The role of interdigitation in sagittal growth of the maxillomandibular complex in Macaca fascicularis.

The role of the interdigitation of posterior teeth in maxillomandibular growth and development was studied longitudinally in Macaca fascicularis monkeys. Fourteen monkeys were divided into a control group (n = 7) and an experimental group (n = 7). At the start of the study, the mean age of the animals was 29 weeks. At that stage the interdigitation in the experimental group was eliminated by grinding the cusps of the molars and canines. The animals were followed until 143 weeks of age and studied with the aid of tantalum implants and lateral radiographs. The findings indicated that elimination of the interdigitation resulted in a deviating anteroposterior relationship between the jaws and a significant inhibition of the vertical growth of the maxilla in the second half of the experimental period, while total face height was not noticeably affected. As a result, a more prognathic mandible and a more mesial occlusion developed. It can be concluded that the interdigitation plays a role in the regulation of vertical and anteroposterior facial growth and constitutes an important factor in the jaw relation in Macaca fascicularis monkeys.