Palatal rugae: An effective marker in population differentiation

BACKGROUND: The superiority of dentofacial structures as scientific identifiers, particularly in mass disasters is well known. Special techniques like rugoscopy are valuable not only in identification of skeletal remains but can also facilitate population differentiation, as few studies have shown. AIM: The present study is to classify and compare the differences in rugae shape in populations of Andhra Pradesh and Odisha and to evaluate the discriminatory ability of rugae shape in population differentiation. MATERIALS AND METHODS: One hundred maxillary casts from each group, equally divided between the sexes and in a narrow age range, were classified as per rugae shapes. The incidence of rugae shape was recorded and their association with ethnicity was tested using Chi-square analysis and step wise discriminant function analysis. All analysis was undertaken using SPSS 16.0 (SPSS Inc., Chicago, Illinois, USA) and MS Excel Package. RESULTS: Straight and nonspecific rugae were most prevalent in Andhra Pradesh, whereas the wavy forms and unifications prevailed in Odisha. A hitherto unknown nonspecific “plaque pattern” was detected in considerable numbers in Andhra Pradesh population. The accuracy of the discriminant function analysis in differentiating the study populations was 93.5%. CONCLUSION: Significant differences in rugae shape between the two populations emerged that also allowed a fair differentiation, thus validating previous reports of a good discriminatory ability of rugae shapes. Perhaps, more studies in genetically diverse populations as in India could also unearth new rugae patterns and further the identification process.