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The importance of considering bone quality during oral implant treatment is increasingly being recognized. Assessment of bone quality in response to changes in the jaw bone is extremely important when planning treatment. The present study analyzed biological apatite (BAp) crystallites, a bone quality factor, in order to investigate crystallographic anisotropy in dentate and edentulous human mandibles. Using mandibular samples from Japanese adult cadavers, a region of interest was established comprising cortical bone in the central incisors. Samples were classified into five morphological categories based on the extent of bone resorption. Bone mineral density (BMD) was measured and diffraction intensity ratios were calculated using a microbeam X-ray diffraction system. While no differences were observed in BMD, differences were observed in BAp crystallite alignment between the measurement points. In the alveolar region, samples with residual alveolar bone showed strong alignment in the occlusal direction, while samples with marked alveolar bone resorption had preferential alignment in the mesiodistal direction. The present findings suggest that tooth loss and the extent of alveolar bone resorption affects bone quality in the mandible. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B: 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 838-846, 2019.

Dental treatment improves the experience of eating by healing illnesses in the oral cavity or through the installation of special devices. However, mastication can often prove difficult for short periods of time after dental treatment, potentially limiting the types of food that can be consumed. Therefore, we proposed a highly nutritious meal strategy for dental outpatients (hereafter, "easy-to-eat meals"). We previously reported patients' subjective assessment of these easy-to-eat meals as determined through a questionnaire survey. The purpose of the present study was to investigate how differences in age affected such assessments. The study participants comprised patients scheduled to undergo dental treatment. They were divided into 2 groups: one of patients aged above and one of those aged below 70 years. All were required to consume provided easy-to-eat meals at the dental hospital directly after treatment and then answer a questionnaire. The questionnaire included items on patient satisfaction with the meals, taste, portion size, convenience, reduction in discomfort, and whether they would consume them again. The format of the questionnaire was a visual analog scale (VAS), ranging from 0 (negative) to 10 (positive). Portion size was to be rated on a scale from 0 ("Not enough") to 10 ("Too much"), with 5 being "Just right". Correlations between the questionnaire items were investigated to determine how they influenced each other. The VAS average for "Reduction in discomfort" was 8.45±1.39 in the non-elderly group and 6.07±2.92 in the elderly group, and the difference was significant (p=0.02); the VAS average for "Taste" was 6.49±2.32 in the non-elderly group and 4.91±0.98 in the elderly group, and the difference was significant (p=0.04). The results of this study suggest that providing such meal plans as nutritional guidance after dental treatment can influence quality of life in elderly patients.

Patients often experience temporary difficulty in masticating during the period immediately following dental treatment. The purpose of this study was to investigate subjectively assessed satisfaction with a specially designed diet for such patients by means of a questionnaire. These "easy-to-eat meals" were planned and provided by this hospital in Japan, and comprised a combination of commercially available and nutritionally rich soft foods, jellied foods, drinks, and other items. The patients were required to commence consuming them immediately following dental treatment. The questionnaire contained 6 categories -Satisfaction, Taste, Meal completion, Convenience, Reduction in discomfort, and Likelihood of reuse - to be evaluated on a 10-cm visual analog scale (VAS). The overall response was positive in all 41 completed questionnaires, with an overall score of 6 or higher for every category. Orthodontics achieved the highest VAS score in every category, followed by oral implantology, prosthodontics, and conservative Original Article doi:10.2209/tdcpublication.2018-0055 dentistry. A correlation was observed between Satisfaction and each of the 5 remaining questionnaire categories (Taste: |r|=0.70, p≤0.00; Meal completion: |r|=0.60, p≤0.00; Convenience: |r|=0.56, p≤0.00; Reduction in discomfort: |r|=0.48, p=0.00; and Likelihood of reuse: |r|=0.79, p≤0.00). An acceptable level of convenience was obtained with these meals, as they were reported to be useful during the period immediately following treatment, when eating out or preparing meals was physically and/or psychologically difficult.

Nakajima K., Matsunaga S., Morioka T., et al. Effects of unloading by tail suspension on biological apatite crystallite alignment in mouse femur. Dental Materials Journal 39, 670 (2020); https://doi.org/10.4012/dmj.2019-187., The aim of this study was clarify the effects of reducing various functional pressures essential for the maintenance of bone homeostasis. Femoral bone mineral density (BMD) and biological apatite (BAp) crystallite alignment were measured in conventionally reared and hindlimb-unloaded mice. The femur was divided into 10 equal segments perpendicular to the longitudinal axis of the bone and measurements were performed on the cortical bone in the five segments closest to the midpoint of the femur. Significantly lower BMD and BAp alignment in the longitudinal (Z-axis) direction were observed in the hindlimb-unloaded group. The present findings suggest that unloading by tail suspension significantly decreases not only mouse femoral bone mass but also BAp crystallite alignment, although minimal uniaxial preferential alignment is retained.

The importance of considering bone quality during oral implant treatment is increasingly being recognized. Assessment of bone quality in response to changes in the jaw bone is extremely important when planning treatment. The present study analyzed biological apatite (BAp) crystallites, a bone quality factor, in order to investigate crystallographic anisotropy in dentate and edentulous human mandibles. Using mandibular samples from Japanese adult cadavers, a region of interest was established comprising cortical bone in the central incisors. Samples were classified into five morphological categories based on the extent of bone resorption. Bone mineral density (BMD) was measured and diffraction intensity ratios were calculated using a microbeam X-ray diffraction system. While no differences were observed in BMD, differences were observed in BAp crystallite alignment between the measurement points. In the alveolar region, samples with residual alveolar bone showed strong alignment in the occlusal direction, while samples with marked alveolar bone resorption had preferential alignment in the mesiodistal direction. The present findings suggest that tooth loss and the extent of alveolar bone resorption affects bone quality in the mandible. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B: 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 838-846, 2019.

A working group established at Tokyo Dental College Suidobashi Hospital considered how to manage patients experiencing difficulties with food intake during the process of dental treatment. This resulted in the opening of an in-hospital booth dedicated to providing advice on such problems. A survey was performed to determine the number of patients utilizing this facility and the department which they were attending with the aim of investigating factors involved in eating-related problems. The results revealed that patients were being referred to the booth from the departments of dental prosthetics, conservative dentistry, oral and maxillofacial surgery (by both dentists and dietitians), oral implantation, and orthodontics. Patients were provided with information on the booth by their dentist or dietician, either by means of introductory materials or verbally. These patients were requested to complete a questionnaire, with informed consent, over a 2-year period. The participants were classified according to age and original dental problem on attending this hospital and the results analyzed. The inability to eat hard foodstuffs, difficulty in chewing, inability to open the mouth, insufficient nutrition, unbalanced nutrition, intraoral pain, and difficulty in swallowing were all identified as problems related to eating. A total of 1,948, 413 visitors had received introductory materials, while 156 had learned of the facility verbally. Looking at department as a factor, the inability to eat hard foodstuffs and difficulty chewing occupied a large percentage of the reported problems for all departments. Taken together, these results revealed that many patients experienced difficulties in eating during the process of treatment. This indicates that it is necessary to give the appropriate eating instructions to each patient according to their specific needs and stage of dental treatment.

The mandible is a unique bone with a two-layered structure comprising the alveolar area that holds the teeth and the base of the mandible. It is subjected to various types of mechanical stress. The mandible has a specialized structure enabling it to sustain localized stress exerted by the teeth. When teeth are lost, the alveolar area is quickly resorbed, and the internal structure of the mandible changes greatly. It is therefore imperative to quantitatively assess changes in the bone microarchitecture that occur with tooth loss. We therefore quantitatively assessed bone mineral density (BMD) and biological apatite (BAp) crystalline orientation in human edentulous mandibles and elucidated the structural characteristics of human edentulous mandibles. Japanese edentulous mandibles were divided into samples with a high and well-rounded alveolar area and thin cortical bone in the alveolar area (α-type), thick cortical bone (β-type), and those with a low and flat alveolar area (γ-type). BMD and BAp crystalline orientation were measured in the alveolar area and base of the mandible of the site corresponding to the first molar (the region of interest). Although BMD did not differ by site, comparisons of the different types revealed BMD to be high in the α-type and low in the βand γ-types. BAp crystalline orientation in the alveolar area was observed in the vertical direction to the virtual occlusal plane (Y-axis) and Buccalingual direction (Z­ axis) in the α-type, whereas weak preferential orientation in the mesiodistal direction (X-axis) was 2 observed in the βand γ-types. BAp crystals in the base of the mandible showed uniaxial preferential alignment along the X-axis in all three sample types (p < 0.05). High BMD values and orientation along the Yand Z-axes were observed in the alveolar area of α-type mandibles with an ultra-thin cortical bone, whereas preferential orientation along the X-axis was observed in the alveolar areas of the βand γ-type mandibles that have thick, morphologically stable cortical bone. Moreover, comparisons of BAp crystalline orientation in the X-axis directions in the alveolar area and base of the mandible revealed significantly lower values in the alveolar area. These findings demonstrate that a most part of the human edentulous mandible develops long bonelike characteristics with resorption of the alveolar area, and that orientation in the alveolar area varies with morphological changes in the alveolar bone.

The aim of this study was to quantitatively clarify the c-axis alignment of biological apatite (BAp) crystallites (hereafter referred to as BAp alignment) in the cortical bone of the human mandible first molar. Six mandible specimens were collected from the cadavers of six dentulous Japanese adults (mean age, 63.0 +/- 12.1 years) held at the Department of Anatomy, Tokyo Dental College. A microbeam x-ray diffraction system was used to determine BAp alignment in the mesiodistal direction. Bone mineral density (BMD) was also measured using 3-dimensional trabecular structure measurement software. The results showed that the degree of BAp alignment in the mesiodistal direction was low in the alveolar area and high at the base of the mandible, suggesting that BAp alignment in the alveolar area is affected by occlusal force. Moreover, it was observed that the correlation between BAp alignment and BMD was small, indicating that BAp alignment and BMD could be independent factors. Therefore, determining BAp alignment was important in the evaluation of bone quality, including bone strength.