Continuing medical education.

A 28-year-old male was referred from his dentist for further investigation of an asymptomatic expansion of the anterior mandible. The patient reported periodical mild pain in the area for the past 12 months and mild paresthesia of the left side of the lower lip for the last 4 months. Panoramic radiograph revealed a unilocular radiolucency with thin sclerotic border, extending from the right first premolar to the distal aspect of the left second premolar and causing thinning of the lower border of the mandible in the midline area (fig. 1). The left mental foramen was not demonstrated. An open biopsy, under local anesthesia was performed and the histopathological examination revealed a cystic cavity lined by thin epithelium with a corrugated parakeratotic surface and a palisaded basal cell layer, devoid of rete ridges (fig. 2). The involved teeth were preoperatively treated with root canal therapies and the cyst was completely surgically excised, under local anesthesia, after identification, dissection and preservation of the left mental nerve. No clinical and radiological findings of recurrence were noticed 15 months postoperatively.