Occlusal Contact Points, Areas and Bite Force Distribution in Angle’s Class I, II and III Patients using T-scan

Abstract

Introduction: Number of occlusal contacts and uniform bite force distribution during maximum intercuspation are determinants of a good functional occlusion. Distribution of posterior contacts in the three malocclusion groups along with force distribution has been a topic of research. Aim: To quantify the number of occlusal contacts and areas, bite force distribution in Angle’s Class I, II, III subjects using T-scan and to identify the centre of force trajectory. Materials and Methods: This cross-sectional, observational study was conducted in the Department of Orthodontics, SRM College, Chennai, Tamil Nadu, India, from June 2018 to December 2018. Total 45 subjects in the age group of 18 to 24 years were divided into three groups of 15 subjects each based on Angle’s classification of malocclusion with teeth in normal line of occlusion. T-Scan system sensor and software were used to record and store data. The collected data were analysed with IBM Statistical Package for the Social Sciences (SPSS) software version 23.0. The descriptive statistics were performed, followed by Analysis of Variance (ANOVA). Post hoc Tukey test was done to find the difference between the groups. Chi-square test was done for the categorical data and the Paired t-test for determining the significant difference between the bivariate samples in paired groups. Level of significance was set at p<0.05. Results: Out of three study groups, mean contact points (p<0.001), contact areas (p<0.001) and bite forces (p=0.0032) were statistically highly significant in Angle’s class I group when compared to the other groups. Statistically, the right and the left side differences in force distribution of the three groups were significant with the forces predominantly being higher on the right side. Conclusion: Subjects with Angle’s Class I molar relation had greater contacts, contact area and better bite force distribution. There was preference to the right side in bite force distribution in all the three groups. Centre of force trajectory was concentrated between first and second molars in all the groups