Predicting Pain Intensity after Mandibular Third Molar Surgery using Cold Pressor Testing: A Quasi-Experimental Study

Patients complain differently about their experiences of post-operative pain. However, clinicians are often guided by their own viewpoints despite the highly subjective nature of pain resulting in suboptimal post-operative pain management. This impacts negatively on the quality of life of patients in the immediate post-operative period. Investigating patients' pain behavior in the pre-operative period may therefore help to predict the intensity of post-operative pain, thereby assisting in identifying patients who are at risk of greater pain after third molar surgery, and allocating extra resources for pain control.

This study aims to predict the intensity of pain after third molar surgery by correlating post-operative pain perception with the sensory-discriminative dimension and affective response to a cold pressor stimulus.

This study is a quasi-experimental study that was conducted in the oral surgery clinic of (name of hospital in the title page). The procedure was undertaken in an isolated clinic cubicle with well-controlled room temperature and minimal distraction. Study participants were recruited by convenience sampling. Forty-three consenting participants, 20 years and above, who met eligibility criteria were subjected to pre-operative cold pressor testing. Subsequently, third molar surgery was done and post-operative pain intensity was recorded at specific intervals. Data analyses were completed using IBM SPSS version 25. The Kolmogorov-Smirnov (KS) test was used to test for normality of continuous variables. Ordinal regression was used to test for contributory value of pre-operative measurement while Spearman's rank correlation test was used to test their degree of relationships with post-operative pain P < 0.05.

The median pain threshold was 20 s (Interquartile Range, IQR 12.75-32.25) and the median pain tolerance was 33 s (IQR = 23.00-54.00) from the cold pressor test. The peak median pain score in this study was reached at 3-h after the last stitch. There was a statistically significant predictive effect of both variables on post-operative pain at 3-h.

Sensory-discriminative dimension and affective response to cold pressor test are significant predictors of peak post-operative pain after impacted mandibular third molar surgery.