Indications for Mandibular Advancement

The word retrognathism—class II dysgnathia, mandibular retrognathism—is derived from Latin retro (“backward”) and the Greek word γνάθος (gnáthos, “jaw”). Clinical symptoms can be very diverse. They include negative anterior steps in the dentition, a volumetrically small lower third of the face up to the receding chin in conjunction with a symmetrical or asymmetrical mandibular growth deficiency of various degrees. A narrow upper jaw with crowding and retrusion of the central/lateral incisors is typical in class II/2 dysgnathias, but also compensatory extraverted upper jaw fronts as well as compensatory protruded lower incisors (class II/1). Furthermore, it must be differentiated whether the respective class II is a forward displacement of the maxilla or a horizontal or combined horizontal and vertical growth deficit in the mandible. A combination of both symptoms is possible. Mandibular retrognathism can be treated at different ages and stages of development. In most cases, pure orthodontic treatment with functional orthodontic appliances is sufficient. However, if growth induction by orthodontics is insufficient or when the growth deficit is too pronounced, different surgical means can be used. Common to all these means of treatment is that they are perceived as esthetically positive by the patients. Often, in combination with mandibular advancement, there is also a need/possibility for correction of the chin position (genioplasty)