Study on vibrations of the mandible.

In order to elucidate the phenomenon of vibrations of the mandible, a simplified plaster model was prepared and the fundamental vibrations were investigated. Studies using either dried human skulls or in situ mandible yielded similar results. The results obtained were as follows: 1. The vibrations generated by tapping a simplified mandible model were similar to those of the transverse type of a bar and tuning fork. 2. Both vibration models belonged to the transverse type bar vibrations. 3. Similar results were obtained by tapping the teeth of the mandible in situ. 4. The presence of fractures and cysts in the mandible might induce changes in vibrations.