Evaluation of dimensional relationship of different anatomical structures of the skull in term of gender in adolescent ages using cone beam computed tomography images

Abstract

Introduction: In forensic dentistry, facial bone indices can be used to determine gender. In facial bone features, each person has their own characteristics, which are stable with increasing age and its accuracy can be compared with fingerprints. In the current study, we measured the length and width of the clivus, dimensions of the frontal sinus and measured the length and width of the nasal bone in post-puberty age using Cone Beam Computed Tomography (CBCT).

Methodology: In order to conduct this descriptive-analytical study, 200 CBCT images of patients referred to the oral, maxillofacial radiology department of the Faculty of Dentistry, who met the conditions for entering the study, were used. The length and width variables of the nasal bone, clivus, as well as the anterior-posterior and medio-lateral dimensions of the frontal sinus were measured. Data were analyzed by SPSS 24 software and using U-Man Whitney and independent t tests and logistic regression. The significance level of P was considered less than 0.05.

Results: The length and width of the nasal bone, the length and width of the clivus, and the length and width of the frontal sinus (on both sides) were significantly greater in men than in women (p<0.001). In both sexes, the frontal sinus width on the right side was significantly larger than the left side (p<0.001). But the length of the frontal sinus was greater on the right side than the left side only in men (p<0.001). The sensitivity and specificity of the model, with the values of 78 and 77.20%, indicated the average power of the model in determining gender, and the level under the ROC curve with the value of 0.88 indicated the average ranking of gender determination by the logistic regression model.According to logistic regression results, frontal sinus length (=0.92, p<0.001), nasal bone width (=0.69, p<0.001), clivus length (=0.83, p<0.001) and clivus width (=0.73, p<0.001) were able to determine gender.

Conclusion: The length and width of the nasal bone, the length and width of the clivus, and the length and width of the frontal sinus (on both sides) were significantly greater in men than in women. The length of the frontal sinus had the most predictive power to determine gender. Combining the measurement of three skull structures, including the length and width of the clivus, the length and width of the nasal bone, and the anterior-posterior and lateral length of the frontal sinus, is effective in separating gender by 77.60%, and the combination of these three structures can be used to determine identity.