Cephalometric norms for Sri Lankan Sinhalese adolescents with Class I malocclusion

Abstract

Context: Comprehensive cephalometric analysis plays a significant role in orthodontic diagnosis and treatment planing and variety of cephalometric standards have been developed for different populations. It is important to develop standard cephalometric norms for different populations. Aims: The aim of this study was to develop cephalometric standards for Sri Lankan Sinhalese adolescents with Class I malocclusion and to test the hypothesis that there are racial differences in cephalometric measurements between Sri Lankan and Caucasian norms. Setting and Design: Cross sectional , hospital based, descriptive study. Materials and Methods: Lateral cephalograms were obtained from 33 males (aged 15.7 ± 1.99 years) and 42 females (aged 15.6 ± 2.29 years). Inclusion criteria were healthy individuals with normal growth and development, straight facial profile, average vertical facial proportions, full complement of dentition (excluding third molars), normal overjet and overbite, Class I incisor, canine and molar relationship, and no crossbite in the anterior/posterior region. Eight angular and four linear measurements were analyzed in skeletal, dental, and soft-tissue assessment. Statistical Analysis Used: Statistical analysis was performed using the statistical software R 3.5.0. Results: In the dentoalveolar assessment, the Sri Lankan subjects had a significantly proclined upper (UI to N-A = 23.28) and lower incisor (LI to N-B = 6.56 mm and 28.3) inclinations compared with the Caucasian norms. In the assessment of soft-tissue profile, both upper (1.66 ± 2.7mm) and lower lip (2.8 ± 2.6mm) protrusions were slightly increased than the norms of the Steiner analysis, and these findings were clinically significant. There were no apparent differences in relation to anteroposterior and vertical skeletal relationship when compared with Caucasian norms. Conclusions: The results of the present study suggested that Sri Lankan Sinhalese adolescents with Class I occlusion are likely to present greater incisor proclination than Caucasians. Key Messages: The present study suggested that Sri Lankan Sinhalese adolescents are likely to present greater incisor proclination than Caucasians in Class 1 malocclusion.