Complications causing patients to discontinue using oral appliances for treatment of obstructive sleep apnea

Purpose: Oral appliances (OAs) are commonly used as a noninvasive treatment for obstructive sleep apnea syndrome (OSAS). These devices are worn during sleep and create mandibular anterior traction to enlarge the upper airway. Continuous use of the device is essential for the success of OA therapy, but some patients stop using the OA for various reasons. The purpose of this research was to investigate complications in OA therapy that might prevent continuous use of these devices. Methods: The progress of 90 OSAS patients who visited Tokushima University Hospital and underwent OA therapy was investigated with a mailed questionnaire. All patients had been receiving OA therapy for more than 12 months. Results: Forty patients responded to the questionnaire and of these, 22 were not wearing their OA during sleep. The average period before stopping OA therapy was 9.6 months. Answers from 38 patients who were treated with two-piece Herbst®-type oral appliances were analyzed. The main reasons for stopping OA therapy were: (1) it was bothersome to use; and (2) it did not effectively prevent sleep apnea. Comparison of OA complications between current OA users and nonusers revealed significant differences for the items ‘‘difficulty sleeping’’ and ‘‘stifling feeling’’. OA users recorded better scores for sleep quality than nonusers. Conclusions: The results of this study indicate that patients discontinued OA therapy because the appliance was ‘‘bothersome to use’’ and because it had ‘‘little or no effect’’ rather than because they experienced the typical complications of OA therapy

歯科インプラント周囲の骨吸収に関する臨床疫学研究

Background: During functional loading, the design of the dental implant may have an effect on the response of marginal bone. Objectives: The purpose of this study was to report the prevalence of peri-implantitis, and to compare radiographic parameters around Brånemark and Replace Select dental implants and evaluate whether disparities in the morphologic features of these two indistinct implant systems, particularly their abutment-implant attachment, had an influence on the health of surrounding tissues and marginal bone loss (MBL). Materials and Methods: Collection of data was done at the Department of Fixed Prosthodontics, the Department of Maxillo-Facial Prosthodontics, and Oral Implant Center of Tokushima University Hospital, in Tokushima, Japan; between March 2003 and followed until January 2017. Patients who have been treated with the Replace Select internal type implant and the Brånemark variety were selected as cohort. Marginal bone level measurements were evaluated via periapical and panoramic radiographs taken at regular follow-up visit. These dimensions were calculated, starting from the orientation mark at the implant abutment interface to the bottommost perceived contact area of marginal bone with the aforementioned implant system. The change in the level of bone was estimated by calculating the variation involving an initial reference value and the follow-up values. Results: An average loss of bone at 0.65 ± 1.51 mm (range 0.36 to 7.89 mm) in the Replace Select group was observed, while in the Brånemark group 0.7 ± 1.32 mm (range 0.62 to 8.64 mm) was observed. Spearman rank correlation exhibited a statistically significant positive correlation between progress of bone loss around implant body and interval from implantation in the Brånemark group, whereas in the Replace Select group it was not significant. The Brånemark group exhibited significant (P = 0.0269) negative correlation of MBL and its diameters, whereas the Replace Select group did not exhibit such correlation. Conclusion: Within the limits of this study, it can be concluded that deviations in the morphologic attributes of these two diverse implant systems had an influence on the health of surrounding tissues and MBL. The Brånemark implants showed a significant increase in MBL (> 1.8mm) as the time of placement elapses. This marked MBL was greater in females than males, in posterior than in anterior, and in the narrow platform implants than the regular platform implants or the wide platform implants. On the other hand, results suggested that this bone loss was greater in the mandible than the maxilla, in single-unit implant crowns than multiple implant restorations in the Replace Select group

Comparison between flipped classroom and team-based learning

Purpose: We previously investigated the effects of team-based learning (TBL) on fixed prosthodontic education and reported that TBL could have higher efficiency with high student satisfaction than traditional lecture. In the current report, we introduced flipped classroom to the fixed prosthodontic education and compared their effectiveness based on the final examination score in addition to TBL. Methods: Participants were forty-one students from XXXXXX University School of Dentistry who attended a fixed prosthodontics course. The first six classes adopted the flipped classroom style while the latter eight classes adopted TBL. To evaluate the relationship between learning styles and their effectiveness, we compared results from the term-end examination between the curriculum covered by flipped classroom and TBL-style classes. To draw comparisons, a referential examination with the same questions was conducted to eight faculty members who had not attended any of these classes. Results: Term-end examination results showed that TBL classes had slightly higher scores than flipped classroom classes. Referential examination results also showed higher scores for the same curriculum and no significant interaction was found between class formats and the term-end and referential examination scores. Analysis revealed no noticeable difference in the effectiveness of the class formats. Conclusion: Our previous study reported that TBL had higher efficiency than traditional style lecture. In the current study, there was no statistical difference in the examination score between flipped classroom and TBL. Therefore, we conclude that both styles are highly effective than traditional style lecture and constitute valid formats for clinical dental education

Validity of Peer Evaluation for Team-Based Learning in a Dental School in Japan

The aim of this study was to determine the validity of peer evaluation for team-based learning (TBL) classes in dental education in comparison with the term-end examination records and TBL class scores. Examination and TBL class records of 256 third- and fourth-year dental students in six fixed prosthodontics courses from 2013 to 2015 in one dental school in Japan were investigated. Results of the term-end examination during those courses, individual readiness assurance test (IRAT), group readiness assurance test (GRAT), group assignment projects (GAP), and peer evaluation of group members in TBL classes were collected. Significant positive correlations were found between all combinations of peer evaluation, IRAT, and term-end examination. Individual scores also showed a positive correlation with group score (total of GRAT and GAP). From the investigation of the correlations in the six courses, significant positive correlations between peer evaluation and individual score were found in four of the six courses. In this study, peer evaluation seemed to be a valid index for learning performance in TBL classes. To verify the effectiveness of peer evaluation, all students have to realize the significance of scoring the team member’s performance. Clear criteria and detailed instruction for appropriate evaluation are also required

Current status of space gravitational wave antenna DECIGO and B-DECIGO

Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could be produced during the inflationary period right after the birth of the universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in the heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry-Perot Michelson interferometers with an arm length of 1,000 km. Three clusters of DECIGO will be placed far from each other, and the fourth cluster will be placed in the same position as one of the three clusters to obtain the correlation signals for the detection of the primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder of DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand the multi-messenger astronomy.Comment: 10 pages, 3 figure

Current status of space gravitational wave antenna DECIGO and B-DECIGO

The Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could have been produced during the inflationary period right after the birth of the Universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the Universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry–Pérot Michelson interferometers with an arm length of 1000 km. Three DECIGO clusters will be placed far from each other, and the fourth will be placed in the same position as one of the other three to obtain correlation signals for the detection of primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder for DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand multi-messenger astronomy

Comparison between Flipped Classroom and Team-based Learning

Active learning is a concept that allows students to study and learn actively by themselves to get knowledge. There are several methods of active learning, including flipped classroom (FC) and team-based learning (TBL). In FC, students are required to study before classes. In TBL, students also study before class, take individual readiness assurance test (iRAT) and team readiness assurance test (tRAT), then discuss group assignment projects (GAPs) during class. The purpose of this study was to compare the effectiveness between FC and TBL. The effectiveness of FC and TBL was assessed from the results of the term-end examinations, questionnaires and practice examinations. To check the difficulty of the term-end examinations, control dentists took the same examinations and we calculated the equating score with item response theory. Statistical analysis showed that the correct answer rate in term-end examinations was significantly different in comparison with the time of the trial, and for the participants (students and dentists). The term-end examination score of FC and TBL did not show a statistical difference. The student questionnaire showed that TBL had higher scores than FC on various factors such as student positive attitude, preparation, ingenuity of teacher and achieving the class goals. The crown & bridge score from the practice examination of 6th-year students who had FC + TBL were constantly higher than the Japanese national average score. The identification index of FC and TBL did not show the statistical difference and there was no statistical difference on item response theory between FC and TBL

Prefrontal Hemodynamic Changes Associated with Subjective Sense of Occlusal Discomfort

We used functional near-infrared spectroscopy to measure prefrontal brain activity accompanying the physical sensation of oral discomfort that arose when healthy young-adult volunteers performed a grinding motion with mild occlusal elevation (96 μm). We simultaneously evaluated various forms of occlusal discomfort using the visual analogue scale (VAS) and hemodynamic responses to identify the specific prefrontal activity that occurs with increased occlusal discomfort. The Oxy-Hb responses of selected channels in the bilateral frontopolar and dorsolateral prefrontal cortices increased in participants who reported increased severity of occlusal discomfort, while they decreased in those who reported no change or decreased occlusal discomfort during grinding. Moreover, the cumulative values of Oxy-Hb response in some of these channels were statistically significant predictive factors for the VAS scores. A generalized linear model analysis of Oxy-Hb signals in a group of participants who reported increased discomfort further indicated significant cerebral activation in the right frontopolar and dorsolateral prefrontal cortices that overlapped with the results of correlation analyses. Our results suggest that the increased hemodynamic responses in the prefrontal area reflect the top-down control of attention and/or self-regulation against the uncomfortable somatosensory input, which could be a possible marker to detect the subjective sense of occlusal discomfort

Quality of Life and Job Satisfaction among Female Dentists in Japan

Background: In the current social scene of Japan, there has been a steady growth of female dentists. Nevertheless, studies that delve into the female Japanese perceptions have been scarce. Objectives: The purpose of this study was to determine the quality of life (QoL) and evaluate the factors affecting job satisfaction of female dentists in Japan. Materials and Methods: Via a researcher-made questionnaire, a cross-sectional survey was done on a total of 156 Japanese female dentists. Results: As per the outcome, 80.8% agreed that they have attained satisfaction with their QoL, while 30.8% strongly agreed. The job satisfaction factors were then listed in descending order of statistical significance as ownership type, having children, pursue PhD, marital status, and annual income. Multivariable logistic regression analysis showed significance in the participants' responses pertaining to ownership type (OR = 2.833, p = 0.013) and the pursuance of a post-graduate course immediately after attaining undergraduate education (OR = 0.425, p = 0.046). Conclusion: Findings suggest that majority of the female dentists in Japan perceive to have attained satisfaction in their QoL. Actual ownership type and immediate pursuance of a post-graduate course were found to be the significant factors related to job satisfaction. This implies that Japanese universities and dental colleges should focus on promoting immediate post-graduate opportunities for female dental graduates