Results, experience, and problems in the operative treatment of anomalies with reverse overbite (mandibular protrusion)

Abstract

Re-examination of seventy-six cases at least one year after operation has shown the following: 1. 1. Trauner's method is followed by few relapses, but it is not really satisfactory from an aesthetic point of view as the angle of the jaw remains too far forward. Obwegeser's steplike osteotomy has an inclination to relapse (19 per cent). 2. 2. The ostectomy in the horizontal ramus was without relapses, but the operation can be performed on only a limited number of patients because of esthetic reasons (angle of the jaw). 3. 3. Reduction of the tongue should be performed in all cases of ostectomy; otherwise, pseudarthrosis or delayed healing could result. 4. 4. Operations on the alveolar process of the mandible or surgical interventions on the maxilla are indicated in rare cases only. Our experience, as reflected by statistics, led us to a partial change in procedure, as follows: 1. 1. Tongue reduction is performed not only in cases of ostectomy of the body but also sometimes in operations on the ascending ramus. 2. 2. For extreme protrusion with an elongated ramus and an obtuse angle of the jaw, an arch-shaped ostectomy (Köle) or an oblique osteotomy (Thoma) is now recommended because the angle of the jaw can be restored to normal by these methods. 3. 3. In the remaining cases of tooth-bearing protrusion with an obtuse angle of the jaw, Obwegeser's operation as modified by Dal Pont is recommended because, with this method, the posterior fragment remains in its place and therefore the direction of the fibers of the masseter muscle is not altered. 4. 4. For the edentulous patients with protrusion and an obtuse angle of the jaw, the arch-shaped ostectomy of the ramus is indicated. 5. 5. Dingman's ostectomy, combined with a tongue reduction, may be chosen in cases of a well-shaped angle of the jaw and clongated body or of manidbular protrusion with open-bite. 6. 6. The inlay ostectomy described by Toman is indicated for edentulous patients or in cases of lateral toothless protrusion with an elongated body. 7. 7. Procedures to improve the profile (for example, cartilaginous transplants to rebuild the maxilla) or correct the chin may be performed separately or in combination with the operation for prognathism. They should be used more frequently, for satisfactory results often can be attained only by means of these combined procedures.