The efficacy of dexamethasone injection on postoperative pain in lower third molar surgery

BACKGROUND Surgery on the lower impacted third molar usually involves trauma in the highly vascularized loose connective tissue area, leading to inflammatory sequelae including postoperative pain, swelling, and general oral dysfunction during the immediate post-operative phase. This study aimed to investigate the effectiveness of preoperative injection of a single dose of 8 mg dexamethasone for postoperative pain control in lower third molar surgery. METHODS A controlled, randomized, split-mouth, prospective study involving lower third molar surgery was performed in 31 patients. The randomized sampling group was preoperatively injected, after local anesthesia, with a single dose of dexamethasone (8 mg in 2 ml) through the pterygomandibular space; 2 ml of normal saline (with no dexamethasone) was injected as a placebo. RESULTS The pain VAS score was significantly different on the day of the operation compared to the first post-operative day (P = 0.00 and 0.01, respectively), but it was not significantly different on the third and seventh postoperative day between the control and study groups. There was a significant reduction in swelling on the second postoperative day, and a difference between the second postoperative day and baseline value in the study group (P < 0.05). Trismus was highly significantly different on the second postoperative day and between baseline and second postoperative day between the groups (P = 0.04 and 0.02, respectively). Descriptive statistics and independent-samples t- test were used to assess the significance of differences. CONCLUSIONS Injection of 8 mg dexamethasone into the pterygomandibular space effectively reduced the postoperative pain and other postoperative sequalae.