Anomalies of permanent tooth number in three Asian ethnicities

Li Qian,Foong Kelvin Weng Chiong,Hung Chew Wong,Ming Tak Chew,Mimi Yow

doi:10.21307/aoj-2020-100

Li Qian, Foong Kelvin Weng Chiong + Show 3 more

Open Access

https://doi.org/10.21307/aoj-2020-100

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Abstract

Abstract Objective The objective of this comparative study was to determine the proportion and distribution of tooth number anomalies in the permanent dentition in a sample of Chinese, Indian and Malay orthodontic patients in Singapore. Methods The cross-sectional study was carried out using radiographic and clinical data from the National Dental Centre of Singapore. Panoramic radiographs and clinical records of 1080 (Chinese (N = 415), Indian (N = 317) and Malay (N = 348)) orthodontic patients aged 12 to 16 years were examined for evidence of tooth number anomalies. Fisher’s exact test was applied to compare the occurrence of hypodontia and hyperdontia between the ethnicities and genders. Results The prevalence of hypodontia in Chinese, Indian and Malay orthodontic patients was 13.7%, 6.0% and 14.4%, respectively. Chinese patients had a significantly higher prevalence of hypodontia compared with Indian patients (OR 2.50, 95% CI 1.29–4.83, p < 0.001). Malay patients had a significantly higher prevalence of hypodontia compared with Indian patients (OR 2.63, 95% CI 1.34–5.17, p < 0.001). The most commonly missing tooth in the Indian patients was the upper lateral incisor (39.0%), whereas that in the Chinese and Malay patients was the lower second premolar (26.1% and 26.2%, respectively). The prevalence of hyperdontia in Chinese, Indian and Malay patients was 7.0%, 3.8% and 7.8%, respectively. Male patients had a significantly higher prevalence of hyperdontia compared with female patients (OR 1.87, 95% CI 1.14–3.07, p = 0.015). Supernumerary teeth occurred more frequently in the anterior maxilla (34.1%) than in other regions of the jaws. Supernumerary teeth also occurred more frequently in the maxilla (76.9%) than in the mandible (23.1%). Conclusion There are significant differences in the presentation of anomalies in tooth number in the permanent dentition of Chinese, Indian and Malay orthodontic patients in Singapore.

Highlights

A variation in tooth number in the permanent dentition is a developmental anomaly commonly encountered in dental practice.[1]
The present study complied with the STROBE guidelines[12] and was conducted with the approval of the SingHealth Centralized Institutional Review Board (CIRB), reference 2014/765/D
There was no statistically significant association between gender and hypodontia in the sample

Summary

Introduction

A variation in tooth number in the permanent dentition is a developmental anomaly commonly encountered in dental practice.[1] It can present as the absence of permanent teeth, or the presence of extra permanent teeth. Hypodontia is the developmental absence of up to five teeth, excluding third molars.[2,3,4] The term oligodontia is used to describe the absence of six or more permanent teeth, and anodontia describes the Australasian Orthodontic Journal Volume 33 No 2 November 2017 developmental absence of all teeth.[5] The term dental agenesis is preferred by some as it describes the developmental disorder involved.[6]. Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the expected number.[7,8,9,10] The major types of supernumerary tooth forms include conical, tuberculate, supplemental, and odontomes.[11]

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Discussion

Conclusion