This study was designed as a retrospective case-control study, and port placement was one of the differences in operative procedures between the two groups. Patients with ovarian dermoid cysts were evaluated at Taipei Veterans General Hospital from June 13, 2011 through June 12, 2013. Approval for the study was obtained from the hospital's ethics committee, and informed consent was obtained from all patients (VGHIRB 2011-06-004IA).