A maxillofacial orthotic appliance comprises: a maxilla expander fixed to the maxilla in the mouth of a human and a towed-unit which is connected to the maxilla expander and is towed in an anterior direction from the human. The towed-unit includes: a left wire whose one end is inserted into the left hole of the maxilla expander and the other end is protruding out of the mouth, a right wire whose one end is inserted into the right hole of the maxilla expander and the other end is protruding out of the mouth, a connecting tube provided on the left or right wire and extending in the direction of the distance variation, caused by the maxilla-expander adjusting mechanism, between the left and right contact parts and a connecting wire provided on the other of the left and right wires and inserted into the connecting tube slidably.