Macrognathism is an abnormally large or protruding jaw.^[1] The opposite condition is called micrognathia.

• Heredity^{[citation needed]}
• Pituitary gigantism^{[citation needed]}
• Paget's disease of bone^{[citation needed]}
• Acromegaly^[1]
• Fetal alcohol syndrome^[2]
• Leontiasis ossea^{[citation needed]}
• Cleidocranial dysplasia

Treatment is surgical. Osteotomy may be done in case of maxillary macrognathia. Mandibular macrognathia is generally managed by resection of a portion of the mandible.^{[citation needed]}