The relationship of shammah (Arabian snuff) chewing to the risk of oral cancer and oral potentially malignant disorders.

<bold>Introduction: </bold>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.<bold>Materials and Methods: </bold>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.<bold>Results: </bold>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).<bold>Conclusion: </bold>Shammah use seems to increase the risk of development of OPMD and/or oral cancer. [ABSTRACT FROM AUTHOR]