Autogenous Coronoid Process As A New Donor Source For Reconstruction Of Mandibular Condyle

Temporomandibular joint is a diarthrodial joint with both translational and rotational movements, and mandibular condyle is one of the major components. Many abnormal conditions that were frequently encountered in craniofacial surgery may cause the damage of condylar process and require surgical resection. Although reconstruction of mandibular condyle by far has been performed with various autogenous bony tissues, these procedures suffer from several drawbacks repeatedly stated in the literature such as exploration of two surgical sites and donor-site morbidity.Reconstruction of mandibular condyle with autogenous coronoid process grafts had achieved good results from the reported clinical experiences. And this method avoids a second surgical site. However, these data rested largely on clinical outcomes and there was almost no published basic study on this surgical approach. Therefore, a goat model of autogenous coronoid process grafts for condylar reconstruction was established in this experiment, by which we tried toinvestigate the morphological and histological changes of the grafted coronoid process, and to evaluate the feasibility and effectiveness of this method.6 goats were used in this study. Each animal underwent unilateral total condyle and disc removal and was treated by grafting autogeneous coronoid process. Gross investigations, CT scanning films were taken at various intervals. All animals were sacrificed at the end of 24 weeks after operation, and the bone samples were harvested for histological examination. The TMJs from the unoperated side were served as normal controls.The results as follows:1) All animals tolerated the surgical procedure well and satisfactory jaw functions were observed during 24-week follow-up.2) The graft gradually remodeled to a neocondyle that was similar to a normal condyle in the shape and histological structure.3) Dense connective tissue covered the upper surface of the neocondyle, which might play the role of articular disc.4) The resected coronoid process was totally regenerated. Based on the positive results of this study, the autogenous coronoidprocess graft would be a good alternative for the reconstruction of mandibular condyle.