The Prevalence of the Carabelli Trait in Selected Nepalese Population

Aims: The purpose of this study is to determine the prevalence and degree of expression of the carabelli trait in the permanent first and second maxillary molars in a selected Nepalese population residing in Madi village of Chitwan district.
Study Design: Cross sectional descriptive study.
Place and Duration of Study: Madi village of Chitwan district in the month of April 2014.
Methodology: The study was conducted among the 300 dental patients of age 14 years and above attending a dental health camp. The palatal surfaces of the mesio-lingual cusp of the left and right maxillary first and second molars of the subjects were examined with mirror and probe for the presence or absence of the Carabelli trait. When present, the Carabelli trait was graded as I-IV, pit (I), groove (II), cusp without free tip (III), and well developed cusp (IV) according to the classification of Goose and Lee.
Results: The mean age of the patients was 39.47 +/-16.33 years with male: female ratio of 1:1.01. Two hundred five (68.3%) of the cases had presence of carabelli trait on either of the first molars. Further, 75 (25.0%) had carabelli trait on either of the second molars. None of the cases had the trait only in second molars. The association of carabelli trait had no significant relation to sex (P=0.15). Bilateral presence of the carabelli trait in 16 and 26 was noticed in 151 (73.7%) of the total 205 cases. Likewise, the bilateral expression in 17/27 was seen in 53 (70.7%) of the total 75 cases. The association of the trait bilaterally was significant for both the sides (P<0.001).
Conclusion: The expression of carabelli trait in the selected Nepalese population is fairly high although frank cusp was rarely noticed. The bilateral presence of the trait was common. The bilateral presence of the trait was common. The study of the presence and degree of expression of the trait is implied in the determination of ethnic origin of the individuals.