Chin Deformities: Macrogenia, Microgenia, and Their Associations

Mandibular excess is always associated with a Class II molar and canine relationship.

Mandibular deficiency is characterized by a retruded chin and an everted lower lip.

Mandibular excess and maxillary excess can occur simultaneously, leading to a normal facial profile.

Mandibular asymmetry is caused by excessive growth of both condyles.

Mandibular asymmetry can occur in individuals without the presence of malocclusion.

Mandibular deficiency is associated with an increased overjet in the incisor area.

The long face syndrome is characterized by an excessive appearance of the lower third of the face.

The short face syndrome is associated with a decreased mandibular occlusal plane angle.

Apertognathia, or open bite, is characterized by premature anterior occlusion with the absence of posterior occlusion.

The long face syndrome is often accompanied by lower facial asymmetry.

The three basic facial types are brachyfacial (short facial type), dolichofacial (long facial type), and mesofacial (ideal facial type).

The presurgical treatment phase includes periodontal, restorative, and orthodontic considerations, as well as final treatment planning.

Le Fort I osteotomy is used to correct deformities involving both the maxilla and mandible simultaneously.

In cases of severe maxillary and mandibular discrepancies, a combination of Le Fort I osteotomy and mandibular surgery may be performed.

Le Fort II osteotomy is designed to move the entire face forward, including portions of the eye socket, but does not involve the mandible.

In cases of cleft palate, only Le Fort I osteotomy is performed, without any mandibular surgery.

Le Fort III osteotomy, also known as craniofacial disjunction, is used to correct deformities involving both the maxilla and mandible simultaneously.