Continuous eruption of some adult human teeth of ancient populations.

It has been argued that the teeth maintain a potential for eruption throughout life and that eruption takes place whenever an opportunity occurs. Thus continuous, active eruption would be expected when the occlusal surfaces of the teeth have been affected by severe attrition. Radiographs of teeth and jaws of adult skulls with marked attrition from the Romano-British, Anglo-Saxon and Mediaeval periods were measured using the inferior alveolar canal (IAC) as a reference structure. Statistical analysis of the measurements from 164 of the specimens showed that the worn occlusal surfaces (OS) maintained a more or less constant distance from the IAC with age, and the distance from the IAC to the cemento-enamel junction increased continuously. Likewise, the distance from the IAC to the alveolar bone crest (AC) and the distance OS-AC remained almost constant. In most groups there was a slow, continuous deposition of bone at the lower border of the mandible which could account for the increased face height of older individuals. Hence continuous eruption occurs at least up to about 45 years providing that there is inter-occlusal space available into which the teeth may erupt; furthermore, there is potential for eruption whether or not attrition occurs in all human adults at a similar age.