日本人skeleatl I, skeletal III症例の歯列弓と顎顔面頭蓋における形態学的関係に関する研究

Available studies about differences among races, related to prevalence of malocclusion or morphology of head and dental arches, suggest a hypothesis that the high prevalence of skeletal Class III malocclusion in Asian ancestry populations could be correlated with a tendency toward a brachycephalic head form and larger arches widths. The purpose of the present study was to evaluate anteroposterior relationship of upper and lower jaws associated to form of dental arches, maxilla, mandible, face and head. Materials in this research consisted of pretreatment lateral and posteroanterior cephalometric radiographs and orthodontic models of Japanese females with skeletal Class I and Class III. Strong correlations between head form and jaws anteroposterior relationship could not be found. However, results indicated that skeletal Class III have statistically significant smaller length of maxilla and greater length of mandible, than the skeletal Class I group. Moreover, basal arch length and width of mandible were significantly bigger in skeletal Class III group. These results suggest that skeletal Class III, at least in this sample, might be associated to local malformation factors

WIDGET: System Performance and GRB Prompt Optical Observations

The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRBs). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62 degree x 62 degree every 10 secounds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. The unfiltered magnitude is well converted to the SDSS r' system at a 0.1 mag level. Since 2004, WIDGET has made a total of ten simultaneous and one pre-trigger GRB observations. The efficiency of synchronized observation with HETE-2 is four times better than that of Swift. There has been no bright optical emission similar to that from GRB 080319B. The statistical analysis implies that GRB080319B is a rare event. This paper summarizes the design and operation of the WIDGET system and the simultaneous GRB observations obtained with this instrument.Comment: 19 pages, 11 figures, Accepted to appear in PAS

セファロX線規格写真を用いた日本人小児頭蓋骨の性別判定

Facial reconstruction is a technique that allows human skeletal remains to be used to build a facial image of the target individual during life. This technique is based on databases of facial soft tissue thickness. However, application of this technique is facilitated by accurate information such as age, sex and ancestry. Little information is available from the skull alone for building face reconstructions, particularly for skulls from juveniles. This study estimated sex differences from the cranial bases of juvenile skulls and observed significant differences between male and female in the S-N plane for Japanese children at 6-to 18-years-old

Difference in treatment outcome of British and Japanese surgical class III patients associated with mandibular setback

The purpose of this clinical research was to examine the racial differences in skeletal morphology of skeletal Class III abnormalities and in the ortho-surgical treatment outcome of Class III malocclusion associated with mandibular setback sagittal osteotomy between Japanese and British Caucasian female adult Class III patients. The sample consisted of 35 Class III Japanese female surgical subjects in MDU Hospital and 30 Class III British subjects (23 female and 7 male). The operative procedure was solely a backward sliding sagittal split osteotomy with a wire fixation. True skeletal open bite cases associated with high mandibular plane angle were excluded. The original skeletal differences in Japanese and British Caucasian Class III subjects showed a significant difference in the length of the anterior cranial base (S-N) (p<0.001). The Japanese Class III subjects showed a significant difference in the parameters of U 1-UR and L 1-LR to palatal plane and Go-Me to palatal plane (p<0.001), and in the axis of maxillary incisor to S-N (p<0.01) and S-N-L 1 (p<0.05). At post-retention (1 year after op.), Go-Me to ANS-PNS and the length of Go to the palatal plane and Ar-Go (ramus height) related to the vertical position of point Go showed a larger difference (from p<0.05, 0.01 to 0.001). The Japanese surgical cases showed a more vertical problem with the increased mandibular plane angle compared to the British Caucasians

A study on curriculum development for indirect proof: understanding and constructing the process of proof by contradiction

本研究の目的は，間接証明に関するカリキュラムの開発である。その狙いは，十分に理解されていないと考えられる間接証明をよりよく学ぶと共に，学びの過程を通して論理を扱う能力を育むことである。本稿においては，その基礎として，間接証明を学ぶ過程を明らかにすることを目的とした。ただし，間接証明が何かという統一見解は見られないため，今回は背理法に限定して考察した。 目的のため，まず背理法に関する知識を分析し，特に数学史を参照しながら，背理法を構成することが期待される学習を設計した（アプリオリ分析）。高等学校1年生に授業を実施した結果，生徒の実態を十分想定出来ていなかったことから，学習自体は十分に成功しなかった。しかしながら，背理法に関する知識の分析それ自体については，かなりの部分が妥当であることは示された。本時の課題を元に，改善した学習を実施することで，知識の分析の妥当性や限界を明らかにし，カリキュラム開発に繋げることが今後の課題である。The purpose of our study is to develop a curriculum of indirect proof. It aims to increase students’ understanding about indirect proof, and to improve their ability to use logic. Furthermore, we aim to construct a process of indirect proof, as the base of the curriculum. However, as there is no consensus regarding the definition of indirect proof, we only consider proof by contradiction. For this purpose, we designed a lesson in which students will probably be knowing indirect proof and then construct a process of the proof based on their conception (a priori analysis). We conducted the lesson in a 10th grade mathematics class. However, the lesson was not as successful as expected because we overestimated the students’ actual level of cognition. In contrast, most of our analysis of the knowledge is validated. Our future task is to design an improved lesson to deliver to students. We would also need to clarify the validation and limitations of our analysis

Improving Mathematics Lesson and Evaluation through Setting Inquiry Problem-Solving Activities

The purpose of this research is to make a theoretical framework for improving mathematics lesson and evaluation through setting inquiry problem-solving activities effectively in junior high and senior high mathematics lessons. To achieve this, we first carried out a questionnaire survey to capture how students perceive learning mathematics and, based on the results, made a framework incorporated these activities for lesson design and evaluation of student’s learning. Then, sample lesson conducted in a junior and senior high school based on the framework was analyzed to investigate its effectiveness and get some practical suggestions

Clinical statistical study of patients with jaw deformity in the Department of Orthodontics, Matsumoto Dental University Hospital

Clinical and statistical analyses were conducred of patients with jaw deformity who visited the Department of orthodontics, Matsumoto Dental University hospital. One hundred and two patients with jaw deformity were treated in the department from January 2003 to December 2012. (1) The total number of patients was 102; the male–female ratio was 1: 1.32. (2) Mandibular protrusion was the most frequent diagnosis, with 35 cases (34.3％), followed by mandibular protrusion + maxillary retrusion (16 cases, 15.7％), and mandibular protrusion + asymmetry (15 cases, 14.7％). (3) As for the tooth extraction sites for presurgical orthodontic treatment, although non–tooth extraction was the highest from 2003 to 200₇, maxillary first premolar tooth extraction was the highest from 2008 to 2012. (4) Sagittal split ramus osteotomy (SSRO) was the most commonly performed procedure (5₇.8％), followed by Le Fort I + SSRO (36.3％). Le Fort I + SSRO showed an increasing tendency

歯科用CTを用いた解剖学的下顎頭運動の多点解析

The aim of this study was to develop a method for integrating morphological coordinates obtained with dental computer tomography (CT) and jaw movement coordinates acquired with a mandibular movement measuring device in order to enable multipoint analysis of anatomical condylar movements to be performed. The study subjects were two volunteers. One of the subjects displayed mandibular deviation and had a deformed condyle (on the deviated side), while the other subject exhibited normal occlusion and had healthy condyles. We placed three lead markers in front of each of the subjectsʼ ears and used them to integrate dental CT–derived morphological volume data and jaw movement data, both of which were obtained while the subjects were in the same seated position. Regarding the reproducibility of the reference point data, the positioning and orientation data obtained with the condylar movement measurement system exhibited maximum standard deviation values of 0.162 mm and 0.0₇4°, respectively, while the equivalent data acquired with the CT coordinate system displayed maximum standard deviation values of 0.068 mm and 0.00₇°, respectively. This suggested that reference point errors had little effect on our multipoint analysis of anatomical condylar movement and that the method used to transform the CT coordinates was highly precise. These results indicate that our method for integrating dental CT–derived coordinates with those acquired using a condylar movement measuring device leads to minimal errors in the positional/rotational data for the reference markers and hence, facilitates multipoint analyses of anatomical condylar movement