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) , and received important contributions by Babcock in 1909 .
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 .
Sagittal ramus osteotomy is one of the most efficient of these techniques . 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 , the technique received a number of improvements. Schuchardt (apud Obwegeser)  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  and Obwegeser  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  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. Retromolar osteotomy was performed at the distal level of second molar, from the external oblique line to the inferior border of the mandible. The author proposed two types of fracture. For the sagittal type, the fracture extends to the posterior border of the ramus, and the masseter and medial pterygoid muscles are inserted in the proximal and distal fragments respectively. For oblique osteotomy, the path of medial fracture is within the mylohyoid groove, and both muscles are inserted into the proximal fragment.
Hunsuck  suggested that medial osteotomy should be extended up to the posterior region of the lingula, with no need for involvement of the posterior border of the ramus. Lateral osteotomy, on the other hand, according to his suggestion was performed at the junction of the ramus and body of the mandible.
Gallo, Moss and Gaul  introduced a modification to the Dal Pont method, aimed at treating retrognathism. According to their suggestion, vertical retromolar osteotomy of distal fragment starts near the external oblique line, extending through half the distance to the basilar region. The osteotomy tracing is turned horizontally according to the desired orientation for mandibular advancement, defining a step larger than the planned advance. Vertical osteotomy is then resumed, in a more anterior position. The area of contact between the fragments is increased, allowing metal osteosynthesis in the region of the mandibular body. Furthermore, rotation of the proximal fragment is prevented.
Epker  suggested an important change to the Obwegeser and Dal Pont method, minimizing complications such as excessive oedema, neurological complications related to the inferior alveolar bundle, hemorrhage and avascular necrosis of the segments. According to this proposition, no blind posterior dissection and periostal stripping of the masseteric-pterygoid sling is done. The author suggested gentle dissection of medial tissue from ramus just above the lingula (not extending to the posterior border of the ramus) for visual inspection of the inferior alveolar neurovascular bundle and elevation up to the antegoniac incisure, without posterior extension. Osteotomy starts above the lingula, extending inferolaterally up to the inferior border of the mandible, as recommended by Hunsuck . The inferior cut, on the other hand, completely involves the basilar region, which makes sagittal split easier.
The use of different types of reciprocating saws was introduced in the decade of 1980. This technology resulted in a reduction in size of equipments and blades, allowing their use in sagittal osteotomies of the mandible . Some of the items, such as the blade for basilar cutting developed by Wolford and Davis Jr , were specifically designed for particular stages of surgery.
The methods for fixation of these bone segments evolved from wire osteosynthesis. For rigid fixation in mandibular sagittal split ramus osteotomy, bicortical bone screws [14, 15] and miniplates and screws [16–21] are now available.