Photobiomodulation Therapy/Photodynamic Therapy Versus Steroid Therapy for Oral Lichen Planus: A Systematic Review and Meta-Analysis

Objective: To evaluate the efficiency of photobiomodulation therapy (PBMT) or photodynamic therapy (PDT) in treating oral lichen planus (OLP) as well as identifiy the side effects when compared with steroid therapy. Background: Nowadays, PBMT and PDT are increasingly applied for treating OLP with minimal adverse effects. Methods: The electronic databases of PubMed, Cochrane Central Register of Controlled Trial, Web of Science, and Embase were searched until March 13, 2020. Randomized controlled trials (RCTs) with 1 month of follow-up period were selected. Two reviewers extracted data from selected studies independently. Cochrane collaboration's tool for assessing risk of bias was used for assessing the quality of the RCTs. The random-effects model was employed for meta-analysis. Results: One thousand fifteen studies were initially identified. Finally, nine RCTs were included for quality assessment and seven studies for meta-analysis. Four RCTs were of unclear risk of bias and five were assessed as high risk of bias. The comparison showed no significant differences for pain scores [visual analog scale (VAS)] [mean differences (MD) = 0.38, confidence interval (CI) = 95% -0.64 to 1.40] and severity scores (reticular-atrophic-erosive scores) (MD = 1.67, CI = 95% -1.13 to 4.46) between topical corticosteroid therapy and PBMT after 1 month. For PDT, no significant differences were observed for sign scores (Thongprasm sign scoring) (MD = -0.31, CI = 95% -1.52 to 0.91) and pain scores (VAS) (MD = -2.30, CI = 95% -5.88 to 1.28) of the lesions when compared with topical corticosteroid therapy after 1 month of follow-up period. One study reported the discomfort of the affected area in patients of the PDT group when probe tip was moved. Conclusions: PBMT and PDT could be reliable alternatives to topical corticosteroids for OLP with no or less severe complications in a short-term period. However, further well-designed RCTs with long-term period are recommended to consolidate the conclusions in this regard.