Increased occlusal vertical dimension in adult monkeys.

Splints which opened the vertical dimensions on all posterior teeth in five rhesus monkeys were studied over a period of 3 to 36 months. Findings were as follows: 1. The increased vertical dimension of occlusion did not have a pathologic effect on the TMJs. 2. The posterior teeth attached to the splint and the teeth opposing the splint were intruded into the alveolar processes. 3. The nonoccluding incisor teeth extruded, but the epithelial attachment remained close to the cementoenamel junction. 4. The vertical dimension as measured between the markers in the bones of the mandible and maxillae gradually returned toward the pretreatment vertical dimension, although complete closure to this position was not accomplished during the time period of the experiment. 5. The relationship between the epithelial attachment and the cementoenamel junction remained undisturbed by the experiment. 6. After completion of growth, there appeared to be a definite tendency for rebound to the normal pretreatment vertical dimension following increase of the vertical dimension. This was recorded by measurable movements of the teeth.