**2.1. Indications**

BSSRO is a perfect option for surgical treatment of dentofacial deformities including the mandibular deformities. The mandible can be repositioned in three dimensions of the space such sagittal direction (as advancement, setback), transversal direction (asymmetries and shifting from one side to the other or transversal rotation), and axial plane (clockwise or counterclockwise rotation). For each movement a patient-specific osteotomy and muscle dissection should be kept in mind to avoid postoperative relapse and skeletal disfigurement. On the other hand, while planning such osteotomies, the facial harmony, speech, tongue size, esthetics, and most importantly the airway should be precisely evaluated. As an example huge magnitude of setback of the mandible would result as decreased airway volume and in advance as OSAS. The preoperative evaluation should include a 3D airway evaluation. If such compromise occurs, other osteotomy techniques should be analyzed such as mandibular ostectomy, IVRO. Also in macroglossia patients, tongue reduction surgery should be kept in mind before or during operation in setback surgeries to avoid dentoskeletal relapse. The incision would be placed on the ascending ramus in proximal segment and be carried inferiorly on the distal segment over the external oblique linea, while a mouth gag or a position stabilizator is placed on the opposite side with maximum mouth opening. Care must be taken to avoid dislocation 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

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

The history of orthognathic surgical techniques goes back to the mid-1800s. Both in Europe and the USA, the corrective jaw surgeries at their first steps begun to be heard by the population. Schuchardt was the author who first described the sagittal split in 1942 in German literature [1]. In English literature, Trauner and Obwegeser were the pioneers in 1957 who described and discussed the technique in detail [2]. Dal Pont [3], Hunsuck [4], and Epker [5] all added modifications to the technique such as to maintain more surface contact between bony segments at outer cortex, obtaining a minimal horizontal cut in the medial surface of ramus just beneath the lingula and minimal muscle detachment to avoid postoperative blood

BSSRO is a perfect option for surgical treatment of dentofacial deformities including the mandibular deformities. The mandible can be repositioned in three dimensions of the space such sagittal direction (as advancement, setback), transversal direction (asymmetries and shifting from one side to the other or transversal rotation), and axial plane (clockwise or counterclockwise rotation). For each movement a patient-specific osteotomy and muscle dissection should be kept in mind to avoid postoperative relapse and skeletal disfigurement. On the other hand, while planning such osteotomies, the facial harmony, speech, tongue size, esthetics, and most importantly the airway should be precisely evaluated. As an example huge magnitude of setback of the mandible would result as decreased airway volume and in advance as OSAS. The preoperative evaluation should include a 3D airway evaluation. If such compromise occurs, other osteotomy techniques should be analyzed such as mandibular ostectomy, IVRO. Also in macroglossia patients, tongue reduction surgery should be kept in mind before or during operation in setback surgeries to avoid dentoskeletal relapse. The incision would be placed on the ascending ramus in proximal segment and be carried inferiorly on the distal segment over the external oblique linea, while a mouth gag or a position stabilizator is placed on the opposite side with maximum mouth opening. Care must be taken to avoid dislocation

**2. Bilateral sagittal split ramus osteotomy (BSSRO)**

Fort I and SSRO.

112 Current Approaches in Orthodontics

loss and hematoma.

**2.1. Indications**

**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).

edema, paresthesia, and pain and patient satisfaction and operation times of orthognathic surgical operations performed with conventional drills and piezoelectric surgery. A total of 200 patients with completed skeletal growth and malocclusion due to mastication dysfunctions were retrospectively evaluated. These patients were divided into two main groups named control group and piezo group. Each group was divided into three subgroups about the type of surgical procedure performed, which are, Le Fort 1 subgroup, bilateral sagittal split ramus osteotomy (BSSRO) subgroup, and bimaxillary subgroup. The evaluation between the groups is made at postoperative 1 day, 1 week, and 1, 3, and 6 months. To evaluate each subgroup, the data acquired from a specific subgroup was compared to the subgroup with the same name in the other main group. After piezoelectric surgery edema, neurosensory dysfunction and pain levels were found to be lesser than conventional techniques. Patient satisfaction was found to be higher in piezoelectric surgery patients. When operation times were compared, piezoelectric surgery was discovered to take longer to finish the osteotomy because of its lower cutting efficiency. This study shows that the selective cutting ability of the piezoelectric surgery device provides an extremely safe osteotomy for patients by performing a selective osteotomy, thus preserving critical adjacent soft tissues [10]. The piezosurgery begins with the medial aspect of the ramus just over the mandibular foramina, and the cutting tip of the handpiece will be directed 45° angle at posterior start point with around a depth of 2 mm and comes anteriorly. On the ascending ramus, the tip is applied without angulation as deep as possible through the cortex to reach the medullary bone and declines inferiorly on the external oblique linea. If the procedure is a mandibular setback surgery, it is better to extend the osteotomy till the anterior border of the external oblique linea which would help the removal of bony segment for desired positioning of the distal segment similar to Hunsuck-Epker modification. In my experience if a rotational or laterognatic corrective sagittal split osteotomy is going to be performed, the anterior vertical osteotomy on the lateral cortex would be like Obwegeser technique that goes posteriorly to the angulus of the mandible. Besides if the rotation amount is excessive, care must be taken not to dislocate the proximal segment laterally. If such situation occurs, a greenstick fracture must be performed on the posterior part of the distal segment distal to the last molar. In thin and small volumetric mandibles generally, piezoelectric ultrasound surgery is enough to complete the whole osteotomy running from the superior cortex border to the inferior bony cortex border through a fashion without chisel and hammer or separators. Also, this would avoid unfavorable fracture of the segments during rotation split maneuver of the osteotomes that are placed between proximal and distal segments. To avoid undesired inferior border, splitting piezoelectric surgical instruments tips can be directed to the inferior border to maintain a bone cut at the inferior border initiating from the end of the anterior vertical osteotomy back to the posterior end just inferior to orthogonal projection of the lingula. The osteotomy and separation of the proximal and distal segments will simultaneously be completed via this technique without chiseling and hammering. I personally call this technique as Piezotomy Technique®. If the osteotomes are needed to complete the osteotomy, thin osteotomes would be helpful to complete cortex osteotomies keeping them away from the neurovascular bundles. While osteotomizing the inferior border of the mandible, the Obwegeser channel retractor is essential to guard the underlying soft tissues and vital structures. It is better to use a thin osteotome to start separation of the segments seen in **Figure 3**. Completing the osteotomies bilaterally and

Current Approaches in Orthognathic Surgery http://dx.doi.org/10.5772/intechopen.83547 115

**Figure 2.** Ramus single white arrow: alveolaris inferior neurovascular bundle; double white arrow: Obwegeser ramus retractor; and three white arrows: Obwegeser ramus channel retractor. Please note that the Obwegeser periosteal raspatorium is placed above the foramina and protecting the neurovascular bundle. Also a sub periosteal dissection has been performed creating a tunnel to avoid haemorrhagia. Also pay attention to pencil drawing along the ascending ramus declining on the external oblique linea finalizing at the anterior most inferior edge of the linea. This cut will create a separation between distal and proximal segments.

describes the process of vaporization, bubble generation, and subsequent implosion (growth and collapse of bubbles) into many minute fractions of its original size (microscopic gas bubbles) that will occur in a flowing liquid because of the decrease and increase in pressure that is caused by the ultrasonic vibrations. In ultrasonic osteotomy, the cavitation phenomenon helps to maintain good visibility in the operative field by dispersing a coolant fluid as an aerosol that causes the blood to essentially be washed away. Furthermore, the cavitation effect will bring about hemostasis, which results in a bloodless surgery. Walmsley et al. have suggested that the cavitation effect fragments the cell walls of bacteria and therefore has an antibacterial efficiency [7]. Also, piezoelectric device has a selective cutting effect and has a sound alert warning system when the tip has reached to a nonresisting part such as neurovascular bundle or sinus membrane that avoids trauma to soft tissues. Therefore, hemorrhagic and neurosensory deficits are rare in piezoelectric surgery. Afterward Vercellotti published his experience with piezoelectric surgery [8]. In orthognathic surgery Landes et al. shared their experience with piezo-osteotomy feasibility as a substitute for the conventional saw in orthognathic surgery that was evaluated regarding operative technique, blood loss, time requirement, and nerve and vessel integrity. Fifty patients who had orthognathic surgery procedures using piezo surgical osteotomy showed that piezoelectric osteotomy reduced blood loss and inferior alveolar nerve injury at no extra time investment, compared with 86 patients who received conventional saw and chisel osteotomies [9]. We have also evaluated piezosurgery in PhD thesis and compared the conventional rotary instruments with piezosurgery. The aim of this study is to comparatively evaluate primary postoperative patient complaints such as edema, paresthesia, and pain and patient satisfaction and operation times of orthognathic surgical operations performed with conventional drills and piezoelectric surgery. A total of 200 patients with completed skeletal growth and malocclusion due to mastication dysfunctions were retrospectively evaluated. These patients were divided into two main groups named control group and piezo group. Each group was divided into three subgroups about the type of surgical procedure performed, which are, Le Fort 1 subgroup, bilateral sagittal split ramus osteotomy (BSSRO) subgroup, and bimaxillary subgroup. The evaluation between the groups is made at postoperative 1 day, 1 week, and 1, 3, and 6 months. To evaluate each subgroup, the data acquired from a specific subgroup was compared to the subgroup with the same name in the other main group. After piezoelectric surgery edema, neurosensory dysfunction and pain levels were found to be lesser than conventional techniques. Patient satisfaction was found to be higher in piezoelectric surgery patients. When operation times were compared, piezoelectric surgery was discovered to take longer to finish the osteotomy because of its lower cutting efficiency. This study shows that the selective cutting ability of the piezoelectric surgery device provides an extremely safe osteotomy for patients by performing a selective osteotomy, thus preserving critical adjacent soft tissues [10]. The piezosurgery begins with the medial aspect of the ramus just over the mandibular foramina, and the cutting tip of the handpiece will be directed 45° angle at posterior start point with around a depth of 2 mm and comes anteriorly. On the ascending ramus, the tip is applied without angulation as deep as possible through the cortex to reach the medullary bone and declines inferiorly on the external oblique linea. If the procedure is a mandibular setback surgery, it is better to extend the osteotomy till the anterior border of the external oblique linea which would help the removal of bony segment for desired positioning of the distal segment similar to Hunsuck-Epker modification. In my experience if a rotational or laterognatic corrective sagittal split osteotomy is going to be performed, the anterior vertical osteotomy on the lateral cortex would be like Obwegeser technique that goes posteriorly to the angulus of the mandible. Besides if the rotation amount is excessive, care must be taken not to dislocate the proximal segment laterally. If such situation occurs, a greenstick fracture must be performed on the posterior part of the distal segment distal to the last molar. In thin and small volumetric mandibles generally, piezoelectric ultrasound surgery is enough to complete the whole osteotomy running from the superior cortex border to the inferior bony cortex border through a fashion without chisel and hammer or separators. Also, this would avoid unfavorable fracture of the segments during rotation split maneuver of the osteotomes that are placed between proximal and distal segments. To avoid undesired inferior border, splitting piezoelectric surgical instruments tips can be directed to the inferior border to maintain a bone cut at the inferior border initiating from the end of the anterior vertical osteotomy back to the posterior end just inferior to orthogonal projection of the lingula. The osteotomy and separation of the proximal and distal segments will simultaneously be completed via this technique without chiseling and hammering. I personally call this technique as Piezotomy Technique®. If the osteotomes are needed to complete the osteotomy, thin osteotomes would be helpful to complete cortex osteotomies keeping them away from the neurovascular bundles. While osteotomizing the inferior border of the mandible, the Obwegeser channel retractor is essential to guard the underlying soft tissues and vital structures. It is better to use a thin osteotome to start separation of the segments seen in **Figure 3**. Completing the osteotomies bilaterally and

describes the process of vaporization, bubble generation, and subsequent implosion (growth and collapse of bubbles) into many minute fractions of its original size (microscopic gas bubbles) that will occur in a flowing liquid because of the decrease and increase in pressure that is caused by the ultrasonic vibrations. In ultrasonic osteotomy, the cavitation phenomenon helps to maintain good visibility in the operative field by dispersing a coolant fluid as an aerosol that causes the blood to essentially be washed away. Furthermore, the cavitation effect will bring about hemostasis, which results in a bloodless surgery. Walmsley et al. have suggested that the cavitation effect fragments the cell walls of bacteria and therefore has an antibacterial efficiency [7]. Also, piezoelectric device has a selective cutting effect and has a sound alert warning system when the tip has reached to a nonresisting part such as neurovascular bundle or sinus membrane that avoids trauma to soft tissues. Therefore, hemorrhagic and neurosensory deficits are rare in piezoelectric surgery. Afterward Vercellotti published his experience with piezoelectric surgery [8]. In orthognathic surgery Landes et al. shared their experience with piezo-osteotomy feasibility as a substitute for the conventional saw in orthognathic surgery that was evaluated regarding operative technique, blood loss, time requirement, and nerve and vessel integrity. Fifty patients who had orthognathic surgery procedures using piezo surgical osteotomy showed that piezoelectric osteotomy reduced blood loss and inferior alveolar nerve injury at no extra time investment, compared with 86 patients who received conventional saw and chisel osteotomies [9]. We have also evaluated piezosurgery in PhD thesis and compared the conventional rotary instruments with piezosurgery. The aim of this study is to comparatively evaluate primary postoperative patient complaints such as

a separation between distal and proximal segments.

114 Current Approaches in Orthodontics

**Figure 2.** Ramus single white arrow: alveolaris inferior neurovascular bundle; double white arrow: Obwegeser ramus retractor; and three white arrows: Obwegeser ramus channel retractor. Please note that the Obwegeser periosteal raspatorium is placed above the foramina and protecting the neurovascular bundle. Also a sub periosteal dissection has been performed creating a tunnel to avoid haemorrhagia. Also pay attention to pencil drawing along the ascending ramus declining on the external oblique linea finalizing at the anterior most inferior edge of the linea. This cut will create

detaching the muscle attachments that are resisting for mobilization of distal segment, the surgical splint is placed, and an exact intermaxillary fixation is secured. In this period if it is a setback surgery, the excess bone is removed. At this point, for rigid fixation, the surgeon can prefer lag screws or miniplates with screws to stabilize the segments. My personal choice is to use sagittal plates with self-drive mono cortical screws for rigid fixation. This is essential to avoid condylar sag and distortion of proximal segments as well, especially in the laterognatic and asymmetric cases that require shifting or rotation of the mandible. Also bending the plates geometrically to create a step would stabilize the segments in passive but stable position avoiding the relapse phenomenon. The proximal and distal segments are rigidly fixated (**Figure 4**). After bleeding control the wound edges will be sutured with 3.0 resorbable sutures.

Current Approaches in Orthognathic Surgery http://dx.doi.org/10.5772/intechopen.83547 117

The maxillary discrepancies and the midface abnormalities can easily be corrected by Le Fort I level osteotomy with variable surgical modifications. In 1927, Wassmund performed the first Le Fort I osteotomy for an open-bite deformity [11]. The advancement of maxilla was performed by Axhausen [12], and Bell was the first to show the vascular supply and safety of the procedure at this osteotomy level [13]. The quadrangular Le Fort I was first described by Obwegeser in 1969 [14].

The patient is intubated via nasotracheal preformed intubation tube (RAE tube) to avoid nasal deformation during the surgery. Prior the incision a circular infiltrative local anesthesia is administrated with vasoconstrictor agent. A mucosal incision at the vestibular fornix region from one premolar to another is initiated with Colorado Needle electrocautery (**Figure 5a**). To avoid repetitive coagulation, layer-by-layer single application is essential for deeper soft tissue structures down to the periosteum. A mucoperiosteal flap is raised both on sagittal and vertical plans. Laceration of the periosteum would result in discomfortable bleeding and herniation of Bichat fad pad. Depending of the level of the osteotomy, the reflection of the flap may extend up to the infraorbital region. A curved periosteal elevator would be essential for the elevation of the nasal mucosa on the medial sinus wall and midpalatal suture for each side (**Figure 5b**). If a collective fashion of haemorrhagia occurs, a fine rat tail tamponade with tranexamic acid solution will control it. Using piezoelectric ultrasonic surgery device, osteotomy will be initiated at the apertura priformis back to the crista zygomaticus and through the tuberosity of the posterior maxilla. Also via the piezosurgery tip, the medial antral wall osteotomy may be completed. Thanks to its selective cutting effect with cavitation phenomenon, also the palatine bone can be cut via piezosurgery. Even in some cases, from anterior nasal spine to posterior nasal spine, septal separation from midpalatal suture can be performed via piezoelectric surgery (**Figure 5c**). For each maneuver special piezo cutting tips can be preferred even for the pterygomaxillary junction region (**Figure 5d**). When all the

Suctioning drains are placed if required.

**3. Le Fort I osteotomy**

**3.1. Technique**

**Figure 3.** (a) Osteotomy line starting from medial surface of ramus down to ascending ramus to he external oblique linea inferiorly with ultrasonic surgery; (b) thin osteotome is placed for separation of outer cortex of the inferior border.

**Figure 4.** The sagittal mini plate has been bended and passively adopted to proximal and distal segments with monocortical mini self-drive screws and let mandible for early functioning.

detaching the muscle attachments that are resisting for mobilization of distal segment, the surgical splint is placed, and an exact intermaxillary fixation is secured. In this period if it is a setback surgery, the excess bone is removed. At this point, for rigid fixation, the surgeon can prefer lag screws or miniplates with screws to stabilize the segments. My personal choice is to use sagittal plates with self-drive mono cortical screws for rigid fixation. This is essential to avoid condylar sag and distortion of proximal segments as well, especially in the laterognatic and asymmetric cases that require shifting or rotation of the mandible. Also bending the plates geometrically to create a step would stabilize the segments in passive but stable position avoiding the relapse phenomenon. The proximal and distal segments are rigidly fixated (**Figure 4**). After bleeding control the wound edges will be sutured with 3.0 resorbable sutures. Suctioning drains are placed if required.
