Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory disease in early age. It affects one or more joints, lasts more than 3 weeks, and appears in patients younger than 16 years. Juvenile idiopathic arthritis is classified according to the International League of Associations for Rheumatology consensus depending on the number of affected joints in the beginning of the disease. When JIA affects the temporomandibular joint, the development of the mandible is constrained. Patients show a tendency toward retrognathism and a vertical facial development pattern. The purpose of this study was to present a rare case of a young teenager who experienced JIA and Crohn's disease at the same time. The patient was referred to the hospital for aesthetic and functional problems, mainly convex facial profile and obstructive sleep apnea caused by the craniofacial abnormality. The patient was treated by sagittal split mandibular advancement osteotomy and advancement genioplasty. The mechanisms of obstructive sleep apnea development and the surgical treatment through osteotomies are commentated on. The surgical outcome is functionally and aesthetically favorable and solid 2 years after the operation. Surgical management of the craniofacial region can be a problem-solving treatment modality for patients with juvenile arthritis.