This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': "Which of the following is a myofunctional appliance? \nSelect and explain. \nA. Catalan's appliance, B. Hawley's appliance, C. Expansion screw, D. Derichsweiler appliance.", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Catalans or lower anterior inclined plane appliance is used to treat cross bites. The inclined plane has a 450 angulation, which forces the maxillary teeth in cross bite to a more labial position. It is teeth supported functional appliance. Expansion screw and Derichsweiler are expansion appliances.', 'role': 'assistant'}]