successor with an extraction approach or watch and wait approach.24 A more recent retrospective study involving 307 luxation injuries sustained by 222 patients found no significant association between the type of treatment rendered and secondary successor hypoplasia for intrusions (P= 0.38).19 These findings therefore imply that any damage would have been done at the time of injury and so a conservative management would therefore be appropriate. However, a recent controlled study examining the effect of traumatised primary teeth on its permanent successors had findings to the contrary. Of the injured primary teeth (n=214) in this study, only 44.1% (n=19) of intruded primary teeth had no sequelae in the permanent successor, with 20.9% (n=9) showing enamel discolouration and 18.6% (n=8) with enamel hypoplasia, with other injuries including crown dilaceration (4.6%; n=2), odontoma-like formation (2.3%; n=1), root dilaceration (2.3%; n=1), and sequestration

of tooth germ (2.3%; n=1) reported.25 This study found a significant association between primary tooth intrusion and permanent tooth sequelae (p=0.001)25 and therefore it appears to cast some doubt on the more conservative approach to primary tooth intrusion in general. While aesthetic concern over qualitative enamel defects would depend on the degree of enamel discolouration; the risk of other more serious permanent teeth sequelae must be weighed when considering available management options for primary tooth intrusions.

Severe intrusion

For proponents of the “watch and wait” approach, controversy exists also over whether severe intrusions should still be left for observation. This specifically relates to a third degree intrusion on the von Arx scale26, as opposed to the treatment approaches described in the IADT guidelines according to apex orientation.12 While one recommendation is extraction in this situation9, another approach is to still leave the tooth for observation.15 One case report successfully reported for conservative management for a complete intrusion of a primary incisor.27 However, another case report on the permanent tooth sequelae of a primary tooth subluxation, outlines the albeit rare but serious consequences that a seemingly less traumatic dental injury can have on the permanent successor which subsequently sequestrated some years later during routine daily activity, and the possibility of severe sequelae to permanent tooth need  to be considered against the benefits of conservative approaches.10 Another author recommends to leave the tooth for spontaneous eruption unless the root tip has punctured the floor of the nasal cavity, in which case the tooth should be removed through the nares.28 Proponents of this approach, again, would argue that any damage done to the permanent successor has been done already as shown in previous studies.6,22,23 It is also suggested that extraction of an intruded tooth itself can pose the risk of damaging the permanent successor.29

If one adopts a conservative option of leaving an intruded primary tooth to observe for re-eruption, the clinician must follow up for signs of periapical infection or pulp necrosis. Its importance is highlighted by one study which shows that a significant relationship exists between necrosis and hypoplasia of the succedaneous tooth (P = 0.80)19, and the reported percentage of intruded primary teeth that subsequently develop pulpal necrosis varies. One source cites that 65% (n=46) of 68 intruded primary teeth had developmental disturbances in the permanent successor.30 Such developmental disturbances may include enamel discolouration or hypoplasia, crown dilaceration, odontoma like formation, root duplication, vestibular root angulation, root dilaceration, arrestment of root formation, sequestration of the permanent tooth germ, or disturbance in eruption.30 Another source cites the ratio of pulp vitality to pulp necrosis as being almost  50%  in  patients  aged  0-3  years.3 In considering this, however, younger children seem less likely to develop pulp necrosis as a result of traumatic injury to the primary dentition. A study by Holan and Ram showed that young children less than 1.5 years of age were less likely to develop pulpal necrosis in spite of the fact they had the highest frequency of intrusion. On the other hand, the eldest children greater than 5.5 years of age had a ten-fold greater risk of pulpal necrosis even though the most common injury was subluxation. The authors proposed that an explanation for these findings were that a young child’s tooth has a high vascular supply and wide open and short pulp.21

Intrusion- leave and wait – how long for?

The proposed follow-up time to observe for re-eruption of intruded primary teeth varies in the dental literature. Schreiber (1959) suggested that an intruded tooth with the root displaced buccally would usually be expected to re- erupt within six weeks.31 Similarly, Andreasen and Ravn (1973) proposed that in the same scenario that this period was three to four weeks.32 On the other hand, Crespi (1992) stated that this period was three months.33 Ravn (1968) proposed that intruded primary teeth would usually re-erupt after six months.22

LATERAL LUXATION

Some controversial/alternative management options exist for lateral luxation injuries in the primary dentition. There is limited evidence in the dental literature on the prognosis of primary teeth with lateral luxation injuries in the primary dentition. A study by Ravn (1968) showed that of the six luxated teeth evaluated, four were extracted immediately, and two that were repositioned later needed extraction.22 Sequelae to the permanent successor following primary tooth lateral luxation is documented in a recent study investigating the sequelae to permanent teeth from primary tooth injury. It found that of the injured primary teeth (n=214), 68.1% (n=15) of primary tooth lateral luxation injuries had no sequelae in the permanent dentition, with 18.1% (n=4) having enamel hypoplasia, one case observed for enamel discolouration (4.5%; n=1), partial arrest of root formation (4.5%; n=1), and eruption disturbance (4.5%; n=1). The exact type of emergency treatment administered was not clear in these cases.25

In general, most guidelines, including those proposed by the IADT12, suggest that management of laterally luxated teeth is determined in part by whether there is occlusal interference.3 It is suggested that if there is no occlusal interference, that the tooth be left to reposition spontaneously.15,19 One study that supports this recommendation reports that out of 104 laterally luxated teeth, 99% repositioned spontaneously within one year.15 Another retrospective study involved 331 primary teeth with lateral luxation left without treatment.34 It found that the estimated risks after three years for pulpal canal obliteration (PCO) were 41.3%, pulpal necrosis (PN) 19.8%, infection related resorption (IRR) 7.0%, ankylosis related resorption (ARR) 1.4% and premature tooth loss as 24.8%.35 This study concluded that conservative management was associated with a relatively high healing potential.34 On the other hand, in laterally luxated teeth with severe occlusal interferences, leaving the tooth to spontaneously reposition may further compromise its prognosis.36

If there is minor occlusal interference as a result of lateral luxation, slight odontoplasty is advocated, as per the IADT guidelines.12 However, it is suggested that care must be taken as severe grinding may cause exposure of dentinal tubules, pulp exposure and lead to loss of pulp vitality of the tooth.37 In such a case, topical fluoride may be applied to minimise the risk of sensitivity.

It is also suggested that if there is occlusal interference, that the primary tooth be actively repositioned and splinted to the adjacent teeth for two to three weeks15,38 and this is consistent with that of the IADT guidelines.12 While success with this approach has been documented in one case report involving repositioning, splinting with composite resin and pulpectomy of the injured tooth38, an observational study found that while 60% of 52 teeth left for spontaneous repositioning did not show complications, active repositioning of lateral luxations was associated with an increased risk of developing pulpal necrosis.19 Another recent retrospective study assessing the outcomes of splinting in primary teeth with root fractures, lateral and extrusive luxations, found that splinting in lateral or extrusive luxations were not associated with a good prognosis.39 In addition, active repositioning cannot be performed when there is delayed presentation of the injury.

In cases of severe luxation injury of the primary tooth in a labial direction, the IADT guidelines stipulate that extraction is the treatment of choice.12 However, it is suggested that extraction of anterior teeth in young children can lead to poor aesthetics, phonetics and loss of function and may cause psychological and social problems.17,36

Alternative methods of managing primary tooth luxations were documented in two case reports which involved a novel approach to achieve gradual repositioning of a primary tooth in cross bite caused by lateral luxation.36,37 An incisal plane fabricated with composite resin was created by placing additional composite over the opposing teeth.36,37 Other novel approaches to management include the use of a wooden tongue blade to reposition a primary tooth displaced by lateral luxation. However, this approach is thought to be spurious as the success of this technique depends heavily on the cooperation of both the parents and the child.19,36 Another technique involves the placement of a reversed stainless steel crown over the opposing tooth as an inclined plane to allow gradual repositioning of the laterally luxated tooth. While this method has been successful, the reversed stainless steel crown affords poor adaptation to the tooth .36,40  The use of a removable acrylic appliance with  a Z-spring has also been reported in the literature as the proposed management to move the displaced incisor forward.36 However, the success of these treatment approaches depend on the age (at the time of the injury) and compliance of the child.

The evidence in the literature is unclear about the definite approach for lateral luxation injuries in primary teeth in terms of prognostic outcomes according to treatment type. A study previously described in this review suggested splinting of lateral luxations was associated with a poor prognosis.39 A retrospective study involving 307 teeth found that there was no significant association between the type of treatment rendered and the occurrence of hypoplasia in the permanent successor in instances of lateral luxation injuries (p=0.13).19 With the exception of extraction, current guidelines suggest that all luxation injuries should be afforded adequate clinical and radiographic follow-up, as per the recommended schedule, until the eruption of the permanent successor, to detect signs of infection, or dark discolouration .12

PRIMARY TOOTH EXTRUSION MANAGEMENT

There is little evidence to support current guidelines for management of extrusive luxation injuries in the primary dentition. Various guidelines, including the IADT guidelines, propose that for minor extrusion injuries of less than 3 mm, the management should be to either leave the tooth for spontaneous alignment or to reposition and splint the tooth .3,12,17 There was no published literature on the approach involving repositioning with splinting at the time the IADT guidelines were published on the management of primary tooth extrusion injury.3 One recent retrospective study reported the treatment outcomes of splinting in the primary teeth of 137 children with root fractures and lateral and extrusive luxation injuries. Of 183 teeth examined, semi- rigid splints were placed on 80 teeth, and it was found that splinting for extrusive luxations was not associated with favourable prognosis (p<0.05), and this differs from the splinting recommendation in the IADT guideline.39 An earlier retrospective study followed 26 primary tooth extrusion injuries in 24 patients, where these teeth were repositioned without splinting. Follow-up examinations were performed periodically up to one-year post-injury and also when the patients were six years old. The study found that after three years, estimated risks were reported as PCO being 39.8%, PN as 15.6%, IRR as 3.8%, and PTL as 43.3%. The IADT and other previously published guidelines recommend that cases involving severe extrusive luxation greater than 3 mm in the primary dentition should be extracted.3,12,17

CONCLUSION

In conclusion, the evidence for the clinical approach toward luxation injuries in the primary dentition is controversial. The evidence is conflicting and that there is relatively little substantive scientific evidence to discredit one approach over another. Many factors including patient age, presence of concomitant injuries, orientation of the teeth, patient and parent factors and consent also have a bearing on the clinical approach in paediatric patients. When treating such injuries, it is important that clinicians should also be aware of such factors in addition to the various management options available for that injury. All these factors can help clinicians in making the most informed decision regarding the best approach that is tailored for the individual child.

ACKNOWLEDGEMENT

Appreciation is expressed to Dr Sobia Zafar for her assistance in critically reviewing the manuscript.

POTENTIAL CONFLICTS OF INTEREST

None declared.

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25. Lenzi MM, da Silva Fidalgo TK, Luiz RR, Maia LC. Trauma in primary teeth and its effect on the development of permanent successors: a controlled Act Odontol Scand. 2019;77:76-81. https://doi.org/10.1080/00016357.2018.1508741

26. Von Arx [Deciduous tooth intrusions and the odontogenesis of the permanent teeth. Developmental disorders of the permanent teeth following intrusion injuries to the deciduous teeth]. Schweiz Monatsschr Zahnmed. 1994;105:11-7.

27. Torriani DD, Bonow ML, Fleischmann MD, Muller Traumatic intrusion of primary tooth: follow up until eruption of permanent successor tooth. Dent Traumatol. 2008;24:235-38. https://doi.org/10.1111/j.1600-9657.2007.00474.x

28. Nowak A, Slayton R. Trauma to primary teeth: Setting a steady management course for the Contemp Pediatr. 2002;19:99.

29. Andreasen JO, Andreasen FM. Injuries to the primary dentition. Essentials of traumatic dental injuries to the Copenhagen: Munksgaard; 1990. p. 141-54.

30. Andreasen JO, Andreasen FM, Andersson Textbook and Color Atlas of Traumatic Injuries of the Teeth. 2018.
31. Schreiber The effect of trauma on the anterior deciduous teeth. Br Dent J. 1959;106:340-43.

32. Andreasen J, Ravn J. Enamel changes in permanent teeth after trauma to their primary Eur J Oral Sci. 1973;81:203-09. https://doi.org/10.1111/j.1600-0722.1973.tb00330.x

33. Crespi Intrusive injuries to the dentition. N Y State Dent J.1992;58:35.

34. Lauridsen E, Blanche P, Yousaf N, Andreasen JO. The risk of healing complications in primary teeth with extrusive or lateral luxation- A retrospective cohort Dent Traumatol. 2017;33:307-16. https://doi.org/10.1111/edt.12340

35. Lauridsen E, Blanche P, Yousaf N, Andreasen JO. The risk of healing complications in primary teeth with intrusive luxation: A retrospective cohort Dent Traumatol. 2017;33:329-36. https://doi.org/10.1111/edt.12341

36. Arikan V, Sari S. Using composite resin inclined plane for the repositioning of a laterally luxated primary incisor: a case Eur J Den. 2011;5:117-20.

37. Wankhade AD, Pandey RK, Singh RK, Gondhalekar R. A novel approach in management of lateral luxation of primary tooth. BMJ Case Rep. 2013.

https://doi.org/10.1136/bcr-2012-007984

38. Holan Conservative treatment of severely luxated maxillary primary central incisors: case report. Pediatr Dent. 1999;21:459-62.

39. Cho WC, Nam OH, Kim MS, Lee HS, Choi SC. A retrospective study of traumatic dental injuries in primary dentition: treatment outcomes of Acta Odontol Scand. 2018;76:253-56. https://doi.org/10.1080/00016357.2017.1414956

40. Croll Fixed inclined plane correction of anterior cross bite of the primary dentition. J Pedod. 1983;9:84-4.

Syed Ameer Hamza                                                                           BDS

Arsalan Wahid                                                                                    BDS, M.Phil

Mian Farrukh Imran                                                                        BDS, MDS

Khaled Khalaf                                                                                     FDS, RCS

Syed Akhtar Hussain Bokhari                                                      PhD

Syed Ameer Hamza                                                                           BDS

Arsalan Wahid                                                                                    BDS, M.Phil

Mian Farrukh Imran                                                                        BDS, MDS

Khaled Khalaf                                                                                     FDS, RCS

Syed Akhtar Hussain Bokhari                                                      PhD

OBJECTIVE: Poor oral health is not uncommon among the population of Pakistan. Malocclusion may be one of the causes known so far. This study has evaluated the association of anterior teeth crowding with plaque, bleeding on probing and gingivitis and has noted the trend in families.

METHODOLOGY: Eleven families comprising of 41 members aged 30.3±15.3 (12-55) years were recruited for this cross-sectional study. Crowding of anterior teeth (canine-canine) of upper and lower jaws was recorded on study casts. Oral hygiene parameters of plaque, bleeding on probing and gingivitis were noted for the anterior teeth. Variables were analyzed in means and percentages and study participants were compared for differences in study parameters using the t-test and Chi- squired test. Statistical significance was set at p<0.050.

RESULTS: Forty eight percent showed severe crowding, 34% had severe plaque, 100% showed mild to moderate gingivitis, 24% exhibited bleeding on probing. Significant difference (p=0.003) was noted among orthodontic cases and family members. No significant difference was observed between inter- and intra-family regarding oral hygiene parameters. Comparison between parents and siblings showed no difference in all study parameters.

CONCLUSION: A significant association was found between the presence of anterior crowding and gingival index. This study has supported the notion that an association exists between crowding of anterior teeth and gingivitis.

KEY WORDS: Anterior Crowding, Plaque, Bleeding on probing, Gingivitis

HOW TO CITE: Hamza SA, Wahid A, Imran MF, Khalaf K, Bokhari SAH. Exploring the relationship of anterior crowding and oral hygiene: a pilot study. J Pak Dent Assoc 2019;28(2):78-84.

DOI: https://doi.org/10.25301/JPDA.282.78

Received: 29 October 2018, Accepted: 04 February 2019

INTRODUCTION

Poor oral health is not uncommon among the population of Pakistan.1 Mal-alignment of teeth might be one of the many predisposing factors supposed to be responsible for this condition. Irregularities in dentition cause difficulties in the cleaning of teeth and maintenance of good oral hygiene, therefore prompting to gingivitis and periodontitis.2 However, there exist contradictions in research findings concerning the relationship between dental irregularity and periodontal disease.3 These contradictions arise due to difficulty in distinguishing the effects of irregularity from those of other important factors such as social class, gender, motivation, education and family background.4 The main influence, in addition to other factors, on gingivitis would be through differences in the effectiveness of oral hygiene measures.

Buckley LA5 found that individual tooth irregularity had a low, but statistically significant correlation with plaque and gingival inflammation in a group of 300 teenagers. Although he considered the likely reason was that crowded and irregular teeth facilitated the accumulation of bacterial plaque, thus indirectly contributing to gingival inflammation. However, no account was taken of the family background including education, socioeconomic status (SES) and motivation.

Ainamo et al.6, noted in a study of 154 army recruits that periodontal disease was worse adjacent to malaligned maxillary anterior teeth and it was possible to envision malalignment as the cause, which makes it extremely difficult if not impossible to attain high standards of plaque control. The problem still remains that we do not know as yet the magnitude of risk of development of oral disease in individuals having malalignment. In addition, what is lacking in the literature is the exclusion of confounders as differences in familial background, SES and education status all of which have a role in maintaining oral hygiene.

Data on incisor irregularity is extremely limited7, the same trend has been observed in Pakistani population. The changes in diet patterns of Pakistani population, with the inclusion of soft diet, and use of pacifiers and bottles at a younger age may have led to the increase in prevalence of malocclusion including limitation of space and therefore tooth eruption in a regular manner has been affected. This highlights the importance of conducting detailed research in the Pakistani population to investigate the risk of development of oral disease based on malocclusion. Therefore, this pilot study was designed to assess the association of anterior crowding with oral hygiene after controlling SES, education status and family background and plan a large-scale study.

METHODOLOGY 

Study Type and Setting

A pilot cross-sectional study was conducted by applying purposive convenient sampling technique. The study was conducted at Dental Clinics of the Medina Teaching Hospital, The University of Faisalabad, Pakistan.

Study Sample

Patients attending the dental clinics for orthodontic treatment over a period of two months, 11th August-10th September 2017 were screened as per inclusion/exclusion criteria detailed below. Sixty five cases were screened for the study during the above mentioned period. Eligible individuals were fully informed about the study and requested to participate in the study.

INCLUSION CRITERIA 

.     Age 14 to 25 years for orthodontic cases

.     Both male and female patients

.     Families resident of Faisalabad for the last (ten) years matching all educational and socioeconomic backgrounds

.     Two siblings and at least one parent of family with anterior crowding

.     Presence of full complement of the permanent dentition from the first permanent molar to the contra-lateral first permanent molar

.     Absence of any active periodontal disease and dental caries

EXCLUSION CRITERIA

.     Orthodontic patients with no anterior crowding

.     Patients having systemic diseases and medically compromised individuals

.     Mentally and physically challenging patients

.     Smokers and ex-smokers

.     Mouth breathers

.     Antibiotic therapy during the last three months

.     Abnormal para-functional habits

.     Abnormal hard and soft tissue morphology like cleft lip and palate patients

.     Patients having craniofacial syndromes

.     Previous history of periodontal therapy

.     Previous orthodontic treatment

.     History of extraction of both primary and permanent dentition

.     Congenitally missing teeth

.     Supernumerary teeth

.     Aberrations of tooth size and shape

.     The presence of large restorations and fractured teeth

.     Families  with  single  child  and  single  parent.

Clinical Examination

Recruited orthodontic patients, who gave informed consent for the study, were asked to bring their siblings and parents for collection of socio-demographic information and detailed assessment of malocclusion and oral hygiene.

Measurement of Crowding

Dental casts were constructed for all study participants and the mesio-distal dimensions of all anterior teeth (from the right canine to the left canine) of the upper and lower jaws were measured according to the method prescribed by Moore’s and Reed8 using a digital caliper set at 0.01mm accuracy under natural light. The anterior upper and lower dental arches were measured using a brass wire placed on the top of the dental arches from the distal surface of one canine to the distal surface of the contralateral canine. The wire was then spread out and its length measured using the digital caliper. The discrepancy between the sum of the mesiodistal measurements of the anterior teeth and the corresponding dental arch measurement was calculated which represented the amount of crowding. Crowding was classified according to the following criteria

Score 0 = <2mm crowing

Score 1 = 2.1-5.0 mm crowding

Score 2 = 5.1-9.0 mm crowding

Score 3 = > 9.0 mm crowding

Oral Hygiene Measures

Oral hygiene was recorded through 1) plaque index, 2) Gingival index, and 3) Bleeding on probing (BOP)9

Examiners’ Training and calibration

Two calibrated examiners (Dental internees) performed the clinical oral examinations and recorded anterior crowding on the study models. Calibration of examiners was performed by an experienced orthodontist and a periodontist with more than five years of experience in their respective fields.

Statistical Analysis

Data was entered into computer for analysis with the help of SPSS version 16. Data was analyzed among study participants on the basis of all clinical parameters for inter- and intra-family members. Analysis of categorical data was carried out using Chi-squared test and independent t-test was used for continuous variables. For analysis purpose, crowding was classified into Category 0 (No crowding) (2mm or less), category 1 (Mild) (2.1-5.0mm), category 2 (Moderate) (5.1-9.0mm) and category 3 (Severe) (>9.00mm). Plaque index and Gingival index were categorized into mild- to-moderate and sever categories. Bleeding on probing (BOP) in percentage (%) was categorized into gingivitis (>20% bleeding sites) and no gingivitis (<20% bleeding sites). Logistic regression was applied for evaluation of association between study parameters. All values were rounded off to the nearest digit.

Ethical Approval

Study was approved by the Research and Ethical Committee of the University of Faisalabad vide approval letter No: BASR/TUF/2109/2015.

RESULTS

 Eleven families comprising of 41 members who consented to participate were registered for the current study over a period of two months. Eleven (27%) were orthodontic cases and 30 (73%) were parents and siblings. Mean age of participants was 30.34±15.35. Fourteen (34%) were males. Twenty-eight (68%) had higher secondary education and 35(85%) belonged to the low-income group. All subjects reported that they were using toothbrush as oral hygiene measure (Table 1).

Twenty (48%) had severe crowding, 7(17%) had moderate, 5(12%) had mild crowding and 9(22%) had no crowding. Oral hygiene parameters of plaque, gingivitis and bleeding on probing were noted. Only 14(34%) showed severe plaque deposition, 41(100%) had mild to moderate gingivitis and 10(24%) demonstrated bleeding on probing. Nine (22%) subjects had no anterior crowding, 20(48%) had severe (>9.00mm) crowding (Table1).

A comparison of crowding and oral hygiene parameters between orthodontic cases and parents showed that 9(82%)

Table 1: Distribution of Study Participants with respect to Study Variables

cases had severe crowding as compared to 11(37%) of family members and it was significant (t-test p=0,003 and Chi- squire test p=0.026). Four (36%) orthodontic cases had severe plaque as compared to parents (33%). Plaque amount was insignificantly higher in orthodontic cases (36% vs 33%), severe gingivitis was insignificantly higher in family members (13% vs 9%) and bleeding on probing was also

Table 2: Comparison of Anterior Crowding and Oral Hygiene Variables between ‘Cases and Family Members’ and ‘Siblings and Parents’ [n (%)]

Table 3: Comparison of Crowding and Oral Hygiene Variables between Male and Female Participants [n (%)]

shown higher in family members (27%) as compared to cases (18%). A comparison between siblings and parents also showed no statistically significant difference in crowding as well as in oral hygiene variables (Table 2).

Difference of anterior crowding was insignificant among genders, although more females had a severe crowding. No gender differences were noted in oral hygiene variables. A comparison of males and females among siblings and parents also did not show any statistically significant difference in all study variables (Table 3).

Relationship of oral hygiene variables was observed in different categories of crowding. Statistical difference was noted only in mean bleeding on probing (p=0.012). Mean values of all other variables and distribution of study participants was insignificant. (Table 4)

Pearson correlation coefficient values for crowding and oral hygiene measures is presented in table 5. A significant

Table 4: Relationship of Crowding and Oral Hygiene Variables among Study Participants [Mean±SD and n (%)]

Table 5: Pearson Correlation Coefficients for anterior crowding versus plaque index, gingival index, and BOP sites

relationship is noted between crowding and plaque in all subjects. Family members showed significant relationship of crowding with gingival index. A significant relation was also  found  between  gingival  index  and  BOP sites.

DISCUSSION

A relationship between malocclusion (mainly crowding) and occurrence of poor oral health (hygiene) measured through plaque amount and gingivitis has been assessed and reported (10-12). This pilot study assessed the status and association of anterior teeth crowding and plaque amount, gingivitis and bleeding on probing in 11 families and tried to observe any relationship of study parameters between siblings and parents. In Pakistan, studies on relationship of oral hygiene parameters (gingivitis, plaque and bleeding on probing) and malocclusion in adolescents and adults are scarce.

Malpositioned teeth are one of the predisposing factors to inadequate oral hygiene because oral hygiene becomes more difficult without exerting additional efforts, time and be meticulous to further details and undercuts between the crowded teeth which are difficult to reach, bacterial plaque is retained and accumulates and, therefore, proliferates and leads to pathological periodontal changes.13 The findings of this study has given some support to the notion that an association exists between crowding of anterior teeth and gingivitis as it was found that there was a statistically significant difference in BOP between the different categories of crowding. Furthermore, a significant correlation was found between the presence of anterior crowding and gingival index.

This study has shown that a statistically significant difference in status of crowding between cases and their family members. However, no statistically significant difference could be observed between siblings and parents. This shows that crowding was not traceable in the next generation as compared to their parents thus lending some support to the role of environment to the etiology of crowding .14,15 This study did not find any statistical significant difference in oral hygiene parameters between cases and families nor between siblings and parents.

Level of malocclusion in subjects of this study is comparable with that of Nalcaci et al16 however, this study reports more severe crowding. No significant difference was observed in crowding between males and females, but females had more severe crowding than males. This finding agrees with a study by Mugonzibwa et al17 that reported no statistically significant differences in dental crowding between genders. No significant gender differences were also noted in oral hygiene parameters among cases, families, siblings and parents. Similar finding was also reported by a previous investigation.18

Status of oral hygiene parameters in categories of crowding has shown no statistical difference except in plaque and bleeding on probing. Irregular teeth retained more plaque than straight teeth by a modest extent though statistically significant (p<0.05), but no significant differences in the incidence of gingivitis.2

Correlation and Regression analysis has shown a modest but significant relationship (r=0.328 p=0.036) only between crowding and gingivitis. Addy M et al.19 also observed a modest but significant positive correlation (r=0.24, p<0.001) between the subjects’ mean plaque and mean irregularity indices in 11-12 years aged children. Ashley et al2 also observed a relationship between incisor teeth irregularity and gingivitis not only in subjects with moderate oral hygiene, but also in subjects with poor oral hygiene with the majority of subjects of this study had mild to moderate level of oral hygiene measures.

Statistically significant results were found in the present study regarding the relationship between malocclusion and oral hygiene status (t=1.16, P=0.022). A recent study by Arora and Bhateja10 found that there was a decrease in oral hygiene status of the school children having malocclusion (Mean Plaque1.21±0.41) than those children who were having normal occlusion (1.12±0.33). Similar results were also achieved by Buckley et al12, Ingervall et al20, and Behfelt et al21. Helm and Petersen22 have also reported higher scores for gingivitis and periodontal pocketing in subjects with various malocclusions. Dhar et al23 has observed 97% and 38 % adolescents with mild to moderate gingivitis and malocclusion respectively. This finding is concordant with this study where we have observed the same level of gingivitis.

In a study by Chiapinotto et al24, visible plaque was 89.7% (95% CI 88.0-91.3) and gingival bleeding on probing was 78.4% that corresponds to some extent to this study (76%). Behlfelt et al21 found plaque and gingivitis were more widespread around malaligned upper lateral incisor and lower second premolars in 30 children with mean age 14.4 years. This study also demonstrated a strong relationship of gingival index and  bleeding on probing (p=0.040). A previous study has shown that individual tooth irregularity measured as tilting, rotation, displacement and crowding had a low but statistically significant correlation with plaque, calculus and gingival inflammation. However, the study showed that these features of malocclusion were far less important than the extent of plaque and calculus deposits in the development of gingival inflammation5. As this study was conducted on subjects from same families and all families did not show any statistical difference in their sociodemographic parameters; therefore whatever relationship of anterior crowding is found with those of oral hygiene parameters can be interpreted as independent of the sociodemographic parameters. One of the limitations of this study is being a pilot study and thus of a small sample size. However, the findings of this study recommend further research work using a larger sample so that conclusions that would be more definitive could be drawn.

ACKNOWLEDGEMENT

 Services of dental internees are thankfully acknowledged in the conduction this study.

CONFLICT OF INTEREST

 Authors have no conflict of interest of any nature.

REFERENCES 

1. Khan AA. Oral Health in Pakistan: Dental Disease Pattern. J Pak Dent Assoc 1989;5: 215-19.

2. Ashley FP, Usiskin LA, Wilson RF, Wagaiyu E. The relationship between irregularity of the incisor teeth, plaque, and gingivitis: a study in a group of schoolchildren aged 11-14 years. Euro J Orthodont 1998;20:65-72

https://doi.org/10.1093/ejo/20.1.65

3. Shaw WC, O’Brien KD, Richmond S, Brook Quality control in orthodontics: risk/benefit considerations. Br Dent J 1991;170: 33-37 https://doi.org/10.1038/sj.bdj.4807399

4. Addy M, Griffiths GS, Dummer PM, Kingdon A, Hicks R, Hunter ML, Newcombe RG, Shaw The association between tooth regularity and plaque accumulation, gingivitis and caries in 11-12 year old children. Eur J Orthod 1988a;10:76-83 https://doi.org/10.1093/ejo/10.1.76

5. Buckley The relationship between malocclusion, gingival inflammation, plaque and calculus. J Periodontol 1981; 52: 35-40 https://doi.org/10.1902/jop.1981.52.1.35

6. Ainamo J. Relationship between malalignment of the teeth and periodontal disease. Scand J Dent Res 1972;80:104-10 https://doi.org/10.1111/j.1600-0722.1972.tb00270.x

7. Wagaiyu EG, Ashley Mouth breathing, lip seal and upper lip coverage and their relationship with gingival inflammation in 11-14 year old schoolchildren. J Clin Periodontol 1991;18: 698-702 https://doi.org/10.1111/j.1600-051X.1991.tb00112.x

8. Moores CFA, Reed RB. Correlations among Mesiodistal Crown Diameters of Permanent Dentition of American Negroes. Am J Orthod.1969; 55:600-16

9. Ngom PI, Diagne F, Benoist HM, Thiam Intraarch and interarch relationships of the anterior teeth and periodontal conditions. Angle Orthod 2006;76:236-42

10. Arora G, Bhateja S. Prevalence of dental caries, periodontitis and oral hygiene status among 12-year old school children having normal occlusion and malocclusion in Mathura city: A comparative epidemiological Indian J Dent Res 2015;26:48-52 https://doi.org/10.4103/0970-9290.156801

11. Mtaya M, Brudvik P, and Astrøm Prevalence of malocclusion and its relationship with socio-demographic factors, dental caries, and oral hygiene in 12- to 14-year-old Tanzanian schoolchildren. Eur J Orthod. 2009;31:467-76.

https://doi.org/10.1093/ejo/cjn125

12. Buckley LA. The relationships between irregular teeth, plaque, calculus and gingival disease. A study of 300 subjects. Br Dent J 1980;148:67-9

https://doi.org/10.1038/sj.bdj.4804378

13. Gusmão ES, Queiroz RDC, Coelho RS, Cimões R, Santos

Association between malpositioned teeth and periodontal disease.

Dental Press J Orthod. 2011;16:87-94

https://doi.org/10.1590/S2176-94512011000400015

14. Botero B, Etiology of crowding of the front lower teeth, Temas Odontol. 1974;12(117):488-500

15. Normando D, Almeida MA, Quintão CC. Dental crowding: the role of genetics and tooth Angle Orthod 2013;83:10-5 https://doi.org/10.2319/020112-91.1

16. Nalcaci R, Demirer S, Ozturk F, Altan BA, Sokucu O, and Bostanci
17. The relationship of orthodontic treatment need with periodontal status, dental caries, and sociodemographic factors. Sci World J. 2012;2012:498012

https://doi.org/10.1100/2012/498012

17. Mugonzibwa EA, Eskeli R, Laine-Alava MT, Kuijpers-Jagtman AM, Katsaros Spacing and crowding among African and Caucasian children. Orthod Craniofac Res. 2008;11:82-9 https://doi.org/10.1111/j.1601-6343.2007.00416.x

18. Oberoi SS, Mohanty V, Mahajan A, and Oberoi A. Evaluating awareness regarding oral hygiene practices and exploring gender differences among patients attending for oral prophylaxis. J Indian Soc Periodontol. 2014;18:369-74.

https://doi.org/10.4103/0972-124X.134580

19. Addy M, Dummer PM, Hunter ML, Kingdon A, Shaw Changes in the prevalence of plaque, gingivitis and pocketing in a group of South Wales schoolchildren examined at the ages of 11-12 years and 15-16 years. Community Dent Health. 1988b;5:345-54

20. Ingervall B, Jacobsson U, Nyman A clinical study of the relationship between crowding of teeth, plaque and gingival condition.

J Clin Periodontol 1977;4:214-22

https://doi.org/10.1111/j.1600-051X.1977.tb02275.x

21. Behlfelt K, Ericsson L, Jacobson L, Linder-Aronson The occurrence of plaque and gingivitis and its relationship to tooth alignment within the dental arches. J Clin Periodontol 1981;8:329-37. https://doi.org/10.1111/j.1600-051X.1981.tb02042.x

22. Helm S, Petersen PE. Causal relation between malocclusion and periodontal Acta Odontol Scand 1989;47:223-28. https://doi.org/10.3109/00016358909007705

23. Dhar V, Jain A, Van Dyke TE, Kohli A. Prevalence of gingival diseases, malocclusion and fluorosis in school-going children of rural areas in Udaipur J Indian Soc Pedod Prev Dent 2007;25:103-5 https://doi.org/10.4103/0970-4388.33458

24. Chiapinotto FA, Vargas-Ferreira F, Demarco FF, Corrêa FO, Masotti Risk factors for gingivitis in a group of Brazilian schoolchildren. J Public Health Dent. 2013;73:9-17. https://doi.org/10.1111/jphd.12001

Danish Shahnawaz                                                                           BDS

Hira Akhtar                                                                                         BDS

Ziaullah Choudry                                                                              BDS, MSc

Farah Naz                                                                                            BDS, FCPS

Arshad Hassan                                                                                  BDS, FCPS

Javeria Ali Khan                                                                               BDS, FCPS

Danish Shahnawaz                                                                           BDS

Hira Akhtar                                                                                         BDS

Ziaullah Choudry                                                                              BDS, MSc

Farah Naz                                                                                            BDS, FCPS

Arshad Hassan                                                                                  BDS, FCPS

Javeria Ali Khan                                                                               BDS, FCPS

OBJECTIVE: Dental esthetics is a prime consideration for all patients. While restoring teeth, high importance should be given to the size and shape of teeth for better esthetic results. Various proportions have been recommended to describe the relationship between maxillary anterior teeth. Golden Proportion and Golden Standard are two ratios most commonly used. The purpose of this study was to evaluate the golden proportion and golden standard in maxillary anterior teeth among Pakistani undergraduate students.

METHODOLOGY: A cross sectional study, conducted in the department of Operative Dentistry at Dental Section of Dow International Medical College (Dow University of Health Sciences). One hundred students (28 males and 72 females) meeting the inclusion criteria were selected, their dental casts were analyzed for actual width and length and apparent width by digital caliper. From these measurements golden standard and golden proportion were calculated.

RESULTS: Mean value of golden standard was found to be 0.82 (82%, p=0.04) as compared to the ideal standard value of 80%. Mean value of golden proportion was found to be 1.67 (p=2.09X10-7)

CONCLUSION: Within the confines of this study, Golden Proportion and Golden Standard were not found to exist in the sample Pakistani population.

KEY WORDS: Golden Proportion (GP), Golden Standard (GP), Tooth proportion, Maxillary Anterior teeth, Esthetic.

HOW TO CITE: Shahnawaz D, Akhtar H, Choudry Z, Naz F, Hasan A, Khan JA. Golden proportion and golden standard assessment of maxillary anterior teeth among undergraduate students”. J Pak Dent Assoc 2019;28(2):74-77.

DOI: https://doi.org/10.25301/JPDA.282.74

Received: 29 January 2019, Accepted: 06 March 2019

INTRODUCTION

Dental esthetics is a prime consideration for all patients. The size and shape of the maxillary anterior teeth have significant affect not only on the dental esthetics, but also on the overall facial esthetics of a person.1 A mismatch between size and shape of restored teeth and the facial symmetry, may lead to patient developing psychological and social problems.2 To provide a restoration which is esthetically pleasing and good, various maxillary anterior teeth proportions have been recommended. These include; golden proportion, golden standard, golden percentage, recurring esthetic dental proportion and Chu’s proportion.3

Recurring Esthetic Proportion (RED) proposes that the consecutive sizes of the teeth follow a constant ratio, when succeeding distally from the midline.8 Chu suggested a fixed difference in the size of maxillary anterior teeth.3 Golden percentage is a two-sided measurement of each tooth dimension as a percentage of the total six anterior teeth.3 All these parameters represent a balanced and harmonious smile design.4 Of all the ratios the two most commonly used and researched dental proportions are golden proportion and golden standard.

The application of the ”golden proportion (GP)” is considered a keystone of smile design theory.4 Lombardi identified GP as an important tool in determining the anterior teeth width for their restoration. It was first applied in dental aesthetic by Levin, who suggested that apparent width of central and lateral incisor should be in GP to that of their adjacent teeth when viewed from the front.5 Levin was the pioneer advocate of applying GP value to dental aesthetics, he proposed that when the face was viewed from the front, the apparent width of the central incisor should be 0.618 to the width of the lateral incisor and the lateral incisor should be in 0.618 to the width of the canine.4 The existing value of 0.618 is regarded as the “golden proportion value”.4 Golden Standard (GS) is defined as the ideal width to height ratio of an individual tooth.6 According to this ratio, the width of an anterior tooth should be 80% of its height.

If this ratio is higher, it means teeth are wider; a lower ratio signifies longer teeth.2,7

Numerous studies have been performed throughout the world on various racial and ethnic groups to assess the existence and variation in dental proportions.9,6,10,11 Locally, the data is still scarce regarding dental proportion esthetic norms of Pakistani Population.

This study is the first research performed on Pakistani population to assess the existence of GP and GS. The purpose of the study was to evaluate the golden proportion and standard in the anterior teeth among undergraduate Pakistani students.

METHODOLGY

This cross sectional study was conducted in the Operative Dentistry department at Dental Section of Dow International Medical College, Dow University of Health Sciences for a period of 6 months from October 2014 till March 2015. Total sample size of 100 was calculated using PASS version II, one sample t-test with 95% confidence interval, 99% power of test with a mean difference of p-value of 0.05 and standard deviation of 0.069.6

One hundred undergraduate students including 28 males and 72 females were selected using non-probability purposive sampling technique. Participants within the age range of 18-23 years, with no missing anterior teeth, sound gingival and periodontal conditions with no interdental spacing, rotation and/or crowding and no history of orthodontic treatment were included in the study. Participants having maxillary anterior teeth with an evidence of gingival alteration, dental irregularities, apparent loss of tooth structure due to attrition, fracture, caries, restorations or anterior prosthesis and any developmental facial and dental defects were excluded.

Ethical approval was taken from the ethical review committee (IRB) of Dow university of Health Sciences (Reference L e t t e r No. REG/IRB- 1001/DUHS/approval/2018/52). After obtaining signed informed consents from all participants, dental impression of each subject was obtained by Alginate (Tulip, Cavex- Holland) and cast was made by Dental Stone (Garreco- USA). Measurement for actual width and length of each individual tooth and apparent width of each individual tooth (from maxillary right canine to left canine) was taken with the help of digital Vernier caliper (Hornady-USA) with a least count of 0.01mm. Data analysis of each individual maxillary tooth was documented on pre-designed working form.

Golden Proportion (GP) of each individual tooth from central incisor to canine (both right and left sides) was determined. Mean of all these values for an individual were taken for analysis. Assessments of GP were conducted by drawing vertical lines. This was achieved by placing the casts on a flat surface. The perceived mesio-distal widths of the teeth were marked according to eye level when viewed from front (Figure 1). Measurements for the spaces in the lines was calculated using the digital caliper. The formula used was

Golden proportion= a+b / a as devised by Levin4 Where,

a: actual width of mesial tooth

b: apparent width of lateral tooth

GS of each individual tooth from central incisor to canine of both right and left sides was determined by measuring actual length from incisal edge to the gingival line and width from the mesial contact angle to the distal contact angle. The width /length ratio was calculated for each tooth and mean was taken.

Data analysis was done on SPSS version 16 (Chicago, IL) with level of significance a = 0.05 at 95% confidence interval. Independent sample t-test was used to find the difference in Male to Female ratio, one sample t-test was applied for golden standard and Sign test for golden proportion.

RESULTS

In present study out of 100 participants including 28 males and 72 females, males presented a GS value of 80.2% which is nearer to the ideal GS value (80%) as compared to females presented a value of 83.03%. Male to Female ratio was found to be insignificant as seen in Table I. Mean value

of GS was significant and calculated to be 0.82 (82%, p-value= 0.04) as seen in Table II. Mean value of GP was recorded as 1.67 (P-value = 2.09×10-7) which is highly significant when compared to ideal GP value of 1.62; as shown in Table II.

DISCUSSION

Dental esthetics is dependent upon numerous factors and their inter-relationships. Although information concerning GP is important for clinicians when working within the esthetic zone, racial differences should be taken into regard. Esthetic proportions need to be adapted in accordance to these differences. The key aesthetic determinant is the size and morphology of central incisor. Previous studies have used extracted teeth for measuring tooth size but nowadays pictures and casts are more commonly used.1 The results of the present study showed that male have more pleasing GP and GS as compared to female participants. Males presented a golden standard value of 80.2 % as compared to 83% for female, signifying females have squarer teeth. GP ratio in present study was calculated to be 1.67; this result is supported by the studies conducted by Ong and Mahshid who also found that the prevalence of the golden proportion had not been an influential factor of  determining dental attractiveness.9,13

The results of the present study are different when compared to the ideal ratio of 80%, which is documented in literature as golden standard. The results of the present study are in contrast to results conducted in Turkish population, they reported the width-to-height ratios percentages of 76- 86% in both genders1. This determines that maxillary anterior teeth in Pakistani population are narrower compared to Turkish population but this can be attributed to differences in racial characteristics. Another study by Al-Marook, Majeed et al reported that GP and GS values did not exist in the sample Malaysian population.6 On the other hand similar results to present study were recorded by Wolfart14 who reported a width-to-length proportion of 82% in German population.

In 2010, a novel pilot study evaluating GP was conducted on the Pakistani population, this study concluded that GP should not be considered as a significant factor of defining dental desirability. It should be a range other than a particular value.12 Similar conclusion was reported by Parnia and Hafezeqoran they reported no significant difference between proportions of width-to-height of central incisors and GS in Irani population.15

There is no concrete evidence that supports GP as an essential or ideal esthetic standard that mandates consideration when creating space for replacement of missing lateral incisors.16,17 Alhabahbah et al evaluated the validity of mathematical proportion that between the maxillary anterior teeth widths.18 They found that the mean perceived widths of anterior teeth were significantly larger for males compared to females. This result is quite contrary to what we found in our study; moreover, the GP did not exist between the perceived widths of maxillary anterior teeth.18 The difference in results may be attributed to variations in regional perception of aesthetics. In 2018, Al-Kaisay and Garib studied Kurdish and Arab populations19, they reported GP to exist between apparent widths of lateral and central incisors but not for lateral incisors and canines. Furthermore, no ideal ratio of width and height was found in this study, which is similar to our study in case of female participants.

As mentioned earlier, several studies have been conducted and a consensus is reached that in order to achieve harmony among tooth lengths, GP should not be used as a singular ratio to produce a satisfactory appearance rather it should be taken as a range.9,20,21 In order to attain an esthetic result, discovery of a geometrical and mathematical relationship between anterior teeth is important. A statistically reliable value explained in the form of range to support the existing theories on esthetic parameter would be more clinically applicable for dental practitioners.22

It is our recommendation that further studies should be carried out on a larger sample with equal male to female ratio; in order to assess any gender difference really exists. Future studies should also account for populations belonging different to Asian ethnicities as well; in an attempt to evaluate racial and/or ethnic variabilities. This will enable the clinicians to better understand and design the “treatment plan phase” while considering the esthetic desires of patients.

CONCLUSION

 Within the limitations of our study, the ideal Golden Standard and Golden Proportion values were not found to exist in younger population of Pakistan. It would be clinically more applicable for dental practicioners to use a specific range rather than an absolute value.

CONFLICT OF INTEREST

 None declared

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