Influence of excision of the facial and inferior dental nerves on mandibular growth and development.

The purpose of this study was to evaluate the role of the facial and inferior dental nerves on mandibular growth and development. A sample of 10 mongrel dogs was randomly divided into two equal groups. Avulsion of the right inferior dental nerve was carried out on the first group. Surgical cutting of the extracranial portion of the right facial nerve was performed on the second group. Sham operations were made for the left sides of the mandibles of all animals. The animals were killed 3 months later and their mandibles visually and radiographically examined. Measurements were recorded in a double-blind experimental design. The data were statistically analyzed. The results obtained from this study indicate that surgical cutting of the extracranial portion of the facial nerve resulted in unilateral facial paralysis of the muscles of expression. However, after the animals were killed, no significant statistical differences were found between the nerve-devoid and sham sides of the mandible for both the facial nerve group and the inferior dental nerve group. Nevertheless, for the inferior dental nerve group, visual and radiographic examinations revealed various morphologic differences at the angular process regions of the mandibles. The impact of neural deprivation on mandibular growth and development was thus determined.