The Department of Oral Surgery, Osaka Medical and Pharmaceutical University has developed a new, fully customizable device for mandibular reconstruction. This device solves the problems encountered when using conventional jawbone reconstruction plates, such as the need for bending, the difficulty of restoring facial features with complex shapes, the reduction in metal strength due to bending during surgery, and the risk of fractures caused by mastication. The development of a new medical device requires various processes, such as applying to the Japan Agency for Medical Research and Development (AMED) for assistance in commercialization, including research funding, and consulting with the Pharmaceuticals and Medical Devices Agency (PMDA) on pharmaceutical regulatory matters. As these processes are complex, it is not always possible to stay on schedule.
　This paper describes an organized overview of the development process to date for this new device. The author hopes that this will encourage the promotion of medical device development in Japan in the future.

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　After continuous disarticulation of the mandible, reconstruction with a free osteocutaneous flap with vascular is effective. However, problems such as occlusal deviation 16.7％ (4/24) and facial deformity 8.3％ (2/24) may occur in the medium- to long-term course. In particular, when the muscle process and mandibular nucleus are resected and the proximal residual bone is small, dislocation is likely to occur, and intraoperative positioning of the jaw is not only difficult, but also tends to change over time.
　The TruMatch Reconstruction system is a new system that has become available in Japan due to the development of surgical simulation software and the progress of 3D printers. This system is not only accurate in mandibular reconstruction, but also enables accurate resection of tumours according to the preoperative plan by using a cutting guide. It also reduces operative time and blood loss, and is considered to be an effective item for mandibular reconstruction.
　However, there are issues that need to be improved in the future, such as the low degree of freedom of the plate and the long time between planning and completion of the product.

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　Purpose: We performed definitive concurrent chemoradiotherapy with retrograde superselective intra-arterial infusion (IACRT) for patients with advanced oral cancer who refused to undergo surgery. Although IACRT has excellent antitumor effects, it is associated with several acute adverse events, especially significant oral mucositis and radiation dermatitis, which often result in difficulty in food ingestion. In this study, we report on the outcomes of 119 patients with advanced tongue cancer, adverse events related to ingestion and swallowing, changes in dietary intake and nutritional status over time, and factors influencing dietary intake in this population.
　Materials and methods: A total of 119 patients (stage Ⅱ and Ⅲ, 47 cases; stage Ⅳ, 72 cases) with tongue cancer who had received IACRT between January 2008 and December 2018 were included in this study. The adverse events, Functional Oral Intake Scale (FOIS), and Onodera-Prognostic Nutritional Index (O-PNI) were assessed before and after treatment. Factors affecting FOIS after three months of treatment were also subjected to multivariate analysis.
　Results: The median follow-up period was 52 months. Grade 3 or 4 oral mucositis was observed in 92％ of the patients and radiation dermatitis in 41％ of the patients. The median FOIS was 6 before treatment, 1 immediately after treatment, 6 at three months after treatment, and 7 at one year after treatment. The FOIS differed significantly before treatment and three months after treatment. However, there was no significant difference between before treatment and six months after treatment. Multivariate analysis revealed that the radiation dose was an independent factor influencing FOIS at three months. O-PNI was 47.2 ± 6.3 before treatment, 34.4 ± 4.5 immediately after treatment, and 42.9 ± 9.2 at three months after treatment, with a significant difference between before and immediately after treatment, and no significant difference between before treatment and three months after treatment.
　Conclusion: Patients treated with IACRT had difficulty in dietary intake during treatment, however they were gradually able to eat as they did before treatment. After three months of treatment, the nutritional status of patients was equivalent to that before treatment. Moreover, after six months of treatment, dietary intake tended to be equivalent to that before treatment.

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　Malignant glomus tumor is a rare malignant tumor of mesenchymal origin arising from the smooth muscle cells of the glomus body. Glomus tumors occur prevalently in the subungual region and rarely in the oral cavity. We report a malignant glomus tumor arising in the mandible. The patient was a 27-year-old woman who had undergone excisions of undiagnosed cysts or tumors in the right side mandible and oral floor six times since she was a child. Panoramic radiograph and CT images showed a multifocal, ill-defined transmission image. A segmental mandibular resection was performed under general anesthesia, and a histopathological diagnosis of malignant glomus tumor was obtained. After surgery, she had two local recurrences and multiple pulmonary metastases and died of the disease five years and 10 months after the initial examination.

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　Although lipomas are benign tumors that can occur throughout the body, they rarely occur in the oral region. Myxolipomas, a subtype of lipoma, are accompanied by myxomatous changes within the lipoma, and are extremely rare in the oral cavity. We report a case of myxolipoma in the retromolar mandible. The patient was a 47-year-old man who visited a nearby dental clinic with the chief complaint of a mass in the retromolar mandible on the right side. In March 2023, tumor resection was performed under general anesthesia. Postoperatively, the patient has been doing well without functional impairment. We plan to continue follow-up.

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