**1. Introduction**

The orthognathic surgical procedures are performed for the correction of abnormalities of the facial skeleton that are present from the birth or arise during growth or acquired secondarily during lifetime. The variety of the underlying reasons of the facial deformities would require different types of surgical strategies, but mainly orthognathic surgical techniques are preferred for the rehabilitation of the deformities. Due to the cover of this book as orthodontics, I would prefer to summarize some commonly used techniques to correct the dentofacial deformities.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Skeletal anchor systems, some basic interdental osteotomies, or complex mechanics that are applying orthopedic corrective forces are currently being used by the orthodontics rather than surgeons. Even we have published all these techniques at their popular time period with our orthodontist colleagues. Therefore in this chapter, I will focus on the most commonly used surgical applications to solve the skeletal discrepancies mainly called as Le Fort I osteotomy and BSSRO. These techniques can be applied as a single-jaw surgery or doublejaw surgery depending on the magnitude of discrepancy of the jaws to each other. Besides these basic techniques can also be preferred in association with distraction osteogenesis or orthodontic elastic traction forces for gradual and slow motions of the segments as well, but I think it is better to discuss the indication not in this chapter. Therefore the scope of this chapter is going to be including my personal experience and some technical details with Le Fort I and SSRO.

of any condyle during this point (**Figure 1**). An electrocautery knife or a 15 blade would be preferable depending on the surgeon. My choice is the Colorado Needle which may help us for delicate incision without necrosis of the soft tissue with a good bloodless vision. The trick with the electrocautery is to perform repetitive coagulations on the same soft tissue plane to avoid tissue necrosis. A layer-by-layer dissection of mucosa muscles and periosteum is necessary. Adequate amount of soft tissue should be remained on the attached gingival side for wound closure. The mucoperiosteal full thickness flap is raised on the external oblique linea. If the temporal muscle tendons are identified, they can also be reflected. An Obwegeser ramus retractor or a curved hemostat is positioned on the tip of coronoid process. The anterior inferior border of the mandible which is close to the external oblique linea can also be reflected, and during bone osteotomies an Obwegeser channel retractor should be placed on the inferior mandibular border. The lingula and the mandibular foramina should be identified on the medial surface of the mandibular ramus and a Williger or Obwegeser raspatorium is used to protect the neurovascular bundle above its insertion to foramen mandibularis. This maneuver will guide to horizontal medial bone osteotomy just above the foramina. There is no need to perform posterior dissection to the posterior border of the mandible. It is better to create a soft tissue tunnel subperiosteally and keep it just to the posterior of the foramina. This will also reduce the possible intraoperative excessive bleeding arising posteriorly and medially from the adjacent muscle and vessel structures (**Figure 2**). Once all the bony aspects of the desired osteotomy lines have been approached, depending on the surgeon's preference, a cutting instrument like saws, rotary handpiece, or piezoelectric surgery handpiece can be used. If the patient has no cardiac disease like arrhythmias or is not a pacemaker user, my first choice is piezoelectric ultrasonic surgery. The piezoelectric ultrasonic surgery is a well-defined system, the first steps of which were discovered by Pierre and Jacques Curie Brothers in 1880. Piezoelectricity is the electric charge that accumulates in certain solid materials (such as crystals certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress. The first ultrasonic alveolar bone cut was performed by Horton on the dog alveolus in 1975 [6]. In piezoelectric surgery, the cavitation phenomenon

Current Approaches in Orthognathic Surgery http://dx.doi.org/10.5772/intechopen.83547 113

**Figure 1.** The incision line placed over the external oblique line and ascending ramus. Carrying it to high and medially

will cause herniation of temporoparietal fat pad (Bichat's fat pad).
