Longitudinal evaluation of the effects of low-power laser phototherapy on mandibular movements, pain, and edema after orthognathic surgery.

The aim of this study was to longitudinally evaluate mandibular movements, pain, and edema in patients who underwent low-power laser (LPL) phototherapy after bimaxillary orthognathic surgery. A double-blind, randomized, controlled clinical trial was conducted using 30 patients, who were divided into a study group (n = 15) and control group (n = 15). The former group received postoperative LPL (3 J/cm, 808 nm, and 100 mW) and the latter group received placebo LPL phototherapy. Over a period of 60 days, these groups were evaluated for: mandibular movements - opening, laterality, and protrusion; pain - visual analogue scale; and edema - measured between cephalometric points. The study group showed significantly better jaw opening (p = 0.009), laterality (p = 0.036), and protrusion (p = 0.029) after 2 weeks in most comparisons. The study group showed significantly less postoperative pain (p < 0.001) in most comparisons, and they recovered from pain earlier than the control group. There was a reduction in edema, with no statistically significant difference for most measurements. As observed in most analyses, there were increases in values for all mandibular movements, no significant differences in the occurrence of edema, and decreases in the occurrence of pain.