Reactions of the condylar tissues to attempts to increase mandibular growth.

The relationship between the condyle and the glenoid fossa was changed in growing Long Evans/Turku rats by provoking an artificial cranial synostosis of the interparietal, temporoparietal and lambdoidal sutures. As a result the glenoid fossa was displaced posterosuperiorly, the length of the mandible was slightly increased and the condyle appeared flattened in shape by 50 days. The mesenchymal cell layer was thickened and chondrogenesis was disturbed. This disturbance was carried over to the cartilage in the course of growth, where it was seen in the presence of acellular and necrotic regions. The findings indicate that any attempt to increase the growth of the mandible by carrying it forwards should be executed gradually in order to allow the mesenchymal cells in the posterosuperior region of the condyle to alter their metabolism.