The aetiology of Proteus syndrome (PS) is yet unclear. This disease includes partial gigantism of the hands and/or feet, nevi, hemihypertrophy due to overgrowth of long bones, subcutaneous tumours, macrocephaly, cranial hyperostosis, and pulmonary and renal abnormalities. This case report is about a 17-year-old boy with two uncommon findings associated with PS: apnoea-hypopnoea and mandibular retrusion. A multidisciplinary team was important to provide professional care for this patient. Dentists and physicians proposed an adjusted treatment plan. Maxillary disjunction was achieved with a combination of orthodontic treatment and surgical procedure. This represented the initial care for malocclusion treatment and also the preparation for orthognathic surgery. The oral maxillofacial surgeon and the otorhinolaryngologist proposed this approach in an attempt to improve pharynx airflow. The patient has been followed for almost 3 years.