Prevalence of and risk factors for postoperative hemorrhage after lower third molar extraction on warfarin therapy: a multicenter retrospective study in Japan

Postoperative hemorrhage after tooth extraction is a critical and clinically important issue for clinicians and patients receiving anticoagulants. The purpose of the present study was to investigate the prevalence of and risk factors for postoperative hemorrhage after lower third molar extraction in Japanese patients receiving warfarin therapy. A total of 142 patients who underwent lower third molar extraction between January 2010 and December 2016 were included, and their medical records were retrospectively reviewed. The prevalence of and risk factors for postoperative hemorrhage were investigated. The prevalence of postoperative hemorrhage after lower third molar extraction was significantly higher in patients receiving warfarin than in healthy subjects (21.8% vs 0.7%, P