A case of a unique factitious disorder resulted from self-inducement of oral lacerations, erosions, and abrasions. Previous medical investigations included evaluations by two general dentists, one oral surgeon, two periodontists, one internist, one otolaryngologist, and one infectious-disease physician. The patient had two gingival biopsies and one hospitalization. The lesions were unresponsive to several therapeutic regimens including temporary discontinuation of tooth brushing, antibiotics, and gingival dressings. The differential diagnosis included infectious, nutritional, immunologic, and factitious disorders. An apparent initial response to corticosteroids suggested the possibility of an immunologic inflammatory disease; however, no organic cause could be found. The enigma was resolved by discussion with the patient who reported that the lesions were self-induced and the manner in which this was done.