Tissue Repair After Condylectomy in Growing Macaca fascicularis

Abstract

In order to determine the nature of tissue repair after removal of condyles, bilateral condylectomies were performed in seven growing female Macaca fascicularis. Two animals underwent condylectomies only, and five animals were fitted with maxillary and mandibular splints before undergoing condylectomies. One condyle from each condylectomized animal was processed for histologic examination. Four animals, with intact condyles, were available as controls: Two had splints placed, while the other two did not undergo any treatment. Nine mo after surgery, the histology of 12 resection sites and 12 control condyles (seven removed at condylectomy and five at death) was compared. In the control condyles, hypertrophic cartilage was seen over the entire condylar surface. From the 12 resection sites, five showed hypertrophic cartilage, non-hypertrophic cartilage cells were present in three, and four demonstrated bone apposition and resorption. Cartilage was present only at the medial and central aspects of the surgical site, and in every specimen, bone was seen at the lateral pole. Two out of 12 fossae overlying surgical sites contained hypertrophic cartilage, while the five control glenoid fossae showed bone, an intermediate zone, and a fibrous capsule. Because of the variety in tissue response and the small number of animals in each group, the effect of the splints could not be determined. Based on the results of this study, the following was concluded: (1) Regeneration of organized hypertrophic cartilage with inherent growth potential can take place after condylectomy, albeit not in every instance and only in the medial aspect of the stump. In the lateral aspect, and also medially if hypertrophic cartilage does not reform, bone is predominant. The original height is not recovered. (2) The cartilage of the glenoid fossa is capable of adaptive changes similar to those seen in condylar cartilage.

Regeneration of mandibular condyle following unilateral condylectomy in canines

“…A number of experimental studies have investigated the effect of unilateral mandibular condylectomy in animals (Sprinz, 1963;Hayes, 1967;Poswillo, 1972;Soni and Malloy, 1976;Bakker et al, 1984;Miyamoto et al, 1999aMiyamoto et al, , 2001Miyamoto et al, , 2002Miyamoto K et al, 1999). These studies have indicated that loads on the joint and articular disc, in addition to animal age, represent important factors in regeneration of the condyle.…”

“…Loads on the TMJ may influence regeneration of the resected condyle in animal experiments (Bakker et al, 1984;Miyamoto et al, 2002). Unilateral resection of the condylar head involves rotation and displacement of both condyles, and the loads on both TMJs change (Bakker et al, 1984;Alexandridis et al, 1991).…”

“…Unilateral resection of the condylar head involves rotation and displacement of both condyles, and the loads on both TMJs change (Bakker et al, 1984;Alexandridis et al, 1991). Loads on the operated joint are greater after unilateral condylectomy than after bilateral condylectomy (Alexandridis et al, 1991), and repair of the resected condyles take longer following bilateral condylectomy than after unilateral condylectomy (Sprinz, 1963;Alexandridis et al, 1991).…”

“…Loads on the operated joint are greater after unilateral condylectomy than after bilateral condylectomy (Alexandridis et al, 1991), and repair of the resected condyles take longer following bilateral condylectomy than after unilateral condylectomy (Sprinz, 1963;Alexandridis et al, 1991). Different functional loads using standard animal models can control the effect of condylectomy on regeneration of the condyle (Bakker et al, 1984;Miyamoto et al, 2001Miyamoto et al, , 2002. In man, unilateral condylectomy results in increased anterior loading in the resected condyle with torsion, which is anterior to the glenoid fossa (Bakker et al, 1984;Alexandridis et al, 1991).…”

Evaluation of Regenerative Processes in a Rat Model of Mandibular Condyle Defect using in vivo Micro X-Ray Computed Tomography

“…Several studies have observed the restoration process after mandible defects in various large animals such as sheep and monkeys, among others [1][2][3] . In many of these studies, transection of the mandibular head and the muscular process was performed; however, few studies have evaluated only mandibular head defects.…”