Akira Kimoto

Retrospective study of changes in the sensitivity of the oral mucosa: sagittal split ramus osteotomy (SSRO) versus intraoral vertical ramus osteotomy (IVRO).

We investigated changes in the sensitivity of cutaneous points and the oral mucosa after sagittal split ramus osteotomy (SSRO) and assessed the differences between SSRO and intraoral vertical ramus osteotomy (IVRO). The subjects included in this study were 46 patients with mandibular prognathism who underwent IVRO (88 rami) and 30 patients who underwent SSRO (59 rami). An objective evaluation of the neurosensory status of each patient was completed preoperatively and at 1, 4, 8, 12, and 24 weeks postoperatively. Other variables studied for each patient included sex, age, magnitude of mandibular setback, and amount of blood loss during surgery. We found that a neurosensory recovery occurred earlier in the oral mucosa than at cutaneous points. The number of oral mucosa points showing reduced neurosensory function and neurosensory disturbance after SSRO was significantly higher than after IVRO at 1, 4, and 8 weeks (P<0.05). The nerve recovery observed after SSRO was delayed for a longer period than that noted in our previous study of IVRO. In conclusion, we found changes in sensitivity at cutaneous points and the oral mucosa after SSRO and assessed the differences between SSRO and IVRO.

Plexiform perineurioma of the lip: A case report and review of literature

We describe a plexiform perineurioma, which is an extremely rare variant of soft tissue perineurioma. A 43‐year‐old Japanese man presented with a painless, well‐demarcated, elastic, soft tumor measuring 2.0 × 1.9 cm on the upper lip that had persisted for three years. Microscopically, a plexiform tumor composed of minimally atypical spindle cells with wavy nuclei was located in the lamina propria of the oral mucosa. Tumor cells were concentrically arranged around small vessels and aligned in parallel with delicate collagen fibers on a fibromyxoid background in the hypocellular area. Tumor cells were immunohistochemically positive for EMA, GLUT‐1, claudin‐1, and CD34 and negative for S‐100 protein. The histopathological and immunohistochemical profiles of the excised tumor indicated a diagnosis of plexiform perineurioma. The patient has remained free of recurrence for sixteen months. Intraoral soft tissue perineurioma is rare and two of the four reported plexiform perineuriomas, including that described herein, notably involved the intraoral area. According to previous reports, plexiform perineuriomas largely develop in middle‐aged women without a history of type 1 or type 2 neurofibromatosis. The clinical courses of all reported plexiform perineuriomas have been benign.

Postradiotherapy Dental Implant Insertion Into Bone Grafts Harvested From Nonirradiated Tissue: Case Reports.

Background:Prostheses and dental implants are often used to aid oral rehabilitation after surgery (with/without radiotherapy) for oral cancer. However, some studies have reported that the insertion of dental implants into irradiated bone results in a higher frequency of implant failure than the insertion of such implants in nonirradiated bone. Materials and Methods:This report describes the cases of 4 patients with oral cancer who underwent surgery and radiotherapy (total dose: 50–86 Gy) and then had dental implants inserted within the irradiated area. In each case, an ilium bone graft or a latissimus dorsi myocutaneous flap containing scapular bone was transferred to the dental implant site before the insertion of the implants. Results:Twenty-three implants were inserted. After loading, 2 implants were lost, and 21 remained stable. Conclusion:In patients who have undergone radiotherapy for oral cancer, transferring bone grafts harvested from nonirradiated tissue to the irradiated site before implant insertion might help to improve dental implant survival rates.

CT Evaluation of Morphology of Transferred Fibula for Implant Placement in Reconstructed Mandible.

Background:Dental rehabilitation with osseointegrated implants in reconstructed mandibles remains one of the most challenging procedures for oral and maxillofacial surgeons. Satisfactory outcome requires appropriate assessment of graft morphology. There are few analyses of the morphology of fibulae in reconstructed mandibles, although cadaver studies on fibular shape have been performed. Materials and Methods:In this study, we used postoperative computed tomography to retrospectively evaluate the shape, height, and orientation of fibulae transferred after mandibulectomy in 19 patients. Results:The average height of transferred fibulae was 14.3 mm (range, 10.8–20.5 mm). The cross-sectional morphology of transferred fibulae could be classified into 2 types: apex and nonapex. The former type included knife-edged and triangular shapes; the latter included square and circular shapes. Conclusion:When implant insertion is planned in a reconstructed mandible, the orientation of the apex of transferred fibula should be evaluated preoperatively to allow for adjustments in implant procedure because the ridge at the apex of the fibula is narrow.