Temporomandibular joint (TMJ) ankylosis is one of the most disabling pathological conditions that can occur in the maxillofacial region, often occurring at an early age, limiting growth and causing facial deformity, which significantly affects the quality of life of the individual. The objective of the study was to evaluate the contribution of Jaw Functional Orthopedics (JFO) in TMJ ankylosis after the surgical phase. The case of a 7-year-old female patient diagnosed with bilateral condylar ankylosis (fibrous ankylosis on the right side and bony ankylosis on the left side) is presented. On clinical examination, facial asymmetry, retrognathia, muscle contraction and opening limitation were observed. Treatment consisted of temporalis muscle flap rotation surgery with condylectomy and coronoidectomy, physical therapy, and functional therapy with OFM. The clinical results at 4 months of follow-up suggest significant progress in oral opening and protrusion. The patient showed a high degree of satisfaction with the results obtained. She is currently continuing with the use of orthopedic appliances to correct the sequelae of ankylosis and improve mandibular kinematics.