Is Adjuvant Laser Therapy Effective for Preventing Pain, Swelling, and Trismus After Surgical Removal of Impacted Mandibular Third Molars? A Systematic Review and Meta-Analysis

PURPOSE: To assess the efficacy and safety of low-level laser energy irradiation (LLEI) for decreasing pain, swelling, and trismus after surgical removal of impacted mandibular third molars (IMTMs). MATERIALS AND METHODS: MEDLINE, EMBASE, and the Central Register of Controlled Trials of the Cochrane Library were searched from their inception, and conference proceedings, cross-references, and gray literature were searched for the last 5 years for randomized and quasi-randomized controlled trials that evaluated the effects of any type of LLEI, compared with active or inactive treatments, in patients undergoing surgical removal of IMTMs. Risk of bias in included studies was assessed by 2 independent evaluators using the Cochrane Risk of Bias tool. A random-effects model meta-analysis was used to estimate the mean difference of trismus between the groups. Heterogeneity was assessed using Cochran χ(2) and I(2). RESULTS: Ten eligible trials were included in this systematic review. The included studies overall had a moderate risk of bias. Because of heterogeneity in the intervention and outcomes assessments, pain and swelling outcomes were only qualitatively summarized and indicated no beneficial effects of LLEI over placebo. Patients receiving LLEI had an average of 4.2 mm (95% confidence interval, 1.2 to 7.2) and 5.2 mm (95% confidence interval, 1.8 to 8.2) less trismus than patients receiving no active treatment on the second and seventh day after the surgery, respectively. CONCLUSIONS: There was no benefit of LLEI on pain or swelling and a moderate benefit on trismus after removal of IMTMs. It is necessary to standardize the intervention and outcomes assessment and to conduct adequately powered, well-designed trials to evaluate the efficacy of LLEI.