Importance of palatal rugae in individual identification

Abstract

Background: Rugae are anatomical folds or wrinkles, the irregular fibrous connective tissue located on the anterior third of the palate, behind the incisive papilla. They are also called 'plica palatine.' These rugae patterns are studied for various purposes, mainly in the fields of anthropology, genetics, orthodontics, prosthodontics, and forensic science. Objective: To determine the stability of the palatal rugae during fixed orthodontic treatment and to verify the accuracy rate of identification by comparing the rugae patterns on preoperative and postoperative orthodontic casts. Materials and Methods: Thirty preoperative and postoperative dental casts were selected. Thirty casts were randomly selected for the present study. The postoperative and the randomly selected casts were trimmed so that all areas except the rugae area of the hard palate were removed. The 30 postoperative casts were mixed with the 30 randomly selected casts. Thirteen examiners were selected as evaluators. They were instructed to match the 30 preoperative dental casts with the 60 dental casts (30 postoperative and 30 randomly selected casts). The case numbers of those that were correctly matched were noted. Results: During fixed orthodontic treatment, dental changes and sometimes bony changes occurred, but no changes occurred in the rugae pattern. The 13 examiners achieved 90% correct matches, which is the median in the present study. We used kappa statistics to assess the agreement between evaluators for matching preoperative with postoperative casts. Conclusion: Palatal rugae patterns are unique to an individual, and can therefore be used for individual identification in forensic odontology.