title: Evaluation of the Association between Oral Lichen Planus and Hypothyroidism: a Retrospective Comparative Study.
abstract: BACKGROUND
  Oral Lichen planus (OLP) is an autoimmune mucocutaneous disease. There are some reports of thyroid diseases, especially hypothyroidism, to have association with OLP in some studies.
  
  
  OBJECTIVE
  Based on the controversial results of former studies in other populations about the association of hypothyroidism and OLP, the current study aimed to evaluate this association in a sample of Iranian population.
  
  
  METHODS
  This retrospective comparative study evaluated 523 patients with OLP referring to the Oral and Maxillofacial Department of Shiraz Dental Faculty as the test group and 523 age- and sex-matched patients as the control group. Those participants with oral lichenoid reactions and other mucosal lesions were excluded. The odds ratio (OR) with 95% confidence intervals (CI) for the association of OLP and thyroid diseases were estimated by logistic regression adjusted for the matched age and sex.
  
  
  RESULTS
  In the test group, 74% (n=387) and in the control group 73.8% of the patients were female (n=386). In the test group, 26% (n=136) and in the control group 26.2% of the samples were male (n=137). A total of 4% of the patients in the control group (n=21) and 6.7% in the case group (n=35) had a history of hypothyroidism. The reported OR for association of thyroid disease and OLP was 1.714 (CI=0.984-2.987).
  
  
  CONCLUSIONS
  The results of this study showed no significant association between hypothyroidism and OLP in comparison with the age- and sex-matched control group.
authors.affiliation: Dept. of Oral & Maxillofacial Disease, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Lavaee
authors.affiliation: Dept. of Endodontics, School of Dentistry, Kurdistan University of Medical Sciences, Sanandaj, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Majd
keywords: Association; Hashimoto disease; Hypothyroidism; Levothyroxine; Oral lichen planus