Oral Maxillofacial Surg Clin N Am 14 (2002) 377–384 Genioglossus muscle advancement techniques for obstructive sleep apnea N. Ray Lee, DDS* Private Practice, 716 Denbigh Boulevard, Suite C-1, Newport News, VA 23608, USA Department of Oral and Maxillofacial Surgery, Medical College of Virginia, Virginia Commonwealth University, 520 North 12th Street, Richmond, VA 23298, USA Department of Otolaryngology–Head and Neck Surgery, Eastern Virginia Medical School, P.O. Box 1980 Norfolk, VA 23501, USA Genioglossus muscle advancement is a viable ing the probability it will prolapse into the posterior adjunctive procedure in the reconstruction of the airway space during sleep [5,6]. upper airway. The author has not experienced the The functional genioplasty for surgical reconstruc- complications of osseous segment necrosis, and with tion of the upper airway (UA)was first described by appropriate drain placement with the anterior man- Riley et al [6] as the inferior sagittal osteotomy (ISO). dibular osteotomy and trephine osteotomy tech- The hyoid was also suspended and fixed to the inferior niques, the risk of infection is low. Neurosensory border of the mandible as an adjunct to the genioglos- changes and dental-pulp necrosis may occur, there- sus advancement. This technique was referred to as fore, patients must be informed accordingly. genioglossus advancement-hyoid myotomy. In a later The role of the genioglossus muscle in posterior study, the hyoid suspension was modified by suturing airway occlusion has been investigated at length the hyoid to the thyroid cartilage [7]. The ISO was [1–3]. A study of 10 obstructive sleep apnea (OSA) modified by Powell and Riley [5] because of an patients and 4 symptom-free controls found that dur- increased number of midline mandibular fractures; ing subsequent tidal breathing, the timing of the however, this osteotomy and all future modifications genioglossus onset progressively decreased after the of the technique maintained the same objective: ad- onset of inspiration until the next OSA occurred [4]. vancement of the genial tubercle and genioglossus This finding suggests that the timing relationship muscle. The ISO was then modified and described between genioglossus inspiratory activity and inspi- by Riley et al [5] to retain continuity of the inferior ratory effort is physiologically important in the patho- border of the mandible by limiting the osteotomy to a genesis of OSA. The rationale for advancement of the rectangular window, including the genial tubercle. genioglossus muscle is as follows: the hypopharyn- This osteotomy is called an anterior mandibular oste- geal airway is stabilized by the forward movement of otomy (AMO). Further modification of this procedure the genial tubercle and genioglossus muscle, which was described by Lee and Woodson [8] as a circular places tension on the base of tongue thereby decreas- osteotomy of the genial tubercle. All procedures have the same objective of ultimate stabilization of the hypopharyngeal airway by advancing the genioglos- sus muscle. Johnson and Chinn [1] reported a positive response rate of 77.8% in nine patients treated with a * Virginia Commonwealth University, Medical College combination of UA procedures and genioglossus of Virginia, Department of Oral Maxillofacial Surgery, 716 muscle advancement. Lee et al [2] reported a positive Denbigh Boulevard, Suite C-1, Newport News, VA 23602. response rate of 69% in 35 patients treated with UA E-mail address: [email protected] (N.R. Lee). procedures and genioglossus muscle advancement. 1042-3699/02/$ – see front matter D 2002, Elsevier Science (USA). All rights reserved. PII: S1042-3699(02)00037-7 378 N.R. Lee / Oral Maxillofacial Surg Clin N Am 14 (2002) 377–384 Fig. 1. (A) The mucusal incision. (B) The dissection of the mental nerves. (C) The full-thickness periosteal incision. (From Lee NR. Genioplasty techniques. Oral Maxillofacial Surg Clin N Am 2000;12:755–63; with permission.) Therefore, when combined with other UA procedures, in stress-shielding the forces of mastication and is the genioglossus muscle advancement is a viable removed in 6 weeks. All patients who undergo this surgical treatment for OSA. procedure are requested to restrict their diets to non- chewable foods for 6 weeks following the procedure. The soft tissue approach is the same as for the Inferior sagittal osteotomy cosmetic intraoral genioplasty (Fig.1). The osseous midline is scored on the anterior surface of the sym- ISO is a technique reserved for the OSA patient physis. The genial tubercle pedicle is outlined with an with significant anteroposterior deficiencies in the oscillating saw in the anterior surface, with emphasis horizontal menton position (microgenia). The inferior on completion of a full-thickness osseous pedicle that border of the mandible is disrupted and advanced contains the entire genioglossus muscle attachment. with only the dentoalveolar process intact; therefore, The inferior portion of the osteotomy is the same as the a lingual splint is constructed and placed with inter- dental stainless steel 24-gauge wire. This splint aids Fig. 3. An anterior mandibular osteotomy showing the Fig. 2. Inferior sagittal osteotomy to advance the genio- advanced and rotated segment, which includes the genial glossus musculature for obstructive sleep apnea. (From Lee tubercle and genioglossus musculature. (From Lee NR. NR. Genioplasty techniques. Oral Maxillofacial Surg Clin N Genioplasty techniques. Oral Maxillofacial Surg Clin N Am Am 2000;12:755–63; with permission.) 2000;12:755–63; with permission.) N.R. Lee / Oral Maxillofacial Surg Clin N Am 14 (2002) 377–384 379 Fig. 4. System sizing. Select the appropriate trephine system (12 or 14 mm) using the radiograph template and panorex X ray. (From Stryker-Leibinger; with permission.) horizontal augmentation genioplasty, extending bilat- Anterior mandibular osteotomy erally and posteriorly toward the gonial notch region. The osseous pedicle is mobilized and advanced ante- The AMO technique is reserved for the OSA pa- riorly full thickness. The lingual cortex superior to the tient with a normal, horizontal, soft tissue menton genial tubercle is brought to rest on the lateral plate of position. The objective is the same as for the ISO— the dentoalveolar process with attention to coordina- to advance the genial tubercle and genioglossus mus- tion of the midline. Stabilization can be achieved by cle without disruption of the inferior border of the application of two precontoured chin plates at either mandible to improve stability of the hypopharyn- side of the midline symphysis tubercle process. Soft geal airway. tissue closure is accomplished in two layers, mentalis The soft tissue approach is the same as described muscle and mucosa (Fig. 2). for the intraoral genioplasty, except that osseous Fig. 5. Drilling pilot hole. Drill two superior 1.5-mm holes for guide-plate placement. (From Stryker-Leibinger; with permission.) 380 N.R. Lee / Oral Maxillofacial Surg Clin N Am 14 (2002) 377–384 Fig. 6. Guide-plate selection. Choose appropriate guide plate (S, straight; A, angled) depending on tooth root location and genioglossus muscle position. (From Stryker-Leibinger; with permission.) exposure is significantly reduced posteriorly. Peri- The muscle bundle cannot be palpated through the osteal dissection is accomplished posterior to and just mylohyoid muscle; however, accurate interpretation distal to the cuspids bilaterally. The mental nerves of the position of the tubercle can be achieved with do not require exposure and neurosensory deficit the anatomic knowledge that the genial tubercle is is minimal. The patient may experience dental-pulp approximately 5 to 8 mm inferior to the apices of the necrosis of the mandibular anterior dentition, and mandibular incisors. amputation of the cuspid root tips may occur. This A bicortical 2-mm bone screw is placed at the complication is treated by endodontic therapy when midpoint of the genial tubercle location. A micro- the tooth is diagnosed as nonvital. The genioglossus sagittal oscillating saw is used to complete a rec- muscle attachment is located by lingual palpation. tangular osteotomy, with the screw serving as a Fig. 7. Guide-plate fixation. Fixate guide plate to mandible using 2.0-mm-diameter bone screws with sufficient length to accommodate guide-plate profile. Alternate placement of the screws to ensure level guide-plate placement. (From Stryker- Leibinger; with permission.) N.R. Lee / Oral Maxillofacial Surg Clin N Am 14 (2002) 377–384 381 Fig. 8. Trephine stop assembly. Place trephine stop at a depth sufficient to osteotomize inferior border completely. Secure trephine stop by tightening the Square-fit set screw. (From Stryker-Leibinger; with permission.) central guide for a symmetrical segment that contains complication. After mobilization, the segment is the genioglossus muscle. Care must be taken not to transpositioned full thickness anteriorly. The lingual shorten the lingual plate by excessive angulation of cortical plate is then positioned anterior to the lateral the saw during the osteotomy, with emphasis directed cortical plate and rotated 90°. The medullary bone toward parallel walls of the symphysis osteotomy. and lateral cortical plate are osteotomized, which The bicortical bone screw ensures mobilization of leaves the lingual cortical plate and genioglossus both cortical plates. If the segment does not mobilize, muscle attachment. The segment is then stabilized the lingual osteotomy may not be complete