The first criterion in diagnosing the necessity of maxillofacial surgery is the identification of a healthy and normal jaw from an unhealthy and abnormal jaw.

The most important indicator of jaw health is the correct penetration of the molar teeth in the maxilla and mandible. Also in a normal jaw, the front teeth of the upper jaw rest on the front teeth of the lower jaw. So that the upper jaw teeth cover in about one to two millimeters the lower teeth.

In a person who has teeth with these features, a normal jaw is considered, thus there is no need for maxillofacial surgery to straighten the teeth.