摘要:

Oral submucous fibrosis (OSF) is a high risk precancerous condition, predominantly affecting Indians. Consumption of chilli was hypothesized as an etiologic factor on the basis of ecological observations and a solitary animal experimental study. Subsequent epidemiologic studies that included case‐series reports, large cross‐sectional surveys, case‐control studies, cohort and intervention studies have identified areca nut as the major etiologic agent. Tissue‐culture studies involving human fibroblasts, areca nut extracts and areca nut alkaloids supported this etiologic hypothesis by showing fibroblastic proliferation and increased collagen formation. Currently, the role of genetic susceptibility and that of autoimmunity are receiving attention. The influence of nutritional factors, if any, remains

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01156.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The aim of this study was to investigate the enamel microhardness and the histological features of eight enamel pearls of various size. The microhardness of the pearl enamel ranged from 272.4 to 407.2 Vickers microhardness values (VMV) and resembled that of the enamel of the carrier teeth (277.1–424.3). A histological resemblance between the tissues of the enamel pearls and those of the carrier teeth was also found. The resemblance was more pronounced in larger pearls, which showed a variability of the enamel microhardness and structure in the occlusal‐cervical direction typical of the tooth crown. Large pearls also exhibited a root and a pulp. Some histological features of the enamel pearls were probably caused by pressures exerted on the developing pearl by its surroundings. It is suggested that the histogenesis of small and large pearls is based on the ability of the developing root of the carrier tooth to behave in part as a new tooth g

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01157.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The immunohistochemical distribution of collagens type I, III, IV, V, VI, of undulin and tenascin. and of integrins α2, α3, α4, α5, α6 and β4, was studied in 14 biopsies of oral lichen planus (OLP), 5 biopsies of orthokeratinized gingiva and 4 biopsies of oral fibrous hyperplasia. The localization of extracellular matrix proteins showed altered expression in OLP when compared to normal oral mucosa, with two principal patterns corresponding to the reticular or atrophic type. Whereas in the reticular type a focal loss of immunoreactivity for collagen types I, III, V, VI and undulin was noted in areas with a cellular infiltrate, in the atrophic variant almost complete loss of immunoreactivity of the subepithelial extracellular matrix was found. There was no clear correlation between the distribution of extracellular matrix proteins and their integrin receptors. The present findings suggest that the autoimmune reaction in OLP might not be primarily targeted to oral keratinocytes but to an unknown antigen in the connective tissue stroma. The changes in the subepithelial extracellular matrix associated with the inflammatory reaction might, especially in the atrophic variant, impair the cross‐talk between epithelium and mesenchyme and favour both the loss of barrier function and the development of erosions in the clinical course of the

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01158.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Cell proliferation in oral leukoplakia has been studied by estimating the number of cells in the S phase usingin vitro3H thymidine labelling. The labelling index was found to be increased 1.77 fold in leukoplakias compared to the clinically normal control sites (P<0.005). This rise in labelling index was found to be related to an increase in the proportion of the cells in the basal cell layer engaged in cell production. Both leukoplakia and the control specimens showed epithelial atypia, although in the latter samples this was mild yet suggestive of a possible field change in the oral epithelium of a small group of tobacco users. A significant positive correlation was found between the epithelial atypia score and the labelling index. This raises the possibility of using the labelling index as an objective prognostic marker in assessing potential malignancy in oral leukoplakia lesions.

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01159.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The aim of the present investigation was to analyse the fibroblast phenotype in the main groups of odontogenic cysts. We have examined the muscle differentiation markers alpha‐smooth muscle actin (ASMA) and desmin and the presence of vimentin using immunocytochemistry. Fibroblasts of other cyst types, hyperplastic fibrous lesions, and from several normal sites were used as controls. All fibro‐blasts stained for vimentin, but a variable proportion of cyst wall fibroblasts were also positive for the antibody to ASMA. Their distribution was not random and two positive zones could be distinguished, an inner subepithelial layer and an outer region adjacent to the bone‐facing surface. This staining pattern was observed for all the types of odontogenic cysts studied, although the subepithelial staining was more frequent in the presence of an inflammatory infiltrate. The contractile nature of these cells was supported by their ultrastructural appearance. Some non‐odontogenic cysts showed subepithelial fibroblasts strongly labelled with ASMA; in the control tissues ASMA was negative except for pericytes and some groups of cells in supracrestal gingiva. These results demonstrate a distinct cell population with a myofibroblast phenotype in the odontogenic cyst wall and with a distribution which may enable them to contribute to wall elasticity constraining cyst expansion. Their presence in all types of odontogenic cyst studied would suggest that myofibroblast formation is independent of the pattern of cyst

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01160.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Exfoliative cheilitis is an uncommon condition affecting the vermilion zone of the upper, lower or both lips. It is characterized by the continuous production and desquamation of unsightly, thick scales of keratin; when removed, these leave a normal appearing lip beneath. The etiology is unknown, although some cases may be factitious. Attempts at treatment by a wide variety of agents and techniques have been unsuccessful. Three patients with this disease are reported and its relationship to factitious cheilitis and candidal cheilitis is discussed.

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01161.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Liposarcomas of the oral tissues are rare. There have been 28 previously reported in the literature. A clinicopathologic study of 4 patients with liposarcoma involving the oral tissues is presented ‐ one in the tongue, one in the palate, and two in the submandibular space. Two of the tumors were myxoid, one was of well‐differentiated type and one was of pleomorphic type. Three of the lesions were diagnosed clinically as benign. The most important lesson to be learned from the histopathology is the positive identification of atypical lipoblasts. Follow‐up data indicate that prognosis generally corresponds to the tumor type. The patients with myxoid and well‐differentiated liposarcoma remain alive and with no evidence of disease. The patient who died of tumor had a pleomorphic liposarcoma. Treatment of these lesions should consist of wide surgical excision and consideration of adjunctive or palliative radio

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01162.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The inductive fibroameloblastoma is a rare odontogenic tumor that occurs in young cats of either sex, predominantly in the anterior maxilla. This article critically reviews the previously published examples with emphasis on microscopic features, relationship to ameloblastic fibroma, and biologic behavior; an additional example is described. This tumor differs microscopically from human ameloblastic fibromas in that it is not well‐circumscribed but rather originates multifocally within the supporting connective tissue as characteristic, spherical condensations of fibroblastic connective tissue (ectomesenchyme) associated with islands of odontogenic epithelium. Its biologic behavior requires further study but the tumor apparently is unique to cats and is distinct from human ameloblastic fibroma. Consequently,feline inductive odontogenic tumoris suggested as being a more appropriate designation than inductive fibroameloblastom

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01163.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1995.tb01164.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY