SUBMANDIBULAR SWELLING IN PATIENTS WITH FIBRODYSPLASIA OSSIFICANS PROGRESSIVA

Fibrodysplasia ossifcans progressiva (FOP) is a rare genetic disorder characterized by congenital malformation of the great toes and by prog ressive heterotopic ossification of soft tissues, Although ankylosis o f the temporomandibular joint occurs commonly in the late stages of th e disease, only one well-documented case of submandibular heterotopic ossification in a patient who had FOP exists. Twelve (11%) of our 107 patients who have FOP had submandibular heterotopic ossification that was mistaken initially in seven of the patients for mumps, angioneurot ic edema, abscess, mononucleosis, or neoplasm. Two male patients and 1 0 female patients ranging in age from 6 to 47 years (mean, 21 years) w ere studied. Ten patients survived following assiduous precautionary m easures. One patient who required emergency tracheostomy and ventilato ry support also survived. Another patient died of inanition from chron ic swallowing difficulty, An effective treatment program includes earl y identification of the submandibular flare-up, nutritional support, a nd glucocorticoid therapy. Submandibular swelling in patients who have FOP can be a medical emergency and requires intensive precautionary m easures to avoid catastrophic clinical deterioration. These measures i nclude avoidance of lesional manipulation, airway monitoring, and aspi ration precautions. Submandibular swelling should be recognized as a v ariable feature of FOP.