Prevalence of cusp 7 in permanent mandibular first molars in an Indian population: a comparative study of variations in occlusal morphology

Abstract

The aims of the present study were to determine the prevalence of cusp 7 in permanent mandibular first molars in an Indian population, and to comparatively evaluate the variations in occlusal morphology of these teeth, including the difference in the number of cusps and fissure patterns. A total of 1123 Indian participants from the Government College of Dentistry, Indore, Madhya Pradesh, India, were selected for the study. For the analyses of cusp 6 and cusp 7 in permanent mandibular first molars, the Arizona State University Dental Anthropology System was used. Groove patterns were analyzed and classified as Y, +, X, and Ұ. Of the 1123 individuals, 132 (11.75%) were found to have cusp 7, while 78 (6.95%) had cusp 6. Thus, a total of 210 participants had the six-cusped mandibular first molars, 98 (8.73%) had the four-cusped mandibular first molars, and two had the seven-cusped variant. Overall, the most common fissure pattern was the Y pattern (50.36%), while the least common was the X pattern (1.25%). Mandibular first molars with cusp 7 demonstrated a highly significant (P<0.05) dominance of the Ұ pattern (36.80%) over the Y (30.74%), + (27.71%), and X (4.46%) fissure patterns. A significant prevalence of cusp 7 (11.25%) in permanent mandibular first molars was found in the present study in an Indian population.