RESUMO
OBJECTIVE: This systematic review aimed to answer whether, in (P) individuals undergoing orthognathic surgery, (I) low-level laser therapy (LLLT) during or shortly after the surgical procedure compared to (C) pharmacologic therapy alone or no therapy for improvement of post-intervention complications relieves (O) postoperative inflammatory events in (S) randomized clinical trials. MATERIAL AND METHODS: A preliminary electronic search was conducted for references with language following a Latin (Roman) alphabet in seven databases index, and gray literature without restriction on language or publication period. Risk of bias was performed by RoB 2.0 tool, and meta-analysis used mean differences (MD) for edema and mouth opening and standardized mean differences (SMD) for pain scores (p < 0.05, Revman®). RESULTS: A total of 91 control patients and 114 LLLT patients were included. The wavelengths ranged from 660 to 940 nm, and the applied energy density was between 5 and 100 J/cm2 at mostly extraoral distributed points. LLLT significantly reduced edema (MD = - 4.27, CI95% - 5.13 to - 3.41 mm) in the period from 5 days to 2 weeks postoperatively (p < 0.001) and showed strongly reduced pain scores (SMD = - 1.37, I95% = - 1.99 to - 0.75) between 1 day and 5 weeks (p < 0.001), without significantly interfering with mouth opening (p = 0.110). Despite the low risk of bias, high heterogeneity among studies (I2 > 70%) and small sample sizes made the certainty of GRADE evidence low. CONCLUSION: This SR demonstrated that LLLT effectively controls pain and edema after orthognathic surgery. CLINICAL RELEVANCE: Systematic review that summarizes the use of photobiomodulation on orthognathic surgery.