Hideki Mizutani

Ultrastructural study on adhesions in internal derangement of the temporomandibular joint

PURPOSE This study examined the ultrastructural characteristics of adhesions in the upper joint compartment of temporomandibular joint (TMJ). MATERIALS AND METHODS Tissue biopsy specimens of adhesions were obtained during arthroscopic operation on 36 joints in 22 patients with internal derangement (ID). The biopsy specimens were examined by light and transmission electron microscopy. RESULTS Adhesions were grossly divided into two types based on arthroscopic observation: 1) a band-like type, which connected the articular fossa and TMJ disc, and 2) a pseudowall-like type, which faced the synovial fluid and was lined by articular tissue. Two types of collagen arrangement were observed at the electron microscopic level: orderly arranged collagen bundles and randomly arranged collagen bundles. Orderly arranged collagen bundles were prominent in the band-like adhesions. In pseudowall-like adhesions, mainly the randomly arranged collagen bundles were seen. However, in some dense fiber parts, orderly arranged collagen bundles also were observed. In other pseudowall-like adhesions, only orderly arranged collagen bundles were seen. Elastic fibers were abundant in some pseudowall-like adhesions with randomly arranged collagen bundles. There were no elastic fibers in the band-like adhesions, some dense fiber parts of the pseudowall-like adhesion, pseudowall-like adhesions consisting of only orderly arranged collagen bundles, and in the synovial membrane. CONCLUSION The different arrangement of collagen fibers and presence or absence of elastic fibers were observed in the two types of adhesions. These findings served to show that extracellular components correspond to a dysfunction involving an ID of TMJ.

Nerve terminals extend into the temporomandibular joint of adjuvant arthritic rats

The innervation of the temporomandibular joint (TMJ) has attracted particular interest because of the close association with complex mandibular movement. Although the pathological changes of disk innervation may have a crucial role in the development of TMJ pain, the innervation of the TMJ disk by experimentally induced arthritis has rarely been examined in detail. Arthritic rats were induced by injection with 0.1 ml solution of Complete Freunds adjuvant (CFA). We investigated three‐dimensional distribution of nerve fibers in the TMJ disk using immunohistochemistry for protein gene product‐9.5 (PGP‐9.5) and calcitonin gene‐related peptide (CGRP) in naive and arthritic rats. To clarify the possible role of nerve growth factor (NGF) and its receptor on changes in peripheral innervation of the TMJ, the expressions of trkA and p75 receptor in trigeminal ganglia were examined. Although PGP‐9.5 and CGRP immunoreactive (ir) fibers were seen in the peripheral part of the TMJ disk, they were not seen in its central part. The total length and the length density of PGP‐9.5 ir and CGRP ir nerve fibers increased in arthritic rats. The innervation area of fibers proliferating in the rostro‐medial part merged with that of fibers in the rostro‐lateral part in the arthritic rats. In addition, the ratio of trkA‐ and p75‐positive small‐ and medium‐sized cells increased in trigeminal ganglia. It is assumed that increasing innervation of the TMJ disk may be important for the pathophysiology of TMJ pain. NGF and its receptors are likely involved in pathological changes of the TMJ disk.

Influence of food consistency and dental extractions on the rat mandibular condyle: a morphological, histological and immunohistochemical study.

The purpose of this study was to investigate the relationship between food consistency and the growth of the mandibular condyle in rats. Secondly, the effect of dental extractions on cartilage of the mandibular condyle was examined in young adult rats fed foods of varying consistency. Thirty-six male Wistar rats were divided into four groups: (A) Solid diet--non-Extraction (non-Ext.) group; (B) Solid diet--Extraction (Ext.) group; (C) Powder diet--non-Ext. group; and (D) Powder diet--Ext. group. Extractions were performed at 12 weeks of age. The mandibular condyles were removed at 1, 4, and 8 weeks after the extractions. The shape of the mandibular condyles in the powder diet groups (C and D) was significantly narrower. In the Ext. groups (B and D), the thickness of the hypertrophic zone was reduced one week after the extractions. In the powder diet groups (C and D), the intensity of the staining of fibronectin decreased in the proliferative zone regardless of the extractions. In group B, a decreased intensity of this reaction was observed one week after the extractions. From these results, it appeared that food consistency and/or dental extractions affected the morphology of the mandibular condyle and the histological characteristics of the mandibular condylar cartilage.

Trichofolliculoma of the upper lip: Report of a case

A trichofolliculoma occurring in the mid-philtrum of the upper lip of a 17-year-old boy is reported. It presented as an asymptomatic, 10 mm deep sinus and histology showed keratin-filled cysts or sinuses lined by stratified squamous epithelium.

Temporal Necrotizing Infection Of Dental Origin

Recently, the frequency of occurrence of serious odontogenic infections has decreased because of improved chemotherapy with antibiotics. A small number of odontogenic infections, however, have a fulminant course and result in major complications. Necrotizing fasciitis is a severe soft-tissue infection that spreads rapidly through the tissue spaces. It is well described in the general surgery literature, but necrotizing fasciitis is a rare occurrence in the head and neck. The rate of spread is rapid, with the tendency toward systemic toxicity related to delay in initiation oftreatment. Affected patients generally have a concomitant systemic conditionsuch as diabetes mellitus. This report describes a poorly controlled diabetic patient who developed a temporal necrotizing infection from a pericoronitis.

An ultrastructural study of extracellular fibrillar components of developing mouse mandibular condyle with special reference to type VI collagen.

The localization of type VI collagen was examined from birth to 8 weeks of age. Immunohistochemical staining with anti-type VI collagen antibody was strongly positive in the hypertrophic zone and moderately positive in the fibrous zone and the outer periphery of the proliferative zone, but negative in the inner area of the proliferative zone and mature zone. After ATP treatment, type VI collagen periodic fibrils with about 80-nm intervals were frequently observed but only in the fibrous zone. They occurred mainly in the superficial area of this zone, where striated collagen fibrils were sparse, while a few were noted in the inner area, where bundles of collagen fibrils were abundant. From these distributional differences of both components, a subzonation of the fibrous zone into superficial and inner area is suggested. Moreover, with ATP treatment there were fewer type VI collagen periodic fibrils formed with increasing age (8 weeks). Testicular hyaluronidase digestion before ATP treatment facilitated the formation of periodic fibrils, in all the ages examined, in the intercellular space and around the fibroblastic cells. The interaction of type VI collagen with other components such as collagen fibrils, glycosaminoglycans or proteoglycans may play a part in maintaining the structural integrity of extracellular matrix in the mouse mandibular condyle.

Activity of dipeptidyl peptidase II and dipeptidyl peptidase iv in human gingiva with chronic marginal periodontitis

The activity of DPP II was higher in gingiva from patients with periodontitis, but the activity of DPP IV, post-proline cleaving enzyme and collagenase-like peptidase was not significantly higher than that of the control group. As DPP II activity is known to be altered in immunological diseases, these findings may suggest some role for DPP II in the pathogenesis of chronic marginal periodontitis.

Fever of unknown origin caused by dental infection: Report of a case

There are indications that dental infections may be causally related to a wide spectrum of systemic and local disorders. We present a case report of a fever that lasted more than 50 days and discuss the pathogenesis of associated dental infections.

Local recurrence of sclerosing mucoepidermoid carcinoma with eosinophilia in the upper lip: a case report

IntroductionSclerosing mucoepidermoid carcinoma with eosinophilia is a rare morphological variant of thyroid carcinoma associated with Hashimoto’s disease. To date, only three such tumors have been reported in the minor salivary glands. We describe the first case, to the best of our knowledge, of recurrent sclerosing mucoepidermoid carcinoma with eosinophilia in the minor salivary glands of the upper lip.Case presentationA 61-year-old Japanese man was referred to our hospital with a mass in his median upper lip of four years’ duration. An examination of his median upper lip revealed a well-defined tumor measuring 9×12mm in diameter, which was subsequently resected. Three years after the first surgery, the tumor recurred and was resected. Both tumors were confirmed by histopathology to be sclerosing mucoepidermoid carcinoma with eosinophilia. Neither recurrence nor metastasis was observed in three and a half years of follow-up after the second surgery.ConclusionOur findings indicate that sclerosing mucoepidermoid carcinoma with eosinophilia can originate in the minor salivary glands and may be clinically or pathologically misdiagnosed as other conditions.

Successful Hemostasis after Dental Extraction with the Use of Recombinant Activated Factor VII in a Factor VII Deficient Patient

Abstract We report our experience of successful hemostasis after dental extraction with the use of rF VII a in a FVII deficient patient. Preoperative PT% was 25%, FVII was less than 3%. Thirty minutes before tooth extraction, 1.2 mg of rFVII a was injected. At the beginning of the operation, PT% was more than 200%, FVII was 336%, the hemostasis after dental extraction was excellent. rFVII a was used effectively and safely for dental extraction in this case of FVII deficiency.