Differences in 5 anatomic parameters of mandibular body morphology by gonial angle size in dentulous Japanese subjects

This study aimed to determine the differences in 5 anatomical parameters of the mandibular body on dental panoramic radiographs (DPRs) of 234 dentulous Japanese subjects (21-78 years; mean, 25.76; median, 27 teeth) according to gender and gonial angle (GA) size, and to analyse the correlations between GA size and each variable by gender. The subjects were divided into low (LGA ≤ 120°) and high gonial angle (HGA ≥ 125°) groups. Linear, angular, and morphological measurements were obtained using the DPRs. Statically significant differences were determined using the Mann-Whitney U and χ2 tests and simple regression analysis. Mandibular cortical width - MCW, antegonial notch depth - AD and angle - AA, and panoramic mandibular index - PMI in the LGA group were significantly larger than those of the HGA group. In men, a significant difference was observed in the distribution of the 3 mandibular cortical index categories between both GAs. Sexual dimorphism for MCW and AD was significantly greater in men than in women. There were significantly negative low correlations between the GA and variables of the MCW, AD, and PMI. These results suggest that the MCW and AD can show significantly different morphology according to gender and GA size.