Determination of Gender using Measurements of the Mandible taken from Orthopantomogram and Cephalogram

Abstract

Abstract:-Determining of age is essential in forensic and medico legal practices. Most dimorphic bone of the skull is mandible. Therefore, in sex estimation, mandible plays a dominant role. Since the measurements of the mandible vary with the ethnicity, it is important to evaluate the measurements of the mandible which are important in determining gender for a Sri Lankan population. The aim of this study was to determine the gender using measurements of mandible taken from orthopantomogram and cephalogram. This prospective cross sectional study was conducted among 116 SriLankan Sinhala patients (female 93, male 23) who underwent both orthopantomography (OPG) and lateral cephalometric examination at National Dental Teaching Hospital, Colombo 07. Maximum and minimum ramus breadth, condylar height, projective height, ramus height, coronoid height, biogonial width were taken from the OPG image and gonial angle was taken from the lateral cephalometry using left mandible of the patient. According to the statistical analysis, mean values of maximum ramus breadth, minimum ramus breadth, condylar height, projective height, ramus height, coronoid height, biogonial width of males were higher than females. Mean value of gonial angle of males were lower than females. Projective height was the most significant predictor in determining gender (P=0.000). Among the sample, 67.2% predicted the gender accurately using the prediction model found in the present study. 67.7% were predicted as females and 60.9% were predicted as males accurately. In conclusion, the most reliable measurement of the mandible is projective height in determining the gender of a Sinhala population in SriLanka.