Hakubun Yonezu

A Longitudinal Study of the Effect of Experimental Osteoporosis on Bone Trabecular Structure in the Rat Mandibular Condyle

Abstract The authors performed a longitudinal study of the microstructural changes occurring in the mandibular condyle during osteoporosis using the findings obtained from micro-CT. The subjects used in this study were eight Sprague-Dawley rats. Among them, five were administered the immunosuppressant drug FK506 by injection for five weeks, while the other three were administered saline solution in the same manner. Micro-CT images were taken of the bilateral mandibular condyle, hip, and knee joints in all animals on days 1, 8, 15, 22, 29, and 36 following injection. Six indices of morphometric analysis were compared between the two groups. Significant differences were observed in BV/TV, Tb.Th, Tb.N, and Tb.Sp in the mandibular condyle, while trabecular bone density appeared to decrease in the immunosuppressant group on three-dimensional (3D) imaging. And, in comparison with the mandibular condyle and femur, they were similar. These results suggested that osteoporosis affects not only the femur, but also the mandibular condyle.

Instrument for lateral release in temporomandibular joint hypomobility

mandibular joint (TMJ) by Ohnishi,1 intervention by arthroscopic examination and surgery have become popular worldwide for treating TMJ disorders. The investigators of many studies have reported that arthroscopic sweep, lysis, and lavage improve joint function and relieve the pain caused by persistent closed lock of the TMJ.2 There are a few reports of lateral release and stretching of the capsule. Ohnishi1 was the first to report the use of arthroscopy to show adhesive tissue in the lateral region of the upper joint cavity. Murakami et al3 and Moses and Poker4 suggested the importance of the capsular stretch procedure or capsular release for joint mobility. Although previous reports suggested that lateral lysis and stretching of the lateral capsule

Use of a new instrument for lateral release in arthroscopic surgery of the temporomandibular joint: a preliminary study.

We developed a new instrument, which we call a lateral releaser, to improve the safety of either a blind lateral release or lateral stretching within the TMJ We used it during arthroscopic surgery in patients with chronic painful hypomobility of the temporomandibular joint (TMJ). We operated on 24 TMJs in 17 patients (15 women and 2 men). At operation, the mean increase in the interincisal distance was 22 mm (range 10-32). No instruments were broken. No serious surgical complications were reported during or after operation. Many of the patients currently have an interincisal distance exceeding 38 mm.