Orthognathic surgery, is often required for patients with rare diseases in order to normalize occlusion that is generally severely affected. There is no one specific surgical approach because anomalies encountered in this population often require various complex technical procedures. Unlike common dental malocclusions, agenesis, skelettal dystrophies and functional problems are gathered. Orthodontic preparation, before surgery, is made difficult, resulting in a challenging treatment process. In certain cases, the stability of the result can be uncertain due to major dysfunctions. However, given the functional as well as morphological improvement that these procedures bring about, they should be planned if the dysmorphia is significant.

Orthognathic surgery has as its objective the repositioning of basal bone in the framework of maxillo-mandibular deformities. Its results are both esthetic and functional. For adults, improved aesthetics results is becoming increasingly important in these procedures to the point where some patients seek only an esthetic amelioration and not a functional one. To achieve their aesthetic purpose, it is becoming progressively more necessary for orthodontists, oral surgeons, and general dentists to collaborate effectively in a well-coordinated effort. In what has now become a true sub-specialty, orthognathic surgeons must master the complementary techniques of rhinoplasty, osseous apposition, aesthetic facial surgery, fat injection or injectable anti-aging tratments. In this article we propose a diagnostic classification based on the aesthetics of the adult smile and describe the therapeutic modalities appropriate for each element.