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Objectives The purpose of this study was to verify whether application of a quantitative computed tomography (QCT) technique was helpful for quantitative measurement of bone density using dental cone-beam CT (CBCT).

Recent developments in digital computer technology have enabled radiological diagnosis to be performed using a monitor screen. In medical radiography, the importance of monitors has been shown in many diseases. Digital imaging and communication in medicine (DICOM)-compatible monitors are widely used. However, the effect of monitors on the diagnosis of oral disease has not yet been clarified and remains controversial. The aims of this study are to compare the caries diagnostic ability between DICOM monitors and other monitors and to examine if monitor capability affects the diagnosis. One hundred proximal surfaces of 50 extracted human upper premolar teeth were used as specimens. Intra-oral radiographs of all specimens were taken digitally. Three types of monitors were compared in terms of caries diagnostic ability: a DICOM standard-compatible monitor, a standardized personal computer (PC) monitor, and a tablet PC. Six oral radiologists diagnosed each radiograph independently. Areas under the receiver operating characteristic (ROC) curve were generated and compared. Area under the ROC curve (AUC) of the DICOM monitor, PC monitor, and tablet PC was 0.68147, 0.67002, and 0.60189, respectively. There was no significant difference between the DICOM monitor and the PC monitor, but the tablet PC showed significantly lower accuracy. There were no significant differences among the monitors for dentin caries (p > 0.05). DICOM-compatible monitors and PC monitors have similar capabilities, but tablet PCs showed lower diagnostic accuracy, especially for superficial caries. Appropriate monitors are needed for radiographic diagnosis on monitor screens.

We report our experience of a case with a malignant tumor of the mandible in which diagnostic imaging played an important role in the differential diagnosis and therapeutic strategy decisions. The patient was a 78-year-old woman who visited our hospital because of poor healing after tooth extraction. Multiple cytological diagnoses provided class II results, and a histopathological diagnosis of a biopsy also failed to show malignant findings. Therefore, a definitive diagnosis could not be made. Although the patient had a history of osteoporosis treatment, details of her medications were unclear. Therefore, bisphosphonate-related osteonecrosis of the jaw (BRONJ) could not be excluded, causing difficulty in management of the patient’s condition. Eventually, we mainly focused on the diagnostic imaging and planned the therapeutic strategy in accordance with treatment for a malignant tumor. A postoperative histopathological examination of the surgical specimen revealed squamous cell carcinoma. It is sometimes difficult to differentiate among atypical diseases such as malignant tumors of the mandible and BRONJ, based solely on clinical or diagnostic imaging results. However, in the present patient, diagnostic imaging suggested a malignant tumor, and the appropriate treatment could be selected.

To determine the potential of fluid-attenuated inversion recovery (FLAIR) imaging of oral and maxillofacial vascular malformations as an alternative to contrast-enhanced magnetic resonance imaging (MRI), we investigated the influence of differences in T1 and T2 values on image contrast in FLAIR images and evaluated the diagnostic utility of such images.FLAIR imaging and heavily T2-weighted (hT2-weighted) imaging were performed using a phantom. FLAIR and hT2-weighted images of 32 lesions (11 mucous cysts, 12 vascular malformations, and 9 tumors) were also studied retrospectively. The contrast-to-noise ratios (CNRs) and CNR change ratios were compared.All aqueous solutions except those with a short T2 value were discriminated by CNR change ratio (P .05). All 3 types of lesions were discriminated by CNR change ratio (P .05).FLAIR imaging has potential as an alternative to contrast-enhanced MRI in differentiating vascular malformations from other types of lesions in the oral and maxillofacial region.

A case of myoepithelioma presumed to have arisen from an accessory parotid gland is reported. Preoperative fine-needle aspiration cytological findings suggested a malignant tumor, possibly an adenoid cystic carcinoma, while histopathological findings acquired during surgical resection revealed a myoepithelioma. The tumor was located adjacent to the Stensen duct, suggesting an accessory parotid gland origin. The diagnostic potential of magnetic resonance imaging and contrast-enhanced computed tomography in diagnosing this disease is discussed.

Aneurysmal bone cysts, benign lesions of bone tissue, are composed of sinusoidal and vascular spaces filled with blood and surrounded by fibrous tissue septa. They are uncommon, occurring usually in the long bones and spine, and only very rarely in the jaw, where approximately 160 cases have been reported, of which two thirds were located in the mandible and one third in the maxilla. We report two rare cases of aneurysmal bone cyst occurring in the mandible. A literature survey revealed 34 cases of this disease in the jawbone in Japan. An analysis of aneurysmal bone cysts of the jaw was performed in 36 cases, including the present ones. The mandible was affected in 28 cases (78%) and the maxilla in 8 (22%). Aneurysmal bone cyst was observed to occur most frequently between the mandibular body and the ramus. Patient age ranged from 6 to 87 years, with a mean age of 27.7 years. Patients under 30 years of age occupied 60% of the total. Treatment options suggested in the literature include percutaneous sclerotherapy, therapeutic embolization, curettage, block resection and reconstruction, radiotherapy, and systemic calcitonin therapy. The extent of surgery will depend on the size and position of the lesion, ranging from simple curettage to extended resection.

Patients with facial pain and jaw function problems constitute a large and heterogeneous group. Disk displacement and osteoarthritis are the most common intra-articular abnormalities observed at imaging. As disk displacement is seen rather frequently in asymptomatic volunteers, it is a challenge to explain why disk displacement sometimes is symptomatic and sometimes is not. The present review focuses on abnormalities in the condylar bone marrow and the intra-articular soft tissues accompanying the disk displacement. The findings of temporomandibular joint in asymptomatic volunteers and in temporomandibular disorder (TMD) patients are reviewed. Both bone marrow edema and marrow necrosis are documented at histology and at magnetic resonance imaging (MRI) in TMD patients. Intra-articular soft tissue changes, such as synovitis, are additionally documented at arthroscopy. However, there is a controversy concerning which diagnostic imaging information is essential. Although there is no doubt that disk displacement and osteoarthritis may be accompanied by inflammatory alterations in the bone marrow and the intra-articular soft tissues, it has been difficult to consistently relate a specific imaging manifestation (bone edema, joint effusion, and synovitis) to joint pain. Longitudinal studies are needed to evaluate the importance of MRI abnormalities in the management of TMD patients.

The inferior alveolar artery (IAA), accompanied by the inferior alveolar nerve, runs through the mandibular canal. The mandibular canal can be observed by conventional radiography and computed tomography, although it is sometimes difficult to identify on these images. This study examined visualization of the IAA with phase-contrast magnetic resonance angiography (PC-MRA). Phase-contrast magnetic resonance angiography images were obtained in the double oblique sagittal plane by using a two-dimensional, fast, low-angle shot (2D FLASH) sequence in five healthy volunteers. A flow-encoding gradient was applied from anterior to posterior, with velocity-encoding numbers (VENCs) of 10, 8, 6, 4, 2, and 1 cm/s. Two observers subjectively evaluated the detectability of the IAA in three mandibular regions on all PC-MRA images. The IAA appeared as a line of high signal intensity on the PC-MRA images. In the mandibular ramus region, the rating scores at VENCs of 1 and 2 cm/s were significantly higher than those at VENCs of 8 and 10 cm/s (p

Both benign tumors and cysts in the oral and maxillofacial region show clear borders and homogeneously high signal intensity on magnetic resonance (MR T2-weighted images, making differentiation difficult without contrast enhancement. Windowing for brightness and contrast adjustment may be helpful in interpreting relative signal intensities on MR images. This study was performed to determine whether re-windowing against targeted lesions on T2-weighted images was a useful procedure that would enhance differentiation without invasive contrast enhancement. Twenty-six lesions (13 benign tumors, 13 cysts) that showed clear borders and homogeneously high signal intensity on T2-weighted images were examined. The windowing parameters of axial images were readjusted to emphasize contrast only inside the lesions using automatic density adjustment. Re-windowed images were reviewed by three experienced oral radiologists and categorized based on the internal homogeneity of the lesion into four grades: 0, heterogeneous; 1, slightly heterogeneous; 2, slightly homogeneous; 3, homogeneous. Re-windowing was then evaluated for its usefulness in differentiating between benign tumors and cysts. For cysts, the rates of homogeneous (grades 3 and 2) and heterogeneous intensity (grades 1 and 0) were 66.7 (26/39) and 33.3% (13/39), respectively. For benign tumors, these rates were 33.3 (13/39) and 66.7% (26/39), respectively. Cysts showed a higher rate of homogeneous intensity, while the opposite was true for benign tumors. A significant difference in distribution was observed between cysts and benign tumors (P

Summary The discrepancy between osteoarthritic findings on images and symptomatology can sometimes be problematic in clinical work. In this article, we focus on osteoarthritis and related entities on images, and especially on MR images.

An approach of 3D-visualization of the temporomandibular joint (TMJ) with special focus on the articular disc based on magnetic resonance imaging (MRI) was developed for the purpose of diagnosis support. Mandibular condyle and fossa were reconstructed as 3D-surfaces. Articular disc, retrocondylar tissue, and the lateral pterygoid muscle were visualized by means of direct volume rendering. By simultaneous visualization of both, the bony surfaces and the soft tissue, anterior disc displacement could be recognized in 3D-context. Additional superposition of the 3D-visualization with the original 2D-MRI slices allowed for a combination with conventional diagnostics. The method was tested for clinical T1-, T2-, and proton density weighted MRI data from four independent medical institutions. For all cases, the skeletal anatomy could be reproduced. Applied validation approaches showed good results. Anterior disc displacement could be clearly depicted as well as the incidence of reduction of the disc. By several experienced observers, the approach was rated as significant. Although partially non-standard in the clinical routine the new method provided promising results for efficient diagnosis support. Its validity in the medical practice, namely, its impact for dislocation/deformity of the mandibular disc will be further analyzed.

The purpose of this study was to clarify the presence of pain and a correlation between pain and characteristics of signal intensity of mandibular bone marrow in temporomandibular joints (TMJ) with osteoarthritis (OA). A total of 196 joints in 98 patients with TMJ disorders were examined using magnetic resonance imaging (MRI). A pain score and signal intensity on mandibular bone marrow were analyzed in the TMJ with OA. TMJ with OA showed a higher degree of pain compared to those without (p

To visualize the temporomandibular joint (TMJ) and the surrounding tissues in detail utilizing high-resolution MR images for the diagnosis of soft- and hard-tissue abnormalities. Clinically routine MR slices are processed by tissue segmentation and three-dimensional (3D) reconstruction and viewed with visualization software.A 1.5 T MRI system was used. The double-echo procedure for taking oblique sagittal images was applied to obtain both proton density-weighted (PDW) and T2 weighted (T2W) images simultaneously, with separate examinations in both open and closed mouth positions. Diagnosis of the abnormality in the placement and morphology of articular discs and the joint effusion status is usually performed using multiple MRI slices. Clinically routine continuous MR slices were processed by segmentation, reconstruction and visualization algorithms, and the mandibular condyle, fossa, articular disc and other intra-articular tissues were visualized on the 3D and two-dimensional (2D)-3D fusion images.In a clinical case, the anterior disc displacement without reduction, with mouth open and closed, was clearly depicted in the 3D images. Also 2D-3D superposed images with changeable tissue transparency successfully depicted the stereoscopic TMJ morphology in three dimensions.High-resolution PDW- and T2W MR images could be processed by tissue segmentation and 3D-reconstruction procedures, and the resultant images showed the anatomical details in an easily recognizable way. By the simultaneous visualization of both bony surfaces and soft tissues, disc displacement and deformity can be recognized in a 3D context. The additional superposition of the 3D visualization with the original 2D MR slices allows for a combination with conventional diagnostics.

In benign tumors in the mandibular condyle such as osteoma and osteochondroma, symptoms such as pain and limited-mouth-opening are rarely observed. Therefore, these tumors are often detected after the development of changes in occlusion and mandibular midline deviation. We encountered a very rare patient with mandibular condyle osteoma who showed acute pain and markedly limited-mouth-opening.

Many studies have shown that MRI findings are reliable when experienced calibrated observers work as a group. The hypothesis was that MRI findings can be used as the gold standard also when evaluation is made by single expert observers.Temporomandibular joint (TMJ) MRIs of 34 patients were evaluated independently by four reviewers with expert knowledge of radiology for the presence of 13 specified pathologic entities, as well as the quality of the images, on a 5-step scale from "Sure Yes" to "Sure No". Intraclass correlation coefficients were calculated to estimate the rating reliability of the examiners. A coefficient of at least 0.8 was deemed good, between 0.60 and 0.80 was deemed acceptable, and less than 0.60 was considered poor. Additionally, weighted kappa statistics were used for pair-wise comparisons across all four reviewers.The hypothesis was not supported by the results. None of the 13 correlation coefficients for comparisons between single examiner evaluations of pathologic entities was good and 8 were poor.A diagnosis of TMD based on MRI examination protocols made by a single examiner should not be accepted as a gold standard with regard to TMJ disorders.

To investigate the clinical significance of magnetic resonance (MR) evidence of joint effusion of the temporomandibular joint after mandibular condylar fractures, magnetic resonance imaging (MRI) was performed on 18 joints in 15 patients with either unilateral or bilateral mandibular condylar fractures using a 1.5 Tesla MRI scanner (Signa, General Electric, Milwaukee, WI). MR evidence of joint effusion was evaluated and compared with the types and the positions of the fractures. MR evidence of joint effusion was observed in 11 of 18 TMJs, which was 61% of the condylar fractures. It appeared more frequently after fractures with dislocation than those without dislocation (p0.05). In addition, MR evidence of effusion appeared more frequently in TMJs after high condylar fractures (head to upper neck) than low condylar fractures (lower neck to subcondylar) (p0.05). These findings indicate that MR evidence of joint effusion may serve as a marker for the detection of severe intra-articular damage to the TMJ after mandibular condyle fractures.

Magnetic resonance imaging has evolved as a prime diagnostic method for soft-tissue abnormalities of the temporomandibular joint. The most common temporomandibular joint abnormalities are internal derangement and osteoarthritis, but there are many other reasons for pain and dysfunction that are often overlooked. The purpose of this paper is to illustrate several of these more unusual and less well-recognized causes for temporomandibular joint pain and dysfunction. For example, internal derangement is often seen in asymptomatic individuals. Another purpose is to illustrate the difference in magnetic resonance imaging of asymptomatic and symptomatic internal derangement.

The purpose of this study was to investigate temporomandibular joint (TMJ) effusion on magnetic resonance (MR) images, and its association with specific categories of disk displacement, bone marrow abnormalities and pain. From a series of 523 consecutive TMJ MR imaging studies of patients referred to imaging because of pain and dysfunction, those with TMJ effusion, defined as an amount of fluid that exceeded the maximum amount seen in a control group of asymptomatic volunteers, were analysed. The selected patients were reassessed and the amount of TMJ fluid was graded bilaterally according to a set of reference films. Other parameters recorded included disk displacement categories and condyle marrow abnormalities. Pain self-records were obtained from the patients immediately before MR imaging. The association between the recorded parameters and TMJ pain was analysed with t-tests and regression analysis. Of the 523 patients, 70 (13%) had TMJ effusion, which was unilateral in 61%. Only 9% of the 70 patients had effusion bilaterally, whereas bilateral disk displacement was found in 80%. In the 76 joints with effusion, 83% showed two specific categories of disk displacement at closed mouth. Condyle marrow abnormalities were found in 31% of the 70 patients, mostly on one side, and in 24% of the 76 joints. An in-patient regression analysis of the side difference in TMJ pain showed that effusion and condyle marrow abnormalities were significant pain-increasing factors. In conclusion, patients with TMJ effusion represent a subgroup with pain and dysfunction with more severe intra-articular pathology than those with disk displacement but no other joint abnormalities.

To compare the prevalence and type of temporomandibular joint (TMJ) disk displacement in asymptomatic volunteers with those in patients.Bilateral oblique sagittal and oblique coronal intermediate-weighted magnetic resonance (MR) images of the TMJs in 58 patients with pain and dysfunction were analyzed and compared with corresponding MR images of 62 asymptomatic volunteers.Forty-five (78%) of 58 patients had disk displacement compared with 22 (35%) of 62 asymptomatic volunteers. Complete disk displacement was found in 46 (40%) of 115 joints in patients compared with three (2.4%) of 124 joints in asymptomatic volunteers, whereas partial disk displacement occurred in 26 (22.6%) and 27 (21.8%) joints, respectively. Two types of complete disk displacement, anterolateral and anterior, occurred frequently in patients, seldom in volunteers. Only minor differences were found between other types of disk displacement when prevalence in patients was compared with that of volunteers. The disk reduced to a normal position on open-mouth images in all joints in the volunteers compared with 76% of the joints in patients.TMJ disk displacement was less prevalent and was of a different type in asymptomatic volunteers compared with patients with pain and dysfunction.

頭頸部腫瘍術後嚥下障害に対する頸部聴診法の判定精度を明らかとするため, 頭頸部腫瘍患者の頸部より検査条件を規格化して検出した嚥下時産生音を対象として, 嚥下障害の有無について音響特性の臨界値による判定および聴覚による判定の精度を検討し, 以下の結果を得た。1. 嚥下音 (159音) の持続時間の臨界値 (0.79秒) による判定とVF所見との判定一致率は77.3%であった。2. 嚥下後呼気音 (194音) における0～250Hz帯域の補正音圧レベルの臨界値 (25.3dB) による判定とVF所見との判定一致率は77.3%であった。3. 嚥下前の呼気音・嚥下音・嚥下後の呼気音からなる44サンプルについて, 6名の検者による聴覚的判定とVF所見との判定一致率は83.5%であった。

Temporomandibular joint (TMJ) sound is one of the most commonly recognized signs in patients with temporomandibular disorders (TMD) but is also frequently seen in asymptomatic individuals. Sound recording is therefore only meaningful if the sounds from a normal healthy joint can be differentiated from those in patients. In this study, the amplitude and power spectrum of the TMJ sounds from symptomatic patients and asymptomatic individuals were recorded and compared. The result showed that TMJ sounds from symptomatic patients had a larger amplitude than sounds from asymptomatic subjects. A significant proportion of sounds had frequencies between 2000 and 3000 Hz. It was concluded that the characteristic amplitude is worthy of further study as a sign of possible diagnostic value. Secondly, the bandwidth of the sensors used at electronic TMJ sound recording should not be less than 3000 Hz.

われわれが行っている頭頸部腫瘍術後患者に対する嚥下機能訓練法を紹介するとともに飲み込み検査で評価した訓練中の嚥下機能の経時的変化とアンケートを用いて調査した嚥下機能に対する患者の主観評価について報告する。対象は透視検査で嚥下障害が確認された頭頸部腫瘍術後患者24名で, 飲み込み検査では水30ml, プリン5g, および粥5gを飲み切るまでの時間を計測した。機能訓練の効果と嚥下機能に対する満足度についてはアンケート表を用いて患者の主観評価を調査した。機能訓練期間平均13日間で, 飲み込み時間は水では30.7秒から8.5秒, プリンでは32.8秒から9.4秒, 粥では33.3秒から11.4秒と顕著に短縮した。機能訓練の効果については15名中13名が「非常に効果があった」と回答し, 訓練後の嚥下機能に対する満足度については15名中10名が70%以上の高い満足度を示した。以上の結果はわれわれが行っている嚥下機能訓練法の有効性を反映し, これらの方法が患者のQOLの向上にも十分役立つことを裏付けたものと考えられた。

Objectives Edema and necrosis of the temporomandibular joint (TMJ) have been described in terms of bone marrow signal abnormalities in magnetic resonance imaging (MRI). However, painful joints often show no such signaling abnormalities, making the diagnosis of TMJ disorders difficult in the clinical setting. An association has been suggested between TMJ bone marrow change and TMJ pain, but even when such change results in slight pain, it may be too slight to be visually apparent on MR images. We hypothesized that fluid-attenuated inversion recovery (FLAIR) can be used to detect such minimal changes. The purpose of this study was to determine whether there is an association between signal intensity on FLAIR images and pain in the TMJ. Methods The study included 85 TMJs in 45 patients referred to our department for MRI. The signal intensity on FLAIR images was measured. Pain was evaluated based on the visual analog scale. An unpaired t test and Pearson’s product-moment correlation coefficient were used for the statistical analysis. A p value of

The cause of pain associated with TMJ disk displacement and internal derangement is unclear. In clinical work with MR imaging we have noted increased T2 signal from the retrodiskal tissue in some patients with TMJ pain and dysfunction. The purpose of this study was to analyze a possible association between pain and the T2 signal intensity from the retrodiskal tissue on MR images. The study was based on 48 joints in 33 patients referred for MR imaging of the TMJ. The T2 signal from the retrodiskal tissue was measured on the MR scanner and was correlated to the degree of pain. The results showed a statistically significant (p < 0.05) association between pain and increased T2 weighted signal. The T2 signal intensity ranged between 251 and 478 and was highest in the painful joints and lowest in the joints without pain. We conclude that the average T2 signal from the retrodiskal tissue is higher in painful joints than in nonpainful joints. This might reflect an increased vascularity of the joint tissue.

Osteosarcoma of the head and neck is relatively rare and accounts for less than 10 percent of all osteosarcomas in general. We report a case of osteosarcoma in which imaging and histopathology of the hard palate of an 11-year-old boy yielded atypical findings. An approximately 8×15mm lesion found in the center of the palate was hard and healthy in color. Subsequent biopsy resulted in a diagnosis of nonepithelial malignant tumor. No abnormalities were observed in the maxillary bone or tooth on panoramic or occlusal radiographs. Computed tomography images revealed a mass lesion approximately 7×9×9mm in size on the hard palate extending into the maxilla. The cortex of the maxilla adjacent to the lesion was unclear in parts. The internal structures were slightly inhomogeneous and its density was lower than that of muscle. On magnetic resonance images, the lesion was represented by low signal intensity on T1-weighted (T1W) images and high signal intensity on T2-weighted images with fat-suppression. The margin of the lesion was a little unclear and the internal structures were slightly inhomogeneous. The lesion was enhanced homogeneously on post-contrast T1W images with fat-suppression. The histopathological diagnosis was fibrogenesis-type osteosarcoma. No findings specific to osteosarcoma such as localized enlargement of the periodontal ligament space alongside the root, cortical destruction, periosteal ossification or osteogenesis were found in this case.

Objectives The purposes of this retrospective study were to compare various methods of apparent diffusion coefficient (ADC) measurement for head and neck lesions in half-Fourier single-shot turbo spin-echo (HASTE) diffusion-weighted imaging (DWI) and determine the threshold ADC value for predicting malignancy. Study Design HASTE DW images of 46 lesions (10 cysts, 14 benign tumors, and 22 malignant tumors) were studied retrospectively. The ADC values were compared among the 0-1000 method, 500-1000 method, and weighted linear regression (WLR) fit. Results The highest overall accuracies of 83.3%, 86.1%, and 88.9% were obtained when ADC values of 1.24 × 10−3 mm2/s (0-1000 method), 0.98 × 10−3 mm2/s (500-1000 method), and 1.23 × 10−3 mm2/s (WLR fit), respectively, were used for the threshold. Conclusions The present results indicate that ADC measurement with HASTE DWI is useful in predicting malignancy of head and neck lesions.

Objective The aim of this study was to investigate the imaging findings of non-Hodgkin lymphoma (NHL) involving the mandible. Study Design The imaging studies of 4 patients with NHL involving the mandible were retrospectively reviewed. Panoramic and computerized tomographic (CT) images were available for all patients. Magnetic resonance imaging (MRI) was available for 3 patients. Results On panoramic images, an apparent radiolucent lesion was found in only 2 of 4 cases. However, in all cases careful observation demonstrated imaging findings suggesting malignancy. On CT and MRI, tumor replaced the bone marrow in all cases and spread to the surrounding soft tissue in 3 cases. Cortical bone destruction tended to be mild for the extent of tumor involvement. Conclusions NHL involving the mandible tended to show slight or mild cortical bone destruction relative to the extent of the tumor involvement. Careful observation was considered to be necessary when interpreting conventional images, because they might not clearly demonstrate bone destruction.

Varicella-zoster virus reactivation causes zoster (shingles), a syndrome characterized by severe pain and a vesicular rash. The present report details a case of varicella-zoster virus reactivation of the maxillary and mandibular division of the right trigeminal nerve without evidence of vesicular rash (zoster sine herpete). It is difficult to identify owing to no typical clinical signs such as vesicular eruption. Zoster sine herpete of the trigeminal nerve, in particular, is rarely reported. In this case, the diagnosis was based on clinical findings and was supported by the demonstration of an immunoglobulin G antibody. Zoster sine herpete of the trigeminal nerve, in particular, should be considered in patients with severe facial pain over specific dermatomes, if they do not demonstrate appreciable findings of traumatic neuropathy, tumor or herpes zoster.

Evaluation of swallowing has been made possible by cine-Magnetic resonance (MR) imaging with high time resolution. However, the spatial resolution in cine-MR imaging remains inadequate for the detection of anatomical structures. Therefore, it is necessary to refer to static MR images in conjunction with cine-MR imaging. The aim of this study was to determine which MR parameters were appropriate for static imaging of the anatomical structures involved in swallowing. MR imaging was carried out, and T1-weighted, T2-weighted and proton-density-weighted MR images were obtained in the sagittal plane in 5 healthy volunteers. Each image was evaluated for anatomic landmark clarity by 3 oral radiologists. The anatomic landmarks selected were the lip, tip of tongue, center of tongue, tongue base, soft palate and epiglottis. Differences in clarity among 3 imaging modalities were evaluated. A 3-point score rating system was used. The results showed that lower TE sequences, i.e., either T1-weighted or proton-density-weighted images, were the most suitable for use in conjunction with cine-MR imaging in diagnosing swallowing disorders.

A case of squamous cell carcinoma presumed to have arisen from the right Stensen duct is reported. The patient, a 62-year-old man, was referred to our hospital with swelling in the right cheek. Magnetic resonance imaging (MRI), including contrast-enhanced MRI, and contrast-enhanced computerized tomography (CECT) enabled diagnosis of a solitary mass in the Stensen duct. Fat-suppressed T(2)-weighted imaging, in particular, demonstrated a mass-like lesion in the dilated Stensen duct and obstructive parotitis where the duct transitions into the parotid gland. Gadolinium-DTPA-enhanced T(1)-weighted imaging demonstrated the mass-like lesion surrounded by signal-hyperintense layer showing continuous transition from the thickened Stensen duct wall, which was also hyperintense. The CECT revealed peripheral annular enhancement surrounding the tumorous mass, with no enhancement of the duct wall itself, reflecting an increase in micro blood vessels in the stroma of the neoplasm. These image findings correlated well with subsequent histopathologic findings. A mass with rim enhancement and dilated Stensen duct accompanied by parotitis and no salivary calculus may suggest a differential diagnosis of malignant tumor of Stensen duct.

With the arrival of arthrography, computed tomography, and magnetic resonance imaging, diagnostic imaging of the temporomandibular joint has improved tremendously over the last 20 years. In patients with temporomandibular joint pain and dysfunction, the main focus was on meniscal pathology. The purpose of this article is to discuss several osseous abnormalities and demonstrate their association with temporomandibular joint pain and dysfunction.

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level. The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p = 0.033). The mean age was higher in joints with osteonecrosis (p < 0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.

Diagnostic imaging of TMJ has improved remarkably in the last 20 years. Various abnormalities related patient symptoms. Further studies using the latest imaging techniques will allow a better understanding of the sources of joint pain and the discrepancy between imaging findings and patient symptoms. For clinical practice, appropriate clinical examinations are needed to determine exactly which imaging findings are significant.

Objective. The purpose of this study was to analyze the relationship between abnormal bone marrow of the mandibular condyle and osteoarthritis. Study Design. The relationship between abnormal bone marrow and osteoarthritis of the mandibular condyle was analyzed in magnetic resonance images of the temporomandibular joints of 74 patients. Thirty-seven patients had magnetic resonance evidence of abnormal bone marrow, and 37 control patients had magnetic resonance images with normal bone marrow. Results. Fifteen of 37 patients with magnetic resonance evidence of abnormal bone marrow had no magnetic resonance evidence of osteoarthritis; the other 22 patients had both abnormal bone marrow and osteoarthritis. Conclusions. Abnormal bone marrow of the mandibular condyle can occur separately from osteoarthritis; nearly one half of the joints with magnetic resonance evidence of abnormal bone marrow did not have any evident osteoarthritis. Abnormal bone marrow may therefore initially represent a separate disease entity. Over time, secondary osteoarthritis probably develops in joints with initial bone marrow abnormalities.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;87:243-52)