Adenomatoid odontogenic tumor originated in the periodontal ligament

Adenomatoid odontogenic tumor (AOT) is a benign (hamartomatous), non-invasive lesion with slow but progressive growth. There are three variants of AOT: follicular, extrafollicular, and peripheral. This report illustrates an unusual case of AOT, i.e., arising within the periodontal ligament. A boy was brought in by his parents for evaluation of a gingival swelling. Periapical radiograph revealed thickening of the periodontal ligament with foci of calcification. Clinical diagnosis was peripheral ossifying fibroma. Biopsy was performed and microscopic examination revealed the presence of an AOT. The patient has been followed-up for eleven months without recurrence.