Faculty of Biology, Anthropology, Ludwig-Maximilian-University Munich
Saturday Afternoon, 301D
A systematical investigation of 17 premolars from the lower jaw of 13 adult human skeletons from early medieval times was performed. Focus of this study was the variability of cementum thickness and incremental line number and the relationship to their location on the cross section of the tooth root. The number of 2,280 cementum thickness measurements and 4,726 incremental line counts permitted for a statistical evaluation. Cementum thickness and line count increased significantly from the cervix to the apex of the tooth root. With regard to the quadrants of the cross section, a likewise significant increase from buccal < lingual < mesial < distal was oberserved.
These results are compatible with and can be explained by the functional demands and physical loads acting on the human dentition, in particular the chewing cycle, the occlusal and mesial drift. A phenomenon previously described as “cementum exuberation” was observed in the majority of investigated teeth and is hypothetically interpreted as areas of minimized physical loading.
We conclude that the functional morphology of the human dentition should largely be responsible for the observed variability in the tooth cementum. Therefore, choice of area on the cross section for the incremental line count should not be at random.