Permanent tooth emergence patterns in Dakshina Kannada region, India: an analysis of polymorphisms

Abstract

Background: The emergence of permanent teeth in humans starts with the eruption of the permanent mandibular first molar at approximately 6 years of age with the rest of the dentition following a fairly predictable sequence of eruption. The estimation of the age of a child between the ages of 5 and 14 years has so far been facilitated by the adoption of published data/databases that have not always relied on the variations in the sequence of eruption between various populations and ethnicities. The review of literature showed that there are 9 different types of polymorphisms relating to the eruption of teeth. Aim and objectives: The aim of the present study was to estimate the sequence of tooth eruption in children of the Dakshina Kannada region of Southern India and establish/determine the polymorphism in the eruption sequence. Methods: In this cross-sectional study, 2536 school children of the ages 4–16 years were examined for the presence of the permanent teeth. This data was tabulated with their corresponding age and gender. The sequence of eruption was then derived using Probit regression model. Results: The eruption sequence derived for the maxilla was M1 I1 I2 P1 C P2 M2 and M1 I1 I2 C P1 P2 M2 for the mandible. The maxillary dentition was acquired faster in the females. The mandible showed more number of polymorphisms with I1 M1 type being the most common type of polymorphism. In maxilla P2 C, eruption sequence was interchanged in majority of the studies. Conclusion: The sequence of emergence of teeth is a population-based variable that shows polymorphism and can be used as an indicator of attainment of a certain age.