Fibrodysplasia ossificans progressiva (FOP) is a rare, severely disabling, autosomal dominant disease characterized by recurrent painful episodes of soft tissue swelling and the development of heterotopic ossification. The main target is the axial musculature, but eventually ectopic bone formation occurs in the ligaments, the fascia, the tendons and the joint capsules. Small soft tissue traumas and intramuscular injections exacerbate this extraskeletal bone formation. We present a 16-year-old male patient who has osseous lesions beginning from the left ramus mandible and extending along the sternocleidomastoid muscle, vertebral region and deltoid, with visible restriction in temporomandibuler joint movement. Surgery was not performed due to parental concerns. Unfortunately, no effective medical therapy for FOP is known. These patients may require extra care during some oral surgery and anesthetic procedures. In this report, the importance of the decision to perform surgery has been stressed.