Odontogenic keratocyst (OKC) is classified as a developmental cyst derived from odontogenic organs such as enamel organs and dental lamina. The main histological feature of OKCs is keratinization in the cyst wall, sometimes including islands of epithelium that may represent daughter cysts in a thin epithelium lining. Clinically, this disease is characterized by a high frequency of recurrence.
In this retrospective study, we examined 91 OKCs treated at the Department of Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University Hospital between 1981 and 1995. The ages of the patients ranged from 7 to 69 years (mean age, 30.5), and 50 were male and 41 were female. The most common sites were the molar region and ramus of the mandible. Most of the OKCs in the maxillary region were treated by enucleation and primary closure. Most OKCs in the mandibular region were enucleated, and the wound was left open. Marginal mandibulectomy was performed in two patients with large lesions arising in the mandible. The postoperative course was uneventful in 52 cysts (85%), and recurrence occurred in 9 cysts (15%) among 61 cysts followed-up for more than 2 years. Recurrence occurred near the roots of teeth.
In most patients, no symptoms were associated with recurrence. Recurrence occurred in 4 patients more than 10 years after operation. Our findings indicate that long-term follow-up and careful treatment of lesions continguous with the roots of teeth are required in patients with OKCs.
