Analysis of the Number and Content of X-ray Examinations in the Oral & Maxillofacial Radiology Department of Tokushima University Hospital over the Past 10 Years

徳島大学病院歯科放射線科における過去10年間のX線撮影件数・内容の分析


Effective use of an extraoral vacuum in preventing the dispersal of particulate matter from metal dental materials.

When dentists adjust prostheses at the dental chairside, particulate matter (PM) from the dental material is dispersed. Little is known about the effective use of an extraoral vacuum (EOV) in preventing PM dispersal. This study aimed to evaluate the effective use of an EOV in preventing the dispersal of metal PM in dental offices. The following experimental conditions were planned: the distance from the EOV to the metallic materials (50, 100, 150, and 200 mm), the horizontal angle between the long axis of the micromotor handpiece and EOV (0°, 45°, and 90°), and the operating time of the EOV (during grinding, during grinding and 1 min thereafter, during grinding and the preceding 1 min, 1 min before and after grinding, and during grinding). Carborundum and silicone points were used for grinding and PM dispersal. Diameters (0.3, 0.5, 1.0, and 3.0 μm) were measured using a laser particle counter. Depending on the instrument used to grind, there were undetectable PMs of different diameters (Carborundum point: 0.3 and 0.5 μm, Silicone point: 0.3 μm). PMNs were reduced as the distance from the EOV to metal materials decreased. Operating the EOV before grinding along the long axis of the micromotor handpiece was effective in reducing the PMNs. PMNs dispersed when grinding metals were effectively reduced by positioning the EOV closer to the grinding surface (within 150 mm) along the long axis of the micromotor handpiece and operating the EOV before grinding.


Development of a Low Radioactivity Detection System Using a Digital Intraoral Radiography Detector (Imaging Plate)

デジタル口内法X線撮影検出器(イメージングプレート)を応用した低放射能検出システムの開発


Changes in Image Examinations at the Department of Oral Radiology -The Number of Intraoral and Panoramic Radiographs-

歯科放射線科の撮影件数の推移 -口内法枚数と口外法件数-

After the computed radiography (CR) system was developed in 1986, it became possible to acquire, view and save digital images for medical diagnosis. Around that time, panoramic radiography was digitized by the CR system, but it was limited to large hospitals. From 1994, it has been digitized at large hospitals and dental clinics. We examined the changes in the number of intraoral and panoramic radiographs in dentistry, and based on the relationships among the numbers of radiographs, patients and dental operations, we discussed the clinical significance of digitization.
We extracted intraoral and panoramic radiography data, the number of dental operations and the number of patients from the database of Tokushima University Hospital from 2002 to 2017. Then, we extracted nationwide data from Statistics of Medical Care Activities in Public Health by the Ministry of Health, Labour and Welfare from 2002 to 2017.
As a result, although the numbers of patients and dental operations at Tokushima UniversityHospital have remained constant, the number of intraoral radiographs has decreased (72%), whereas the number of panoramic radiographs has increased annually since 2011 (131%). In addition, although the number of patients and nationwide insurance points increased in a different manner than that at Tokushima University Hospital, a decrease in the number of intraoral radiographs and an increase in the number of panoramic radiographs were noted across Japan. As panoramic imaging has been improved and adapted to different settings, panoramic radiography has been used instead of intraoral radiography, and it has been widely used in screening applications such as for perioperative patients. Although digitization is progressing, the analog images are still used (intraoral radiography analog rate, 29.7%, panoramic radiography analog rate, 12.4% in 2017).


咬合不全を伴った重度変形性顎関節症症例

咬合不全を伴った重度変形性顎関節症症例

Journal of the Japanese Society for the Temporomandibular Joint


Dental students' levels of understanding normal panoramic anatomy

In dentistry, panoramic radiography is an important examination technique. The Faculty of Dentistry at Tokushima University educates students about panoramic radiographic anatomical landmarks. The purpose of this study was to investigate differences in the understanding of each panoramic anatomical landmark among students. This study analyzed the results of 40 fifth- and 79 sixth-year faculty students who had taken a written examination to clarify their knowledge of anatomical landmarks in 28 panoramic radiographic regions. Anatomical landmarks were classified into 3 categories: <bone structure>, <soft tissue/air layer>, and <ghost images > to compare correct answer rates. The mean overall correct answer rate by the 119 students for the 28 regions was 53%. The rate did not vary between the 2 academic years. On comparison of the 3 categories, significant differences were only observed between <bone structure> and <soft tissue/air layer>, as the values for the latter were lower. Among the anatomical landmarks, the rates for the condylar head, hyoid bone, panoramic innominate line, styloid process, and nasopalatine line were higher, and those for ghost images of the contralateral nasopalatine line, the cervical vertebrae, mandibular foramen, mastoid air cell, and posterior pharyngeal wall were lower. The values for <soft tissue/air layer>, such as the dorsum of tongue, middle and inferior nasal conche, and middle and inferior nasal meatuses, were also lower. These results indicate the necessity of improving educational approaches for regions with lower rates of correct answers.


Posterior disc displacement of the temporomandibular joint -a rare case report

Posterior disc displacement (PDD) of the temporomandibular joint (TMJ) is quite rare. The normal position of a disc is slightly anterior to the condyle, so the chances of disc displacement to the posterior direction are low. A 71-year-old Japanese female reported with a chief complaint of lack of occlusion on the right-side molar teeth. Clinical examination revealed lack of occlusal contact in the right posterior region, nearly normal range of mouth opening (41.0 mm), masseter muscle tenderness, and deviation to the left on opening. MRI of the right TMJ showed PDD in both the open- and closed-mouth position and joint effusion. Conservative treatment with a non-steroidal anti-inflammatory drug, stretch exercise with fingers, and stabilization splint improved symptoms for 9 months. Conservative treatment was effective in managing the patient. A follow-up for 9 months with a repeat MRI was undertaken to monitor the progress.


Prevalence of posterior disc displacement of the temporomandibular joint in patients with temporomandibular disorders: a systematic review with meta-analysis

To assess the prevalence of posterior disc displacement (PDD) in patients with temporomandibular disorders (TMD) through a systematic review of the literature and meta-analysis, as well as to assess features associated with PDD such as chief complaint, signs and symptoms, morphologic condyle and disc alterations, and PDD management. A systematic literature search was performed in the US National Library of Medicine's PubMed/MEDLINE and Cochrane Library databases to identify all peer-reviewed, English-language manuscripts related to PDD. A critical appraisal checklist provided by the Joanna Briggs Institute for studies reporting prevalence data was used to assess the quality of the included manuscripts. A meta-analysis was conducted using software MetaXL 5.3 (EpiGear International Pty Ltd) add-in for Microsoft Excel. Pooled prevalence and 95% confidence intervals (CIs) were calculated using the software. Heterogeneity of the included studies was assessed using the Higgins I test and Cochran's Q (with P value; < .05 was considered significant). A total of 21 articles were selected for qualitative data synthesis: 2 case reports, 14 observational studies, and 5 studies that reported PDD in various conditions. Quantitative data analysis was performed for the 14 observational studies, of which 13 reported prevalence with respect to the number of joints affected and 9 reported prevalence with respect to the number of patients affected. The overall pooled prevalence of PDD for the number of joints affected was 0.7% (95% CI: 0.005 to 0.008). The pooled prevalence of PDD for the number of patients was 0.9% (95% CI: 0.007 to 0.011). PDD was found to be associated with osseous changes, including changes in the morphology of the condyle, disc, and articular eminence; osseous abnormalities (erosion, osteophytes); and joint effusion. This meta-analysis showed a very low prevalence rate of PDD in TMD patients. The limited literature did not allow conclusions to be drawn about the PDD-related features.

Journal of Oral & Facial Pain and Headache


Time-course observation of patients with arthrosis of the temporomandibular joint on MRI

Patients with arthrosis of the temporomandibular joint are examined by MRI, but fewer cases are followed over time by performing MRI several times. The objective of this study was to investigate the presence or absence and types of changes in the structure of the mandibular condyle and articular disc on MR images over time in patients examined by MRI for the diagnosis of arthritis of the temporomandibular joint in order to clarify the usefulness of performing MRI several times.
 MR images for patients who underwent MRI several times based on the clinical diagnosis of arthrosis of the temporomandibular joint were analyzed.
 Twenty-three patients were examined by MRI twice or more. The shortest and longest intervals between the first and final examinations were 75 and 2,588 days, respectively, and the mean was 735 days. Changes in the bone structure of the mandibular condyle were noted on the first MRI in approximately 63 % and new changes were noted on the final examination in approximately 24 %. In addition, the articular disc position in the closed or open mouth had changed on the later examinationin approximately 15 %.
 Performing MRI several times along the clinical course was found to be useful to diagnose the disease stage, judge the treatment effects, and help predict the outcome in patients with arthrosis of the temporomandibular joint.


Numerical Evaluation of Image Contrast for Thicker and Thinner Objects among Current Intraoral Digital Imaging Systems.

The purpose is to evaluate the performance of current intraoral digital detectors in detail using a precise phantom and new method. Two aluminum step wedges in 0.5 mm steps were exposed by two photostimulable phosphor plate (PSP) systems-one with automatic exposure compensation (AEC) and the other without AEC-and a CCD sensor. Images were obtained with 3 doses at 60 kV. The effect of metallic material also was evaluated. The contrast-to-noise ratio (CNR) for thinner steps and the low contrast value (LCV) for thicker steps were obtained. The CCD system was the best under all conditions (P < 0.001), although the Gray value was sensitive to the dose, and the Gray value-dose relation varied greatly. The PSP system with AEC was superior to that without AEC for the LCV (P < 0.001) but was inferior to it regarding the CNR (P < 0.001). CNR and LCV in the PSP system without AEC were not affected by the metallic plate. Intraoral digital imaging systems should be chosen according to their diagnostic purpose. PSP system with AEC may be the best for detecting molar proximal caries, whereas the PSP system without AEC may be better for evaluating small bone regeneration in periodontal disease. The CCD system provided the best performance.


Availability of Japanese Government's supplemental texts on radiation reflecting the Fukushima Daiichi Nuclear Power Plant accident for elementary and secondary education from dental students' understanding

Following the Fukushima Nuclear Power Plant accident, the Japanese government created two supplemental texts about radiation reflecting the accident for elementary, middle school, and high school students. These texts were made to explain radiation and consequently to obtain public consent for the continuation of the nuclear program. The present study aimed to evaluate the appropriateness of the content of the texts and to collect the basic data on the level of understanding necessary to improve radiation education. Lectures on radiology including nuclear energy and the Fukushima accident were given to 44 fourth-year dental students in 2013. The questionnaire was administered in 2014 when these students were in their sixth-year. The survey was also administered to 40 first-year students and 41 fourth-year students who hadn't any radiology lectures. Students rated their level of understanding of 50 phrases used in the texts on a four-point scale (understanding = 3, a little knowledge = 2, having heard = 1, no knowledge = 0). Questions on taking an advanced physics course in high school and means of learning about radiation in daily life were also asked. The level of understanding of phrases in the supplemental text for middle and high school students was significantly higher among sixth-year students (mean = 1.43) than among first-year (mean = 1.12) or fourth-year (mean = 0.93) students (p < 0.05). Overall, the level of understanding was low, with scores indicating that most students knew only a little. First-year students learning about radiation from television but four-year and six-year students learning about radiation from newspaper scored significantly higher (p < 0.05). It was concluded that radiation education should be improved by using visual material and preparing educators to teach the material for improving the public's understanding of radiation use-especially nuclear power generation because the phrases used in the supplementary texts are very difficult for students to understand.


Severe Posterior Open Bite by Posterior Folding of the Retrodiscal Tissue: A Case Report

IOSR Journal of Dental and Medical Sciences


Creation of a dental X-ray unit with a contactless exposure control switch

A new dental radiographic unit (DXRU) with a contactless switch for adjusting exposure conditions and a foot-pedal exposure switch was developed to prevent bacterial or viral contamination from patients and was compared with a conventional DXRU with a panel push-button switch with respect to user friendliness. 45 fourth-year dental school students carried out intraoral radiography using both types of DXRU. Errors regarding dose shortages of X-rays were compared and a questionnaire completed. 22 (49%) of the 45 students failed to provide the correct radiographic exposure and the number of errors was 32 for the conventional DXRU, and 4 (9%) students failed to provide the correct radiographic exposure and the number of errors was 4 for our new DXRU, at the first stage (p < 0.001). At the second stage, the number of students who failed to provide the correct radiographic exposure and the number of errors decreased to 12 and 16, respectively, for the conventional DXRU (p < 0.05). 37 (82%) of the 45 students preferred our DXRU because of its contactless switch and the push-pedal exposure switch. These data suggested that our new contactless mechanism should be used for other DXRUs for contamination control.


口内法X線画像のための新しいDICOMファントムの実用化

口内法X線画像のための新しいDICOMファントムの実用化


Distance Measurement Accuracy of a Digital CCD Sensor Cephalometric System Comparison with a Conventional-type Computed Radiography Photostimulable Phosphor Cephalometric System

CCDセンサー方式セファロシステムによる距離測定精度 ーCRシステムを用いた従来型セファロシステムとの比較ー


Correlation between Magnetic Resonance Image Evaluation and Clinical Findings in Patients with Temporomandibular Disorders

顎関節症患者におけるMR画像所見と臨床所見の比較検討


Sonographic Appearance of Mucus Cysts of the Lip

口唇部粘液嚢胞の超音波画像所見

The ultrasonographic features of 12 histologically proven mucus cysts in the lip were reported. All mucus cysts were of submucosal mass with a smooth border. Ten of 12 cysts contained an anechoic area. Among the 12, 11 had an adjacent hypoechoic zone with blood flow. There were reactive sclerotic or edematous changes outside the cyst wall, caused by the partial extravasation of saliva. This finding was exclusively observed in mucus cysts and would help in differential diagnosis, because most of the cysts with extravasation were difficult to distinguish from solid tumor by physical examination alone.


The Utility of Three Dimensional Ultrasonographic Imaging for Detecting the Cervical Lymph Node Metastasis with Oral Cancer

口腔癌頸部転移リンパ節の検出に対する超音波三次元イメージングの有用性

Three dimensional ultrasonographic imaging was performed for the cervical lymphadenopathy. Forty lymph nodes with suspicion of metastatic lymphadenopathy out of 20 patients with oral cancers were served for the present study. We could not judge the presence/absence of the metastasis by routine B mode or power Doppler imaging alone. Out of the 40 lymph nodes, 18 metastatic lymphadenopathies were proved histopathologically. Additionally, 11 lymph nodes out of 8 patients with nonspecific reactive lymphadenopathies were included as the control. The pattern of the circumferential blood flow of the lymph nodes was reviewed by the three-dimensional maximum intensity projection (3D MIP) view that was obtained from 3D power Doppler imaging. They were divided into 4 categories ; linear blood flow, mesh like blood flow, spotty blood flow and no circumferential flow. The spotty flow was almost exclusively found in the metastatic lymph nodes. Its accuracy, sensitivity and specificity, positive predictive value and negative predictive value for detecting metastatic lymphadenopathy were 0.73, 0.44, 0.95, 0.89, and 0.68, respectively. This spotty flow was situated at the marginal portion and/or around the lymph nodes by the analysis of the two-dimensional display. We could not differentiate whether it was arterial or venous flow. As the three dimensional sonographic imaging is the time-consuming technique compared to the routine B mode or power Doppler imaging, we cannot routinely perform it. However, it would play a supplementary role for detecting lymph node metastasis, especially if we cannot judge them by the two dimensional imaging alone.


Significance of Abdominal CT Examination for the Screening of Distant Metastasis of the Orofacial Malignancies

口腔顎顔面悪性腫瘍の遠隔転移評価における躯幹部CT検査の位置づけ

Abdominal CT examinations for the scouting of distant metastasis (DM) of orofacial malignant tumors were retrospectively evaluated, for the purpose of establishing the standard way of examination. Out of 159 patients with oral malignancies, 247 abdominal CT examinations were performed for the purpose of scouting DM. During the examination, intravenous contrast enhancement (CE) was performed in 166 examinations. DM were detected in 13 patients (8.2%). DM were found in 6 at administration, and 8 were late DM. Nine DM were detected out of 166 (5.4%) examinations with CE, and 5 were detected out of 81 (6.2%) examinations without CE. In detecting the DM, no improvement was found by CE. DM attacked lungs in 13, mediastinum in 3, liver in 2, paraaortic lymph nodes in 1, chest wall in 1, and vertebra in 1. Only 2 patients with DM were free from cervical metastasis, and the remainder was combined with cervical metastasis, regardless the status of the primary sites. Conclusions: Abdominal CT was useful for detecting DM. Intravenous CE was not necessary for scouting the DM. Patients with cervical metastasis had a high potential for developing DM.


An Investigation of Accidental Aspiration and Swallowing during the Dental Treatment at Tokushima University Hospital

徳島大学病院歯科診療部門における誤飲・誤嚥の実態調査

When an accident of aspiration or swallowing occurs during dental treatment, the patient would fall into severe clinical condition such as pneumonia, peritonitis, sepsis, and even death, unless a dentist immediately judges the patient's situation. As most dental material is radiopaque, radiography of a chest or an abdomen allows to see the accidental materials. From 1995 to 2002, 35 radiographic examinations were performed after the accidents at Tokushima University Dental Hospirtal. Mean of accidents was 4.4 cases a year. The incidence was 0.004% in the cumulative numbers of dental examinations. The location of accidental material on the radiography was clearly observed in 18 among 35 cases. Radiography of multiple times was performed 13 in 18 cases in order to confirm the excretion. In 5 cases, accidental materials were not confirmed to excrete. Furthermore, there were many cases in which clinical records about accidents were not described. Present findings indicate that it is necessary to detect precisely the location of accidental materials and that radiographic detection is very important.


スパイラルCTを用いた顎関節の三次元評価法

スパイラルCTを用いた顎関節の三次元評価法

Three-dimensional (3-D) image reconstructed from Computed Tomography (CT) data is an ef>cient method to evaluate temporomandibular joint (TMJ) morphologically. Even the 3-D image reconstructed from spiral CT data has some distortion, typically along to the table feed direction, very few studies were reported about accuracy of reconstructed 3-D image size. The purpose of this research was to evaluate the distortion on 3-D image reconstructed with spiral CT (Somatom Plas4, Siemens Co, Germany) quantitatively. We used three imaging targets, eight ceramic balls placed at corners of cubic frame, a calibration cube that has the CT value nearly equal to cortex bone of human dried mandibular head. We evaluated relation between a threshold level of CT image processing and reconstructed 3-D image size with a custom-made computer program. CT data of ceramic balls clari>ed changes of the reconstructed image, -0.215mm for table feed direction and less than ±0.006mm for the other directions. The calibration cube was used for the arrangement of optimal scanning condition (reconstruction mode, collimation, reconstitution interval) and evaluation of reconstructed image size. The distortion of the image was +0.207mm for table feed direction and less than +0.029mm for the other directions. Changes of dried skull TMJ image reconstructed with the optimal scanning condition were -1.463mm for lateral direction of the condylar head, -0.956mm for back and forth direction and -0.580mm for table feed direction. Results of this research suggested that the level of the 3-D image distortion was mostly affected with the scanning condition. And the size of 3-D image was susceptible to the threshold level of CT image processing. Consequently, we think that the standardization of scanning condition should be concerned for the quantitative evaluation of 3-D TMJ image using CT data.


Early Exposure in the Department of Oral and Maxillofacial Radiology --- -Analysis of Self-evaluation by Students-

歯科放射線科における早期体験実習 --- -学生自身による自己評価の分析-

The Journal of Japanese Dental Education Association

日本歯科医学教育学会雑誌


Postgraduate Clinical Training at the Department of Oral and Maxillofacial Radiology, University Dental Hospital, The University of Tokushima --- The Questionnaire Survey to the Junior Residents

本学歯学部附属病院歯科放射線科における卒後臨床研修 --- 研修医に対するアンケート調査

日本歯科医学教育学会雑誌


A Questionnaire Survey of Undergraduate Oral Radiology Education to Graduates

卒業生に対する歯科放射線学の卒前教育に関するアンケート調査

The Journal of Dental Education Association

日本歯科医学教育学会雑誌


新構想徳島大学医学部歯学部附属病院におけるHIS,RIS,PACS-モダリティ連携と歯科放射線科


Panoramic Radiography of the Temporomandibular Joint Part 5 --- A Study on Image Layer of Lateral Panoramic Temporomandibular Joint Projection

パノラマX線撮影装置を利用した顎関節撮影法 第五報 --- 顎関節側面パノラマ4分割撮影法における断層域の検討


Panoramic Radiography of theTemporomandibular Joint Part 4 --- Detectability of outline of the Temporomandibular Joint in Lateral Panoramic Temporomandibular Joint Projection

パノラマX線撮影装置を利用した顎関節撮影法 第四報 --- 顎関節側面パノラマ4分割撮影法における骨外形の出現度


パノラマX線写真による歯数の観察 --- 加齢と歯の喪失

パノラマX線写真による歯数の観察 --- 加齢と歯の喪失


The Position of the Condyle and the Disc in Temporomandibular Joint Dysfanction --- Comparison between Tomography and Magnetic Resonance Imaging

顎関節症患者の下顎頭位と円板位置 --- X線断層写真とMR画像の比較


パノラマX線画像の視覚評価に関する基礎的検討

パノラマX線画像の視覚評価に関する基礎的検討


Construction of Database about Report of Radiographic Examination of Temporomandibular Joint

顎関節X線検査報告書のデータベース化


日本人顎関節症患者のX線断層撮影による下顎頭の前頭面形態の分析

日本人顎関節症患者のX線断層撮影による下顎頭の前頭面形態の分析

Journal of the Japanese Society for the Temporomandibular Joint


Bone volume in human temporomandibular autopsy joints with and without erosive changes

The aim was to compare the trabecular bone volume (TBV) and the total bone volume (TOBV) of human temporomandibular joints (TMJ) with erosive changes with those of joints without erosive changes. We examined 35 TMJ autopsy specimens from 19 individuals aged 66 88 years. Sagittal sections of the joints were analyzed microscopically for erosive hard-tissue changes. The TBV and the TOBV of the sections were assessed with the aid of computerized image analysis. A significant increase in trabecular and total bone volume was found in condyles with erosive changes (TBV = 21%, TOBV = 54%) as compared with condyles without erosive changes (TBV = 15%, TOBV = 40%). The trabecular bone volume of the temporal component was also increased (TBV = 24%) in joints with erosive changes in the condyle as compared with joints with unaffected condyles (TBV = 16%). The findings indicate that the relative bone mass may play a role in the development of erosive changes in the TMJ.


Panoramic Rdiography of Temporomandibular joint. Part1: Measurements of the Intercondylar distance

パノラマX線撮影装置を利用した顎関節撮影法 第一報 下顎頭間距離について

To obtain a clear image of the temporomandibular joint (TMJ) on a rotational panoramic radiograph, the mandibular condyle should be in the image layer of panoramic equipment. The intercondylar distance in Japanese subjects was measured to identify the position of TMJ relative to the image layer. Submento-vertex radiographs from 848 patients suspected of having temporomandibular disorders (669 females; between 8 and 82 years, 179 males; between 9 and 79 years) were studied. The distance between the center points on long axes of the bilateral condyles was measured as an intercondylar distance. The measurement value was corrected by a magnification factor calculated from the inter-earplug distance on a radiograph and actual distance. The intercondylar distance showed normal distribution, and its mean value was found to be constant in the subjects with 20 years old or older, 101.1±4.7mm in femaless and 106.1±5.3mm in males. To derive a clear image of TMJ from the rotational panoramic radiography, the effective image layer distance between left and right TMJs should be adjustable to several values, for example, 101 and 106mm.


Bone histomorphometry using interactive image analysis --- A methodological study with application on the human temporomandibular joint

The aim was to develop a reproducible method for bone histomorphometry with the aid of a computerized image analysis program, and to examine the variation when assessing the total and the trabecular bone volume. Histologic sections of 18 temporomandibular joint autopsy specimens were read interactively using a cursor. The two parameters total bone volume and trabecular bone volume, of the condyle and the temporal component respectively, were estimated 2 x by 1 observer using 3 different threshold settings: an automatic, a semi-automatic and a manual technique. The threshold was based on the gray-scale distribution of the image. 2 observers read the same sections with the aid of the semi-automatic technique. The intra-observer variation expressed as coefficient of variation ranged between 1.9% and 7.1% for the different parameters, when the automatic threshold setting technique was employed, and between 2.8% and 8.7% with the semi-automatic technique. The manual technique resulted in a high intra-observer variation with a coefficient of variation between 5.2% and 19.9%. There was a systematic difference between the estimates of the 2 observers. In general, intra- and inter-observer variation was higher in the temporal component than in the condyle. The inter-section variation was moderate, the coefficient of variation ranging from 3.8% to 11.1%. The automatic and semi-automatic techniques resulted in comparable intra-observer variation, with a lower bias in the estimates of the semi-automatic technique. By letting one observer apply the semi-automatic technique, it was possible to achieve fast and reproducible analysis of the total and trabecular bone volume.


Panoramic radiography of the temporomandibular joint Part3:Detectability of osseous changes on autopsy mandibular condyles by two different projections in panoramic radiography

パノラマX線撮影装置を利用した顎関節撮影法 第三報 撮影方向の違いによる剖検下顎頭の骨形態異常出現率の比較

The detectability of osseous abnormalities of the mandibular condyle in two different projections using the panoramic x-ray unit was examined. Seventy two autopsy mandibular condyles with macroscopic osseous changes were selected. Corrected sagittal and frontal tomography and panoramic radiography were performed with the condyle in the tomographic layer. Panoramic radiography included two different projections, one at a horizontal angulation of 18° postero-medially from the frontal plane (lateral mode) and another 30° antero-medially (oblique mode). The vertical angulation of the x-ray tube was fixed upward 3° for the lateral and oblique projections. Radiographic concavity, osteophyte, sclerosis and erosion of the condyles were recorded. Sensitivity of the detection of these osseous abnormalities revealed by the two panoramic projections were calculated based on sagittal and frontal tomographic findings as a gold standard. Sensitivity of the detection of each abnormality revealed by lateral panoramic projections/oblique projections/combination of lateral and oblique projections were as follows. Concavity; 0.49/0.22/0.63, osteophyte; 0.69/0.38/0.69, erosion; 0.42/0.71/0.71, sclerosis; 0.46/0.38/0.50, total; 0.73/0.51/0.75. The oblique projection was essential for the detection of erosion, while the lateral projection for osteophyte. When panoramic radiography is employed as a scouting method for temporomandibular joint disease, two different projections are necessary to detect osseous abnormalities sensitively.


Concavity of the posterior surface of the temporomandibular condyle --- clinical cases and autopsy correlation

To elucidate the significance of the radiographic finding of a concavity of the posterior surface of the temporomandibular condyle. Three clinical cases with a concavity were followed up clinically and radiographically. A total of 39 temporomandibular joint (TMJ) autopsy specimens were examined by corrected sagittal tomography and seven condyles with a concavity of the posterior surface found. They were analysed microscopically together with three joints with a normal, rounded condyle. At follow-up tomography, two of the clinical cases revealed no change while the third patient had erosive changes after 7 months. The microscopic findings of the autopsy specimens varied. The articular cartilage in three of the seven joints with a concavity was similar to that in the normal condyles. The outer surface of the articular cartilage was sometimes uneven and the cartilage thickened, with an irregular junction between the articular cartilage and subchondral bone. In three joints the cartilage in the concavity had been replaced by granulation tissue. All seven joints had increased cellular activity in the concavity. The radiographic finding of a concavity in the posterior surface of the condyle is not specific. When small and well-defined it is indicative of remodelling and of osteoarthrosis when larger and with a diffuse outline.


Follow-up examination of the temporomandibular joint disk after splint therapy by magnetic resonance imaging --- a case report

The Journal of Craniomandibular Practice


顎関節症患者における下顎頭の経時的な骨形態変化に関する一考察

顎関節症患者における下顎頭の経時的な骨形態変化に関する一考察


放射線治療が影響したと考えられる開口障害を呈した一例

放射線治療が影響したと考えられる開口障害を呈した一例


顎関節のX線写真計測に関する研究 --- 顎関節多層断層像重ね合わせ法および精度に関する検討


外科的矯正手術患者の経時的観察 --- 手術後の下顎頭の形態変化と下顎頭の位置変化


機能に伴う顎関節骨形態の適合性変化 --- 下顎頭後面の陥凹について

機能に伴う顎関節骨形態の適合性変化 --- 下顎頭後面の陥凹について


顎関節症患者の経時的観察 --- X線検査の時期と下顎頭骨形態の変化

顎関節症患者の経時的観察 --- X線検査の時期と下顎頭骨形態の変化


回転方式パノラマX線写真上での上顎洞内液面形成像の分析

回転方式パノラマX線写真上での上顎洞内液面形成像の分析


The Development of the Dento^Maxillo-Facial Image Database and its Application to the Analysis of Dento-Maxillo-Facial Morphology

口腔領域画像データベースシステムの開発とその歯·顎·顔面形態計測分析への応用


顎関節症患者の経時的観察 X線検査の時期と下顎頭骨形態の変化

顎関節症患者の経時的観察 X線検査の時期と下顎頭骨形態の変化


A Radiological Study on the Adaptive Changes in the Functional Temporomandibular Joint


顎関節症患者における顎関節形態のX線学的研究 --- 予備的検討

顎関節症患者における顎関節形態のX線学的研究 --- 予備的検討


顎関節側面断層撮影の再現性

顎関節側面断層撮影の再現性


顎関節側面断層撮影法の規格化に関する試みとその精度

顎関節側面断層撮影法の規格化に関する試みとその精度


上顎洞根治術後の形態変化および術後性上顎嚢胞のX線学的観察

上顎洞根治術後の形態変化および術後性上顎嚢胞のX線学的観察


日本の歯科学生とインドネシアの歯科学生・歯科衛生士学生における放射線に対する理解度とリスク認識との関係


口内法X線画像用DICOMファイルの規格化および歯科用Viewerの実用化

口内法X線画像用DICOMファイルの規格化および歯科用Viewerの実用化


2種類のデジタル口内法イメージングシステムによるコントラストの比較

2種類のデジタル口内法イメージングシステムによるコントラストの比較


大学病院における労働安全衛生

大学病院における労働安全衛生

日本労働衛生研究協議会雑誌

日本労働衛生研究協議会雑誌


口内法X線撮影における感染予防対策

口内法X線撮影における感染予防対策

全国歯科大学・歯学部附属病院 診療放射線技師連絡協議会会誌

全国歯科大学・歯学部附属病院 診療放射線技師連絡協議会会誌


Accuracy of three-dimensional temporomandibular joint reconstruction using spiral CT

スパイラルCTを用いた顎関節の三次元構築精度(B2-8)

Journal of the Japanese Society for the Temporomandibular Joint