An investigation study on sex identity through mandibular canine index directed to detect sexual dimorphism using the Mesio-Distal width of mandibular permanent canines and inter canine and inter canine arch width in the mandible was conducted in the Department of Oral Medicine and Radiology, Bapuji Dental College and Hospital, Davangere. 360 patients were subjected to the mesio-distal measurement and inter canine arch width. Males were detected correctly in 83.3% and in females 81%. They were statistically significant and the related literatures reviewed.