The genioglossus muscle has its origin at the oral side of the mandible. The surgical principle consists in mobilizing the whole area of this muscle insertion by incorporating the genial tubercle on the inner cortex via an osteotomy of the chin, and then moving it toward anterior (Fig. 8.1.1). In this new position, the bone segment is fixated osteosynthetically, either with a 24-gauge stainless steel wire or a screw. External cortex and cancellous bone are removed in order to prevent a cosmetically disagreeable protrusion of the chin.

The surgical approach is completely intraoral. The mucosal incision is made approximately 10-15 mm below the mucogingival junction and a subperiostal flap is developed to expose the symphysis. Exposure and identification of the mental nerves are unnecessary. In order to reduce the extent of the dissection, entailing a reduction of potential complications, Riley et al. have twice revised their technique of inferior sagittal osteotomy. Figure 8.1.2 shows the most recent technique [410] which we have adopted in our center. Miller et al. [467] recently recommended the use of the Genial Bone Advancement Trephine system (Stryker leibinger Corp.; Kalamazoo) and reported good results.

A rectangular osteotomy encompassing the estimated location of the genial tubercle/genioglossus muscle complex is performed under copious irrigation. The superior horizontal bone is cut approximately 5 mm below the root apices to prevent incisor root injury and the inferior horizontal bone is cut approximately 10 mm above the inferior border (Fig. 8.1.2). Occasionally, the superior horizontal bone cut has to be made 1-2 mm above the incisor root apices because of the vertical position of the genial tubercle/genioglossus muscle complex [469]. Due to the elongated canine tooth roots that are often present, the vertical bone cuts are made just medial to the canine roots to avoid root injury. Before completing the osteotomy, a titanium screw is placed in the outer cortex to control and manipulate the bone flap. The amount of advancement depends on the thickness of the mandible. The bone flap is advanced and rotated about 30-45°, just sufficient to create bone overlap for a fixation screw.

Li et al. [410] control bleeding with electrocautery and a hemostatic agent such as Gelfoam R (Pharmacia and Upjohn Co, Kalamazoo). Bone wax is not recommended due to extrusion problems. These authors do not use surgical drains. In their hands, the procedure is routinely completed within 30-40 min.

In treating the hypopharyngeal site of obstruction, most authors combine the GA with a HS [499, 587, 608]. Fibbi et al. [196] recommend the combination of GA with a tongue suspension suture (Repose^R) (Sect. 7.4 in Chap. 7). Furthermore, the GA is part of some multilevel surgery protocols as discussed in Chap. 10.

The GA is performed under general anesthesia on an inpatient basis. In cases where no further procedures involving the upper airway have been performed, a hospital stay of about 2 or 3 days is sufficient. We administer an intraoperative single-shot antibiosis with, e.g., 1 × 2 g cephazoline. The administration of corticoids is not necessary.

As GA is a used in severe OSA, some authors generally protect the upper airway with the routine use of nasal continuous positive airway pressure (CPAP) during the postoperative phase. We observe our patients in the recovery room for some hours and apply CPAP only in cases that show repeated apneas. If a CPAP therapy is necessary, the auto-CPAP mode is used. Observation in an intensive care unit is usually not necessary after MO.

As minor complication a wound dehiscence has been observed intraorally. It usually heals spontaneously without sequela. Furthermore, transient numbness of the lower lip and lower central incisors for several weeks [467], dysphagia for up to 1 week, and self-limiting aspiration have been reported [499]. In general, tooth root injuries, mental nerve injuries, and mandibular fracture as potential complications have been reported only very rarely [410]. In our own group of patients one subject developed a severe wound infection several days after surgery requiring surgical intervention. Similar cases have been reported by other authors as well [395, 605]. Speech or swallowing problems have neither been reported nor have they been seen in our own patients.

Like HS, GA is an invasive surgical method with potential complications. For the tongue base, a minimally invasive alternative exists in the form of radiofrequency treatment (RFT). We therefore see no primary indication for the HS for primary snoring, and mild OSA.

In the case of moderate and severe sleep apnea with tongue base obstruction, the GA is a surgical treatment option. In our center, we have completely ceased to perform this technique as we encountered several complications. We have had better experiences with HS. The latter can be performed more rapidly, is the only procedure which can be performed under local anesthesia, uses less osteosynthesis material, and is at least in our hands less prone to complications. Nevertheless, in the hands of an experienced surgeon GA may be a viable alternative in the treatment of moderate to severe OSA.

Although MMA is a routine procedure in maxillofacial surgery, it is technically demanding and performed by a team of surgeons in a hospital environment under general anesthesia [581].

MMA can be considered the most successful surgical procedure for the treatment of OSA after tracheotomy with respect to treatment outcome. Several controlled studies have demonstrated a comparable reduction of the Apnea Hypopnea Index (AHI) after MMA to continuous positive airway pressure (CPAP) therapy [284, 582, 607] (Table 8.2.1). Furthermore, an equivalent optimization of the sleep architecture compared to CPAP has been reported after MMA [123].

The successful results seem to be maintained for long follow-up periods. The Stanford studies report a short-term success rate of 97% after 6 months [607], and a success rate of 90% after 51 months [405].

Furthermore, Li et al. [402] were able to show by way of radiocephalometry and nasopharyngoscopic examinations that pharyngeal depth increased by 48% of the amount of the maxillary advancement and that pharyngeal length increased by 53% of the maxillary advancement in 5 patients after MMA.

For patients suffering from severe OSA, it is recommended to start nasal CPAP at least 1 month before surgery to stabilize the cardiovascular system and reduce upper airway edema [51].

After surgery, extubation should be performed by the operating room staff with the patient being fully awake. MMA patients require careful monitoring, including continuous pulse oximetry, in an ICU environment [581]. Minor desaturations do not call for a CPAP therapy; yet frequent desaturations or apneas require CPAP ventilation therapy. When feasible, nonopioid drugs are used for postoperative analgesia (see Chap. 13).

Nutritional counseling emphasizing clear liquids during the first week, followed by a soft diet for 2 months, is recommended. Today, most authors do not favor prolonged intermaxillary fixation and use modern titanium plate systems for osteosynthesis. The usual hospital stay for MMA lies between 2 days [581, 607] and 1 week [51]. On average, patients return to their normal activities after 2-4 weeks. Patients should be asked to continue nasal CPAP until a follow-up polysomnography has confirmed the surgical success. Nasal decongestants should be administered for the first postoperative week as maxillary osteotomies lead to tearing of the nasal mucosa and edema with impaired nasal respiration.

Temporomandibular joint dysfunction is a potential complication after maxillomandibular surgery. Kerstens et al. [353] reported that 11.5% of the 480 patients who underwent surgery for dentofacial deformity developed temporomandibular joint symptoms after surgery. Similar data were given by White and Dolwick [814] (7.9%). However, temporomandibular joint problems can be often found in patients suffering from dentofacial deformities and the vast majority of the patients presenting preoperative temporomandibular joint symptoms reported improvement after surgery [409]. Here two patient groups have to be distinguished: firstly, patients with normal occlusion who undergo MMA for OSA treatment only and secondly, patients with marked maxillary/mandibular retrusion where MMA is intended for relief of OSA and to improve occlusal relationship.

Further complications are temporary mild-to-moderate hypopharyngeal edema (20%) and hypopharyngeal hematoma (5.7%), partly obstructing the airway [411]. In large maxillary advancements patients frequently develop velopharyngeal incompetence of a temporary nature. Predominantly velopharyngeal incompetence is a phonetic deficit without liquid regurgitation. But there are also singular prolonged cases of velopharyngeal incompetence with regurgitation up to a duration of maximally 12 months [412].

Hypesthesia of the lower lip is the typical complication of BSSO (anesthesia <1%; hypesthesia <5%) [51, 607]. A high percentage of resolution within the first months after surgery is reported. Recovery of full mandibular function (maximum mouth opening; bite force) will take some time and will not be gained in all instances. A further frequent complication is occlusion disturbances in up to 50% of the cases, requiring minor occlusial equilibration by way of orthodontics or prosthodontics [788].