A new technique for mandibular osteotomy

Osteotomies of the mandible have fundamental importance for correction of dental facial deformities (ICD K07). Osteotomy of the condylar neck was originally introduced by Jaboulay and Bérard in 1898 (apud Caldwell and Letterman, 1954) [1], and received important contributions by Babcock in 1909 [2].Osteotomies of the mandibular ramus are currently preferred to osteotomies of the mandibular body. Their main advantages are related to lower risk of damage to the inferior alveolar neurovascular bundle, maintenance of extension of the mandibular body and no need for tooth extraction. They also allow for better aesthetic results in the region of the mandibular angle, through correction of the obtuse angle which characterizes prognathism [1].Sagittal ramus osteotomy is one of the most efficient of these techniques [3]. The original designs for sagittal ramus osteotomy, performed with extra-oral access and involving a horizontal cut above the lingula, presented problems related to the small surface of contact between the resulting bone segments. Complications such as open bite and pseudarthrosis were usually a consequence of the procedures. Since the suggestion of cuts with inclined orientation by Kazanjian [4], the technique received a number of improvements. Schuchardt (apud Obwegeser) [5] suggested cutting the medial cortical surface of the ramus above the lingula, and the external surface 10 mm below the first cut. Trauner and Obwegeser [6] and Obwegeser [7] suggested that this distance should be increased to 25 mm, allowing for a larger area of contact. They were also responsible for the introduction of intra-oral access for performance of the technique.Dal Pont [8] modified Obwegeser's method with the introduction of retromolar osteotomy. This alteration resulted in smaller displacement of the proximal segment due to muscle activity (jaw elevator muscles), so that the method could be used for other anomalies besides prognathism, such as retrognathism and open bite. Re