Predicting Pain After Tooth Extraction: Pain Prediction Index.

Abstract

To identify relevant variables that may predict pain after routine extraction of erupted teeth, to construct a Pain Prediction Index (PPI) based on these variables, and to verify how these variables are related by using valid structural equation modeling (ie, path analysis). This study was designed as an observational prospective study for postoperative memory of pain after dental extraction of erupted teeth. Data from a total of 781 surgical procedures related to dental extractions were included. Pain was self-reported by the patients and was evaluated by a verbal category scale (VCS) on the seventh postoperative day. The database was searched for predictive variables that were significantly (P < .05) associated with postoperative pain. Pain was scored by patients as none in 65.4% of cases (511); light in 22.9% (179); moderate in 11% (86); and severe in 0.6% (5). Seven predictive variables were strongly related to postoperative pain: gender (female); age (younger than 33); number of extracted teeth (three); surgical technique (surgical flap, ostectomy, or teeth sectioning); number of local anesthetic cartridges (more than three); time in surgery (greater than 25 minutes); and any surgical complications. These variables were used to compose the PPI. The retained PPI classified 66.3% of the patients correctly for both pain and no pain; however, when more than three points were scored on the PPI, it correctly predicted pain in 55.6% of cases. The present study identified seven predictive variables that were strongly related to postextraction pain and documented that the PPI could correctly predict pain in the majority of patients.