Study of Palatal Rugae Patterns and their Use in Sex and Ethnicity Identification in a Sample of Adult Egyptians and Malaysians

Palatal rugoscopy is the use of palatal rugae for identification of unknown persons. The majority of the population in Egypt consists of native Egyptian people. However, some Malaysian people live in Alexandria city of Egypt for the purpose of education. So, in case of mass disaster, there is a critical need for a reliable and easy method to differentiate between Malaysians and Egyptians. This study aimed to determine the palatal rugae patterns in two diverse populations; Egyptians and Malaysians and its relation to sex and population difference. Eighty students of Alexandria Faculty of Dentistry; forty Egyptians (20 females and 20 males) and forty Malaysians (20 males and 20 females). The age ranged 18-30 years. Impressions were taken with alginate (irreversible hydrocolloid impression material). Thomas and Kotze classification was used to assess palatal rugae regarding their length, shape, direction and unification. Data were introduced to the computer and processed using IBM SPSS software version 20.0. Qualitative data were defined using number and percent. The Kolmogorov-Smirnov test was applied to attest the normality of distribution. Significance of the obtained results was judged at the 5% level. Significant difference was noted between Malaysian males and females according to total number of rugae on both sides (t= 2.210 and p= 0.033). Malaysians had significantly higher total rugae number on both sides than Egyptians. Curved shape was the predominant shape in the total sample in the four studied groups (42.9%, 36.3%, 46.8% and 44.1%). Significant difference was detected between Egyptians and Malaysians according to the predominant palatal rugae direction on both left and right sides (x2 = 6.293 and p=0.043) (x2 =6.620 and p=0.037) respectively. Egyptian females had significantly higher percentage of absent unification than Egyptian males. Binary logistic regression models for sex and ethnicity identification were built up.