Kats L, et al. - In this retrospective case-control study involving 102 patients, researchers examined possible connections between oral lichen planus (OLP, a chronic immune-related condition of the oral mucosa of unknown exact etiology) and thyroid gland diseases (TGDs). Study participants included patients who have been diagnosed, clinically and histopathologically, with OLP. No significant associations were found between the co-existence of OLP and TGD or related-medications. Interestingly, the authors discovered that in the OLP group smoking habit was considerably less common than in control. The results agree with some of the comparable research earlier published but are controversial with others. Further well-designed, multicenter studies with large patient groups and controls may help determine the nature of the OLP-TGD associations.