Placebo hypoalgesic and nocebo hyperalgesic effects in post-extraction patients-A cross sectional study.

Background and objectives: Pain is an unpleasant sensory and emotional experience that affects people's physical, mental, and social health. Patients at times present with postoperative pain with no clinical signs after the surgical dental procedures and adequate pharmacological management. This can be due to the amplified emotional component of the individual in their postoperative period. Hence, this study aimed to estimate the association between placebo, nocebo effects, and postoperative pain associated with tooth extraction procedures.

Methods: A cross-sectional study was conducted among 301 patients attending the Department of Oral and Maxillofacial Surgery for tooth extraction. Preoperatively, the expected postoperative pain score was recorded using the "Numerical Rating Scale" (NRS), Anxiety and Depression were assessed using the "Hospital Anxiety and Depression Scale" (HADS), and Patients' expectancy regarding the treatment outcome was assessed using the "Credibility Expectancy Questionnaire" (CEQ). Observed postoperative pain scores at the 6th hour, 24th hour, and peak pain score of the day were recorded using the NRS.

Results: There were statistically significant associations (p < 0.05) found between expected and observed postoperative pain, preoperative anxiety and observed postoperative pain, preoperative depression and observed postoperative pain, placebo, nocebo effects, and observed postoperative pain.

Interpretation and conclusion: Our study showed a strong association between these variables suggesting that post-extraction pain is a multifaceted condition wherein pain expectation, preoperative anxiety, depression, and expectancy regarding the treatment outcome should be scrutinized before the extraction procedure.