法医学研究ジャーナル

Mandibular Ramus and Gonial Angle Measurements as Predictors of Sex and Age in an Egyptian Population Sample: A Digital Panoramic Study

Abstract

Noha Saleh Abu-Taleb and Dina Mohamed El Beshlawy

Objective: The determination of sex and age is necessary in forensic practice and medico legal purposes. Mandible may play a vital role in sex estimation as it is the most dimorphic bone of skull that often recovered intact. In this respect, the availability of plentiful antemortem orthopantomograms may be of great value in studying and developing population specific standards for accurate sex and age estimation. Therefore, the purpose of the current study was to assess the usefulness of various mandibular ramus linear and gonial angle measurements on digital panoramic images as indicators for sex and age in an Egyptian population sample.

Methods: 191 panoramic images (105 males and 86 females) of Egyptian patients aged (6-70) years old were selected. Five mandibular ramus linear measurements (upper ramus breadth, lower ramus breadth, projective height,condylar ramus height and coronoid ramus height) and gonial angle measurements were performed bilaterally resulting in a total of 382 rami being assessed. Stepwise discriminant and regression analyses were performed to determine the most significant predictors of sex and age respectively.

Results: Males showed statistically significant higher mean linear ramus measurements and lower mean gonial angle values than females. Condylar and coronoid ramus heights were the most significant predictors for sex and age respectively. The discriminate function equation was: (D= 14.698 - 1.895 Condylar ramus height) with an accuracy of 81% in males and 77.9% in females and an overall accuracy of 79.6%. The regression equation for age estimation in the whole studied sample was: (Age= - 32.306 + 8.481 Coronoid ramus height) that yields no significance on comparing actual and estimated ages.

Conclusion: In the selected Egyptian population sample, the mandibular ramus showed a high sexual dimorphism and proved to be beneficial in sex and age estimation; while, the gonial angle could assist in sex estimation only.