A Study of Palatal Rugae Patterns in the Populations of Mongoloid and Tharu Ethnic Groups of Eastern Nepal

Background and Cbjectives: Palatal rugae patterns are relatively unique to an individual and are well protected by the lips, buccal pad of fat and teeth. They are considered to be stable throughout life following completion of growth, although there is considerable debate on the matter, they can be used successfully in post mortem identification provided an antemortem record exists. Thus the aim of this study was to examine palatal rugae shape and pattern among two Nepalese populations. Methods: The study was conducted in 200 maxillary casts obtained by making impressions of 200 people from two ethnic groups of Nepal. Impression of maxillary arch was obtained using alginate impression material and stone cast was made. The rugae was delineated on the cast using a sharp graphite pencil under adequate light and magnification and recorded according to classification given by Thomas and Kotze (1983). Results: Chi-Square analysis showed significant difference in straight and curved patterns between the two populations. The mean number of primary palatal rugae in Mongoloids is 4.2 in right side and 4.8 in left side. The curved pattern is more prevalent in Mongoloids (42.81%). In Tharus, number of primary rugae is 5.6 in right side and 4.8 in left side. The straight pattern of rugae is more prevalent than other patterns in Tharu ethnic group (56.72%). Conclusion: The number of palatal rugae on right and left sides was not significantly different in both ethnic groups. The pattern of rugae was seen different in these ethnic groups.