Analysis of the sublingual artery using contrast-enhanced computed tomography

This in vivo study aimed to clarify the position of the sublingual artery (SLA) relative to the mandibular bone and to infer the potential risk for injury during dental implant surgery. Contrast-enhanced computed tomography images of the mouth of 50 edentulous patients (100 sides) treated at Tokushima University Hospital were reviewed. Curved planar reconstructed images perpendicular to the alveolar ridge were processed and classified into molar, premolar, canine, and incisor regions. The SLA and its branches were identified, and the distance from the mandible to the SLA was measured. The SLA was located close to the mandible (<2 mm) in the molar, premolar, canine, and incisor segments in 12.0% (95% confidence interval 5.6%-18.4%), 20.6% (12.6%-28.7%), 30.5% (21.3%-39.8%), and 41.8% (28.8%-54.9%) cases, respectively. The SLA was located within ±3 mm craniocaudally to the upper wall of the mandibular canal in the molar and premolar regions in 50% of cases and within ±5 mm craniocaudally to the mylohyoid ridge in the canine and incisor regions in the other cases, with no sex or age-related differences. The vertical distance from the alveolar ridge to the SLA was influenced by sex and age owing to alveolar resorption, indicating that the alveolar ridge is not a reliable reference for predicting SLA position. As the risk of SLA injury always exist during dental implant placement and there is no way to confirm the SLA pathways in a patient, clinicians must avoid injuring the sublingual soft tissue.

Clinical Implant Dentistry and Related Research


Computed tomography-based morphological analysis for intraoral vertical ramus osteotomy in patients with mandibular prognathism


Radiomics analysis of [18F]-fluoro-2-deoxyglucose positron emission tomography for the prediction of cervical lymph node metastasis in tongue squamous cell carcinoma

This study aimed to create a predictive model for cervical lymph node metastasis (CLNM) in patients with tongue squamous cell carcinoma (SCC) based on radiomics features detected by [F]-fluoro-2-deoxyglucose (F-FDG) positron emission tomography (PET). A total of 40 patients with tongue SCC who underwent F-FDG PET imaging during their first medical examination were enrolled. During the follow-up period (mean 28 months), 20 patients had CLNM, including six with late CLNM, whereas the remaining 20 patients did not have CLNM. Radiomics features were extracted from F-FDG PET images of all patients irrespective of metal artifact, and clinicopathological factors were obtained from the medical records. Late CLNM was defined as the CLNM that occurred after major treatment. The least absolute shrinkage and selection operator (LASSO) model was used for radiomics feature selection and sequential data fitting. The receiver operating characteristic curve analysis was used to assess the predictive performance of the F-FDG PET-based model and clinicopathological factors model (CFM) for CLNM. Six radiomics features were selected from LASSO analysis. The average values of the area under the curve (AUC), accuracy, sensitivity, and specificity of radiomics analysis for predicting CLNM from F-FDG PET images were 0.79, 0.68, 0.65, and 0.70, respectively. In contrast, those of the CFM were 0.54, 0.60, 0.60, and 0.60, respectively. The F-FDG PET-based model showed significantly higher AUC than that of the CFM. The F-FDG PET-based model has better potential for diagnosing CLNM and predicting late CLNM in patients with tongue SCC than the CFM.


Evaluation of anatomical references for locating the course of the posterior superior alveolar artery for dental implant surgery

This retrospective cohort study aimed to identify the best anatomical reference for predicting the posterior superior alveolar artery (PSAA) location. Computed tomographic images of 90 maxillary sinuses were evaluated. We studied five references, including the alveolar crest, maxillary sinus floor, zygomatoalveolar crest, hard palate and soft palate, and measured the distances between them and the PSAA. Variations in the distance were evaluated by the standard deviation and coefficient of variation (CV). The zygomatoalveolar crest was an unstable reference, owing to its high standard deviation and CV. The smallest CV was for the distance between the alveolar crest and PSAA, although the distance was smaller in edentulous jaws than dentulous jaws. The distance between the sinus floor and PSAA was larger in male and edentulous patients. The PSAA was detected in 40.0%, 44.4%, 54.4% and 56.7% of the sinus walls at the first and second premolar and the first and second molar positions, respectively. At these tooth positions, the respective heights above the hard palate were 11.2 ± 4.9, 8.2 ± 4.9, 6.2 ± 2.8 and 8.1 ± 2.9 mm. The hard palate was the most stable reference for predicting the location of the PSAA, irrespective of sex, age and dentition.

International Journal of Oral and Maxillofacial Surgery


強度変調放射線治療に伴う放射線性顎骨壊死の頻度と危険因子の検討

強度変調放射線治療に伴う放射線性顎骨壊死の頻度と危険因子の検討


Radiopacities in Periapical and Panoramic Radiographs

-白いものが写っていますが，何でしょうか?- デンタルやパノラマ写真の不透過像


Prevalence and imaging characteristics of nasopharyngeal and eustachian tube tonsilloliths in 2244 patients determined using computed tomography

Nasopharyngeal tonsilloliths (NT) and eustachian tube tonsilloliths (ET) are not as well-known to radiologists as palatine and lingual tonsilloliths. The aim of this investigation was to determine the prevalence and imaging characteristics of NT and ET using CT and panoramic radiographs. We retrospectively assessed the scans of 2244 patients who underwent consecutive CT and panoramic radiographs of the maxillofacial region. The prevalence, size, number, and position of NT and ET were analysed. NT and ET were detected in 14 (0.6%) and 6 (0.3%) of 2244 patients on CT, respectively, but they were undetectable on panoramic radiographs. No significant difference was found in the prevalence with respect to sex. Although there was also no significant difference in the prevalence among age groups, tonsilloliths were most commonly noted in patients over 40 years old; they appeared as small and round calcified bodies, ranging from 1 to 3 mm in diameter. All NT were found 0 to 3 mm beneath the nasopharyngeal mucosal surface. The prevalence of NT and ET on CT was lower than that of palatine and lingual tonsilloliths. However, since they are encountered more frequently than clinically significant calcifying diseases such as retropharyngeal calcific tendinitis, clinicians should be able to correctly diagnose NT and ET based on their anatomical features.


Lingual tonsillolith: prevalence and imaging characteristics evaluated on 2244 pairs of panoramic radiographs and CT images

Lingual tonsilloliths are not as well-known to radiologists than palatine tonsilloliths, although they might be common in clinical practice. The aim of this investigation was to clarify the prevalence and imaging characteristics of lingual tonsilloliths using panoramic radiographs and CT images. This study included 2244 patients without pathology at the base of tongue who had undergone panoramic radiography and CT of the maxillofacial region. The size, number and position of lingual tonsilloliths relative to the mandible and tongue were evaluated. Lingual tonsilloliths were observed in 33 (1.5%) and 108 (4.8%) of all patients on panoramic radiographs and CT images, respectively. The prevalence was higher in patients aged ≥40 years than in those aged < 40 years (χ, p < 0.01). They appeared as small, round- or rod-shaped calcified bodies, and they always located closely anterior (1-17 mm) to the anterior border of oropharyngeal airway on panoramic radiographs. Lingual tonsilloliths were superimposed over the surrounding soft tissue inferior to the body of the mandible, posteroinferior to the angle of the mandible and posterior to the mandible in 16 (48.5%), 15 (45.5%) and 1 (3.0%) individual, respectively. A significant correlation was observed between the detectability on panoramic radiographs and size (Spearman's r = 0.961, p < 0.01) of tonsilloliths, as revealed by CT images. Lingual tonsilloliths commonly appear on CT. They also appear on panoramic radiography and may superimpose the surrounding soft tissue of the mandible. Although lingual tonsilloliths may resemble other pathological calcifications including submandibular sialoliths and lingual osseous cholistoma, they can be differentiated by carefully observing panoramic radiographs. When clinicians detect calcified bodies near the base of tongue, lingual tonsilloliths should be included in the differential diagnoses.


徳島県における口腔がん検診の現状

徳島県における口腔がん検診の現状

日本歯科人間ドック学会誌

日本歯科人間ドック学会誌


Prevalence and imaging characteristics of palatine tonsilloliths evaluated on 2244 pairs of panoramic radiographs and CT images.

Palatine tonsilloliths incidentally detected on diagnostic imaging should be differentiated from pathologic calcifications to enable correct diagnosis and treatment. The aim of this study is to clarify the prevalence and imaging characteristics of palatine tonsilloliths on panoramic radiographs. We retrospectively reviewed 2244 individuals who underwent pairs of consecutive panoramic radiography and computed tomography (CT) of the head and neck region. The imaging characteristics of palatine tonsilloliths on panoramic radiography were compared with the findings from CT, which was considered the gold standard. Tonsilloliths were detected in 300 (13.4 %) and 914 (40.7 %) of the 2244 individuals on panoramic radiographs and CT, respectively. On panoramic radiographs, tonsilloliths were superimposed over the ramus of the mandible at the level coincident with and inferior to the soft palate in 176 (7.8 %) and 90 (4.0 %) individuals, respectively. Tonsilloliths were also superimposed over the surrounding soft tissue inferior to the body of the mandible, postero-inferior to the angle of the mandible, and posterior to the ramus of the mandible in 33 (1.5 %), 26 (1.2 %), and 28 (1.3 %) individuals, respectively. A significant correlation was observed between the detectability on panoramic radiographs and the size (Spearman r = 1.000) and number (Spearman r = 0.991) of tonsilloliths, as revealed by CT images. The present results suggest that tonsilloliths are commonly detected on panoramic radiographs. Furthermore, they can be superimposed on both the mandible and the surrounding soft tissue. Clinicians should include tonsilloliths among the differential diagnoses when calcified bodies are detected on panoramic radiographs.


口腔がん患者の歯科疾患罹患状況

口腔がん患者の歯科疾患罹患状況

日本歯科人間ドック学会誌

日本歯科人間ドック学会誌


Intraoral Ultrasonography of Tongue Mass Lesions

To demonstrate the usefulness of intraoral ultrasonography (IOUS) for tongue mass lesions, we analyzed surgery cases excluding squamous-cell carcinoma and leukoplakia and compared IOUS and pathological findings. We used the hospital information system and Radiology Information System to evaluate the IOUS and pathological findings of patients who underwent surgeries for tongue masses in the past 11 years. Surgeries for the tongues were performed in 268 cases. Imaging examinations were carried out in 52 (19.4%) cases including 42 (15.7%) cases by IOUS. The pathological results of the surgeries were as follows: 36 cases were inflammatory lesions, 74 cases were tumours, 131 cases were hyperplasia, 8 cases were cystic lesions and 19 cases were other miscellaneous lesions. On the other hand, the number of patients who received IOUS in the same period was 87, and 42 of them had surgeries. In 32 out of the 42 (76.2%) cases, pre-operative IOUS features matched with pathological results. Most of the haemangiomas and lipomas could be diagnosed by IOUS alone. IOUS of the tongue revealed the nature of the lesions including the border, size, location, depth, the presence or absence of a capsule and the internal structure including vascularity of the mass. The ultrasonographic findings well reflected the histological findings. IOUS is a simple and useful technique that provides additional information beyond inspection, clarifying the internal structure, blood flow and relationships with the adjacent tissues. In this article, we indicated 11 representative cases (fibrous polyp, haemangioma, pyogenic granuloma, lipoma, liposarcoma, chondroma, lymphangioma, schwannoma, neurofibroma, pleomorphic adenoma and amyloidosis) to show the usefulness of IOUS.


Swallowing sound waveform and its clinical significance: Evaluation using ultrasonography

Background: Cervical auscultation is a technique frequently used for the screening of dysphagia. However, this method is difficult to evaluate objectively and it is unclear how sound is generated during the swallowing process. The aim of this study was to analyze the waveform of swallowing sound and clarify the sound production process using recordings of swallowing sounds and ultrasound images (USI), performed simultaneously.Materials and Methods: Commercial natural spring water and natural carbonated water were used in experiments 1 and 2, respectively. In experiment 1, a microphone was attached to the skin of the neck of 20 young participants and swallowing sounds were recorded and analyzed. In experiment 2, swallowing processes in three participants were recorded by a medical ultrasonography apparatus. The ultrasonic probe was placed on the skin over one of the thyroid cartilages or the thyroid gland.Results: The swallowing sound wave (SSW) was divided into three sectional periods. The mean duration of the first, second, and third SSW was 210 ± 147 ms, 458 ± 113 ms, and 91 ± 61 ms, respectively. The mean intensity ratio of the first, second, and third SSW was 7.8 ± 5.2, 29.2 ± 16.5,and 5.8 ± 5.1, respectively. When the ultrasonic probe was placed on the skin over one of the thyroid cartilages, in the phase between the production of the second SSW and the silent period, the USI revealed an accumulation of swallowed material around the valleculae and oropharynx. In the silent period of the second SSW, the swallowed material accumulated around the hypopharynx. When the ultrasonic probe was placed on the skin over the thyroid gland, in the silent period of the second SSW, the USI revealed that the swallowed material had passed through esophagus.Conclusion: Waveform and USI findings from this study suggest that swallowing sound can be divided into three sectional periods: an oral phase, a pharyngeal phase, and a repositioning phase.


Neuroendocrine tumor in the mandible: a case report with imaging and histopathologic findings

Neuroendocrine tumors (NETs) arise from neuroendocrine cells and are mostly observed in the gastrointestinal tract, pancreas, and lungs. NETs in the oral and maxillofacial region are extremely rare. We report a case of a 59-year-old woman with an NET in the mandible. The patient did not show any symptoms except for remarkable swelling and bleeding. The lesion appeared as a radiolucent honeycomb abnormality with bone destruction on panoramic radiography. The histopathologic diagnosis following a biopsy was NET. Contrast-enhanced computed tomography (CT), (18)F-fluorodeoxyglucose positron emission computed tomography ((18)F-FDG PET/CT), and adrenal scintigraphy-labeled meta-iodobenylguanidine were the modalities added to identify the primary site. Multiple lesions were confirmed in the gastrointestinal tract. Endoscopy was performed to identify the lesions, and several lesions were observed protruding from the mucous membranes. However, the endoscopy specimens did not yield an accurate diagnosis because adequate samples were not acquired. Blood and urine tests revealed no functional activity caused by the tumors. Although the origin was not histopathologically confirmed with endoscopy, this patient was situationally diagnosed with nonfunctional NET originating from the duodenum, as demonstrated by the metastases in the mandible.

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology


Prevalence and Imaging Characteristics of Palatine Tonsilloloths Detected by CT in 2,873 Consecutive Patients


Preoperative evaluation of patients with squamous cell carcinoma of the oral cavity: fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and ultrasonography versus histopathology.

PET/CT and US are complementary tools to evaluate preoperative patients.


Mechanical and Clinical Performance of Pulse-Inversion Tissue Harmonic Imaging in Superficial Region


Evaluation of the Field of View in Maxillofacial Ultrasonography

顎顔面領域における超音波画像表示領域に関する検討

The purpose of this study was to compare the advantages of different fields of view (FOV) between Linear, Sector, and real-time panoramic view (SieScape^TM) in B-mode ultrasonography for the maxillofacial region. <Materials and methods> This prospective study included 103 maxillofacial examinations of 60 patients with space-occupying lesions and/or suspected of metastatic regional lymph nodes from oral cancer. These lesions were examined by ultrasonographic study with three different kinds of FOV, including Linear, Sector, and SieScape^<TM>. These images were digitally recorded and compared. Each examination was classified into 5 maxillofacial anatomical parts, 1) buccal & lip part, 2) parotid gland part, 3) submandibular part, 4) submental & sublingual part, and 5) neck part. The advantage of FOV was evaluated according to these anatomical parts. <Results> 1) Buccal & lip part: 16 examinations were collected. Linear and/or sector FOV provided sufficient images for observing the lesion and adjoining anatomical landmarks. 2) Parotid gland part: 7 examinations were obtained. The whole gland could be observed only in SieScape^<TM> in a single image. 3) Submandibular part: 43 examinations were obtained. The whole submandibular gland could be observed in Sector FOV, which was also useful to observe the structure adjoining the mandible, because the slanting ultrasound beam avoided the lingual mandibular bone and the deeper structure of the gland could be observed. Furthermore, for cases with many submandibular lymph nodes, sagittal SieScape^<TM> images provided a suitable reference image for later observation. 4) Submental & sublingual part: Linear FOV provided sufficient images. Sector FOV was also useful, if the lesion was large or located next to the mandible. 5) Neck part: The quality of diagnostic information did not differ between the three kinds of FOVs employed here, since this area was too large to observe in a single image. Furthermore, the exact location was hard to identify in the later evaluation since the anatomic structures did not much differ between upper and middle neck portions. <Conclusion> In the ultrasonographic examination of the maxillofacial area, we should select proper FOV to obtain useful diagnostic information.


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.


Evaluation of spatial resolution for high-frequency multidimensional array probe in ultrasound imaging.

超音波用高周波積層プローブの空間分解能の評価


Nontraumatic pseudoaneurysm of the lingual artery/ A case report

舌動脈に生じた非外傷性仮性動脈瘤の1例


Examination of the roots of paramolar tuberoles with computed tomography: Report of 3 cases

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology


Adenoid Cystic Carcinoma of the Maxilla with Perineural Invasion into the Cranium. Report of a Case

頭蓋内へのPerineural invasion を伴なった上顎部腺様嚢胞癌の一例


Panoramic Radiography of the Temporomandibular Joint Part 2:A Study of Horizontal Optimum Angle of X-ray Beam to Mandibular Condyle

パノラマX線撮影装置を利用した顎関節撮影法 第二報 水平方向の至適X線入射角度の検討

The horizontal angle of x-ray beam projection to obtain an optimum anterior-oblique view of the mandibular condyle on a panoramic radiogram with least superimposition of the cranial base structures was examined. Eleven left temporomandibular joints from 11 dried human skulls were studied. Thirteen images were obtained for each joint, projected from 8° posterior to 52° anterior in 5° steps. The possible structures superimposing the condyle were the eminence from infratemporal crest to sphenoid spine, the eminence from articular tubercle to sphenoid spine, post glenoid process, anterior wall of the external auditory meatus, and mastoid process. None of the structures except mastoid process caused any problem in tracing the contour of the condyle. The part of the condyle with superimposition of the mastoid process was difficult to interpret, and extent of the part spread gradually as the projection angle increased. Nine out of 11 (82%) condyles were not superimposed with the mastoid process when a 30° anterior projection was adopted. This was considered to be the most suitable angle to obtain an anterior-oblique aspect of the mandibular condyle keeping good visibility.


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.


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.


Studies on temporomandibular joints in elderly Japanese --- Macroscopic evaluation of autopsy condyles

日本人高齢者の顎関節に関する研究 --- 下顎頭の肉眼的観察

Journal of the Japanese Society for the Temporomandibular Joint


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)