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Biomedical subjects

Tetsu Takahashi

Publications and source records attributed to Tetsu Takahashi.

34 records · Page 2Linked to original sources
PubMed2003

Regional differences of type II collagen synthesis in the human temporomandibular joint disc: immunolocalization study of carboxy-terminal type II procollagen peptide (chondrocalcin).

The purpose of this study was to determine the regional differences of distribution of the carboxy-terminal type II procollagen peptide (pCOL-II-C; chondrocalcin) as markers of cartilaginous expression in the human temporomandibular joint (TMJ) disc. Twelve human TMJ discs without morphologic abnormalities were obtained from 12 fresh cadavers. All specimens were analysed for pCOL-II-C expression using polyclonal rabbit anti-human pCOL-II-C antibody in avidin-biotin-peroxidase complex staining. The results were demonstrated that the percentage of pCOL-II-C immunoreactive disc cells was significantly higher in the outer part (the articular surfaces) than in the inner part (the deep central areas) of the disc. These findings suggest that the tissue heterogeneity of cartilaginous expression reflects the functional demands of the remodelling process in the human TMJ disc.

Aged↗
PubMed2003

Inducible nitric oxide synthase and apoptosis-related factors in the synovial tissues of temporomandibular joints with internal derangement and osteoarthritis.

PURPOSE: In this study, we investigated the relationship between oxidative stress and apoptosis in synovial tissues in temporomandibular joint diseases (TMDs), including internal derangement (ID) and osteoarthritis (OA), comparing immunohistochemical, arthroscopic, and histologic findings. MATERIALS AND METHODS: Synovial specimens obtained from patients with ID (31 patients), osteoarthritis (11 patients), and condylar fractures of the mandible (5 patients) during arthroscopy were examined immunohistochemically using antibodies against CD68, inducible nitric oxide synthase (iNOS), Fas, and single-stranded DNA (ssDNA). RESULTS: CD68 and iNOS immunoreactivity were detected mainly in synovial lining cells and subintimal macrophages, and tended to increase with synovial hyperplasia. Fas and ssDNA immunoreactivity was detected mainly in synovial lining cells, and Fas-positive regions exhibited a number of ssDNA-positive cells. Fas expression was significantly greater in fractures than in OA, and ssDNA expression was significantly greater in OA than in ID. Fas expression was significantly greater in iNOS-positive versus iNOS-negative TMJs, and ssDNA expression tended to increase with iNOS expression. CONCLUSION: These immunohistochemical findings suggest that oxidative stress and apoptosis in synovial tissues are involved in the onset and progression of TMDs.

Adolescent↗
PubMed2003

Prevalence of hepatitis viral infection in dental patients with impacted teeth or jaw deformities.

OBJECTIVE: The prevalence of infection with hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis G virus (HGV), and transfusion-transmitted viruses (TTV) was evaluated in patients with impacted teeth or jaw deformities. STUDY DESIGN: Of 486 patients, 268 had serum samples available for retrospective TTV DNA and HGV RNA assays. In addition, the sera of 404 patients were assayed for HB surface antigen and the sera of 340 were assayed for HCV antibody. RESULTS: HGV RNA was detected in 3 of 268 patients (1.1%), and TTV DNA was detected in 60 of 268 (22.4%). Of 404 patients, 3 had HB surface antigens (0.7%). Furthermore, 13 of 340 were HCV-seropositive (3.8%). The rate of infection was similar between patients with impacted teeth and those with jaw deformities, respectively, as follows: 1.1% versus 0%, respectively, for HBV prevalence; 4.1% versus 3.2% for HCV prevalence; 1.8% versus 0% for HGV prevalence; and 22.9% versus 21.4% for TTV prevalence. CONCLUSIONS: Universal precautions to prevent hepatitis and TTV infection during oral surgical procedures are important.

Adult↗
PubMed2003

Magnetic resonance evaluation of the disk before and after arthroscopic surgery for temporomandibular joint disorders.

OBJECTIVE: The purposes of this study were (1) to assess functional and pain outcomes after arthroscopic surgery on patients with temporomandibular joint disorders (TMD); (2) to evaluate postsurgical changes in disk position, mobility, and morphology on magnetic resonance imaging (MRI); and (3) to measure the association between changes in disk position, mobility, and morphology on MRI and clinical outcomes. STUDY DESIGN: A retrospective analysis was conducted of temporomandibular joints with internal derangement and osteoarthritis that were refractory to nonsurgical treatments and underwent arthroscopic surgery and on which MRI was performed within 1 month after the initial visit and 1 year after arthroscopic surgery. Clinical findings were assessed on the basis of mandibular range of motion and joint pain level on a visual analog scale at the initial visit and 1 year after arthroscopic surgery. The disk position, mobility, and morphology on MRI were compared with clinical findings and were statistically analyzed before and after arthroscopic surgery. The treatment outcome was judged according to our success criteria. The associations between changes in disk position, mobility, and morphology and clinical outcomes after arthroscopic surgery were statistically analyzed. RESULTS: Forty-three joints of 43 patients who underwent arthroscopic surgery were assessed in this study. After arthroscopic surgery, mandibular range of motion and visual analog scale results improved statistically. According to the criteria for clinical resolution, 32 surgeries were successful and 11 were unsuccessful. Preoperative and postoperative MRI showed that most joints had anterior disk displacement (ADD) without reduction. Postoperative MRI revealed that, statistically, the number of mobile disks had increased and deformity of the disks had progressed. In the successful group, postoperative MRI revealed that all joints had mobile disks. In both groups, most joints had ADD without reduction before and after arthroscopic surgery, and, statistically, deformity of the disks progressed after arthroscopic surgery. CONCLUSIONS: Arthroscopic surgery was an effective treatment for TMD refractory to nonsurgical treatments. This study provides important information of clinical significance. Disk position remained ADD without reduction, disk mobility increased, and deformity of the disks progressed after arthroscopic surgery.

Adolescent↗
PubMed2003

Immunohistochemical study of syndecan-1 down-regulation and the expression of p53 protein or Ki-67 antigen in oral leukoplakia with or without epithelial dysplasia.

BACKGROUND: Leukoplakia is an oral pre-cancerous lesion that sometimes develops into squamous cell carcinoma. Therefore, leukoplakia with epithelial dysplasia is useful for studying carcinogenesis at the cellular level. The purpose of this study was to evaluate a potential association between the loss of syndecan-1 expression and the expression of p53 protein and Ki-67 antigen, and to identify reliable markers for predicting malignant changes in oral leukoplakia with epithelial dysplasia. METHODS: Changes in the expression of syndecan-1, p53, and Ki-67 were examined immunohistochemically in 43 cases of oral leukoplakia with or without epithelial dysplasia. The subjects were categorized as: none, 13 cases; mild dysplasia, 5 cases; moderate dysplasia, 17 cases; and severe dysplasia, 8 cases. The expression of these molecules in normal oral epithelia (22 cases) was also investigated. RESULTS: Strong syndecan-1 expression was observed on the surface of keratinocytes in normal epithelium. Immunopositivity was lost gradually as the extent of epithelial dysplasia increased. In normal epithelium, p53 and Ki-67 appeared mainly in the basal cell layer, while they were more widely distributed in leukoplakia. Specifically, significant changes were observed in the labeling index of p53 and Ki-67 in leukoplakia as epithelial dysplasia progressed from mild to moderate or severe. CONCLUSION: Our results reveal that overexpression of p53 protein and Ki-67 antigen, and down-regulation of syndecan-1 expression in the lower part of the epithelium, are associated with dysplastic changes. Therefore, the down-regulation of syndecan-1 expression may be the most important reliable marker for dysplastic changes.

Adult↗
PubMed2003

Specific expression of inducible nitric oxide synthase in the synovium of the diseased temporomandibular joint.

OBJECTIVE: The expression of inducible nitric oxide synthase (iNOS) in temporomandibular joint (TMJ) specimens obtained arthroscopically from diseased TMJs was investigated by using immunohistochemistry and compared with clinical, arthroscopic, and histologic findings. STUDY DESIGN: Synovial biopsies were obtained arthroscopically from 18 TMJs in 15 patients with symptomatic internal derangement (ID) or osteoarthritis (OA). We also obtained arthroscopic biopsies from 8 control TMJs (3 with habitual luxation of the mandible, one with ID with clicking, and 4 with mandibular condyle fractures). The expression of iNOS was examined by immunohistochemistry and was compared with clinical, arthroscopic, and histologic findings. RESULTS: Definite or intense iNOS immunoreactivity was observed in both the synovial lining cells and the endothelial cells of TMJs with symptomatic ID or OA. Weaker immunoreactivity was present in synovial fibroblasts. In contrast, in TMJs without synovitis (eg, those with habitual luxation of the mandible) the expression of iNOS was weak or marginal. The expression of iNOS correlated significantly with arthroscopic evidence of synovitis (r = 0.406, P <.05) but not with cartilaginous degeneration (P >.05). The expression of iNOS also correlated with the histologic grade of the synovial lining cell layers (r = 0.530, P <.05). However, in patients with ID or OA of the TMJ, there was no statistically significant correlation between the intensity of iNOS immunoreactivity and clinical, arthroscopic, or histologic findings (P >.05). CONCLUSION: These data clearly suggest that nitric oxide is locally produced in the synovial lining of the TMJ in ID and OA.

Adolescent↗
PubMed2003

Closure of large oronasal fistulas at the time of secondary bone grafting in patients with cleft lip and palate.

Oronasal fistulas often arise after repair of the palate in patients with cleft lip and palate. Those located adjacent to the residual cleft are commonly closed at the time of secondary bone grafting. However, it is not easy to close larger fistulas. We present a method of closing large oronasal fistulas in the anterior palate that are adjacent to the residual cleft at the time of secondary bone grafting, which consists of reducing the size of the inferior nasal turbinate.

Adolescent↗
PubMed2003

Vertical alveolar distraction osteogenesis with complications in a reconstructed mandible.

We report here a case of vertical alveolar distraction osteogenesis with many complications that required further surgical interventions. A 54-year-old man underwent mandibular resection followed by iliac bone grafting as the result of large mandibular odontogenic keratocyst. Eleven months later, alveolar vertical distraction osteogenesis was applied to the patient for prosthetic rehabilitation. Fracture of the basal bone occurred in the consolidation period, and the fracture was fixed by the titanium miniplate system. Radiographic examination after completion of distraction osteogenesis confirmed a radiolucent area in half of the distracted area between the basal bone and the transport segment, and when the distractor was removed the radiolucent area was filled with fibrous granulation tissue. The granulation tissue was removed and endosteal implants were inserted together with a bone graft. Ultimately, all implants were osseointegrated, and adequate esthetics and function of the implant-supported prosthesis were achieved.

Alveolar Bone Loss↗
PubMed2002

Risk factors for late cervical lymph node metastases in patients with stage I or II carcinoma of the tongue.

BACKGROUND: Many histopathologic parameters in squamous cell carcinoma of the tongue have been identified as predictive factors for cervical lymph metastasis. However, predictive factors for occult cervical lymph node metastases and the criterion for elective therapy remain inconclusive. This study analyzed the clinicopathologic factors associated with late cervical lymph node metastases in patients with carcinoma of the tongue. METHODS: The clinicopathologic features of 50 consecutive patients seen between January 1985-December 1996 with previously untreated stage I or II squamous cell carcinoma of the tongue were reviewed. All patients were treated with partial glossectomy without elective neck dissection. Their mean age was 54.5 y (range, 23-90 y) and the male-female ratio was 1.2:1 (27 men and 23 women); 30 cases were stage I, and 20 cases were stage II. Clinicopathologic factors were analyzed to determine factors predicting late cervical lymph node metastasis. RESULTS: The overall cervical lymph node metastasis rate was 14.0% (7 of 50). Clinicopathologic factors significantly associated with the development of cervical lymph node metastasis were tumor size (> or =30 mm), tumor depth (> or =4 mm), differentiation, mode of invasion, microvascular invasion, and histologic grade of malignancy. In a multivariate logistic regression analysis, moderately differentiated squamous cell carcinoma of the tongue with tumor depth > or =4 mm had predictive value for late cervical lymph node metastasis and diminished overall survival (odds ratio, 10.0; p =.02; hazards ratio, 7.0; p =.039). CONCLUSIONS: The findings of this study demonstrate tumor depth > or =4 mm moderately differentiated squamous cell carcinoma of the tongue have a substantially higher rate of late cervical metastases. In the basis of these data, it is our recommendation that this be used in the decision to electively treat the neck.

Adult↗
PubMed2002

Prevalence of hepatitis virus infection in association with oral diseases requiring surgery.

OBJECTIVE: We evaluated the prevalence of hepatitis virus infection in a large population of patients in terms of diseases requiring oral surgery. DESIGN: Retrospective case survey. SUBJECTS AND METHODS: Prevalence of hepatitis B and C virus (HBV, HCV) infection were compared between oral diseases such as inflammation, cysts, cancer, trauma, benign tumors, impacted teeth, or jaw deformity in dental inpatients (n = 5830) with adjustment for age, gender, and history of surgery. RESULTS: Of 4402 inpatients, 94 had HB surface(s) antigen (2.1%), while 151 of 2613 were seropositive for HCV (5.8%). Prevalences of HBs antigen and HCV antibody exceeded those in the general population. HBs antigen was more prevalent in patients with benign oral tumors than in patients with impacted teeth, whether or not adjustment was made for age (odds ratios, 4.246 and 5.055 with and without age adjustment, respectively; P < 0.05). On the other hand, HCV antibody was more prevalent in patients with oral cancer than in those with impacted teeth before adjustment for age (odds ratios, 2.433; P < 0.05), but this difference was reversed with age adjustment (odds ratios, 0.443; P < 0.05). CONCLUSION: HBs antigen was more prevalent in patients with benign oral tumors, while HCV antibody was higher in patients with oral cancer. However, this increased incidence of HCV antibody apparently was a reflection of age. HCV infection may not have an etiologically important association with oral cancer.

Adult↗
PubMed2002

Distraction osteogenesis for reconstruction after mandibular segmental resection.

Distraction osteogenesis with the shortening and lengthening method is a well-established procedure for repairing extremities. We used this technique for reconstruction after mandibular segmental resection. A 74-year-old woman underwent distraction osteogenesis with an intraoral device, initially shortening the mandible after a 20-mm-long segmental resection, followed by lengthening at a rate of 0.8 mm per day for 21 days. Eight weeks after the distraction, the device was removed and a dental implant was placed at the site of distraction. Radiographic observation showed new bone formation, and the implant was completely osseointegrated. Although the follow-up period is relatively short, the clinical course was uneventful. Distraction osteogenesis with the shortening and lengthening method seems to be a feasible option for reconstruction after segmental resection of the mandible.

Aged↗
PubMed2002

Preoperative histologic assessment of head and neck lesions using cutting needle biopsy.

OBJECTIVE: This study assessed the clinical utility of cutting needle biopsy in which a newly developed Monopty biopsy instrument (MBI) (Monopty, Bard Urologic Division; Covington, Ga) was used in the preoperative assessment of head and neck lesions. STUDY DESIGN: Needle biopsies were performed with the MBI in 16 cases of head and neck lesions that included lesions in lymph nodes, salivary glands, palate, and soft tissue. RESULTS: High-quality histopathologic specimens were obtained without complications in all biopsies performed, and the diagnostic target tissue was obtained in 15 of 16 cases. Diagnoses made from MBI needle biopsy specimens were consistent with the final diagnoses made from subsequent surgical materials in 14 cases, and the accuracy rate was 88%. None of the samples demonstrated significant rush artifacts or obscuring blood, both of which are problems commonly associated with manual biopsy techniques. CONCLUSIONS: This technique offers a safe and effective means of obtaining adequate tissue for the histological assessment of head and neck lesions.

Adenolymphoma↗
PubMedDate not supplied

Use of horizontal alveolar distraction osteogenesis for implant placement in a narrow alveolar ridge: a case report.

Although alveolar distraction is a promising method for ridge augmentation involving the atrophic maxilla or mandible for implant placement, techniques of horizontal and oblique alveolar distraction for expanding a narrow alveolar ridge have not been established. A case of horizontal alveolar distraction for implant placement using a titanium mesh plate and a distraction screw is reported. Horizontal alveolar distraction was performed on a patient with an extremely atrophic alveolar ridge in the anterior mandibular region. Two transport segments using horizontal osteotomies were prepared, and 2 horizontal alveolar distraction devices were inserted. After a 7-day waiting period, the devices were activated and alveolar widening was performed labially (0.225 mm twice a day for 14 consecutive days). Three months after consolidation, the distraction devices were removed. The distracted areas were completely filled with newly formed solid bone tissue. Two months after the device was removed, 4 endosseous implants were placed and an implant-supported definitive prosthesis was placed. This method of horizontal alveolar distraction appears to be clinically useful for the placement of implants in atrophic or knife-edged alveolar ridges.

Alveolar Process↗
PubMedDate not supplied

Dental rehabilitation using an implant-supported overdenture after repair of a fracture in a severely resorbed edentulous mandible: a case report.

Treatment of mandibular fracture in senior citizens with severely resorbed edentulous mandibles is extremely difficult. Such treatment must achieve successful osteosynthesis and restore functional mastication. A severely resorbed (Class V) mandible was successfully reconstructed with an autogenous bone graft on the inferior border of the mandible and a titanium mesh plate after a failed attempt to fix the fracture. After the placement of endosseous implants in the mandible, the patient was rehabilitated with an overdenture to restore masticatory function.

Aged↗
PubMedDate not supplied

Magnet-retained facial prosthesis combined with an implant-supported edentulous maxillary obturator: a case report.

The prosthetic rehabilitation of maxillofacial defects is especially challenging when the patient is edentulous. Although dental implants are used to enhance the retention and stability of both facial and maxillary prostheses, combining facial and maxillary prostheses is extremely difficult. This article describes the prosthetic treatment of an edentulous patient with a large maxillary and facial defect. After placing dental implants in the remaining maxilla, a maxillary obturator prosthesis supported by a milled bar attachment was fabricated. The facial prosthesis was retained by a magnetic attachment to the maxillary obturator prosthesis. As the obturator prosthesis was supported securely by this sturdy attachment, the facial prosthesis was stable during mastication and facial movement. The patient reported improvement in prosthesis retention and stability. Both the masticatory and the speech functions of the patient improved.

Aged↗