Study on transplanted auricular cartilage after removal of articular disc or condylar head of the temporomandibular joint

本研究以成年雄性ICR小鼠102只为实验动物，分成三组，分别为单纯切除组、切除联合耳廓软骨移植组和假手术组，研究咬合功能受损与下颌骨切除后垂直距离丢失的关系，以及应用自体耳廓软骨预防咬合功能受损的作用。使用显微外科显微镜进行治疗。术后38~191天处死小鼠。我们通过肉眼检查来研究他们的咬合异常。用苏木精-伊红染色和免疫组织化学方法对移植的耳软骨和对侧TMJ的形态变化进行了研究，结果如下：1.大体观察：49只成功治疗的小鼠中，至少有5只出现咬合损害。他们的下颌骨移位到了…更多的手术侧和切牙接触完全丧失。这一变化导致不能自然进食，从而最终导致老鼠死亡。组织学结果：由于缺乏固定和下颌运动，移植的耳廓似乎改变了位置，即在许多情况下，它们从TMJ滑出。免疫组织化学结果：靠近关节窝关节面和关节突关节面的软骨细胞对转化生长因子-β呈阳性反应，其下方的软骨细胞对转化生长因子-β呈阴性反应。对于成纤维细胞生长因子-2，关节腔内的细胞、关节腔内的细胞和软骨细胞均呈β-2阳性，但以第一类细胞表达最强。移植的耳软骨细胞呈弱部分染色，骨形态发生蛋白(BMP)在上述细胞和耳廓软骨细胞中普遍未见表达，层粘连蛋白在构成关节结构的任何细胞中均未见表达。此外，移植的耳廓细胞未见染色。较少

This study was done to investigate the relationship between occlusal impairment and loss of vertical dimension due to condylar removal, and to investigate the use autologous auricular cartilage for prevention of the occlusal impairment.We used 102 adult male ICR mice in three separate experimental groups for 2 years : condylectomy only ; condylectomy plus auricular cartilage transplantation ; and, sham operation. The treatments were performed using microsurgical microscopy. The mice were sacrificed 38 to 191 days after the operations. We investigated their occlusal abnormalities by macroscopic examination. Morphological changes of transplanted auricular cartilage and the opposite temporomandibular joint (TMJ) were also studied by hematoxylin-eosin stain and immunohistochemical examinations.The following results were obtained :1. Macroscopic findings : Occlusal impairment was observed in at least 5 of the 49 mice which had been successfully treated. Their mandibular bones shifted to the … More operated side and incisal contact was lost completely. This change brought about an inability to feed naturally and thus the eventual death of the mouse.2. Histological findings : Transplanted auricles seemed to change their positions because of a lack of fixation and mandibular movement, that is they slipped out laterally from the TMJ in many cases.3. Immunohistochemical findings : Cells facing the articular cavity and located near the articular surface of the fossa and condyle showed positive reactions to transforming growth factors-β (TGF-β), while chondrocytes under them generally revealed negative staining for TGF-β. Transplanted auricular chondrocytes presented slight positiveness or negative for TGF-β.As for the fibroblast growth factor-2 (TGF-2), cells lining the articular cavity, the cells under them and chondrocytes were all positive for TGF-2 ; however, the first category showed the strongest staining of the 3 different cell categories. Transplanted auricular chondrocytes presented weak partial staining.Bone morphogenetic protein (BMP) was generally not observed in the above mentioned cells and auricular choudrocytes.Laminin was not demonstrated in any cells comprising the articular structures. Further, transplanted auricular cells showed no staining. Less