Sadasuke Hayata

Mandibular osteoradionecrosis (ORN) is difficult to reconstruct because irradiated tissues are fibrotic and devitalized, and postoperative malalignment—particularly loss of condylar position—can compromise function and aesthetics. A 74-year-old man developed advanced right mandibular ORN after chemoradiotherapy for oropharyngeal carcinoma; conservative management failed, and segmental mandibulectomy was indicated. Reconstruction was performed with a left fibula free flap guided by an in-house computer-aided design/computer-aided manufacturing (CAD/CAM) workflow using patient-specific instruments (PSI), including mandibular and fibular cutting guides and a fibula assembly guide. The mandibular guide integrated anterior and posterior cutting components with stabilizing bars to help preserve mandibular continuity and condylar position, and aligned screw holes enabled accurate transfer of the virtual plan and facilitated plate fixation. Operative time was 9 h 58 min with an estimated blood loss of 700 mL. Postoperative imaging showed minor surface deviation of the reconstructed segment (<3 mm) with medial drift of the ipsilateral condyle (~7 mm). At 3 months, the patient maintained stable occlusion with a maximum mouth opening of 30 mm without complications. This case illustrates that PSI-guided fibula free flap reconstruction using an in-house CAD/CAM process can provide a practical and reproducible approach for advanced mandibular ORN while supporting postoperative mandibular alignment.

Background/Objectives: A retrospective study was conducted to clarify the clinical characteristics of taste disorder cases at the Department of Oral Medicine of Hokkaido University Hospital. The subjects were 322 taste disorder patients (86 male, 236 female, average age: 66 (13.1) years, mean duration of disorder: 15.2 (20.0) months) who were treated at our department from 2007 to 2018. Methods: Associations between symptoms and classification were examined. Results: When looking at the taste symptoms, 154 cases of quantitative taste disorder were observed as taste loss, abscission, and dissociative taste disorder, and 168 cases of qualitative taste disorder were observed as spontaneous abnormal taste, dysgeusia, and maltaste. There was no relationship between sex and quantitative/qualitative taste disorders at V = 0.08. When looking at the causes of taste disorders, the majority were psychogenic, idiopathic, and oral diseases. Conclusions: Approximately 20% of taste disorders are caused by oral diseases, so it should be noted that oral diseases such as oral candidiasis and xerostomia can cause taste disorders and that many of them can be improved with oral treatment.