Explaining pain after lower third molar extraction by preoperative pain assessment

Abstract

Purpose: To evaluate whether preoperative pain sensitivity testing and emotional perception of pain could explain the level of postoperative pain after lower third molar extraction.

Patients and methods: Twenty-three patients (16 women, 7 men) scheduled for lower third molar extraction were enrolled in the study. Patients preoperatively were submitted to a nociceptive stimulus by a cold pressor test (immersion of the hand into ice water). Preoperative pain tolerance (seconds), algosity and unpleasantness (visual analog scale), and dental anxiety (Modified Dental Anxiety Scale) were assessed. The duration of surgery was recorded (minutes). Postoperative pain ratings were taken by self-reported registrations on a 100-mm visual analog scale during the 6 days after surgery. Separate stepwise regression analyses were performed to evaluate the usefulness of preoperative scores in explaining the overall maximum postoperative pain level and postoperative pain rates at different intervals.

Results: Preoperative unpleasantness related to the nociceptive stimulus was found to be the best predictor of maximum postoperative pain (adjusted R(2) = 0.39, P = .001). Demographic information (age) and preoperative (dental anxiety, pain tolerance, algosity) and intraoperative (duration of surgery) factors were not correlated with postoperative pain.

Conclusions: These results show that a simple preoperative test is useful to identify patients at risk of developing greater pain after third molar surgery. They are characterized by a higher level of reported pain or unpleasantness after exposure to a nociceptive stimulus. This test may be tailored to specific patient needs for postoperative treatment.