Reliability of palatal rugae patterns in individual identification

BACKGROUND: Dental identification plays a major role in mass disaster identification of human remains. Palatal rugae can be used as a substitute for a comparative method of identification. MATERIALS AND METHODS: The present cross-sectional study was done with 137 pre- and post-orthodontically treated casts of patients, which were divided into 50 cases each of extraction and nonextraction and 37 cases of palatal expansion involving both extraction and nonextraction. Hydrocolloid (alginate) impression of the upper jaw of the patient was taken and then cast in the dental plaster of Paris material. Palatal rugae pattern was classified according to Lysellm, and Thomas and Kotze classification. Two Observers recorded the data, mean of two were taken for analysis. RESULTS: On the right side, there was no significant difference between the extraction and nonextraction groups; however, there was a rise in length in the nonextraction and palatal expansion groups. On the left side, there was little change between the nonextraction and palatal expansion groups, but the extraction group had a modest increase in length. Mean lengths compared within three groups revealed insignificant difference. CONCLUSION: Palatal rugae pattern can be used in establishing identity in forensic medicine provided antemortem data are available. Orthodontic treatment has an impact on stability of palatal rugae. Most reliable and stable points being third rugae, they could be used as reference points to evaluate tooth movements