Prevalence of Occlusal Morphological Patterns of Permanent Mandibular First Molar

Abstract

Teeth are informative indicators for the study of human populations, serving as markers and the
bases for comparisons of genetic origin. Mandibular first molar is represented as 36 or 46 in the FDI system.
The occlusal surfaces of posterior teeth occlude with the opposing occlusal surfaces of posterior teeth. The
occlusal morphology differs in each posterior tooth. The occlusal aspect of posterior teeth is developed into
cusps ( 5 or 4 or 6 ) and grooves ( Y or + or X pattern ). These cuspal patterns and groove patterns help in
forensic identification in cases like gender determination and also to identify the ethnic background of an
individual. Variation in degree of expression and frequency of teeth in dentitions of different populations
is different which may be helpful for forensic identification. The aim of the study was to determine the
prevalence of different occlusal morphological patterns of permanent mandibular first molars. The study
included a predominantly South Indian population. Approval was received from the Institutional Review
Board. Study was conducted with 100 participants who were randomly selected. The occlusal morphology
patterns (number of cusps and groove pattern) of left and right permanent mandibular first molar were
assessed from the photographs of the oral cavity and the date was recorded. Results showed that the most
prevalent number of cusps in permanent mandibular first molar was 5 cusps ( 71% ) and Most prevalent
groove pattern in permanent mandibular first molar was Y pattern. It was also observed that the combination
of the 5Y pattern was more prominent in females than in males.