Recently, significant progress has been made in medical techniques for regenerating bone. However, bone evaluation techniques generally assess bone quantity as opposed to bone quality. The use of c-axis crystallite orientation of biological apatite (BAp) as a bone quality index has recently generated great interest. BAp demonstrates strong crystallographic anisotropy, and preferential alignment of BAp in each bone varies depending on the shape and stress conditions in vivo. In the mandible, complicated bone shape and stress conditions in vivo might be associated with both bone quantity and quality. In this study, we aimed to elucidate changes in the bone microstructure in the mandible using crystallographic orientation of BAp as a bone quality index. Using Crj: CD (SD) IGS female rats, we observed changes in the dentulous mandible during bone growth. Measuring points on the mandible were determined based on its positional relationship with the teeth. For analysis of bone quantity, the area and bone mineral density of cortical bone were evaluated using peripheral quantitative computed tomography (pQCT), while the orientation of the BAp c-axis, as analyzed by a micro-beam X-ray diffraction system, was used to assess bone quality. The results of both bone quantity and quality assessments indicated that changes during bone growth varied depending on the presence of teeth. We concluded that the microstructure (especially the texture) of BAp crystallite changes in correlation with variations in stress distribution in vivo resulting from changes in chewing conditions designed to optimize the dynamic chewing function.

Recently, significant progress has been made in medical techniques for regenerating bone. However, bone evaluation techniques generally assess bone quantity as opposed to bone quality. The use of c-axis crystallite orientation of biological apatite (BAp) as a bone quality index has recently generated great interest. BAp demonstrates strong crystallographic anisotropy, and preferential alignment of BAp in each bone varies depending on the shape and stress conditions in vivo. In the mandible, complicated bone shape and stress conditions in vivo might be associated with both bone quantity and quality. In this study, we aimed to elucidate changes in the bone microstructure in the mandible using crystallographic orientation of BAp as a bone quality index. Using Crj: CD (SD) IGS female rats, we observed changes in the dentulous mandible during bone growth. Measuring points on the mandible were determined based on its positional relationship with the teeth. For analysis of bone quantity, the area and bone mineral density of cortical bone were evaluated using peripheral quantitative computed tomography (pQCT), while the orientation of the BAp c-axis, as analyzed by a micro-beam X-ray diffraction system, was used to assess bone quality. The results of both bone quantity and quality assessments indicated that changes during bone growth varied depending on the presence of teeth. We concluded that the microstructure (especially the texture) of BAp crystallite changes in correlation with variations in stress distribution in vivo resulting from changes in chewing conditions designed to optimize the dynamic chewing function.

Background and Objective  The Projects of Global Growth of Medical Technologies, implemented by NCGM since 2015, have contributed to human resource development through on-site training in partner countries and training in Japan. However, since 2020, online training has become mainstream due to the travel restrictions by COVID-19 impact. As one of the projects, the NCGM and Bach Mai Hospital rehabilitation departments in Vietnam held an interactive online hands-on seminar in FY2022 for Vietnamese occupational therapists and others to provide technical guidance for making splint orthoses to rehabilitate patients with hand dysfunction. This paper aims to report on the preparation and implementation process of the seminar and its results.Preparation and Implementation of the Seminar  NCGM (the instructor) and Bach Mai Hospital (the site of the hands-on training) prepared the seminar through regular online meetings, fostering ownership and collaborative planning on the Vietnamese side, and discussed the program development, necessary materials, participant selection, and obtaining authorization from the Vietnamese Ministry of Health. To ensure the quality of the technical instruction, the seminar was connected via Zoom to both NCGM and Bach Mai Hospital, where the live video of the splinting technique was conducted, along with explanations and Q&A sessions. The post-training evaluation was carried out through a questionnaire with self-assessment of the participants about the knowledge and skills they obtained. Outcome and Discussion  As a result, 96% (27/28) of the participants answered that the seminar was “useful for clinical practice,” suggesting that the interactive online hands-on seminar regarding technical instruction in making splint orthosis was as good as or better than the face-to-face training. We found that the Vietnamese side took ownership from the preparatory stage by establishing a regular online meeting system; the quality of the training was assured by live video by both sides, which enabled detailed technical instruction; the training provider’s skills were improved by more detailed preparation; training was cost-effective compared to on-site training or training in Japan; and the materials used and the training videos can be used as teaching materials, which is expected local benefits and sustainability. These findings can be applied to face-to-face training to make the training more effective and extended as a useful method when similar activities are developed in other countries.