[Genioplasty: technique and applications].

The chin is an element as important in facial profile as the nose and the forehead. It is subject to morphological anomalies in the sagittal (retrogenius or progenius), vertical (excess or insufficient height), or transversal (laterogenius) axes. Genioplasty used alone or in complement to other maxillomandibular osteotomies, allows for the correction of these malformations by modifying the position of the chin bones in three planes. Many types of genioplasty may be used to reach the desire goal, such as advancement, retraction, or adjustment of height or of symmetry. This genioplasty also has functional applications, notably in the treatment of obstructive sleep apnoea disorders. The anatomic bases of genioplasty and the interest of cephalometric analysis in diagnosing chin position anomalies are reviewed as well as the different operative steps for horizontal advancement osteotomy and the specific principles and indications for other types of genioplasty.