Tsunehisa Shimoda

Traumatically induced posterior disk displacement without reduction of the TMJ--a case report.

A case of posterior disk displacement (PDD) without reduction of the temporomandibular joint (TMJ) was observed in this case report. The disk position was altered by using an occlusal splint and intermaxillary elastic traction for 10 days. An anterior displaced disk with reduction (ADDw/R) resulted from this therapy. Proposed criteria for diagnosing the PDD without reduction of the TMJ will be discussed in this study.

Angiography of the temporomandibular joint: Description of an experimental technique with initial results

The vascular supply to the temporomandibular joint is not completely understood. To form a base for advancement in this area we developed a method for experimental angiography of the temporomandibular joint that was applied to fresh temporomandibular joint autopsy specimens. Via the external carotid artery the vessels were infused with a mixture of barium and an acrylic resin. The specimens were sectioned and contact radiographs were obtained. These showed the vascularity of the joint and the surrounding structures with great detail. Most of the vascular supply appears to come from the lateral and medial aspects of the condyle head and from the anterior and posterior disk attachments. The method was applied to both normal and abnormal joints and the results suggest that this method could be used to gather further understanding of the vascularity of the temporomandibular joint relative to disease.

Three-dimensional Assessment of the Accuracy of Maxillary Repositioning by Le Fort I Osteotomy with Emphasis on Maxillary Backward Transference

Objective: To evaluate the accuracy of repositioning of the maxilla by Le Fort I osteotomy with emphasis on maxillary backward transference. Materials and Methods: Thirty patients with jaw deformity who underwent Le Fort I osteotomy were enrolled in the study. The patients were divided into 3 groups: backward transference group, in whom both molar regions were moved >2 mm in the posterior direction; forward transference group, in whom both molar regions were moved >2 mm in the anterior direction; and minor transference group, in whom both molar regions were moved <2 mm. The 3-dimensional position of the maxillary central incisor (U1) and both first molars (R6, L6) were measured on presurgical, surgical, and post-surgical dental models. The difference between planned and actual movements was analysed using Wilcoxon signed-rank test. Results: In the backward transference group, the maxilla was moved backward to excess, probably because of a preconception that forward movement after the operation due to occlusal force will occur. In the forward transference group, the maxilla was located more forward as a consequence of being excessively moved upwards. In the horizontal direction, influence of the operators position and the plate fixation method were thought to explain the differences between the backward transference group and the forward transference group. Conclusion: To perform the operation more precisely, additional reference points with a plane factor are needed for Le Fort I osteotomy. In the future, the infrared sensor might be useful and effective.

Condylar Reconstruction by Vertical Sliding Ramus Osteotomy

Abstract A convenient method for condylar reconstruction through vertical ramus sliding osteotomy after condylectomy of the mandible is described. The method utilises the submandibular approach enabling a modification of the intracapsular temporomandibular joint arthroplasty and avoidance of excessive exposure of the temporomandibular joint capsule. This appears to prevent mandibular dysfunction postoperatively while maintaining the restored vertical dimension of the ramus.

Step cannulation system for both articular compartments of the TMJ

We have developed a step cannulation system consisting of a set of six obturators with increasing diameters for effective use of the arthroscope in the diagnosis and surgical treatment of disorders of the temporomandibular joint.

Salivary Duct Carcinoma of the Minor Salivary Glands

Abstract Salivary duct carcinoma is characterised by aggressive behaviour, with a high risk of local recurrence, and regional and distant metastasis. This report describes a patient with salivary duct carcinoma that originated in the minor salivary glands of the mucosa over the maxilla. Microscopically, vascular invasion varied from 4 to 5 per 10 high-power fields, and immunohistochemical staining with E26 transformation specific-1 was demonstrated in the tumour cells. Ki67 positivity was also revealed in 52% of the specimens examined. These results suggest that salivary duct carcinoma is a highly aggressive malignant salivary gland tumour due to proliferative cell activity, angiogenesis, and vascular invasion.