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Introduction: Shammah is a form of smokeless tobacco commonly used in the Arabian Peninsula. The data on the harmful effects of shammah on oral health, particularly oral malignancies, are scarce. The aim of this review was to explore the association between shammah use and development of oral potentially malignant disorders (OPMD) and/or oral cancer.Materials and Methods: PubMed, EMBASE, Scopus, Web of Science and grey literature from January 1990 up to and including April 2018 were searched. Two independent reviewers performed the study selection according to eligibility criteria.Results: A total of 10 studies that met the eligibility criteria were included. The odds of developing OPMD and/or oral cancer in relation to shammah use varied, with one study reporting a 39 increased risk (39, 95% CI: 14-105). The associated increased risk was relatively low among those that have stopped using shammah and ranged from threefold (3.65; 95% CI: 1.40-9.50) to 12-fold (12.6; 95% CI: 3.3-48.2).Conclusion: Shammah use seems to increase the risk of development of OPMD and/or oral cancer. [ABSTRACT FROM AUTHOR]

Background: Compared with smoking, there is much less information about smokeless tobacco (ST) use in the United States. The purpose of this study is to characterize and compare ST use among American men in 2000 and 2005. Methods: We used US National Health Interview Surveys from 2000 and 2005 to estimate the prevalence of ST use, describe the demographic and socioeconomic profile of ST users and evaluate ST use according to product type and with respect to smoking. Results: The prevalence of ST use among American men was 4.4% in 2000 and 4.3% in 2005. Almost all ST users were white, about half were 25–44 years old and 80% lived in the South or Midwest, commonly in small metropolitan and rural areas. Educational and income levels of ST users were lower than those of never users of tobacco. One-third of ST users also smoked; cigarette consumption was lower among dual users than among exclusive smokers. In 2005, 1.3 million current ST users were former smokers but 3.2 million smokers were former ST users. ST users were evenly distributed between snuff (43%) and chewing tobacco (44%) in 2000 and 13% used both products. By 2005 snuff use was clearly dominant. Conclusions: The prevalence of ST use among men is low but stable; dual use of cigarettes and ST is common, and snuff has become the dominant ST product. [ABSTRACT FROM AUTHOR]

While carcinogenicity of smokeless tobacco (ST) to humans is well established the oral lesions that precede development of cancer are less well characterized. The clinical appearances of ST-associated lesions are variable. Epidemiological studies show a strong significant association of risk with chronic daily use but population differences are noted because of various commercial products in use. Morphological features observed are some what different to oral lesions caused by smoking and oral dysplasia in ST-associated lesions is less common. Effects of ST on oral keratinocytes observed in vitro include alterations in cell proliferation, apoptosis and activation of inflammatory markers. Genetic aberrations caused by ST include activation of ras, uncommon in smokers but mutational hot spots in p53 encountered are similar to those in smokers. [ABSTRACT FROM AUTHOR]

Background: Regular use of snuff is known to cause whitish oral mucosal lesions of variable severity at the usual quid placement site. The main aim of this study was to elucidate cellular mechanisms involved in snuff-induced epithelial changes.Methods: Expression patterns for markers of cell proliferation (PCNA, Ki-67), cell cycle regulation (p53, p21), keratin changes (pankeratin, CK18, CK19), cell stress (HSP 70) and collagen type IV in 14 snuff-induced oral mucosal lesions and 12 control samples were analyzed by immunohistochemistry (IHC).Results: On light microscopy, all snuff-induced lesions were characterized by a hyperkeratinized and thickened epithelium. Some vacuolized cells, markers of cell degeneration, were frequently seen (in 9/14 of the samples) in the superficial layers in epithelia. Expression of PCNA and Ki-67 was found in a statistically significantly fewer cells in snuff-induced lesions (P < 0.001) than in the controls. This indicates that epithelia in snuff-induced lesions are not thickened as a result of increased cellular proliferation, but by protracted turnover of differentiating cells. Of cell cycle markers, p21 was found be up-regulated in 4/14 snuff-induced lesions, probably by p53-independent pathways. Only two snuff-induced lesions showed p53 positivity. However, the number of stained cells with p53 and p21 was not statistically different from that in controls. Expression of CK18, but not any alterations in CK19 expression, was seen in 5 of 14 snuff-induced lesions. Snuff also seems to stimulate the expression of collagen type IV, possibly by basal cells, as indicated by the thickened staining of the basal lamina.Conclusions: The findings of this study showing suppressed cellular proliferation and infrequent p53 dysfunction in snuff lesions may partly explain why dysplastic changes are seldom seen in mucosal lesions induced by the Scandinavian type of snuff. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess possible reversibility of oral mucosal changes, associated with the use of Swedish moist snuff, after change of habit. Biopsies from a total material of 252 regular snuff users, 184 using loose snuff and 68 using portion-bag packed snuff, were screened microscopically to identify histopathologic epithelial changes in addition to, or differing from, those generally seen as a result of snuff use. The main basis for selection of these variables were the criteria of epithelial dysplasia as defined by WHO and the eight histologic features, which have been reported to be the most important discriminators to separate cases with leukoplakia that subsequently developed carcinoma, from those that did not. Twenty-nine subjects, 3 showing Degree 2 lesions, 21 Degree 3 lesions and 5 Degree 4 lesions, all of them loose snuff users were identified. All the 29 users were re-examined clinically and histologically after 3-6 months. The rebiopsy was always secured from the same mucosal area as the original biopsy. At follow-up, 20 subjects had either stopped their snuff habit or changed to portion-bags and changed placement of the quid. All of them showed a healthy mucosa at the previous biopsy site and normal tissue in the histologic examination of the rebiopsies. Seven subjects had changed to portion-bags and variably reduced their daily exposure to snuff. At follow-up they presented with less pronounced clinical changes and the rebiopsies showed evidence of reduced epithelial changes. One major conclusion from this study is that tissue changes, clinically as well as histologically, are reversible following cessation of snuff habit.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

From a total material of 184 Swedish users of loose packed moist snuff and 68 users of portion-bag packed moist snuff, cases were selected from subgroups based on a four-point clinical grading scale. The selected material for the study comprised 70 cases (ten from each clinical grade group, no Degree 4 lesion was found among portion-bag users). Features recognized in biopsies from these cases together with findings in previous studies correlated well with the use of a four-point scale for the grading of clinical changes, especially in the context of discriminating lesions for which special efforts should be undertaken to make the patient stop or change the snuff dipping habit and for selecting patients in whom regular clinical follow-up including a biopsy should be carried out. In this article is also discussed the labeling of the clinical oral mucosal changes seen at the site where a quid of snuff is regularly placed. The conceptual use of "snuff dippers' lesions" is recommended instead of e.g. snuff-induced leukoplakia. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the relative importance for histologic changes of the oral mucosa of such consumption factors as years with regular snuff use, hours and grams of daily snuff use. The material consisted of biopsies of selected cases (two groups) from 252 regular snuff users of whom 184 used exclusively loose and 68 exclusively portion-bag packed snuff. Group 1 comprised 8 pairs of loose snuff users with large differences (14-45 yr) in terms of years with regular habit. Many years of snuff use did not per se seem to result in tissue changes which significantly differed from changes seen in subjects with only a few years of loose snuff use. Group 2 included 5-10 subjects showing the lowest and highest daily consumption of loose or portion-bag packed snuff. Among those with a low daily consumption, portion-bags seem to be related to less pronounced changes than loose snuff. High daily snuff use was associated with relatively somewhat more pronounced epithelial surface changes but histologic differences between the two habit groups were difficult to identify. [ABSTRACT FROM AUTHOR]

This study was to identify histologic tissue changes in the oral mucosa and to compare them in specimens from users of loose can-packed and portion-bag-packed moist snuff. The material consisted of biopsies from 252 regular snuff users. 184 using exclusively loose and 68 portion-bag snuff. An array of structural changes appearing in different combinations were identified among the 252 specimens. Two major patterns were recognized based on changes in the surface layer. Type 1 was characterized by an increased epithelial thickness with vacuolated cells and frequent chevron type changes. Type 2 showed a variably thickened surface layer with evidence of keratinization. Based on these findings, 14 carefully matched pairs of loose and portion-bag users were analyzed and compared. Loose snuff users showed predominantly histologic Type 1 changes while portion-bag users showed more histologic Type 2 or only very discrete changes. [ABSTRACT FROM AUTHOR]

The tumor promoting effects of snuff was studied in Lewis rats initiated with 4-nitroquinoline-N-oxide (4-NQO) and Sprague Dawley rats repeatedly inoculated with herpes simplex virus type 1 (HSV-1). The test substances were administered in a surgically created canal in the lower lips of the rats. There were 15 rats in each test group and 10 rats in the control group. In the groups treated with 4-NQO and 4-NQO + snuff, 8 and 12 tumors (5 and 9 malignant) were found, respectively. In the group subjected to HSV-1 only, 3 tumors were found (2 malignant), in the group subjected to snuff only, 4 tumors were found (3 malignant) and in the group subjected to the combination of HSV-1 and snuff, 13 tumors were found (7 malignant). In the control group only one malignancy was found. The study did not show any promoting effects of snuff in the oral cavity after initiation with 4-NQO. Neither was there any increase in the number of oral tumors in rats treated with HSV-1 and snuff. However, there was a marked increase in the number of malignant tumors outside the oral cavity in the group treated with HSV-1 and snuff, underlining the importance of interactions between these two agents in the development of malignant lesions. [ABSTRACT FROM AUTHOR]

The aim of this study was to register and compare clinical oral mucosal lesions and gingival recessions associated with the use of two different smokeless tobacco products, loose snuff and portion-bag packed snuff. Selected for the study were 252 men (mean age 36.3 yr) of whom 184 (mean age 36.0 yr) used exclusively loose snuff and 68 (mean age 36.9 yr) exclusively portion-bag snuff. Oral mucosal lesions were registered according to a four-grade clinical scale. There was a significantly larger proportion of less pronounced lesions, Degrees 1 and 2, among the users of portion-bag snuff compared with the users of loose snuff. This was also valid when differences in consumption data were considered. Smokeless tobacco-associated gingival recessions were found in 42 (23.5%) subjects among the users of loose snuff and in 2 (2.9%) subjects among the users of portion-bag snuff. The results of this study support previous preliminary assessments that clinical changes of the oral mucosa and the gingival margin are less pronounced among those who use portion-bag snuff than among those who use loose snuff. [ABSTRACT FROM AUTHOR]

Histological and ultrastructural features of 25 oral snuff dipper's lesions with distinctive subepithelial hyaline deposits were investigated. Periodic acid-Schiff reaction with and without diastase digestion demonstrated the presence of glycogen and other carbohydrates, but histochemical stains for normal collagen, elastin and fibrin showed a weak variable reactivity of the deposit. Although in 7/25 cases the deposit was in close proximity to labial salivary glands and on occasions ducts were found within the deposit, the presence of mucin was not a consistent feature. Congo red staining and immunohistochemical investigation with an anti-amyloid antibody did not support the previous contention that such deposits were amyloid in nature. Immunohistochemically, collagen antibodies also provided negative results, but ultrastructural features of three biopsies studied suggest that the bulk of this deposit is made up of collagen, as typical cross-striated fibrils were found. The pathogenesis of this deposit could therefore be interpreted as over-production and/or reduced turnover of collagen by resident fibroblasts, which is further altered by the ingredients of toombak. The deposit does not appear to be a secretory product. [ABSTRACT FROM AUTHOR]

We have shown, by using two monoclonal antibodies (143DB7 and 100EB2), that the expression of the extracellular matrix protein tenascin (Tn) is increased in the connective tissue of biopsies taken from snuff users' and tobacco smokers' oral mucosa. In normal oral mucosa Tn was seen to underlie the epithelium as a thin delicate band. The most increase in Tn reaction was observed in snuff users' mucosa while the immunoreaction in smokers' mucosa was less conspicuous. Often the most prominent Tn reaction took place in association with round cell inflammatory infiltration, indicating epithelial irritation. Tn has been shown to take part in epithelial-mesenchymal interactions during embryogenesis, wound healing and tumorigenesis. Here, a superficial epithelial irritant has been shown to cause conspicuous alterations not only in the epithelial cell layers but also in the underlying connective tissue by increasing its Tn content. As a result of our findings we suggest a further link for Tn in a dynamic epithelial-mesenchymal interplay by virtue of this marked connective tissue reaction in snuff users' and smokers' oral mucosa. [ABSTRACT FROM AUTHOR]

Differences in the expression of cytokeratins (CK) in specimens obtained from snuff-affected oral epithelium of the maxillary vestibular sulcus and clinically normal sulcular epithelium were studied by indirect immunofluorescence staining with a panel of monoclonal antibodies (MAbs). CK 14, a marker of stratified squamous epithelium was not seen expressed in 3/11 of the snuff user's specimens. Terminal differentiation markers, typical of cornified epithelia (CK 1, 9, 10 and 11), were detected suprabasally in the snuff user's keratosis but not in the normal control epithelium. The use of snuff seemed to change the CK staining pattern of the mucosa so that it resembles more that of a cornified type of epithelium. Simple epithelial-type CK were included in the study in order to establish the CK profile of the snuff-induced keratosis, for comparison with normal and dysplastic lesions. MAb to CK 7 and 19 showed reactivity in the basal cells and suprabasally whereas the monospecific MAb anti-CK 7 showed suprabasal staining both in the control and affected epithelia. By using MAbs, we found no immunoreactivity against CK 18 either in normal or affected epithelia, whereas we found suprabasal reaction (5/11) against CK 8 in the snuff user's epithelia. The two MAbs demonstrating the expression of CK 19, normally confined to the basal cells of the stratified squamous epithelium, showed variable patterns of expression both in basal cells and suprabasally in the snuff lesions. The results show that use of oral snuff causes some alterations in the CK expression pattern of the affected epithelium. Whether the alterations are indicative of a premalignant change is, however, uncertain. The results encourage further studies on the subject. [ABSTRACT FROM AUTHOR]