Recent innovations in three-dimensional additive manufacturing technology, such as 3D printers, are being applied in the medical field. In the orthopedic field, titanium joint prostheses are used for various parts such as knees, hips, elbows, and fingers. In the field of dentistry, it is also used in metal frameworks for dentures, crown-bridge prosthetics, and dental implants. Implant bone augmentation using SLM（Selective Laser Melting）titanium mesh plates designed and shaped based on patient CT data has been performed with good results. In August 2021, guidelines were established for the maxillofacial region. These guidelines are expected to lead to the development and clinical application of patient-adapted internal fixation plate that can be optimally adapted to the patient's unique skeletal structure, even in cases where maxillofacial continuity has been lost due to tumor, trauma, or congenital deformity.
　The manufacturing process for the patient-adapted internal fixation plate begins with three-dimensional imaging using CT or other methods. The bone defects are confirmed from the obtained DICOM（Digital Imaging and Communications in Medicine）data, and a surgical simulation is performed using CAD software to design the Patient-adapted internal fixation plate design. The surgeon and designer exchange opinions on the basic design and the position of the plate fixation with screws. The designed data is loaded into the CAM software, and the layout of the support and molding table is set up for the laminate molding.
　The design process and points to keep in mind during the process will be presented. The application of 3D additive manufacturing technology to the maxillofacial region is expected to become more widespread as an innovative medical technology that will enable the realization of the diversity sought by individual patients.

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Reconstruction using a vascularized bone composite flap is currently the standard treatment after resection of the mandible and various types of plates are used. In our department, we mainly perform reconstruction using the scapula and have used three types of plates: mini plates, reconstruction plates, and custom-made plates that have recently been covered by insurance in Japan. In this paper, we compared the miniplate and the reconstruction plate and found that the ischemic time in the cases of the reconstruction plate was shorter than that of the miniplate. In addition, we show an overview of a vascularized scapular flap reconstruction case using a custom-made plate after hemimandibulectomy.

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The free fibula osteocutaneous flap is currently the first-line option for mandibular reconstruction in the authors' department. There have been significant changes in plate fixation methods and preoperative evaluation, including donor side selection. In recent years, custom-made reconstruction methods based on computed tomographic methods have been introduced, including customization of the osteotomy site and reconstruction plate. The present article describes methods of mandibular reconstruction using the free fibula osteocutaneous flap performed in the authors' department to date, in addition to the problems encountered. The ensuing discussion address the utility of the custom-made reconstruction method.
　First, the process leading up to reconstruction surgery and the method of reconstruction was described, followed by a comparison of the types of plates used, their characteristics, and postoperative course. Plate types were classified as mini-, conventional reconstruction, and custom-made reconstruction. Cases involving the custom-made mandibular reconstruction method were presented in addition to a discussion of its utility.
　The current standard method in the authors' department was to manually bend the reconstruction plate to fit the model and fix it to the remaining mandible after shaving the area to be resected on the three-dimensional model. In many cases, no major problems, such as impaired postoperative function, have been encountered. In contrast, positioning was often difficult in patients undergoing hemi-mandibulectomy or median resection of the mandible. Although the authors' experience with custom-made mandibular reconstruction was limited, they have found it to be particularly useful in patients undergoing hemi-mandibulectomy or those requiring division of the fibula flap into multiple segments.
　The currently available custom-made reconstruction method was considered more useful for larger resection areas, but not as advantageous for defects as small as the mandibular body. Further advances and developments in digital technologies are anticipated, which will make custom-made mandibular reconstruction easier to perform in the future. In the meantime, however, it was considered necessary to improve the accuracy of the currently used conventional method through trial and error.

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Currently, 3D models and AR/VR/MR technologies are being actively applied in the medical field as an assist in diagnosis and surgical planning, particularly in surgery. The introduction of these technologies is expected to reduce various costs, shorten operation time, and improve the reliability of surgery, thereby contributing to the improvement of overall treatment outcomes. Nowadays, there is a growing interest in the efficient and effective generation and creation of “3D data,” which can be regarded as the blueprint for these 3D technologies.
　This report provides an overview of “ medical imaging and 3D printing technologies that assist oral and maxillofacial surgeons” based on the author's past experience in 3D CAD operation and 3D models fabrication, and also reports on“ 3D data creation and utilization” that surgeons at the forefront of clinical practice should understand.

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Necrotizing soft tissue infection is a serious infection that progresses widely and rapidly, mainly through the skin, subcutaneous tissue and fascia, but rarely inside muscle. We report a case of necrotizing soft tissue infection triggered by odontogenic infection that progressed inside the sternocleidomastoid muscle （SCM） and was complicated by jugular vein thrombosis.
　The patient was a 52-year-old man who showed trismus, dyspnea and severe swelling accompanied by redness in the right buccal region, submandibular region and neck.
　A blood test showed a WBC of 18,000/μL and CRP of 12.30 mg/dL. A contrast-enhanced computed tomography image showed an abscess with gas accumulation inside the SCM and in the submandibular region, and the internal jugular vein was occluded, with thrombus formation suspected. On the same day, under general anesthesia, the abscess pus and gas were released through a submandibular incision, and a drain was inserted along the SCM. The inflammation gradually improved under 15 days of administration of SBT/ABPC（12 g/day） and CLDM（1,200 mg/day）. Postoperative contrast-enhanced CT showed no occlusion of the internal jugular vein and the thrombus had disappeared. The patient was discharged on the 21st hospital day.

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The goals of the study were to investigate the effects on bone bioactivity of a titanium dioxide layer formed by hydrothermal oxidation of a titanium surface with hydrogen peroxide（H₂O₂） and loading with fibroblast growth factor-2（FGF-2） in vitro and in vivo.
　Ti-6Al-4V discs were hydrothermally oxidized with H₂O₂ and then loaded with FGF-2. After cytotoxicity testing, Ti-6Al-4V mini-implants were subjected to the same treatment, and their osteogenic potential was evaluated histologically in a rat model.
　H₂O₂ hydrothermal oxidation resulted in a dense porous network structure and hydrophilic changes, which improved retention of FGF-2. Morphologically, the cell density was higher, cell elongation was more pronounced, and the cell adhesion area was significantly higher in FGF-2-loaded cells than in those without FGF-2. In a cell proliferation assay using mouse osteoblast-like cells, absorbance tended to increase over time, especially in the FGF-2 group after 7 and 14 days. In a bone differentiation assay based on ALP activity, there was a significant increase in the FGF-2 group after 14 days. In the rat model, H₂O₂ hydrothermal oxidation and FGF-2 loading both resulted in more laminar bone tissue in the bone marrow around the mini-implant.
　These results suggest that titanium surface functionalization using H₂O₂ hydrothermal oxidation and FGF-2 may promote initial cell adhesion, proliferation and osteodifferentiation, and enhance bone bioactivity. These effects all contribute to the early bonding of an implant with the surrounding bone.

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