Delayed-onset infections after lower third molar surgery: a Hungarian case-control study.

OBJECTIVE: Delayed-onset infection is defined as infectious swelling and trismus accompanied by pain or the presence of suppuration starting approximately 30 days after surgery. This study aimed to describe the occurrence and potential predisposing factors of delayed-onset infection. STUDY DESIGN: A retrospective case-control study of 223 lower third molar surgeries was performed. Participants were selected from among 1102 outpatients who underwent surgery between January 2013 and June 2018 at Semmelweis University. The inclusion criterion for the case group was inflammation of the operated area after suture removal. Patients in the control group were healthy nonsmokers <26 years old who healed without complication. Statistical analysis was performed using the Shapiro-Wilk test, the Mann-Whitney U test, and Fisher's exact test. RESULTS: Complications occurred only in patients <26 years old approximately 29.5 days after surgery. A significantly higher risk was observed for younger age, total soft tissue coverage, deeper impaction, lower Nolla stage (P < .001), mesioangular direction (P = .002), and full bone coverage (P < .05). Distal space was inversely correlated with complications (P < .001). CONCLUSIONS: Lower Nolla stage, total soft tissue coverage, lack of distal space, deeper impaction, or mesioangular tilt may promote delayed-onset infection. Follow-up of at-risk patients and the maintenance of oral hygiene are recommended.