Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory oral mucosal disease of unknown etiology. OLP presents as white striations, white papules, white plaques, erythema, erosions, or blisters affecting predominantly the buccal mucosa, tongue and gingiva. Both antigen-specific and non-specific mechanisms are hypothesized to be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8(+) cytotoxic T cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase activation in OLP lesions. These mechanisms may combine to cause T cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T cell migration and keratinocyte apoptosis in OLP. The various hypotheses proposed for pathogenesis of oral lichen planus are discussed in this review.

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Background: The value of silver staining of nucleolar organizer region (AgNOR) counts as a diagnostic aid and has been reported in several neoplastic entities. Previous studies have proven the value of the morphometric evaluation of AgNOR in the detection of incipient cellular alterations. Materials and Methods:Computer-assisted morphometric analysis of AgNORs was performed in normal oral mucosa and mucosa adjacent to oral squamous cell carcinoma (OSCC). Morphometric values were compared between the study groups. Descriptive data were presented as mean ± SD; Student t-test was used for assessing the possible signifi cant difference between the study groups. Results:The results of the present study showed a signifi cant difference in all the four AgNOR-related parameters from epithelium adjacent to OSCC compared to the normal oral mucosa. Conclusion:The nucleolar organizing region (NOR)-related parameters assessed are biologically informative and easy to monitor routinely at a pathology laboratory. Further, AgNORs provide valuable data by which we can study the spectrum of nuclear changes in malignant and premalignant lesions.level and these should be regarded as the true interphase counterpart of the NORs present on the fi ve human acrocentric chromosomes, namely chromosome number 13, 14, 15, 21, and 22. The expression "AgNOR" designates, conveniently, the silver-stained NOR proteins. The argyrophilic silver staining of nucleolar organizer region (AgNOR) technique is remarkably specifi c as a means for the detection of NORs that demonstrates by virtue of silver binding to a wide array of NOR-associated Proteins (NORAPs). These include ribonucleic acid (RNA) polymerase I, C 23 protein (Nucleolin), and B 23 protein. [4] The patterns of NOR by size and distribution, as visualized by silver staining (AgNORs), are known to vary with different cell cycle stages. The number of individual dots may increase during the mitotic phase, whereas in the G 1 phase, there is a tendency for the dots to decrease in number, with a concomitant increase in AgNOR area. Computerized image analysis of the number of AgNORs, AgNOR area, size, and shape is an accurate and reproducible method to study the proliferative potential and cell stability of the tissue analyzed. IntroductionOral mucosa adjacent to squamous cell carcinoma (OSCC) is an interesting model for studying the biology of epithelia, which may have higher risk for malignant change in keeping with the premalignant hypothesis.[1] OSCC usually develops at a single site of the mucous membrane and expands in depth and laterally. Slaughter et al., [2] have suggested that carcinoma would arise from multifocal areas of precancerous change. Thus, lateral growth of the tumor may be due in part to progressive change to cancer of peripheral cells and not solely to expansion and destruction from preexisting malignant cells. Moreover, mucosa may be infl uenced by the paracrine effects of various growth factors produced by the cancer. [1] Nucleolar organizing regions (NORs) are loo...

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Background: The clinical manifestations of these lesions comprises pain, paresthesia, swelling, drainage, tooth loss, root resorption, and facial deformity. Alteration in oral and maxillofacial (OMF) tissues of the lesions may cause esthetically and functionally unfavourable effects in patients. Aims and Objectives: To determine the frequency of odontogenic cysts, tumors, and other lesions. Materials and Methods: Patient's records of histopathological reports from the archives of the Department of Oral and Maxillofacial Pathology were obtained and reviewed over a period of 2 years, and therefore, the lesions were classified into four groups. In cases of recurrent lesions, only the primary diagnosis was considered. The research protocol was approved by the ethical committee of the institution. Results: About 56.4% of males had ameloblastoma, 54.9% of females had cementoma. 59.4% females had giant cell granuloma, 87.5% females had pyogenic granuloma, 77.2% females had osteoma, 65.1% of the female population were belongs to the benign fibro-osseous lesions and 50.2% of females were from fibrous dysplasia in group 3. About 58.8% females had squamous cell carcinoma in group 4. Conclusion: To adequately determine the prevalence and incidence rate of OMF lesions, biopsies performed by other specialists such as otolaryngologists and plastic surgeons in OMF regions should also be evaluated.