Effect of submucosal dexamethasone injection on postoperative pain, oedema, and trismus following mandibular third molar surgery: a prospective, randomized, double-blind clinical trial

Abstract The aim of this study was to investigate the effect of the submucosal injection of 1ml dexamethasone (4mg/ml) on pain, swelling, and trismus following the extraction of retained lower third molars. Ninety patients (mean age 23.5 years) were split randomly into three equal study groups (30 patients in each): the ‘before' group received dexamethasone 15min before surgery and placebo 15min after surgery; the ‘after' group received placebo 15min before surgery and dexamethasone 15min after surgery; the ‘placebo' group received placebo 15min before surgery and placebo 15min after surgery. Postoperative pain was recorded by the patients using a visual analogue scale, numerical rating scale, and the McGill Pain Questionnaire at 1, 2, 4, 6, 8, 12, and 24h after surgery. The patients also recorded the total number of analgesic doses consumed during the 24h after the procedure. Swelling (determined using linear measurements of the face) and trismus (determined through measurement of maximum mouth opening) were assessed at 48h, 72h, and 7 days following surgery. Better control of pain, swelling, and trismus was demonstrated for dexamethasone in comparison to placebo. Postoperative dexamethasone provided better pain control than preoperative dexamethasone. There was no difference in total rescue analgesic intake between the preoperative and postoperative dexamethasone groups.