Chandimal K. M.; Priyadarshani K. M. W. W.; Kanthilatha N.; Chamudi P. M. S. J.; Ihalage W. I. S. M.; Rebeira L.G.

Teeth serve as invaluable sources of information in forensic and archaeological studies for understanding past human populations. Their morphological and morphometric variations, along with sexual dimorphism, provide insights into evolutionary and population differences. The present research aimed to evaluate the variability and indices of mandibular molar crowns—first (M1), second (M2), and third (M3) molars—among prehistoric humans (dating from approximately 5,000 to 36,000 BCE) and present-day Sri Lankans. The study analyzed mandibular molar teeth from eleven prehistoric adult mandibles (five male and six female) and 80 molar teeth from modern Sri Lankan individuals. Two major crown diameters—bucco-lingual (BL) and mesio-distal (MD)—were measured using a digital vernier caliper accurate to 0.01 mm. Using these dimensions, crown index (CI), crown area (CA), and crown module (CM) were calculated. Results revealed that, among prehistoric males, the right first molar (M1) had the largest BL and MD diameters compared to M2 and M3 teeth, showing a decreasing trend from M1 > M2 > M3 on both sides. Similarly, crown area, crown index, and crown module values were highest for the right M1 molar. Overall, prehistoric male mandibular molars showed greater MD, BL, CA, CI, and CM values than those of modern Sri Lankans. Statistically significant differences (p < 0.005) were observed in the right M2 and left M3 molars of prehistoric males compared with present-day individuals. In females, the right M3 molar of prehistoric mandibles also showed significantly higher values (p < 0.005) than modern counterparts. These findings indicate a clear reduction in molar crown size and indices from prehistoric to present- day Sri Lankans, suggesting evolutionary or environmental influences on dental morphology across millennia.

KEY WORDS: Mandibular molar teeth; Prehistoric humans; Morphometry; Present- day Sri Lankan population.

CHANDIMAL, K. M.; PRIYADARSHANI, K. M. W. W.; KANTHILATHA, N.; CHAMUDI, P. M. S. J.; IHALAGE, W. I. S. M.; REBEIRA, L. G.; EDIRISINGHE, E. A. S. T.; BOWATTE, P. G. C. S.; DISSANAYAKE, P. H.; WANIGATHUNGA, K. & YASAWARDENE, S. G. Mandibular molar (M1, M2 and M3) crown morphometrical variations from prehistoric human population to present-day Sri Lankans. Int. J. Morphol., 44(3):974-983, 2026.