Risk factors for inflammatory complications following third molar surgery in adults.

Purpose: To estimate the frequency of inflammatory complications (surgical site infection and alveolar osteitis) following third molar (M3) extraction and identify risk factors for such complications.
Materials and Methods: This study was designed as a prospective cohort study and enrolled a sample composed of subjects having >or=1 M3 extracted as part of the American Association of Oral and Maxillofacial Surgeons' Age-Related Third Molar Study. Predictor variables were categorized as demographic, health status, anatomic, and pathologic factors. The outcome variable was the presence of a postoperative inflammatory complication (ie, surgical site infection or alveolar osteitis). Descriptive and bivariate statistics were computed. Variables with P values less than .15 in bivariate analyses were included in a multiple logistic regression model, used to identify factors associated with inflammatory complications.
Results: The study sample consisted of 4,004 subjects with a mean age of 39.8 +/- 13.6 years having 8,748 M3s extracted. In bivariate analyses, impaction level, periodontal disease in or around M3, pre-existing infection around M3, and M3 pathology were associated with postoperative inflammatory complications. In the multiple regression model, level of impaction (soft tissue: odds ratio [OR] = 2.5; 95% confidence interval [CI], 1.7, 3.7), partial bony OR = 4.7 (95% CI, 3.6, 6.1), full bony, 6.0 (95% CI, 4.7, 7.7); P < .0001), and pre-existing infection (OR = 1.3 [95% CI, 1.0, 1.6; P = .05) or pathology (OR = 3.1; 95% CI, 2.2, 4.3; P < .0001) were associated with an increased risk of inflammatory complications following M3 surgery.
Conclusions: Level of impaction, pre-existing infection, and pathology were associated with increased risk for postoperative inflammatory complications following M3 surgery.