Effect of Experimental Malocclusion on the Microvascular Architecture of the Temporomandibular Joint Disk in the Japanese Monkey

Abstract

This investigation was made on successive changes of the microvascular architecture of the disk of the temporomandibular joint, produced an experimental malocclusion by the following procedures: All upper posterior teeth were extracted and occlusal surfaces of all lower posterior teeth were cut down in the Japanese monkey. These animals were sacrificed on 4, 8, 16 and 24 weeks, respectively. Acryl plastic was injected via the common carotid arteries utilizing the plastic injection method (Ohta et al., 1990) to prepare microcasts around the TMJ. The injected materials coated with gold were employed for scanning electron microscopy. In a beginning period after the above procedures, the distribution density of blood capillaries has decreased in the posterior portion of the disk but increased somewhat in the anterior portion. These changes have gradually returned to the normal aspect in the later period. It can be said that the occurrence of a posterosuperior compression by a posterior dislocation of the condyle in the beginning period may be followed by the gradual and accommodative restoration of the disk tissue.