An 11-year-old girl was referred to an oral and maxillofacial surgeon by her pediatric dentist for evaluation of a posterior right mandibular swelling. Neither the patient nor her mother had been aware of the lesion before the visit, and the patient did not report any associated pain or bleeding. The medical history of the patient was significant for morbid obesity and onset of puberty at the age of 9 years. On intraoral examination, the right mandibular alveolar ridge was markedly expanded. The patient had already developed a full permanent dentition except for the third molars.