Acromegaly is an endocrine disease caused by excessive secretion of growth hormone （GH） after the end of the growth period, due to a pituitary adenoma. Mandibular prognathism, tongue hypertrophy, and bulging of the eyebrow arch are observed in the maxillofacial region. We describe a case with acromegaly for which surgical orthodontic treatment was performed after excision of the pituitary adenoma. A 47-year-old woman who became aware of enlargement of the size of the hands and feet from 35 years old was diagnosed with acromegaly by the Department of Neurosurgery because of a high GH level and a pituitary tumor on MRI. In September 2014, chemotherapy was performed after tumor resection via the nasal cavity. In March 2016, she was referred to the Department of Orthodontics of our hospital for further examination and treatment of malocclusion. Overjet and overbite were −5.0mm and ＋2.5mm, respectively. The occlusal relationship of the molars was Angle class Ⅲ. Angular analysis of lateral cephalometric analysis showed SNA: 80.0°, SNB: 77.0°, ANB: 3.0°, and FMA: 37.9°. Mandibular prognathism was diagnosed based on a Wits appraisal of −7.1. Since there was no clinical activity of acromegaly and hypertrophy of the hard and soft tissues due to acromegaly had stopped, and serum insulin-like growth factor-1 was well controlled by chemotherapy, orthognathic treatment was started in April 2016 and bimaxillary surgery was performed in January 2019. The occlusal relationship was stable and there was no recurrence at 2 years after the surgery. Since acromegaly has various complications, it is necessary to create a treatment plan considering the complications, and to perform extended follow-up due to the potential for recurrence of the disease.
