顎関節円板切除後の耳介軟骨移植に関する実験的研究 Ｉ． 顎関節形態の組織変化

Abstract

Imaging technique advancements have contributed to improved understanding of the pathogenesis of internal derangement of the temporomandibular joint. Although repositioning of the dislocated disc is the most commonly employed to treat this condition, discectomy is indicated for degenerated discs. Arthritic changes have been observed in joints after disc removal, suggesting the need for interpositional material. Since silicone implants placed after discectomy have caused osseous destruction, there is controversy about the use of interpositional materials after discectomy. Recent studies recommend the use of autogenous materials for replacement. Among them, auricular cartilage seems one of the best suited materials for disc replacement. The purpose of this study was to investigate morphological and functional changes after auricular grafts were placed in temporomandibular joints after disc removal. Rabbits for this experimental study were divided into two groups: rabbits in one group underwent discectomy alone, and the other group underwent auricular grafting after discectomy. H & E stain and toluidine blue stain revealed complete resorption of the articular cartilage with surface flattening in the discectomy alone group. Finally, regeneration of the fibro-cartilage cells resulted in retention of the articular cartilage layer on the condyle with a flattened articular surface. In contrast, a virtually normal shape was maintained in the auricular graft group, but the implant underwent resorption and fragmentation after 6 weeks. Finally, a depression was formed only on the surface of eminence. The results indicated that grafted auricular cartilage protected the rabbit condyle from early degenerative changes and suppressed morphological changes after discectomy.