Hizuru Miyamoto

The role of the disk in sheep temporomandibular joint ankylosis

OBJECTIVE The purpose of this study was to determine the role of the disk in intraarticular ankylosis of the temporomandibular joint. STUDY DESIGN Twelve adult sheep were divided into 2 groups. In group 1, removal of the temporal and condylar articular surfaces was performed on the right temporomandibular joint and the disk was maintained; in group 2, removal of the articular surfaces and diskectomy were performed on the right temporomandibular joint. One sheep from each group was killed just after surgery and 5 sheep from each group were killed at 3 months. The joints were examined radiologically, macroscopically, and histologically. The range of jaw movements was recorded preoperatively and at sacrifice. RESULTS Each of 2 sheep in group 2 had lost 4% of their body weight by 3 months; all of the other sheep maintained or increased their weight. The range of jaw motion to the right was significantly lower in group 2 than in group 1 (P<.01). In group 1, fibrous repair of the articular surface and regeneration of the condylar head was seen. In group 2, each of the joints showed a total fibrous ankylosis with some calcification. There was a statistically significant difference in radiologic score between the groups (P<.0001). Histologic scores for group 1 demonstrated significantly lower scores on the degree of ankylosis scale and degree of calcification scale (P<.0001). CONCLUSIONS This study showed that the presence of the disk prevented the development of fibrous intraarticular ankylosis of the temporomandibular joint.

The effect of an intra-articular bone fragment in the genesis of temporomandibular joint ankylosis

The aim of this study was to examine the effect of an intra-articular bone fragment on the genesis of temporomandibular joint (TMJ) ankylosis. Twenty-two adult sheep had a unilateral operation of removal of the temporal and condylar articular surfaces, plus discectomy with or without insertion of an intra-articular bone fragment. Functionally, radiologically, macroscopically and histologically, in the group with the intra-articular bone fragment, the joints showed more advanced ankylosis both at one and three months after the operation, as compared to the group with no intra-articular bone. This study shows that the bone fragment increases the extent of ankylosis in the sheep model. The clinical significance of the various experimental findings of this study and others in the same series is presented.

A sheep model for temporomandibular joint ankylosis

PURPOSE The purpose of this study was to develop an animal model for temporomandibular joint (TMJ) ankylosis. MATERIALS AND METHODS Five sheep had removal of the temporal and condylar articular surface plus discectomy in the right TMJ; the left side was used as a control. One sheep was killed just after operation and four at 3 months. The joints were examined histologically, and a scoring system was developed to evaluate the extent of the ankylosis. The range of jaw movement was compared between preoperatively and 3 months. RESULTS Two sheep lost 4% of their body weight by 3 months. The range of jaw movement, particularly to the left, decreased at 3 months (P < .001). The joint spaces were filled with fibrous tissue and cartilage-like tissue. Development of new bone from the damaged temporal and condylar surfaces was seen, but full bony fusion did not occur. The average histologic score of a zone was 4.9 on the degree-of-ankylosis scale and 1.7 on the degree-of-calcification scale. There were statistically significant differences between the operated and control TMJs for both changes (P < .0001). CONCLUSION Fibrous ankylosis occurs rapidly after removal of the TMJ articular surfaces and the disc. This model can be further developed to isolate relative factors in the development of ankylosis and in evaluation of different treatment methods.

Synovial chondromatosis of the temporomandibular joint

We report two cases of temporomandibular joint (TMJ) synovial chondromatosis, one of which was in the early stage and treated arthroscopically. The second was more advanced and recurred after removal of the free bodies, and so required condylectomy and synovectomy.

Peripheral facial palsy after sagittal split ramus osteotomy for setback of the mandible : A case report

The case of a 21-year-old man who underwent sagittal split setback osteotomy is described. He experienced facial nerve palsy 2 days after his surgery. However, after physical therapy and the administration of vitamins, he regained normal function within 3 months. The literature related to postoperative facial nerve paralysis is briefly reviewed.

Oral verrucous carcinoma: Report of three cases.

高分化型扁平上皮癌の1亜型である疣贅状癌は, 1948年にAckermanによって最初に報告された。日本においては, 1990年に浅海らが52例を報告している。われわれは, 頬粘膜, 舌, 下顎歯肉の3例の疣贅状癌を報告した。頬粘膜および舌の2例は切除し, 下顎歯肉の1例はレーザー切除と蒸散をおこなった。本腫瘍においては, 未分化転換がしばしば起こるため, 化学療法と放射線治療は一般的には行なわれない。われわれの3例では, 外科療法が選択され, 局所制御が得られた。

Clinical study of fifteen parotid gland tumors.

過去8年間に当科にて治療した耳下腺腫瘍の15例を検討した。これらは良性腫瘍または腫瘍類似疾患が11例と悪性腫瘍が4例であった。病理組織学的には, 多形性腺腫が8例, リンパ上皮性嚢胞が1例, 嚢胞を形成した良性リンパ上皮性疾患が1例, グロムス腫瘍が1例, 粘表皮癌が2例, 腺様嚢胞癌が1例, 腺癌が1例であった。これらの症例を臨床的に検討し, 臨床経過を報告する。

A case of angiomyoma in the lower lip and a review of the literature.

血管筋腫は1937年, Stoutが最初に報告した良性腫瘍である。血管筋腫は口腔領域に発生することはまれである。下唇に発生した血管筋腫の1例を報告し, 文献的考察を行った。30歳の男性が左側下唇の腫瘤を主訴として当科を受診した。同日, 局所麻酔下にて腫瘍摘出術を施行した。病理組織学的診断は血管筋腫であった。本邦における口腔領域においての本腫瘍の報告例は, 本症例を含めて65例であった。