Morphometric variations of human mandible in the Indian population: comparison between healthy and ankylosed temporomandibular joints.

This retrospective, cross-sectional study analyzed clinical CT scans from 367 Indian subjects (199 healthy; 168 with TMJ ankylosis) from a tertiary hospital to compare mandibular morphometric parameters between Indian subjects with healthy and ankylosed temporomandibular joints (TMJs) of differing age groups and sex. Furthermore, the study compared mandibular morphometry of the Indian population with that of other countries. Key mandibular parameters, including ramus length and condyle width, were measured from 3D reconstructions. Two-sample z-tests and paired t-tests were used (p < 0.05). Ramus length was significantly shorter in ankylosis subjects across all age groups and sexes, as compared with healthy subjects, while condyle width was higher. However, both ramus length and condyle width in ankylosis group increased with age. The minimum observed ramus lengths in the ankylosis group were 14.01 mm, 20.37 mm, and 24.93 mm in the pre-pubertal, pubertal, and adult age cohorts, respectively, while the maximum observed condyle widths were 25.42 mm, 32.05 mm, and 36.32 mm for the same age cohorts. In unilateral cases, the affected side had shorter ramus length and wider condyle than the unaffected side. When comparing the mandibles of the healthy adult Indian group with those from other countries, Indian mandibles were found to be longer than Brazilian and Chinese, but shorter than Australian and Korean counterparts. This study aimed to establish to what extent TMJ ankylosis influences mandibular structure. The study identified two key mandibular morphometries in the ankylosis group, especially ramus length and condyle width, as being significantly different from those in the healthy group in India. The study also highlighted salient country-specific differences in mandibular morphometry. These findings would be crucial in the development of population-specific TMJ implants to improve clinical outcomes.