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

本研究旨在探讨拔除髁突导致的咬合损害与垂直尺寸丧失的关系，并探讨自体耳廓软骨对咬合损害的预防作用。我们将102只成年雄性ICR小鼠分为三个不同的实验组，为期2年：仅切除髁突；髁突切除加耳廓软骨移植；还有假手术。在显微外科显微镜下进行治疗。术后38 ~ 191天处死小鼠。我们通过肉眼检查来观察他们的咬合异常。采用苏木精-伊红染色及免疫组化检查观察移植后耳软骨及对侧颞下颌关节（TMJ）的形态学变化。得到了以下结果：1。肉眼观察结果：成功治疗的49只小鼠中至少有5只出现咬合损伤。他们的下颌骨转移到手术较多的一侧，完全失去了与切牙的接触。这种变化导致老鼠无法自然进食，最终导致老鼠死亡。组织学结果：移植的耳廓由于缺乏固定和下颌运动而改变了位置，即在许多病例中耳廓从颞下颌关节外侧滑出。免疫组化结果：面向关节腔、靠近窝和髁关节表面的细胞对转化生长因子-β (TGF-β)呈阳性反应，而其下方的软骨细胞普遍为TGF-β阴性染色。移植的耳廓软骨细胞TGF-β呈轻微阳性或阴性。成纤维细胞生长因子-2 （TGF-2）在关节腔内壁细胞、关节腔下细胞及软骨细胞中的表达均呈阳性；但第一类细胞在3个不同的细胞类别中染色最强。移植的耳廓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。在构成关节结构的细胞中未发现层粘连蛋白。此外，移植的耳穴细胞未见染色。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