Does Combined Low-Level Laser and Light-Emitting Diode Light Irradiation Reduce Pain, Swelling, and Trismus After Surgical Extraction of Mandibular Third Molars? A Randomized Double-Blinded Crossover Study

J Oral Maxillofac Surg. 2021 Aug;79(8):1621-1628. doi: 10.1016/j.joms.2020.07.017. Epub 2020 Jul 18.


Purpose: Complications after extraction of mandibular third molars, including pain, swelling, and trismus, are common problematic phenomena for both patients and surgeons. The main objective of the present study was to evaluate the therapeutic effect of combined low-level laser (LLL) and light-emitting diode (LED) irradiation on the recovery rate of such complications.

Patients and methods: The authors implemented a prospective randomized, double-blind crossover design. Forty participants (80 teeth) were enrolled, each with bilateral and symmetrical impacted lower third molars. Participants had lower third molars extracted at 2 separate visits. Participants were randomized to receive LLL plus LED or placebo at the initial surgical procedure. Participants acted as their control during the second surgical procedure. The primary predictor variable was LLL plus LED. The primary outcome variable was pain measured at postoperative days 3 and 7. Secondary outcome variables were swelling and trismus. The Mann-Whitney U, Wilcoxon, and Friedman tests were used for statistical analysis with a P < .05 considered significant.

Results: The sample size of each group was 40 (male to female ratio of 1:1, mean age 24.8 ± 3.9). Preoperative scores of all scales were lower for both groups compared with days 3 and 7 (P < .0001). Postoperative pain levels on days 3 and 7 were significantly less in the intervention group (P = .03 and P = .01, respectively). Compared with the control group, the postoperative trismus level of the intervention group was significantly less on day 3 (P = .006). However, the difference on day 7 was not significant. Postoperative swelling levels on days 3 and 7 were significantly less in the intervention group (P < .0001).

Conclusions: Combined LLL plus LED irradiation could be an effective therapy to decrease postoperative pain and swelling after impacted third molar extractions.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cross-Over Studies
  • Double-Blind Method
  • Edema / etiology
  • Edema / prevention & control
  • Female
  • Humans
  • Lasers
  • Male
  • Molar, Third* / surgery
  • Pain Management
  • Pain, Postoperative / prevention & control
  • Prospective Studies
  • Tooth Extraction
  • Tooth, Impacted* / surgery
  • Trismus / etiology
  • Trismus / prevention & control
  • Young Adult