Showing papers in "Journal of Oral Pathology & Medicine in 1986"
TL;DR: The CRC technique was simple to perform, equally sensitive and superior in quantifying yeast, coliform and S. aureus carriage than the imprint culture technique and should be preferentially employed in future investigations to obtain comparable data from different centres.
Abstract: The sensitivity of the impression culture, the neat rinse culture (NRC) and the concentrated rinse culture (CRC) methods in detecting the oral carriage of yeasts, coliforms and Staphylococcus aureus was estimated in 75 individuals. The recovery of organisms from the imprint cultures of the tongue and the CRC was similar and there was highly significant positive correlation between the two techniques. The CRC was simple to perform, equally sensitive and superior in quantifying yeast, coliform and S. aureus carriage than the imprint culture technique. Hence, it is suggested that the CRC technique be preferentially employed in future investigations to obtain comparable data from different centres.
306 citations
TL;DR: The malignant potential of oral lichen planus was assessed on the basis of observations in 722 patients found among 27,599 individuals examined in various epidemiologic studies in Kerala, Ernakulam district, India and the disease did not appear to be innocuous either.
Abstract: The malignant potential of oral lichen planus was assessed on the basis of observations in 722 patients found among 27,599 individuals examined in various epidemiologic studies in Kerala, Ernakulam district, India. Seven hundred and two patients with oral lichen planus were re-examined annually over a 10-year period with a mean observation period of 5.1 years. Most of the lesions (93%) were observed among tobacco users. Carcinoma developed in 3 (0.4%) patients with oral lichen planus. Clinically, all 3 had atrophic components in their lesions, and all were tobacco users. The relative risk of a lichen planus developing oral cancer compared to a tobacco user was estimated as 3.3. However, this relative risk was not significant. Histologically, 74% of the 94 biopsies from oral lichen planus showed epithelial atrophy. Two of the 3 in whom cancer developed also showed epithelial atrophy. It is felt that epithelial atrophy probably renders the mucosa more vulnerable to the carcinogenic action of tobacco. Although this study could not confirm the precancerous nature of this disease with a high degree of certainty, the disease did not appear to be innocuous either.
158 citations
TL;DR: It is proposed that a critical step is the interaction of bacterial antigens with inflammatory cells, resulting in the production of a cytokine, interleukin-1, whose production may not be dependent on a specific microbial flora but may be triggered by a number of organisms.
Abstract: Much of the connective tissue degradation that takes place in periodontal diseases is mediated by proteolytic enzymes. Previous studies have focused on the action of proteinases released by invading polymorphonuclear neutrophils and macrophages, and bacterial enzymes. In view of recent work establishing that resident connective tissue cells can be induced by cytokines to bring about the destruction of their own matrix, we propose a new hypothesis. In this we envisage that a critical step is the interaction of bacterial antigens with inflammatory cells, resulting in the production of a cytokine, interleukin-1. Our interpretation of in vitro evidence is that the loss of connective tissue attachment and bone matrix resorption in periodontal diseases is mediated by metalloproteinases such as collagenase and stromelysin released by cells of the periodontium. Such proteolytic destruction can be induced by interleukin-1, whose production may not be dependent on a specific microbial flora but may be triggered by a number of organisms. It is now clear that interleukin-1 has multiple actions on both immune and non-immune cells; these include the induction of lymphocyte differentiation and proliferation and the stimulation of bone and cartilage resorption, and prostaglandin and metalloproteinase synthesis by connective tissues. It seems likely that further knowledge about the production and function of this cytokine will have an increasing impact in many diseases that involve resorption, particularly since interleukin-1-like molecules can be produced by cell types other than monocytes/macrophages, including keratinocytes and fibroblasts.
127 citations
TL;DR: The role of these less well-characterised predisposing factors should be considered when one is treating patients with intractable oral candidal infections.
Abstract: A variety of nutritional factors including deficiencies of iron, folic acid, vitamins, and diets rich in carbohydrates have been implicated in the pathogenesis of oral candidal infections. The following reviews the growing body of data, from in vivo and in vitro studies, related to each of these implicated factors. Although much disagreement exists as to the specific roles played by these individual factors, there is little doubt that nutritional factors either acting locally or via systemic mechanisms could significantly affect the pathogenesis of oral candidoses. Hence, the role of these less well-characterised predisposing factors should be considered when one is treating patients with intractable oral candidal infections.
125 citations
TL;DR: The growth of Candida in saliva was accompanied by a rapid decline in pH from 7.5 to 3.2 over 48 h and the major acidic components initiating and sustaining this pH drop were pyruvates and acetates.
Abstract: Growth characteristic and acid production of oral isolates of Candida albicans and Candida glabrata in glucose supplemented and glucose-free, pooled, human whole saliva were examined. Both Candida species exhibited sigmoidal growth curves in batch cultures of mixed saliva, supplemented with glucose. The growth of Candida in saliva was accompanied by a rapid decline in pH from 7.5 to 3.2 over 48 h and the major acidic components initiating and sustaining this pH drop were pyruvates and acetates. These acidic metabolites may play an important role in the pathogenesis of oral Candida infections.
105 citations
TL;DR: The results accord well with studies showing that the floor of mouth is a "high risk area" for oral carcinoma and that there is an increased relative risk of oral cancer for heavy smokers and drinkers and, in particular, for those individuals who consume beverages with a low alcohol content.
Abstract: There is evidence for synergy between tobacco and alcohol in the etiology of oral cancer but the reason for such an effect is unclear. One possible explanation is that alcohol enhances the penetration of carcinogens through the oral lining. We measured the permeability in vitro of three regions of porcine oral mucosa to the tobacco associated carcinogen, nitrosonornicotine (NNN) alone and in the presence of 5% or 50% ethanol. 50% ethanol did not significantly alter the permeability of oral mucosa to NNN except for buccal mucosa, where it was reduced. However, there was a significant increase in the permeability of gingiva and floor of mouth mucosa (but not buccal mucosa) in the presence of 5% ethanol; this increase occurred after far shorter exposures for floor of mouth than for gingiva. These results accord well with studies showing that the floor of mouth is a "high risk area" for oral carcinoma and that there is an increased relative risk of oral cancer for heavy smokers and drinkers and, in particular, for those individuals who consume beverages with a low alcohol content.
95 citations
TL;DR: Tissues from patients with oral verrucous carcinoma were examined for the presence of human papillomavirus (HPV) and the virus in each case was identified as being HPV2.
Abstract: Tissues from patients with oral verrucous carcinoma were examined for the presence of human papillomavirus (HPV). The tissues were stained for the presence of the type common papillomavirus antigen by immunohistochemical staining and the presence of HPV DNA was determined by in situ hybridization with biotin-labelled HPV DNA probes. Seventeen tissue specimens were obtained from 9 patients, and included pre-malignant lesions and primary and recurrent tumors. One pre-malignant lesion was positive for papillomavirus structural antigen. This lesion and lesions from 2 other patients hybridized at low stringency (Tm-35 degrees) to 3 different HPV probes. By hybridization under high stringency conditions (Tm-20 degrees), the virus in each case was identified as being HPV2.
87 citations
TL;DR: The results indicated that the use of such a multifactorial grading system, consisting of 7 morphological parameters, including an evaluation of both the tumor cell population itself and the tumor-host relationship, can serve as an important supplement to clinical judgement in determining the outcome of the oral tumor.
Abstract: In a retrospective histological and clinical study, a multifactorial grading system was used for histological classification and grading of malignancy in 51 cases of squamous cell carcinoma of the tongue and floor of mouth. The results indicated that the use of such a multifactorial grading system, consisting of 7 morphological parameters, including an evaluation of both the tumor cell population itself and the tumor-host relationship, can serve as an important supplement to clinical judgement in determining the outcome of the oral tumor.
82 citations
TL;DR: There are distinct differences in the keratin expression of oral epithelia which are related to the pattern of keratinization assessed histologically.
Abstract: We have examined the keratin proteins in normal human oral mucosa from 6 different regions including hard palate, buccal mucosa, tongue, gingiva and floor of the mouth. Urea-dithiothreitol extracts of EDTA separated epithelia were analysed by SDS-PAGE and immunoblotting. Eight samples from each region were investigated and showed very little individual variation in the keratin profile on Coomasie Blue-stained gels. The keratinizing hard palate and gingiva expressed identical patterns and resembled the pattern of epidermis from the flank region. The normally non-keratinizing buccal mucosa and the mucosa of the floor of the mouth expressed polypeptides distinctly different from those of the keratinizing epithelia and lacked the high molecular weight keratins. The dorsal surface of the tongue and the commissure region showed a pattern intermediate between keratinizing and non-keratinizing epithelia. The greater sensitivity of the immunoblotting technique revealed that the non-keratinizing epithelia synthesized one of the high molecular polypeptides and that the tongue produced all the bands found in keratinizing epithelia, but in very small quantities. There are, thus, distinct differences in the keratin expression of oral epithelia which are related to the pattern of keratinization assessed histologically.
79 citations
TL;DR: A correlation exists between cutaneous discomfort and angular cheilitis among dentate patients, and other etiological factors suggested for this disorder were found to be of subordinate importance.
Abstract: The purpose of this prospective study was to re-examine the relative importance of various factors in the pathogenesis of angular cheilitis. Sixty-four patients with cheilitis were examined clinically and microbiologically. In addition, a subsample of 23 patients was examined for serum iron and transferrin. The clinical appearance of the lip lesions fell into 4 categories. A ground rhagad at the corner of the mouth involving adjacent skin, was the most frequent type among dentate patients, whereas among denture wearers a deep lesion following the labial marginal sulcus was frequently observed. Dentate patients and denture wearers with cheilitis often had atopic constitution or cutaneous diseases. Pathogenic microorganisms were cultured from the lesions in all 64 patients; Staphylococcus aureus in 40 patients and Candida albicans in 45. The results of this study indicate a correlation between angular cheilitis and pathogenic microorganisms. Furthermore, among dentate patients, a correlation exists between cutaneous discomfort and angular cheilitis. Other etiological factors suggested for this disorder were found to be of subordinate importance.
79 citations
TL;DR: Oral verruca vulgaris specimens examined by in situ hybridization with biotin-labelled human papillomavirus (HPV) DNA and by reaction with antibody to type-common antigens and detection by the avidin-biotin-peroxidase complex method to determine the specific HPV types present in the lesions.
Abstract: Eleven oral verruca vulgaris specimens were examined for the presence of papillomavirus structural antigens by reaction with antibody to type-common antigens and detection by the avidin-biotin-peroxidase complex method. The specimens were also examined by in situ hybridization with biotin-labelled human papillomavirus (HPV) DNA to determine the specific HPV types present in the lesions. Six of the 11 specimens were positive for papillomavirus structural antigens. Of these 6, 5 hybridized to the HPV Type 2 (HPV2) probe and one to the HPV4 probe.
TL;DR: Results indicate that while hyaluronic acid is depolymerized in inflamed tissue, no evidence of sulfated glycosaminoglycan degradation was found, and the most likely cause for disruption to the molecular integrity of the proteoglycans is via proteolytic alteration toThe proteoglycan core protein.
Abstract: Proteoglycans have been isolated and analysed from extracts of normal and chronically inflamed human gingiva in order to determine the effects of chronic inflammation on these important soft connective tissue extracellular macromolecules. The uronic acid content of glycosaminoglycans isolated by papain digestion of normal and inflamed gingiva did not differ significantly. Likewise, electrophoretic analysis revealed that the content of hyaluronic acid, heparan sulfate, dermatan sulfate and chondroitin sulfate was similar. The sulfated glycosaminoglycans from both sources eluted from a Sepharose C1-6B column with a Kav of 0.45 (approximate Mr 25,000). However, hyaluronic acid from normal gingiva was predominantly of a large size eluting in the void volume of a Sepharose. CL-6B column, while that isolated form inflamed tissue was mostly a small molecular weight species which eluted in the included volume of a Sepharose CL-6B column. Using dissociative conditions, intact proteoglycans could be more readily extracted from inflamed tissues (90% of the total tissue uronic acid) than from normal tissues where only 80% of the total tissue uronic acid was extractable. Even though DEAE-Sephacel ion-exchange chromatography revealed no differences in charge between normal and inflamed gingival proteoglycans, Sepharose CL-4B chromatography revealed more molecular size polydispersity in samples from inflamed tissue than from normal tissue. Taken together, these results indicate that while hyaluronic acid is depolymerized in inflamed tissue, no evidence of sulfated glycosaminoglycan degradation was found. Therefore, the most likely cause for disruption to the molecular integrity of the proteoglycans is via proteolytic alteration to the proteoglycan core protein.
TL;DR: DNA-biotinylation in conjunction with the biotin-avidin-alkaline phosphatase detection system proved to be a sensitive, convenient and rapid modification of in situ hybridization.
Abstract: Four oral papillomas and 7 carcinomas were studied for the presence of HPV DNA by means of in situ hybridization. Hybridization was carried out with a HPV 16 probe labelled with biotin under different conditions (nick translation/photobiotin). Subsequently, a modified biotin-avidin-alkaline phosphatase procedure was used to visualize virus infected cells. Four/4 papillomas and 4/7 carcinomas were seen to contain HPV harbouring cells. Positive cells were located at intermediate and superficial cell layers in papillomas and in keratinized zones in carcinomas. Analogous results were found with nick translated and photobiotinylated probes. DNA-biotinylation in conjunction with the biotin-avidin-alkaline phosphatase detection system proved lo be a sensitive, convenient and rapid modification of in situ hybridization.
TL;DR: This work describes 3 additional cases of Kimura's disease and discusses these in relation to angiolymphoid hyperplasia with eosinophilia.
Abstract: Kimura's disease, eosinophilic granuloma of soft tissues, is a chronic inflammatory condition and appears as subcutaneous tumor-like nodules in the head and neck regions. Histopathologically, it is characterized by the presence of lymphoid follicles, marked infiltration of eosinophils, fibrosis and vascular proliferation. This disease occurring in the orofacial region is relatively rare, only 14 cases having been previously reported. We describe 3 additional cases of Kimura's disease and discuss these in relation to angiolymphoid hyperplasia with eosinophilia.
TL;DR: The morphological and immunohistochemical analysis revealed the following relation between the different patterns: Origin of the malignant proliferation is presumably the terminal ductal system of the salivary glands (indifferent cell of the reserve cell type).
Abstract: Twenty-four cases of adenoid cystic carcinoma from the Salivary Gland Registry of the University of Hamburg were analysed with respect to their differentiation and subclassification. With immunohistochemical methods, several groups of marker substances were analysed in these tumors: marker for a glandular function; immunoglobulins; metalloproteins; tumor markers; substances associated with the basal membrane and carbohydrate chains. The following patterns of histological differentiation were found: cribriform pattern with typical pseudocysts; tubular pattern with ductal elements; trabecular pattern with predominance of hyalinized stromal elements; basaloid pattern with low differentiated cells. For every pattern, a special immunohistochemical profile could be established. The morphological and immunohistochemical analysis revealed the following relation between the different patterns: Origin of the malignant proliferation is presumably the terminal ductal system of the salivary glands (indifferent cell of the reserve cell type). This cell can differentiate in 2 directions: a myoepithelial and a ductal cell type. Immunohistochemically, the presence of basement membrane-associated substances is accompanied by the appearance of myoepithelial-like cells. The presence of secretory products is a feature of ductal cells.
TL;DR: It is suggested that phosphophoryn is synthesized and secreted only by physiologically-differentiated odontoblasts and that the mineralization processes of mantle, secondary, reparative and DI dentins may be different from that of circumpulpal orthodentin.
Abstract: Dentin phosphophoryn is a highly phosphorylated protein which has a hydrophilic character but is not soluble in dilute acetic acid. A histochemical method was developed for staining this protein with Stains-all® in situ utilizing those chemical properties. We have succeeded in detecting the presence of this protein in circumpulpal orthodentin of human permanent and deciduous teeth, but not in mantle dentin, secondary dentin and reparative dentin. Phosphophoryn staining was also absent in the dentin of dentinogenesis imperfecta (DI) Type II, a genetic disorder of dentin formation. From these results, it is suggested that phosphophoryn is synthesized and secreted only by physiologically-differentiated odontoblasts and that the mineralization processes of mantle, secondary, reparative and DI dentins may be different from that of circumpulpal orthodentin.
TL;DR: Cells infiltrating human periapical granulomas and cysts were analyzed using cell suspensions and lymphocytes infiltrating the lesions were T cells, and more than half of the T cells were of the suppressor/cytotoxic (OKT8) phenotype.
Abstract: Cells infiltrating human periapical granulomas and cysts were analyzed using cell suspensions. Over 50% of the total cells studied were lymphocytes whilst neutrophils were the next most frequent cell type observed. Two percent of the cells were mast cells. Only a few monocytes/macrophages and natural killer cells were found. More than half of the lymphocytes infiltrating the lesions were T cells, and more than half of the T cells were of the suppressor/cytotoxic (OKT8) phenotype. The OKT4/OKT8 ratio was 0.5. The findings are compared to previous reports and the differences discussed.
TL;DR: The findings of a retrospective study of 98 minor salivary neoplasms are reported in this article, where the patient's ages ranged from 13-79 years and there was an equal sex distribution and the difference in age at the time of presentation for patients with muco-epidermoid tumors compared with those with adenoid cystic carcinomas.
Abstract: The findings of a retrospective study of 98 minor salivary neoplasms are reported. The patient's ages ranged from 13-79 years and there was an equal sex distribution. Sixty-one of the lesions were benign, 53 being pleomorphic adenomas and 8 monomorphic adenomas. Of the malignant tumors, 19 were muco-epidermoid tumors, 12 adenoid cystic carcinomas, 4 adenocarcinomas, 1 carcinoma ex-pleomorphic adenoma and 1 epidermoid carcinoma. One striking finding was the difference in age at the time of presentation for patients with muco-epidermoid tumors compared with those with adenoid cystic carcinomas. Seventy-four percent of the patients with muco-epidermoid tumors were under 50 years of age, but 75% of those with adenoid cystic carcinomas were over 50 years.
TL;DR: The results of the present study indicate that MHC antigens are expressed by epithelial cells in RAS and their expression follows a defined sequence.
Abstract: The concept of an immunopathogenesis in the establishment and progression of the recurrent aphthous stomatitis (RAS) lesion is well accepted. In this study the expression of Class I and Class II major histocompatibility complex (MHC) antigens on the epithelial cells in the preulcerative, ulcerative and healing phases of RAS lesions was investigated using monoclonal antibodies in an immunohistological technique. Both Class I and Class II MHC antigens were found on the basal cells in preulcerative lesions. As the lesions progressed to the ulcerative phase, antigen expression occurred on the cell membranes throughout the entire thickness of the epithelium. With healing, the expression of both Class I and Class II MHC antigens on epithelial cells declined to a stage where there was little or no detectable antigen on the cell membranes. Although cytotoxicity of epithelial cells in RAS lesions is accepted, the role of MHC antigen expression on these cells is uncertain and remains to be ascertained. Nevertheless, the results of the present study indicate that MHC antigens are expressed by epithelial cells in RAS and their expression follows a defined sequence.
TL;DR: Ten instances of a white plaque of the lateral tongue unique to homosexual males and referred to as oral hairy leukoplakia were analysed ultrastructurally and showed evidence by electron microscopy of the presence of papilloma virus within koilocytotic nuclei.
Abstract: Ten instances of a white plaque of the lateral tongue unique to homosexual males and referred to as oral hairy leukoplakia were analysed ultrastructurally. The surface epithelial layer exhibited extracellular, intracellular and intranuclear penetration by hyphae of Candida albicans, sometimes accompanied by coccobacilli in the extracellular space. The subcorneal epithelial layer included koilocytoid ballooned cells which had a paucity of cytoplasmic organelles and displayed condensation and emargination of the chromatin. Cells that exhibited these nuclear changes were found to be infected by a herpes-type virus which was visualized by electron microscopy in all ten cases. Clusters of nucleocapsids (86-110 nm in diameter) occurred in the nuclei and enveloped virions (111-175 nm in diameter) occurred in the cytoplasm and extracellular spaces. Virions showed budding from the nuclear envelope. Bundles of tubular structures (20 nm diameter) arranged in parallel occurred in the cytoplasm of some koilocyloid cells. There was no evidence by electron microscopy of the presence of papilloma virus within koilocytotic nuclei.
TL;DR: The only reliable method was immunocytochemistry with an antibody to smooth muscle myosin, with immunofluorescence on frozen tissue and immunoenzyme labelling on methacarn-fixed/paraffin-processed material, but formalin fixation did not permit successful staining.
Abstract: Myoepithelial cells have frequently been implicated in salivary gland tumour histogenesis. A major problem has been the reliable identification of these cells at the light microscopical level, both in tumours and in normal salivary glands. Many methods have been advocated, often with comparatively little evaluation in normal human tissue and with limited comparison between techniques. This paper reviews the application of histological staining techniques, enzyme histochemistry and immunocytochemistry with antibodies to actin, myosin and keratins. The only reliable method was immunocytochemistry with an antibody to smooth muscle myosin, with immunofluorescence on frozen tissue and immunoenzyme labelling on methacarn-fixed/paraffin-processed material. Formalin fixation did not permit successful staining. Monoclonal antibodies to specific keratin polypeptides may prove to be a useful label of myoepithelial cells but at the present time the available cytokeratin antibodies preferentially stain duct cell populations.
TL;DR: The observations indicate that the lesions consist of vegetable remains with an associated foreign-body type of inflammatory response.
Abstract: An unusual giant-cell granulomatous inflammatory oral lesion is characterised by the presence of hyaline rings and by a lack of agreement on their nature, opinions ranging from their being hyaline degenerative blood-vessels to remains of leguminous cells. Ten such lesions and a variety of vegetables have been examined in the present investigation. Light-microscopical examination of the lesions revealed the hyaline rings surrounded by inflamed granulation tissue with associated multinuclear giant cells. Electron-microscopical examination showed them to consist of a material similar to that of vegetable cell walls, sometimes with an associated superficial layer of collagen. The observations indicate that the lesions consist of vegetable remains with an associated foreign-body type of inflammatory response.
TL;DR: It is concluded that a combination of skeletal and dentoalveolar factors contributes to the midface hypoplasia associated with Axenfeld-Rieger syndrome.
Abstract: Apart from the three distinguishing findings for the diagnosis of Axenfeld-Rieger syndrome (oligodontia, failure of periumbilical skin to involute, and ocular anterior chamber defects), a common feature is midfacc hypoplasia. Two theories have been proposed to explain the midfacc hypoplasia. One theory suggests a pleiotropic gene effect of defective neural crest cells, while the other theory proposes that midface hypoplasia is a local effect due to the absence of teeth. This study presents an evaluation of the craniofacial defects in a family affected with Axenfeld-Rieger syndrome. The maxillary deficiency in three affected patients was not limited to the alveolar regions. We conclude that a combination of skeletal and dentoalveolar factors contributes to the midface hypoplasia associated with Axenfeld-Rieger syndrome.
TL;DR: Clinical investigation demonstrated aplasia of all the major salivary glands, lacrimal gland Hypoplasia and enamel hypoplasia in a patient presenting with the symptoms of lifelong xerostomia.
Abstract: A case of a patient presenting with the symptoms of lifelong xerostomia is discussed. Clinical investigation demonstrated aplasia of all the major salivary glands, lacrimal gland hypoplasia and enamel hypoplasia. The management and aetiology of the case is discussed.
TL;DR: The endogenous generation of N-nitroso compounds may be causally related to the development of oral or gastric cancer and the peroxidation of these agents is likely to be one of the degrading reactions.
Abstract: Human whole saliva protects the oral environment in many different ways from invading pathogenic microorganisms. Human saliva is also capable of inactivating mutagenic and carcinogenic agents by various mechanisms. The peroxidation of these agents is likely to be one of the degrading reactions. However, under certain circumstances some potentially carcinogenic compounds, such as N-nitrosamines, may be generated in whole saliva or -even more likely - in the saliva-gastric juice mixture after swallowing. The formation of N-nitroso compounds requires relatively high intake of nitrate e.g. from vegetable juices. Nitrate is partly reduced to nitrite by oral bacterial enzymes. The nitrosation of various secondary amines is favoured by high salivary (or gastric) concentration of thiocyanate and by low pH. The endogenous generation of N-nitroso compounds may be causally related to the development of oral or gastric cancer.
TL;DR: The results reported here apparently differs from the results of earlier investigators who had reported that none of the postmortem subjects without autoimmune diseases or connective tissue diseases showed focal lymphocytic infiltration in minor salivary glands.
Abstract: Focal lymphocytic infiltration in the human labial salivary glands was examined in a series of 190 postmortem subjects after suitable exclusion had been made. Focal lymphocytic infiltration, with or without a slight degree of parenchymal atrophic change, was found in 22.4% of the males and in 35.7% of the females. Of these, 9.0% (12 subjects) of the males and 10.7% (6 subjects) of the females with focal lymphocytic infiltration did not show any atrophic changes of the parenchyma. In the series reported here, the prevalence of focal lymphocytic infiltration apparently differs from the results of earlier investigators who had reported that none of the postmortem subjects without autoimmune diseases or connective tissue diseases showed focal lymphocytic infiltration in minor salivary glands. Although the pathological significance of focal lymphocytic infiltration in the minor salivary glands remains obscure, its diagnostic value for Sjogren's syndrome is discussed.
TL;DR: Overall reduction of cyst size with increasing epithelial atrophy and loss of hyaline bodies and mucous cells, has been shown to occur with increasing cyst age and it is suggested that the majority of radicular cysts heal spontaneously following extraction of the associated tooth.
Abstract: Histological and radiographic study of 33 uninfected residual radicular cysts has shown that there is a slow increase in mineralised deposits within the cyst lumen with time. This becomes prominent histochemically in those cysts more than 8 years old and radiographically 6 years later. It would appear that mineralisation in these elderly cysts is due to dystrophic calcification of degenerate cellular material within the cyst lumen. Inflammation in all cysts, apart from mild granulomatous reactions related to cholesterol within cyst walls, was minimal. Overall reduction of cyst size with increasing epithelial atrophy and loss of hyaline bodies and mucous cells, has been shown to occur with increasing cyst age. It is suggested that the majority of radicular cysts heal spontaneously following extraction of the associated tooth. Furthermore, lesions that persist as residual radicular cysts will also undergo slow resolution if inflammation is not a prominent feature.
TL;DR: The results of this study show that mononuclear infiltration beneath and adjacent to the epithelium, parakeratosis and degeneration of the basal layer of the epithelial layer were consistent features.
Abstract: In a retrospective study of 112 cases, an attempt has been made to further delineate the histopathological parameters which are useful in making a diagnosis of oral lichen planus The results of this study show that mononuclear infiltration beneath and adjacent to the epithelium, parakeratosis and degeneration of the basal layer of the epithelium were consistent features Linear regression analyses of the parameters studied provided partial support for a cell-mediated immune mechanism
TL;DR: Surface demineralization of enamel was observed as the enlargement of micropores, the central core dissolution of crystals, the formation of channels and the enlargements of spaces at prism boundaries, and some new needle-shaped crystals.
Abstract: Electron microscopy of the intact surface zone of white spot and brown spot carious lesions showed that in general their ultrastructure was similar. Their outermost crystalline surface consisted of small crystals similar to those in healthy enamel, crystals with central core dissolution, and rounded crystals. Below this, surface demineralization of enamel was observed as the enlargement of micropores, the central core dissolution of crystals, the formation of channels and the enlargement of spaces at prism boundaries. Remineralization of enamel was observed as the partial occlusion of voids, the rounding and enlargement of crystals, and some new needle-shaped crystals. Some other features indicated combined demineralization and remineralization. The occlusion of spaces at prism boundaries was a more common feature in brown spot lesions, whereas the pockets of rounded crystals were more common in white spot lesions. A relatively uniform distribution of needle-shaped crystals throughout the intact surface zone was a feature of some brown spot lesions only.
TL;DR: Results showed consistent surface erosion occurring on the root face only at a pH level of 5.5 in buffer containing enzymes, suggesting that enzymes may have a contributory effect on caries lesion formation in root surfaces.
Abstract: This study investigates enzyme degradation of collagen at various pH levels and is designed to obtain information pertaining to the effect of proteolytic enzymes on caries-like lesion formation and progression. One hundred and eight sections of human teeth with exposed areas on enamel and root face, were placed into an enzyme/buffer system maintained at pH levels of 4.0, 5.5 and 7.0. Periodically, throughout the experimental period, sections were removed and examined histologically for caries-like lesion formation. Results showed consistent surface erosion occurring on the root face only at a pH level of 5.5 in buffer containing enzymes. Sections placed in pH 5.5 buffer only, which served as controls, showed obvious lesion formation on the root face, but with histologically intact surfaces. This interaction occurring between enzymatic activity and acid demineralization suggests that enzymes may have a contributory effect on caries lesion formation in root surfaces.