In the dental specialty forensic odontology, dimensions of tooth structure is being used to predict gender of a particular population in case accidents and mass disasters. Therefore the aim of our study was to develop a modified based on the mesio-distal dimension of teeth in Saudi Arabian population. The pretreatment orthodontic cast models of patients reporting to Riyadh Elm University, Riyadh, Saudi Arabia to measure the mesio-distal dimensions of all the teeth from permanent second molar of right quadrant to second molar of the left quadrant for both maxillary and mandibular arch with the help of an electronic devices. A significant difference was observed in mesio-distal dimensions for between males and females for canines, premolars and first molars (p≥0.05) except for incisors and second molars. On multi-variate logistic regression analysis a final model was developed which included permanent maxillary right canine (13), permanent mandibular left lateral incisor (32) and permanent mandibular left canine (33). The current modified sex predictive model for Saudi Arabian population displayed 80% accuracy for sex prediction. Based on the specificity of the modified model it can be recapitulated the model has a potential for gender prediction of Saudi Arabian population.