A CT-Based Comparative Analysis of Mandibular Morphology Across Dentofacial Classification

Abstract

INTRODUCTION: Anatomical variations of the posterior mandible have been an ongoing dialogue because of the importance of ensuring the safety of a vital structure that has a risk of damage in mandibular surgeries. Hence, this study aims to analyse the morphology of posterior mandibles across different dentofacial relationships. MATERIAL AND METHODS: A cross-sectional study was conducted utilizing CT scans of the head and neck. The recruitment of samples adhered to specified criteria, which were then categorised according to their skeletal pattern. The CT measurements include height of ramus (R), distance from lingula to sigmoid notch (LS), distance from lingula to inferior border (LI), vertical position of lingula in relation to occlusal plane (L-OP), ramus thickness at the crestal level (RT-C), and ramus thickness midway between sigmoid notch and lingula (RT-M). RESULTS: A total of 60 CT scans were evaluated and classified into Class I, II, and III. The LI and RT-C displayed noteworthy differences (p<0.05) when compared across groups. Other variables showed no significant difference. Nonetheless, a marginal difference was observed in the ramus height (p=0.055). Upon additional post hoc analysis for LI and RT-C, significant differences exist between Class II and III (p=0.019, p=0.023, respectively). CONCLUSION: Significant differences exist in the critical landmarks of the posterior mandible of different dentofacial patterns, where Class II mandibles portrayed a thicker ramus at the crestal level and a shorter distance from the lingula to the inferior border. These findings are crucial information in ensuring safe surgical practice involving the posterior mandible.