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Objectives To analyze the treatment results and late complications of high-dose-rate (HDR) interstitial brachytherapy (ISBT) for early (T1N0, T2N0) mobile tongue cancer using the microSelectron-HDR.

Radiation therapy to the head and neck area frequently causes severe salivary gland dysfunction and xerostomia. Morphological studies of irradiated salivary glands have suggested that the submandibular/sublingual gland may be less radiosensitive than the parotid gland. The purpose of this study was to evaluate the effect of radiation on major salivary gland functions in rats with radiation-induced xerostomia.

Chondrocytes do not undergo terminal differentiation in normal articular cartilage, whereas growth plate chondrocytes synthesize ALPase and induce matrix calcification terminally. Articular chondrocytes in osteoarthritic joints have been reported to express the terminal differentiation phenotypes, suggesting that terminal differentiation of articular chondrocytes is inhibited in normal joints. In the present study, we investigated the underlying inhibitory mechanism of the terminal differentiation in articular cartilage using a culture on type II collagen-coated dishes or a novel culture model on Millipore filters. ALPase activity increased from day 7 to day 8 in growth plate chondrocyte cultures on the collagen-coated dishes, but not in articular chondrocyte cultures. The ALPase expression of growth plate chondrocytes on the collagen-coated dish was completely inhibited when the same number of articular chondrocytes was mixed in the growth plate chondrocyte cultures. When articular chondrocytes or growth plate chondrocytes were maintained on Millipore filters held in 16-mm dishes, they started to synthesize ALPase. The ALPase expression of the chondrocytes on Millipore filters was inhibited by the presence of articular chondrocytes maintained on the bottom collagen-coated substratum in the same dishes. These results indicate that factors that diffused into the medium through the Millipore filters are involved in the inhibition of terminal differentiation. Since the conditioned medium from articular chondrocyte cultures did not affect the ALPase expression, it is considered that the soluble factors, which are continuously released from articular chondrocytes, are responsible for the inhibition of terminal differentiation.

Purpose To evaluate the usefulness of the fat suppression technique for magnetic resonance imaging of oral tongue cancer.

Using the random amplified polymorphic DNA (RAPD) method, we identified genomic instability in head and neck squamous cell carcinoma (HNSCC) tissues. We extracted DNA from tumor and corresponding normal tissues of 30 HNSCC patients and amplified with ten random 10-mer arbitrary primers by the RAPD method. Genomic instabilities, which appeared as banding pattern changes between normal and tumor DNA, were detected by at least one primer in all tumor tissues. Moreover, there was significant correlation between the frequency of genomic instability and the degree of tumor differentiation. These results indicate a possible association of genomic instability with malignant potential of head and neck cancer.

Diagnostic imaging in dentistry has been performed mainly by intraoral and panoramic radiography. Computed tomography and magnetic resonance imaging were put in practical use in 1972 and 1980, respectively. Now it is possible to observe distinct horizontal section images of the human body which could hardly be obtained before. These advanced imagings have been utilized also in oral and maxillofacial region for diagnoses of TMJ disorders, tumors and so forth. Furthermore, through utilization of ultrasonography, scintigraphy and 3-D reconstructed images, these current diagnostic imagings have become much more important tools for diagnosis in the oral and maxillofacial region.Advanced diagnostic imagings mainly of TMJ disorders and dental implant were considered from the view point of prosthodontic treatment.

AIMS: To correlate vascular endothelial growth factor (VEGF) expression in oral squamous cell carcinoma with the clinicopathological characteristics and prognosis; and to assess whether p53 gene status is associated with VEGF expression in human cancers. METHODS: Tumour specimens from 45 patients with oral squamous cell carcinomas were examined. Expression of VEGF was determined using an immunohistochemical method, and a tumour was considered positive when more than 5% of the neoplastic cells showed VEGF immunoreactivity. The p53 gene status was screened using a polymerase chain reaction--single strand conformation polymorphism analysis. RESULTS: VEGF positive staining was detected in 19 (42.2%) of the 45 cases. VEGF immunoreactivity did not correlate with the histological degree of tumour differentiation, clinical stages, or lymph node metastasis. The patients with VEGF positive tumours had a significantly worse prognosis than those with VEGF negative tumours. The five year overall survival rate of the VEGF negative patients was 76.5%, as compared with 48.8% for the VEGF positive patients. No significant association between VEGF expression and the p53 gene status of the tumours was found. CONCLUSIONS: VEGF is a good prognostic indicator of the survival of patients with oral squamous cell carcinoma. The p53 gene status does not seem to be associated with VEGF expression in these cancers.

To investigate the physiological role of hepatocyte growth factor (HGF) in endochondral bone formation, we examined the expression of HGF and its receptor c-met and the effects of HGF on growth plate chondrocytes. HGF was highly expressed in the prehypertrophic zone and hypertrophic zone in rat costal growth plate cartilage. The expression of HGF increased in rabbit chondrocytes as they matured in culture. Conversely, c-met expression was down regulated along maturation of growth plate chondrocytes. HGF had weak stimulatory effects on DNA and proteoglycan synthesis of growth plate chondrocytes. However, HGF strongly inhibited expression of terminal differentiation-related phenotypes, such as type X collagen and alkaline phosphatase (APase) synthesis and cartilage matrix mineralization. When HGF was removed from the cultures, cells quickly expressed type X collagen and APase. Once chondrocytes differentiated to mature chondrocytes, HGF did not inhibit further differentiation of these cells. These results suggested that HGF is a negative regulator of terminal differentiation of growth plate chondrocytes..

CCD detectors used in direct digital intraoral radiography have a linear dose response. When images are displayed on computer monitors a linear display function is also most often employed. Dentists using digital radiography have pointed out that the visual characteristics of such images are different from those of film based images. The aim of the present work was to study the effects of curving the display function. For this purpose 30 digital radiographs were selected, and a computer program was constructed by which the gray level display could be manipulated. Dentists at Osaka University, Osaka, Japan, and Karolinska Institutet, Stockholm, Sweden, were asked to manipulate the display of each individual radiograph so that it exhibited what subjectively appeared to be the best possible characteristics for diagnostic work. The viewers were in agreement in their preference for a curved display function for digital intraoral radiographs. Effects of the curved display are analyzed and discussed. It is concluded that from a purely subjective point of view the dose response function of digital intraoral radiographs should be curved in such a way that contrast is increased in areas with low exposure and decreased in areas with high exposure. Whether or not this has an effect on the diagnostic performance may be studied employing, for example, example, ROC techniques.

Objective. The purpose of this study is to examine the correlation between histopathologic and radiographic findings and to discuss the cause of the simple bone cyst. Study design. Histopathologically, we classified 53 simple bone cysts into two types. Type A has a connective tissue membrane and type B has a partially thickened wall with dysplastic bone formation. Radiographically, we evaluated the following: margin, radiolucency, or radiopacity, relationship with tooth apices, bucco-lingual bone expansion, and displacement of the mandibular canal. Results. Bone expansion and radiopacity were closely related to histopathologic findings although there was no correlation between the histopathologic findings and radiographic margin, relationship with tooth apices, and displacement of mandibular canal. Local recurrence was more likely to be observed in patients diagnosed as having type B than type A lesions. Conclusions. Type A and type B bone cysts may have different causes. Cysts determined radiographically to be radiopaque, those diagnosed as type B histopathologically, and cysts that have been treated surgically should all be followed by radiographic examinations.

Purpose: Patients with cancer of the floor of mouth are treated with radiation because of functional and cosmetic reasons. We evaluate the treatment results of high dose rate (HDR) and low dose rate (LDR) interstitial radiation for cancer of the floor of mouth. Methods and Materials: From January 1980 through March 1996, 41 patients with cancer of the floor of mouth were treated with LDR interstitial radiation using 198 Au grains, and from April 1992 through March 1996 16 patients with HDR interstitial radiation. There were 26 T1 tumors, 30 T2 tumors, and 1 T3 tumor. For 21 patients treated with interstitial radiation alone, a total radiation dose of interstitial therapy was 60 Gy/10 fractions/6–7 days in HDR and 85 Gy within 1 week in LDR. For 36 patients treated with a combination therapy, a total dose of 30 to 40 Gy of external radiation and a total dose of 48 Gy/8 fractions/5–6 days in HDR or 65 Gy within 1 week in LDR were delivered. Results: Two- and 5-year local control rates of patients treated with HDR interstitial radiation were 94% and 94%, and those with LDR were 75% and 69%, respectively. Local control rate of patients treated with HDR brachytherapy was slightly higher than that with 198 Au grains ( p = 0.113). For late complication, bone exposure or ulcer occurred in 6 of 16 (38%) patients treated with HDR and 13 of 41 (32%) patients treated with LDR. Conclusion: HDR fractionated interstitial brachytherapy can be an alternative to LDR brachytherapy for cancer of the floor of mouth and eliminate radiation exposure for the medical staff.

We have retrospectively investigated the presence of Epstein–Barr virus (EBV) DNA in 45 cases of squamous cell carcinomas (SCCs) of the oral cavity using polymerase chain reaction (PCR). We analyzed the association between EBV infection and the clinicopathological characteristics, tumor response to radiotherapy, or prognosis to determine the clinical significance of EBV. EBV DNA was detected in 29 cases (64.4%) of SCCs. No significant differences were observed between the presence or absence of EBV. Our results indicate that EBV infection is not related to tumor response to radiotherapy, or the prognosis of the patients.

The findings of conventional radiography, computed tomography, and magnetic resonance imaging are reported for an odontogenic myxoma arising in the left anterior maxilla of a 50-year-old man. The magnetic resonance imaging characteristics of an intraosseous myxoma are described for the first time. The initial conventional radiographic examination disclosed a unilocular radiolucency with poorly delineated margins as typically seen in malignant tumors. Subsequently, acquired computed tomography scans displayed bony expansion and thinning of cortices on the labial aspect of the lesion. Magnetic resonance imaging revealed a well-defined, well-enhanced mass lesion with homogeneous signal intensity on every pulse sequence. The lesion showed intermediate signal intensity on the T1- and T2-weighted images. Magnetic resonance imaging of the present maxillary myxoma revealed a higher signal intensity on T1-weighted and a lower signal intensity on T2-weighted images than for previously reported myxomas of the soft tissues. This discrepancy might be related to the viscosity of the mucoid substance or the protein density of the tumor.

高線量率 (HDR) 組織内照射は医療従事者の被曝を皆無とした。患者はアイソトープ病室に隔離される必要がなく, 合併症のある患者や高齢者の治療も可能である。1991年6月から頭頸部癌に対するHDR組織内照射の第I/II相試験を行い, 60Gy/10回/1週間を標準的な治療線量とした。舌癌に対するHDR組織内照射単独と低線量率 (LDR) 単独の第III相試験では5年局所制御率はHDRが94%, LDRが90%であった。30～40Gyの外部照射と48～54GyのHDR組織内照射で治療された11例の舌癌患者とLDRで過去に治療された症例と比較すると, 5年局所制御率はHDRが81%であり, LDRが74%であった。HDRで治療された16例の口腔底癌の患者とAuグレイン (LDR) で治療され患者を比較すると, 5年局所制御率はHDRが94%であり, LDRはT1が76%, T2が60%であった。頭頸部癌に対するHDR組織内照射の治療成績はLDRと同等かそれ以上であった。HDR組織内照射はLDRにかわりうる治療方法と考える。

The effects of X-ray irradiation on the proliferation and differentiation of growth plate chondrocytes were examined. Chondrocytes were isolated from the ribs of 4-week-old New Zealand white rabbits and cultured as a packed mass in centrifuge tubes. The cells in the centrifuge tubes proliferated, matured and hypertrophied likein vivo chondrocytes. Irradiation at a dose as low as 3 Gy to proliferating chondrocytes significantly decreased the DNA content, alkaline phosphatase (ALPase) activity, and matrix calcification, without decreasing the proteoglycan content. Irradiation at 10Gy to mature chondrocytes caused significant decrease in ALPase activity and matrix calcification, although it did not have marked effects on DNA and proteoglycan contents. On the other hand, irradiation at 10Gy to hypertrophic chondrocytes did not cause any change in ALPase activity or cartilage-matrix calcification. These findings suggest that the irradiation sensitivity of chondrocytes changes during cytodifferentiation. Furthermore, the inhibition of ALPase expression and matrix calcification by irradiation proved to be independent of the suppression of proliferation.

The retardation of long bone growth caused by irradiation is thought to be closely related to the impairment of growth plate function, but its mechanism remains unclear. In this study, we examined the effects of irradiation on the terminal differentiation of growth plate chondrocytes and on calcification. Chondrocytes were isolated from the growth plate of the ribs of four-week-old rabbits and inoculated at a high density on a type-I collagen-coated dish. Following logarithmic proliferation, they reached confluence (premature chondrocytes), then matured (mature chondrocytes), and became hypertrophied (hypertrophic chondrocytes). 10 Gy or less irradiation of the premature chondrocytes potently inhibited the terminal differentiation and matrix mineralization. Irradiation inhibited chondrocyte hypertrophy and suppressed alkaline phosphatase induction and the expression of type-X collagen without changing the protein composition profile of any other cell layer. Premature cells had the highest radiosensitivity. The sensitivity was decreased as the cells differentiated; the effects of irradiation on hypertrophic chondrocytes with terminal differentiation-related phenotypes were reduced. This study showed that 10 Gy or less irradiation of growth plate chondrocytes impaired terminal differentiation and mineralization. Since chondroclasts and bone marrow cells invade only to the mineralized cartilage, the induction of calcification in cartilage matrices is one of the most important steps in endochondral ossification. Therefore, it is conceivable that the damage in the growth plate induced by irradiation could account for the subsequent abnormal bone and skeletal growth.

頭頸部領域の悪性腫瘍に対しては, 根治性かつ形態および機能温存を目的に放射線治療が最優先される場合がある。今回われわれは根治照射を必要とする頭頸部癌患者に対して, 歯科学的問題である唾液流量, 唾液pH, 味覚および放射線治療後のDMF歯数の変化を検討した。その結果, 頭頸部癌患者 (内訳: 上咽頭3例, 口底: 2例, 舌: 2例) に対する外部照射線量が60Gy～80Gyレベルで唾液流量は0ml/5minに近似する値を示すことが判った。さらに頭頸部癌根治照射後のDMF (D: decay, M: missing, F: filling) 歯数の変化では, 厚生省歯科疾患実態調査におけるDMF歯数の年次推移を対照とした場合, 上咽頭癌 (10例) と中咽頭癌 (8例) グループの照射後・DMF歯数は舌癌グループ (8例) のものよりも増加傾向を示した。

The effects of X-ray irradiation to the salivary glands on the induction of dental caries were examined in specific pathogen-free Sprague-Dawley rats fed either a high (containing 56% sucrose) or a low-sucrose (containing 28% sucrose and 28% wheat flour) diet and inoculated with a strain ofStreptococcus mutans. Hyposalivation was induced by irradiation (35 Gy) and dental caries was significantly enhanced in irradiated rats fed a high-sucrose diet. However, the recovery of the strain ofS. mutans from rats fed high-sucrose was not significantly higher than that of rats fed a low-sucrose diet.

Purpose: In Japan, the role of radiotherapy for gingival carcinomas has not been considered as a radical treatment, but only a pre and/or postoperative treatment. This study was aimed to discuss a possibility of radiotherapy for a radical treatment. In this study, radiotherapy was given as an initial treatment for squamous cell carcinomas of the lower gingiva in simultaneous combination with chemotherapy of bleomycin or peplomycin (Tokyo, Japan). Methods and Materials: When complete regression of the tumor was obtained, subsequent surgery was postponed with or without a booster of radiotherapy of about 30 Gy until a recurrent lesion was confirmed. Results: Sixty-seven percent of 100 patients with T 1 or T 2 had complete regression, while only 22 (35.5%) of 62 patients with T 3 or T 4 had complete regression. The 5-year local control rate by T classification, including the results of secondary treatments (surgery and/or radiotherapy and/or chemotherapy) for recurrent lesions, was 91% for T 1 , 89% for T 2 , 76% for T 3 and 61% for T 4 The 5-year local control rate according to treatment methods was 95% in the group without surgery and 86% in the group with surgery for T 1 and T 2 patients. The rates were 54% and 71%, respectively for T 3 and T 4 patients. The cause specific 5-year survival rate by stage was 75% for Stage I, 87% for Stage II, 71% for Stage III, 51% for Stage IV and 70% overall. Conclusion: The combination of radiotherapy and chemotherapy couldbe a conservative radical treatment for T 1 and T 2 patients with lower gingival carcinoma.

Three-dimensional (3D) CT imaging was performed on three cases (one unilateral, two bilateral) of coronoid process hyperplasia. This technique displayed the impingement of the enlarged coronoid process on an exostosis on the lower border of the malar bone. In addition, a small concavity was found on the inner surface of the malar bone that was not displayed by other imaging modalities. The 3D images were useful in planning surgical treatment. In cases of limitation of opening, finding a malar exostosis on conventional radiographs such as a Water's view should suggest the presence of coronoid process hyperplasia even if the impingement cannot be demonstrated.

For patients with TMJ dysfunction, operators often change the condylar position by various methods. The aim of this study is to investigate how much the changes with time of condylar positions are related to the changes of clinical signs. The subjects were 584 joints of 127 patients with TMJ dysfunction to whom the serial lateral TMJ tomography was performed more than twice. In the most of cases where the condylar position had moved downward, inter-incisal distance had increased and TMJ noise had ameliorated. Furthermore, in many cases where the condylar position had moved forward, the amelioration of the TMJ pain was observed. It was considered that those ameliorations occurred because the positional relationship between the condylar head and the articular disk or posterior attachment had been improved.

The effects of X-ray irradiation to the salivary glands on the induction of dental caries and on the oral microflora were examined in specific pathogen-free Sprague-Dawley rats fed a sucrose diet and inoculated with a strain ofStreptococcus mutans. Hyposalivation was induced by irradiation of 35 Gy and dental caries was significantly enhanced in irradiated rats infected withS. mutans. Bacteriological examinations at the end of the experiment demonstrated that the recoveries of lactobacilli and staphylococci significantly increased in hyposalivated rats with 50 Gy of irradiation. However, the recovery of the strain ofS. mutans from hyposalivated rats were not significantly higher than that of non-irradiated rats. These findings suggest that some acidogenic microorganisms such as lactobacilli and staphylococci may have played some role in promoting dental caries.

Panoramic radiographs of 1203 Japanese patients were examined to detect idiopathic radiopaque foci of dense bone. One hundred seventeen patients (9.7%) exhibited 134 such lesions. The majority (97%) of the opacities were found in the mandible, especially in the mandibular first premolar to second molar region (85.4%). The lesion was most prevalent in the first three decades of life.

Four hundred and seventy-four patients with squamous cell carcinomas of the tongue were treated with radiation therapy at the Department of Radiology, Osaka University Hospital between 1978 and 1987. Brachytherapy was mainly employed for the majority of the patients with T1 and T2 lesions, whereas the combination of external irradiation and brachytherapy was the treatment of choice for the patients with infiltrative T2 and more advanced lesions. Patients treated with brachytherapy alone were given an estimated tumor dose of about 70Gy within a week. Patients treated with the combined therapy received an estimated tumor dose of about 30Gy to 50Gy within 3 to 5 weeks from external irradiation, followed by 50Gy to 60Gy within a week from brachytherapy. The treatments used in this study improved the survival. The 2-year local control rates were 85% in T1, 77% in T2, 60% in T3 and 33% in T4 lesions. The 5-year actuarial survival rates according to the T stage were 78% in T1, 64% in T2, 50% in T3 and 40% in T4 lesions. One hundred and four patients(28%) of three hundred and sixty nine patients who had negative lymph nodes clinically had cervical lymph node metastases subsequently. Whereas twenty six patients(25%) of one hundred and five patients who had positive lymph nodes clinically proved to be false positive. The incidence of osteoradionecrosis was 6.0% in patients treated with the combination of external irradiation(30Gy) and brachytherapy(60Gy), while it was 1.7% in patients treated with brachtherapy alone(70Gy). Brachytherapy is a fairly good therapeutic technique for the majority of the patients with tongue cancers. The multicombined treatment modality could provide the chance for cure of advanced lesions.

大阪大学放射線科で1967～1984年に放射線治療が行われた上顎洞扁平上皮癌は592例で, 放射線治療単独は136例, 化学療法併用は456例である。平均経過観察期間は12年 (6～24年) で全例の5年および10年生存率は, それぞれ34%および24%である。T病期別の5年および10年生存率は次のごとくで, T2 (107例): 57%と37%; T3 (318例): 37%と27%; T4 (158例): 22%と18%である。平均の照射線量はTDFで示すと照射単独群では123 (59～184) で, 5-FU持続動注併用群では90 (49～181) である。5年時点での非再発および実測生存率は照射単独群でそれぞれ11%と20%であり, 5-FU持続動注併用群では42%および57%である。治療法別で最も好成績なのは放射線50Gy/25f/35d (TDF82) 照射と5-FU持続動注2.5gr/10f/35d併用群である。この方法が高い制御率と眼球・上顎を高率に温存できると結論される。

Sixty-nine patients with squamous cell carcinoma of the lower gingiva were treated by external radiotherapy combined with Bleomycin (BLM) or Peplomycin (PEP) at the Department of Radiology, Osaka University Hospital from 1974 to 1986.

Fifty-five cases of odontogenic keratocyst in the mandible were classified into two subtypes according to the histopathologic characteristics of the epithelium (Group-1; the epithelium was parakeratotic with cuboidal or columnar, accentuated and palisadelike arranged basal cells, Group-2; the epithelium was orthokeratotic with a distinct stratum granulosum.) and were examined for the following four factors; 1) age distribution, 2) size of bone destruction, 3) degree of lateral bone expansion, and 4) features of the cyst contents. Most cases of Group-1 indicated radiographically lateral bone expansion and large cystic bone destruction and had fluid cyst content. On the contrary, the majority of Group-2 cases indicated no lateral bone expansion, were relatively small lesions, and their cystic cavities were filled with caseous materials.

1972年から86年までの15年間に大阪大学放射線科でブレオマイシン (BLM) またはペプロマイシン (PEP) 併用による放射線治療を行った頬粘膜扁平上皮癌64例および放射線単独の治療を行った18例について検討した。BLM90mg/6fr/3週またはPEP45mg/9fr/3週, 60mg/6fr/3週と放射線治療30Gy/15fr/3週投与した。非再発生存率は, BLM/PEP併用例は5年73%, 放射線単独例は67%であった。一次治療として放射線治療に引き続いて手術を行った症例を除くと, 2年局所制御率は, BLM/PEP併用例は80%, 放射線単独症例は57%であった。BLM/PEP併用例のCR率は52%であり, このうち一次治療として手術を追加しなかった症例の最終的な2年局所制御率は27/28 (96%) であった。

Although magnetic resonance imaging (MRI) is the modality of choice for evaluation of TMJ disc position, it is sometimes difficult to determine when it is displaced or reduced. The MR images of 273 Patients with a clinical diagnosis of TMJ disorders were assessed for disc position and configuration. Most (90-97%) of the slightly anteriorly displaced discs were reduced to the normal position in the open-mouth position. However, the greater part (76%) of the distorted discs was completely displaced anteriorly and without reduction. Since no distorted discs were found in the normal disc position, we conclude that discs are distorted after displacement.

The mechanisms whereby X irradiation induces palatal clefting were investigated in vivo and in an in vitro organ culture system. When pregnant mice at day 12.5 of gestation were exposed to a 4-Gy dose of whole-body X radiation, the incidence of palatal clefting in their offspring was 91%. The volume of the irradiated palatal shelves was too low for them to make contact with each other. On gestational day 13.5 after labeling, bromodeoxyuridine-positive cells were sparse and apoptotic cells were abundant in the irradiated shelves. To prevent secondary effects of irradiation from the injured maternal body, fetal palatal explants were immediately transferred to an organ culture system after X irradiation in utero. The incidence of palatal clefting was 24%, much lower than the incidence in vivo. The addition of 10(-4) M of dexamethasone to the culture medium increased the incidence of palatal clefting to 56%. These findings indicated that X irradiation inhibited cell proliferation and induced apoptosis, resulting in small-volume palatal shelves that could not fuse with each other. The organ culture data also indicated that 4 Gy of irradiation appears to produce its effects both by a direct action on the fetus and indirectly by affecting the metabolism of the pregnant dam.

Exercise can enhance the signal intensity (SI) of skeletal limb muscles on T2-weighted magnetic resonance imaging (MRI). The purpose here was to evaluate the effects of repetitive maximal clenching exercises involving the mandibular elevator muscles with T2-weighted MRI. Seven normal volunteers were imaged before and immediately after performing repetitive maximal clenching and at 3, 6, 9, 12, 15, 20 min after the exercise in a 1.5 T GE magnet with spin-echo sequences. SI in the masseter, medial pterygoid and temporalis increased significantly (p0.001) and the cross-sectional area (CSA) of masseter increased 10.11% on T2-weighted MRI after exercise. The increased SI and CSA declined approximately to the pre-exercise level in about 20 min after exercise. No SI and CSA changes were found in the inactive neck muscle and no SI changes in the mandibular bone marrow (p0.05). The findings suggest that the use of exercise-enhanced MRI might be helpful in the study of the function and dysfunction of muscles in the orofacial region.

Interleukin-6 (IL-6) levels are markedly increased in the synovial fluid of patients with rheumatoid arthritis or osteoarthritis. However, the effects of IL-6 on proliferation and proteoglycan metabolism in articular cartilage are not known. We demonstrated here the effects of human recombinant (hr) IL-6 on proliferation and proteoglycan metabolism in rabbit articular chondrocyte cultures. In vitro, these cells proliferated and produced abundant extracellular matrices. We found that 1-10 ng/ml of hrIL-6 inhibited proliferation to approximately 65% of control levels and suppressed colony formation induced by bFGF in soft agarose. The same concentration of hrIL-6 depressed proteoglycan synthesis to approximately 60% of control levels. Moreover, hrIL-6 significantly enhanced proteoglycan degradation induced by hrIL-1beta, although hrIL-6 alone did not affect proteoglycan degradation. These findings suggest that IL-6 is a negative regulator for chondrocyte proliferation and articular cartilage metabolism.

The status of the p53 gene in biopsy specimens was analyzed to determine whether it is predictive of the outcome of radiotherapy of squamous cell carcinomas of the oral cavity. Biopsy materials were obtained from 45 patients, and the p53 status of each patient was determined using a single-strand conformation polymorphism analysis. Fourteen of the patients were treated with radiation therapy alone; the other 31 patients underwent radiotherapy in combination with surgery or chemotherapy. Twenty-seven patients had tumors with wild-type p53 and 18 patients had a tumor with mutant p53. The initial tumor response was not significantly different between these two groups. Kaplan-Meier survival plots (log-rank test) showed that the probability of survival was not significantly different between two groups although the patients with mutant p53 had a tendency for longer survival (P = 0.2941). However, among the patients with stage III/IV tumors (n = 24), those with a wild-type p53 status tended to have longer survivals.

To describe the clinical and MRI findings in patients with disc displacement of the temporomandibular joint.Eighty-eight joints in 51 patients referred for suspected TMJ disc displacement were examined by MRI. Two oral radiologists assessed the images. The clinical findings were obtained by retrospective review of the patients' records.Clicking was the most common clinical finding, present in 47 joints. Pain was reported for only 30 joints. Anterior disc displacement with reduction was found in 39 joints, anterior disc displacement without reduction in 31 joints, compound dislocations (anterolateral or anteromedial) in 13 joints and sideways displacement in 5 joints respectively. In about one-fourth of the joints, MRI revealed abnormal configuration of both disc and condyle. The osseous changes were subtle. Only 9% of the joints exhibited an osteophyte. Joint effusion in either the upper or the lower joint compartment was found in 19 joints. Out of 14 patients with joint effusion, six patients complained of pain from the TMJ region.The most extensive soft and hard tissue changes were found in patients with anterior disc displacement without reduction. Pain was not a characteristic symptom for any type of disc displacement.

The radiographic and clinical features of periostitis ossificans in 55 patients with mandibular osteomyelitis were studied. On the basis of whether the original mandibular contour was preserved or not, the lesions could be classified radiographically into two major types, each with two subtypes. Type 1 lesions were of shorter duration than Type II. Type 1-2 and Type II-1 periostitis ossificans were characteristically observed in patients under 25 years of age. Extraction of the lower third molar with pericoronitis was the most frequent cause of periostitis ossificans. An unerupted third molar tooth bud was found in close proximity to the area of periostitis ossificans in six patients. With adequate treatment there can be complete resolution of periostitis ossificans in Type I cases; however, when there has been loss of mandibular contour (Type II cases), mandibular deformity remains even when normal bony architecture has been restored.

We exposed the osteoblast-like cell line, MC3T3-E1, to 1-to 10-Gy X-ray. Irradiation at doses of 5-Gy dose or more decreased the DNA content of cells at the proliferation stage, confluence, and post-proliferation stages. The alkaline phosphatase activity, conversely, was increased by irradiation, and the calcium content of irradiated cells was greater than that of nonirradiated. These findings suggest that irradiation induces terminal differentiation and calcification of osteoblasts.

To study the noise characteristics of the Sens-A-Ray (Regam Medical Systems AB, Sundsvall, Sweden) system, 20 radiographs were obtained at each of three different exposure levels at 70 and 90 kVp with a homogeneous x-ray field. Exposures were measured with an ionization chamber. Noise power spectra were calculated over three areas within each radiograph, and ensemble averages were subsequently found from 60 data files at each exposure level. Noise equivalent quanta were calculated with the noise power spectra and modulation transfer function data from previous studies. Finally, the detective quantum efficiency was calculated by dividing the noise equivalent quanta by the estimated incident photon fluence at the different exposures. The system has a maximum detective quantum efficiency of approximately 0.030 at 70 kVp and 0.025 at 90 kVp. A broad maximum exists at approximately 2 cycles/mm, indicating that the signal-to-noise ratio is most favorable at this spatial frequency.

The effect of IL-1 on expression of the mineralization-related phenotype by chondrocytes was examined. In cultures of rabbit growth plate chondrocytes, IL-1 beta at 0.1 ng/ml caused 95% decreases in alkaline phosphatase activity, alkaline phosphatase mRNA levels, the incorporation of 45Ca into insoluble material, and the calcium content during the hypertrophic stage. These effects of IL-1 beta were dose-dependent and were observed in 24-48 h. Furthermore, IL-1 beta suppressed increase in cell size and the syntheses of 1,25-dihydroxyvitamin D3 receptor and type X collagen, other markers of hypertrophy, but had little effect on the synthesis of total protein including type II collagen. The inhibition of calcification was observed only when chondrocytes were exposed to IL-1 before the onset of calcification: IL-1 treatment from the mineralization stage had a marginal effect on 45Ca incorporation into insoluble material. These results suggest that IL-1 inhibits chondrocyte hypertrophy and the onset of calcification in ossifying cartilage.

One hundred thirty-one arthrographic examinations of temporomandibular joints were performed on 119 patients. The relationships between clinical symptoms, tomographic findings, and soft-tissue perforation were examined. Perforations of the articular disk or posterior attachment were revealed in 58 joints. Joints with crepitation showed a high frequency of perforation (20 of 22). Pain in the joint area and limitation of opening correlated to disk reduction. Perforations were observed in 12 of 21 joints with continuous pain. Osseous changes were detected in 89 joints. Joints with abnormal radiodensity (erosion, sclerosis) combined with abnormal shape (pocket erosion, osteophyte formation, deformity) showed a high frequency of perforation (41 of 45), which corresponded to 84% in this study. In those cases with osseous change or crepitation, positive predictive values of perforation were both 91%. These types of osseous change and their clinical significance might predict soft-tissue perforation with high accuracy before an arthrogram is performed.

Changes in the phenotypic expression of osteoblasts after X irradiation were investigated. Osteoblast-like MC3T3-E1 cells at the actively proliferating, confluent and postproliferation stages were subjected to 10 Gy X irradiation. Irradiation at the confluent stage enhanced accumulation of type I collagen normalized to the DNA content. Irradiation at all stages down-regulated the expression of osteocalcin, but the levels of osteopontin and osteonectin mRNAs were unchanged from the control level. After irradiation at the later stages, the time-dependent increase in alkaline phophatase activity per cell exceeded that in the control cells. The localization of alkaline phosphatase-positive cells was concordant with that of calcification. In addition, the quality of the calcium deposits was found to be similar to that in control cells as determined by energy dispersive spectrometry and the ratio of calcium to phosphorus, even if the cells were not exactly the same morphologically. The changes in phenotypic expression observed here are closely related to the enhancement of calcification observed in a previous study. ? 1998 by Radiation Research Society

The effects of X irradiation on matrix formation by growthplate and articular chondrocytes, as reflected by metabolism of proteoglycans and type II collagen, were examined in a rabbit chondrocyte culture system. Irradiation with 1 to 10 Gy selectively inhibited synthesis of proteoglycans (incorporation of [35 S]sulfate) depending on the stage of differentiation of the irradiated cells; however, synthesis of type II collagen was not affected. Irradiation of an immature culture, in which chondrocytes had just reached confluence, suppressed incorporation of [35 S]sulfate into the glycosaminoglycan, 10 Gy inducing approximately 45-50% inhibition. In contrast, the irradiation of mature cultures, in which chondrocytes had already secreted extensive cartilage matrix, did not affect the rate of synthesis of proteoglycans (incorporation of [35 S]sulfate). We also found that here irradiation stimulated the degradation of proteoglycans, but with the effect differing in growth-plate chondrocytes and articular chondro...

Between 1973 and 1985, 286 patients with squamous cell carcinoma of the oral tongue (T1NO: 72; T2NO: 180; T3NO: 34) were treated with Iridium-192 interstitial irradiation at the Department of Radiology, Osaka University Hospital. Five-year control rates of the primary lesion by Iridium-192 implant alone or in combination with external irradiation was 70% (T1: 77%; T2: 71%; T3: 47%), and ultimate local control rate after salvage surgery only for recurrence was 85% (T1: 93%; T2: 87%; T3: 62%). These results are comparable to those obtained by interstitial therapy with radium needles, with the superior advantage of lower risk to the medical staff.