Masuichiro Oka

Comparison of Functional Recovery After Nonsurgical and Surgical Treatment of Condylar Fractures

This article evaluates 16 cases of condylar fracture treated surgically, comparing them with the 20 cases treated nonsurgically, with a 2-year follow-up. Although severely displaced and luxated fractures were involved in the surgical group with rigid internal fixation, satisfactory postoperative function and occlusion were achieved at the same level as in the nonsurgical group, without severe complications.

An immunohistochemical study of the extracellular matrix in oral squamous cell carcinoma and its association with invasive and metastatic potential

The expression of extracellular matrices (ECMs) laminin (LN), type IV collagen (IV C), heparansulphate proteoglycan (HS-PG), fibronectin (FN), tenascin (TN), decorin and vitronectin (VN) was examined immunohistochemically in 112 primary tumours and 29 metastatic cervical lymph nodes in oral squamous cell carcinoma (OSCC). In highly invasive primary tumours, the expression of LN, IV C and HS-PG in the basement membrane along the tumour-stroma borderline and the expression of decorin and VN in the tumour stroma at the invasive site were all significantly decreased. The expression of FN and TN in the tumour stroma at the same site was markedly increased. In peritumour stroma in metastatic lymph nodes, LN, IV C, HS-PG, decorin and VN were weakly expressed, while FN and TN were strongly expressed. Thus, the staining pattern of the ECMs in the metastatic lymph nodes was similar to that in highly invasive primary tumours. Furthermore, in primary tumours of metastatic cases, the expression of LN, IV C, HS-PG, decorin and VN obviously decreased, while the expression of FN and TN increased when compared with those of the non-metastatic cases. The investigation of ECMs in OSCC was valuable in predicting tumour behaviour.

Complications of miniplate osteosynthesis for mandibular fractures

Postoperative complications of delayed osteosynthesis with stainless steel miniplates were examined in 110 patients with mandibular fractures. The miniplates were removed in 91 of the patients, even if symptom-free, once sufficient bony union was obtained, and the healing conditions and the surrounding tissues were examined. Malocclusion, exposure of miniplates, delayed union, and infection were observed in 3.6%, 3.6%, 1.8%, and 1.0% of the patients, respectively. The complication rates were within acceptable limits even when treatment was performed later than 24 hours after injury. The healing conditions and the surrounding tissues did not show any serious problems. Thus, at least in short-term retention, stainless steel miniplates seem to be effective and suitable for osteosynthesis of mandibular fractures.

Surgical treatment of fractures of the mandibular condylar neck

In this paper, the authors describe their surgical procedures, the clinical management, and radiological evaluation of condylar neck fractures. The condylar neck is the site of approximately two-thirds of all mandibular fractures. These are treated either conservatively or by open reduction. Indications for open reduction are discussed. Approximately 5-30% of all condylar neck fractures are treated surgically, depending on the circumstances of each case. The role of open reduction is realignment of segments, early function and decreased post-operative complaints. It has been our experience that surgical treatment of selected condylar neck fractures is successful.

Age-related changes in the human mandibular condyle: A morphologic, radiologic, and histologic study☆

PURPOSE This study determined the osteoarthrotic changes in the human mandibular condyle in relation to aging and the loss of dental occlusal contacts. MATERIALS AND METHODS Thirty-four condyles obtained at autopsy were studied morphologically, radiologically, and histologically. RESULTS With advancing age, the articular surface of the mandibular condyle morphologically showed severe degenerative changes. The condyles with these changes tended to be from the side of the mandible with minimal areas of occlusal contact. Radiographically, an irregularity of the cortical bone plate was most commonly seen in the fifth and sixth decades, whereas a polygonal or flattened structure was mainly observed after the seventh decade. CONCLUSION The histologic findings suggest that a decrease in the cellular components with advancing age may play a critical role in the development of degenerative changes.

Increased expression of cathepsins E and D in reactive microglial cells associated with spongiform degeneration in the brain stem of senescence-accelerated mouse

Senescence-accelerated mouse (SAM) P8 and P10 exhibit a spongy degeneration, especially in the brain stem, and a brain atrophy mainly in the frontal portion of the cerebral cortex, respectively, with advancing age. In an attempt to clarify the role of two distinct intracellular aspartic proteinases, cathepsins E (CE) and D (CD), in these age-related pathological changes, accumulation and localization of these enzymes were investigated in the brain stem and the cerebral cortex of SAMP8 and P10 and in the senescence-resistant control SAMR1 with four different age groups (1 week and 2, 6, and 12 months). In the brain stem of SAMP8, a marked spongy degeneration was observed at more than 2 months of age. The same degree of spongy degeneration was also observed in the brain stem of age-matched SAMP10 but not SAMR1. The nonlysosomal enzyme CE was barely detectable in the brain stem of all three strains at 1 week of age, but it was markedly accumulated in the brain stem of SAMP8 and P10 at 2 months of age. The lysosomal enzyme CD was found in relatively high concentration in the brain stem of all three strains at 1 week of age. At 2 months of age, CD contents were significantly increased in the brain stem of SAMP8 and P10 compared with those of age-matched SAMR1. At the light-microscopic level, increased immunoreactivities for CE in the brain stem of 2-month-old SAMP8 and P10 were found in reactive microglial cells clustered at the spongy areas but not in microglial cells with resting or ramified morphology and astrocytes. The increased immunoreactivity for CD was observed mainly in reactive astrocytes and partially in reactive microglial cells. Immunoblotting analyses revealed that CE in the brain stem of 2-month-old SAMP10 consisted of only the mature form of 42 kDa, whereas CD in this tissue is composed of mainly the mature form of 44 kDa and partially its degradation products. On the other hand, there was a marked brain atrophy mainly in the frontal portion of the cerebral cortex of 6-month-old SAMP10 but not in age-matched SAMP8 or SAMR1. Although CE was not detectable even in the atrophied cortical area of SAMP10, CD contents in the cerebral cortex slightly increased with senescence in all three strains.(ABSTRACT TRUNCATED AT 400 WORDS)

Heterotopic salivary gland tissue in lymph nodes of the cervical region

The occurrence and composition of intranodal salivary gland tissue (ISGT) in the head and neck region were investigated. ISGT was mainly composed of mature acini, intercalated ducts and intralobular ducts but immature acini (20.8%) and immature small ducts (18.8%) were also observed. The latter resembled salivary gland tissue in an early developmental stage. Various histological changes of ISGT were observed including cyst formation (16.7%), oncocytic metaplasia (8.3%), oncocytic adenomatous hyperplasia (8.3%) and ductal proliferation (20.8%). Thus ISGT may contain immature components with a potential for differentiation and proliferation.

A comparison of glandular involvement between chronic graft-versus-host disease and Sjögren's syndrome.

Patients with chronic graft-versus-host disease (cGVHD) occasionally suffer from symptoms of xerostomia and xerophthalmia, which are also features of Sjógrens syndrome (SS). To identify differences in the glandular involvement between cGVHD and SS, we measured the proportions of infiltrating lymphocyte subsets and the expression of HLA-DR antigen and cell adhesion molecules in labial salivary glands (LSG). In cGVHD, more than 90% of the infiltrating lymphocytes were T cells with a slight predominance of CD8+ over CD4+ cells. In SS, CD4+ cells were predominant, and B cells accounted for 10-30% of the infiltrating lymphocytes. Ductal epithelial cell associated with lymphocytic infiltration expressed HLA-DR antigen in both cGVHD and SS. In SS alone, HLA-DR antigen expression also occurred without associated lymphocytic infiltration. The expression of adhesion molecules on ductal epithelial cells, especially vascular cell adhesion molecule 1, was more intense in SS than in cGVHD, while that on endothelial cell was similar in cGVHD and SS. These data suggest that the pathogenesis of glandular involvement of cGVHD is different from that of SS.

Age-related changes in cellular localization and enzymatic activities of cathepsins B, L and D in the rat trigeminal ganglion neuron

Altered localization and cellular level of three distinct lysosomal proteinases, cathepsins B (CB), L (CL), and D (CD), with aging were investigated in the rat trigeminal ganglion (TG) by immunohistochemical and quantitative analyses. At the light microscopic level, the intracytoplasmic distribution of these three enzymes was found to change with aging: These lysosomal proteinases in the TG of young rats (2-3 months of age) were widely and evenly distributed throughout the cytoplasm as coarse intracytoplasmic granules, whereas they were localized at focal cytoplasmic sites of the TG neurons of aged rats (28-31 months of age) as coarse aggregates. A similar distribution was observed with a major lysosomal membrane sialoglycoprotein having an apparent molecular mass of 107 kDa (LGP107). The cellular distribution of the three cathepsins as well as LGP107 in the TG neurons of aged rats corresponded well with that of autofluorescent lipofuscin. At the electron microscopic level, the age-related redistribution of these cathepsins in the TG neurons was found to be due to their great accumulation in autolysosomes localized at the focal perinuclear sites. The cellular levels of CB and CL determined by activity measurement in the TG of the young rats were 1.8 and 1.7 times as much as those of the aged rats respectively. In contrast, no significant difference was observed between the CD activities in the two age groups. These results strongly suggest that age related changes in localization and cellular level of CB, CL, and CD in TG neurons are closely linked with the increased formation of autolysosomes and lipofuscins, which is the most ubiquitous age-related cytological alteration.

Immunohistochemical detection of desmosomes in oral squamous cell carcinomas: Correlation with differentiation, mode of invasion, and metastatic potential

An expression of desmosomal glycoprotein 1 (DG 1) was immunohistochemically examined in 77 biopsies and 21 metastatic cervical lymph nodes of oral squamous cell carcinomas (SCC). In the primary tumors the DG 1 expression was significantly reduced at the invasive site of poorly differentiated and highly invasive tumors. In cases of metastases in cervical lymph nodes, the DG 1 staining at the invasive site of the primary tumor was significantly less than that of nonmetastatic cases. The DG 1 expression in the metastatic lymph nodes was as weak as that in the primary tumor. Thus, we suggest that immunohistochemical investigation of DG 1 expression in oral SCC is valuable in predicting tumor behavior.