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
Head gear causes 
Select and explain. 
A. Bucco lingual movement of maxillary molars, B. Mesio distal movement of maxillary molars, C. Intrusion of molars, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Headgears are the most commonly used oral orthopedic appliances.
They are indicated in patients with excessive horizontal growth of maxilla. They are used to distalize the maxillary dentition along with maxilla.