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.

Objectives: Oral frailty is associated with sarcopenia and underweight; however, its relationship with sarcopenic obesity remains unclear. This cross-sectional study investigated the associations between oral frailty and body mass index (BMI) categories (underweight/obesity), stratified by sarcopenia status. Methods: Data were obtained from dental checkups for 3829 older adults in Tottori, Japan (1489 men and 2340 women, mean age: 80.1 ± 4.3 years). Participants were divided into sarcopenia risk and non-sarcopenia groups by using the Yubi–Wakka test and then further subdivided by BMI into underweight, normal weight, or obese. Oral frailty was defined as meeting three or more of six oral frailty assessment criteria adapted from previous studies. Multinomial logistic regression analysis was performed to examine the association between oral frailty and each BMI category, with normal weight used as the reference category. Results: In the sarcopenia risk group, both obesity and underweight were significantly associated with oral frailty. The odds ratio (OR) for obesity was 1.727, with a 95% confidence interval (CI) of 1.092–2.732, and the OR for underweight was 1.443, with a 95% CI of 1.066–1.952. In contrast, no significant association between BMI category and oral frailty was observed in the non-sarcopenia group. Conclusions: Among late-stage older adults at risk of sarcopenia, oral frailty was associated with both obesity and underweight, with different contributing factors identified for each BMI category.