Prevalence of and risk factors for postoperative complications after lower third molar extraction : A multicenter prospective observational study in Japan

Lower third molar extraction is the most common surgical treatment among routine dental and oral surgical procedures. while the surgical procedures for lower third molar extraction are well established, the difficulty of tooth extraction and the frequency of postoperative complications differ depending on the patient’s background. To establish a management protocol for the lower third molars, the prevalence of and risk factors for postoperative complications after lower third molar extraction were investigated in a large number of Japanese patients in a multicenter prospective study. During 6 consecutive months in 2020, 1826 lower third molar extractions were performed at the 20 participating institutions. The medical records of the patients were reviewed, and relevant data were extracted. The prevalence of and risk factors for postoperative complications were analyzed. The prevalence of postoperative complications after lower third molar extraction was 10.0%. Multivariate analysis indicated that age (≤32 vs >32, odds ratio [OR]: 1.428, 95% confidence interval [95% CI]: 1.040–1.962, P < .05), the radiographic anatomical relationship between the tooth roots and mandibular canal (overlapping of the roots and canal vs no close anatomical relationship between the roots and the superior border of the canal, OR: 2.078, 95% CI: 1.333–3.238, P < .01; overlapping of the roots and canal vs roots impinging on the superior border of the canal, OR: 1.599, 95% CI: 1.050–2.435, P < .05), and impaction depth according to the Pell and Gregory classification (position C vs position A, OR: 3.7622, 95% CI: 2.079–6.310, P < .001; position C vs position B, OR: 2.574, 95% CI: 1.574–4.210, P < .001) are significant independent risk factors for postoperative complications after lower third molar extraction. These results suggested that higher age and a deeply impacted tooth might be significant independent risk factors for postoperative complications after lower third molar extraction

従業員が若年認知症と診断された場合の就労継続に対する事業所の意向

Objective: The purpose of the present study was to clarify and identify the factors related to the intentions of workplaces to retain employees diagnosed with young onset dementia (YOD). Methods: An anonymous self-administrated questionnaire survey was sent by mail to all １,２9３ workplaces with 50 or more employees in A Prefecture. In addition to providing demographic data for the workplace, employers were asked to answer freely about their intention of continuing to employ employees in the case of their being diagnosed with young onset dementia. Intention regarding continuous employment was analyzed qualitatively using encoded descriptive data. Results: Responses were received from ３5７ workplaces, and ２9２ valid responses were used for analysis. Workplaces intended to consider continuing employment for employees diagnosed with young onset dementia, with a view to offering continued non-discriminatory employment and staying legally compliant. In addition, while considering offering job accommodations and keeping their employees safe according to their abilities, there was also an intention on the part of the business establishment to demand meeting their obligations to customers such as assuring customer safety and satisfaction. In addition, they stated the need for a offering systematic support for workplace personnel and company departments, and wrote that they would consult with their attending physician / industrial physician to identifying dementia-related symptoms and to make decisions with regard to employment continuation and placement. Discussion: Workplaces should understand YOD at an Young stage. It is necessary to provide training and information to businesses so that they can consider continuation of employment

Seismic exploration at Fuji volcano with active sources : The outline of the experiment and the arrival time data

Fuji volcano (altitude 3,776m) is the largest basaltic stratovolcano in Japan. In late August and early September 2003, seismic exploration was conducted around Fuji volcano by the detonation of 500 kg charges of dynamite to investigate the seismic structure of that area. Seismographs with an eigenfrequency of 2 Hz were used for observation, positioned along a WSW-ENE line passing through the summit of the mountain. A total of 469 seismic stations were installed at intervals of 250-500 m. The data were stored in memory on-site using data loggers. The sampling interval was 4 ms. Charges were detonated at 5 points, one at each end of the observation line and 3 along its length. The first arrival times and the later-phase arrival times at each station for each detonation were recorded as data. P-wave velocities in the surface layer were estimated from the travel time curves near the explosion points, with results of 2.5 km/s obtained for the vicinity of Fuji volcano and 4.0 km5/s elsewhere

Research on the process of understanding in elementary school mathematics learning (X) : Focusing on fifth graders' conception of area

本研究は, 子どもが算数を学習していく際の理解過程を, 理論的・実証的に解明しようとするものである。数学的概念や原理・法則などを理解するということは, 本質的には, 個々の子どもの心的活動であり, それは複雑で力動的な過程である。他方, 教室で行われる算数の学習においては, その理解過程は子どもと教師, 子ども同士の社会的相互作用の影響を受けるものである。そこで, 本研究では, 算数学習における理解過程を, これら個人的側面と社会的側面の両面を視野に入れて解明しようとするものである。本年度は, 継続研究の10年目にあたり, 新しい教育課程の創造を視野に入れ, 理論的研究として算数教育における理解に関する文献研究を継続するとともに, 実証的研究として, 小学校第5学年の児童が「面積」の学習において, 自ら図形をつくりながら, その求積方法を創造していく過程で, 基準となる面積をどのように見ていくかという理解過程を実証的に解明したものである

Petrology and geochemistry of the Izu-Bonin Forearc tephras

Numerous marine tephra layers cored at Sites 792 and 793 in the Izu-Bonin forearc region offer additional information about the timing and spatial characteristics of arc volcanism and the evolution of island arcs. Explosive volcanism along the Izu-Bonin Arc, with maxima just before rifting of the arc at ~40 and 5-0 Ma, produced black and white tephras of variable grain sizes and chemical compositions. Most of the tephras belong chemically to low-K and low-alkali tholeiitic rock series with a few tephra of the high-K and alkalic rock series. Most of the tephras (low-K series) were derived from the Izu-Bonin Arc, although a few were produced far to the west of the Izu-Bonin Arc (e.g., from the Ryukyu Arc). Black tephras may have come from nearby sources, such as Aogashima, Sumisu, and Torishima islands. The high-K series of tephras, within the sediments younger than 3 Ma, may reflect thickening of the island-arc crust