Association of gonial angle with morphology and bone mineral content of the body of the adult human mandible with complete permanent dentition.

We investigated the differences between 2 gonial angle (GA) size groups with respect to the morphometry and quantitative bone mineral content (QBMC) of mandibles with all teeth erupted and normal occlusion. We used 19 dried mandibles that were obtained from an Indian population and stored in our department. These mandibles were at Hellman's developmental dental stage VA and were divided into low gonial angle (LGA) (GA ≤ 120°; 8 specimens; 16 sides) and high gonial angle (HGA) (GA ≥ 125°; 11 specimens; 22 sides) groups. After lateral radiography of the mandibles using a titanium step wedge, linear measurements and the QBMC were determined, on hard copies and digital images, respectively. The age and sex of the cadavers to which the specimens belonged were unknown. The mandibular cortical width (MCW) and the antegonial notch depth of the LGA group were significantly larger than those of the HGA group. No significant difference was found in the distribution of the 3 categories of mandibular cortical index (MCI) or in cortical and trabecular bone mineral contents (CBMC and TBMC). The GA size was negatively and moderately associated with the MCW and the mandibular cortical width on the point AG (MCWAG), but was not significantly associated with either variable for CBMC and TBMC. These results suggested that the GA size of these stage-VA mandibles influenced changes in the width of inferior cortex and morphology of antegonial notch. The GA size did not influence QBMC under the mental foramen of the mandible and had negative associations with the MCW and MCWAG.