- Email: [email protected]
Genioglossus muscle advancement: A modification of the conventional technique
Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
Contents lists available at SciVerse ScienceDirect
Journal of Cranio-Maxillo-Facial Surgery journal homepage: www.jcmfs.com
Genioglossus muscle advancement: A modification of the conventional technique José Ramón García Vega a, *, María Mancha de la Plata a, Néstor Galindo b, Miriam Navarro b, Daniel Díez c, Fernando Láncara a Department of Oral and Maxillofacial Surgery (Head: Dr. José Ramón García Vega), Hospital Ruber Internacional, C/La Masó n 38, 28034 Madrid, Spain Department of Otorhinolaryngology, Hospital Ruber Internacional, Madrid, Spain c Department of Orthodontics, Hospital Ruber Internacional, Madrid, Spain a
b
a r t i c l e i n f o
a b s t r a c t
Article history: Paper received 6 March 2012 Accepted 10 May 2013
Obstructive sleep apnoea syndrome (OSAS) is a pathophysiologic condition associated with fragmented sleep and arousals caused by nocturnal mechanical obstruction of the upper airway. This results in behavioural derangements, such as excessive daytime sleepiness and fatigue, and pathophysiologic derangements that cause morbidities and mortality including hypertension, arrhythmias, myocardial infarction, stroke and sudden death. The genioglossus advancement is a proven technique for the treatment of mild to moderate obstructive sleep apnoea syndrome by relieving airway obstruction at the hypopharyngeal level. In this article, we report a modification of the conventional genioglossus advancement described by Riley and Powell. The modification we describe replaces the bone segment at the mandibular basal bone rather than at the mid area of the symphysis. This means a linear movement that allows a greater advancement and avoids the rotation of the genioglossus muscle. Through this article we will describe the advantages of the surgical technique such as greater effectiveness, stability, more pleasing aesthetic outcome and the reduction of potential complications. Ó 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
Keywords: Obstructive sleep apnoea syndrome genioglossus muscle advancement
1. Introduction Obstructive Sleep Apnoea syndrome (OSAS) is a respiratory disorder of sleep characterized by recurrent episodes of obstructive breathing caused by repetitive partial or complete collapse of the upper airway (Riley et al., 1995; Guilleminault and Takaoka, 2009). It is associated with symptoms such as excessive daily sleepiness, fatigue, memory loss and limited attention span and may result in morbidity and mortality in relation to cardiovascular derangement including hypertension, arrhythmias, myocardial infarction, stroke and sudden death (He et al., 1988; Powell, 2009; Schendel et al., 2011; Gasparini et al., 2012). The pathogenesis of the decrease of upper airway patency in OSAS is complex and multifactorial, involving anatomical and physiological factors during sleep (Li et al., 2000). Dynamic
* Corresponding author. Department of Oral and Maxillofacial Surgery, Hospital Ruber Internacional, Address: C/Montesa, 14 1 -centro, 28006 Madrid, Spain. Tel.: þ34 914012681. E-mail address: [email protected] (J.R. García Vega).
diagnostic procedures show a loss of muscular activity of the pharyngeal dilators resulting in airway collapse (Powell et al., 1998). The genioglossus muscle is a major pharyngeal dilator and the main tongue protrusor, so its role in nocturnal airway obstruction has been extensively studied (Remmers et al., 1978; Li, 2009; Oliven et al., 2009). In 1984, Riley and Powell described the advancement of the genial tubercle/genioglossus muscle complex (GGC) for the treatment of hypopharyngeal obstruction in OSAS (Riley et al., 1984). The rationale of this procedure was to stabilized the hypopharyngeal airway by moving forward the GGC which places tension on the base of the tongue and, thereby, expanding the airway during sleep (Powell et al., 1998; Li et al., 2001; Lee and Madani, 2007). The initial case report described a procedure that was essentially a standard horizontal genioplasty advancement. (Riley et al., 1984) As this procedure only included the lower portion of the GGC, a superior extension was designed in order to include the entire genioglossus muscle (Riley et al., 1986; Powell et al., 1994). Riley and Powell modified the surgical procedure in 1989, with the technique involving a bicortical rectangular osteotomy to allow incorporation of the GGC. Thereby, the continuity of the inferior border of the mandible was maintained
1010-5182/$ e see front matter Ó 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jcms.2013.05.007
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
2
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
minimizing the risk of mandibular fractures (Powell et al., 1991; Powell et al., 1994; Li et al., 2001). This procedure is included with success in the phase I of Riley-Powell Stanford surgical protocol (Powell and Riley, 1995). The aim of this article is to report a modification of the conventional genioglossus advancement that is based on the rectangular osteotomy advocated by Riley and Powell, replaces the GGC on a different way and position, offering noticeable advantages. 2. Material and methods Six male patients underwent genioglossus advancement by a single surgeon (J.R.G-V). All of the patients were diagnosed with OSAS by nocturnal polysomnography. Radiographic examination consisted of standard lateral cephalogram and a panoramic radiograph. The location of the GGC and root apices of the incisors and canines was determined before surgery by 3D-TC scan in all patients. The accurate position of the rectangular window in the outer cortex of the mandibular symphysis was established on the three dimensional reconstruction as well as the inclination of the osteotomy to reach the lingual cortex and include the genial tubercles (Fig. 1a and b). The positions of the superior and inferior horizontal osteotomies were measured from a fixed point of reference which was the inferior mid alveolar ridge.
2.1. Surgical technique An intraoral approach is carried out through a mucosal incision in the gingivolabial sulcus. Dissection is performed submucoperiosteally to expose the mandibular symphysis without requiring identification of both mental nerves. A rectangular bone window, centred in the middle of the mandibular symphysis, is then drawn. The superior and inferior horizontal lines (20 mm length) were marked at the positions previously measured at the 3D-TC scan. The superior line should always be located 5 mm inferior to the apices of the mandibular incisors. Both are connected by two vertical lines positioned medial to the root apices of the canines (10 mm in height). The anterior cortical bone is then cut following the drawn rectangle. At this point of the procedure, a 14e 16 mm orthodontic traction screw is placed in the centre of the rectangular corticotomy (Fig. 2). Good care must be taken to make sure that the inclination of the drilling is the accurate to reach the genioglossus tubercles in the inner aspect of the mandibular symphysis. The orthodontic traction screw we use has a long cylindrical head which is the reference for the inclination we should follow performing the horizontal osteotomies. The head of the screw also has a hole in the middle to pass a wire through that enables the manipulation, control and advancement of the osteotomized bone segment (Fig. 3).
Fig. 1. a: Preoperative planification on the 3D-TC scan. Anterior view. b: Preoperative planification on the 3D-TC scan. Posterior view.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
Fig. 2. Bicortical screw placed in the midline of the anterior rectangular corticotomy.
3
Under direct vision, a longitudinal groove, wider at the lingual end than in the labial, is made in the floor of the bone window by means of a tungsten rotatory burr. While making this groove, a residual bone height of at least 8 mm must be kept above the mandibular basal bone (Fig. 5). At this time, the full-thickness bone segment with the attached genial tubercles and genioglossus muscles is advanced anteriorly and inferiorly, towards the basal border of the mandibular symphysis where it is adapted passively. The genioglossus muscles lies on the groove made previously without any torsion. The outer bone cortex and marrow are then removed with a reciprocating saw. The inner cortex is rigidly fixed at its lateral ends to the basal bone with two screws of 2 14 mm (Fig. 6). Finally, the harvested bone is used as an in-lay graft, fixed with wired osseosynthesis, filling the bone defect created (Figs. 7 and 8). After haemostasis has been achieved, the mentalis muscle is suspended and closure of the mucosa is performed. A pressure dressing is placed on the anterior mandible for 48 h to secure the mentalis musculature to its appropriate position. 3. Results The mean age of the six patients was of 43 years (range: 36e51 years). Only one patient had a coexisting medical problem including hypertension and a moderate ventricular hypertrophy.
Fig. 3. The bicortical screw used for control and manipulation of the bone segment.
The osteotomies are then completed using piezo surgery, oscillating and reciprocating saws under copious irrigation, encompassing the full-thickness mandibular bone. Once all the osteotomies are verified and the bone segment is freed (Fig. 4), the latter is pulled backward to expose the floor of the bone window.
Fig. 4. The bone segment is freed.
Fig. 5. The longitudinal groove in the floor of the bone window and the residual height of the mandibular basal bone are shown.
Fig. 6. Fixation of the bone flap at the mandibular basal bone with the genioglossus muscles laying passively on the groove performed.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
4
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
rotation or twist. None of them suffered spontaneous detachment of the genial musculature. There were no intraoperative complications. There was no postoperative bleeding or infection, wound dehiscence, tooth root injury, mental nerve paresthesia or loss of the fixation. There were no mandibular fractures. The postoperative evaluations consisted of a nocturnal polysomnograph (Table 1) and reassessment of the physical symptoms 6 months after the surgical procedure. The mean postoperative RDI was 15 and the baseline mean LSAT 90.2%. All patients reported improvement of physical symptoms such as snoring, daytime sleepiness and fatigue and were also very pleased with the aesthetic result.
4. Discussion The genioglossus advancement is a proven technique for relieving airway obstruction at the hypopharyngeal level (Riley et al., 1993a; Neruntarat, 2003). The American Sleep Disorders Association studied the success rate of all surgical modifications of the upper airway and noted that genioglossus advancement with or without hyoid myotomy seemed to be the most beneficial method for widening the retrolingual space (Sher et al., 1996, Foltán et al., 2007). Riley et al. in 1993 reported to be 70%e80% successful in treating mild to moderate obstructive sleep apnoea syndrome (Riley et al., 1993b). Several osteotomy designs have been used to advance the genioglossus musculature, including standard genioplasty, inferior sagittal osteotomy, circular genioplasty and mortised genioplasty (Riley et al., 1984; Riley et al., 1989; Hendler et al., 2001; Lee, 2002; Lee and Madani, 2007). The current technique advocated by Powell and Riley et al. consists on advancement of the GGC through a rectangular anterior mandibular osteotomy. The bone flap is advanced and rotated 30 a 45 to create bone overlap for a fixation screw (Li et al., 2001; Guilleminault and Takaoka, 2009; Powell, 2009). We consider that this surgical procedure presents significant limitations that we sought to overcome with our modification as well as to contribute new improvements, regarding different aspects of the GGC advancement that will be discussed below.
Fig. 7. Surgical view of the final result.
The mean body mass index (BMI) was 26.1 kg/m2 (range: 25e 30.1 kg/m2), two patients had optimal weight, three patients were overweight and one patient was obese. None of the patients had been able to tolerate nasal continuous positive pressure (CPAP). After polysomnographic analysis (Table 1) one patient was classified as moderate OSAS and five patients as severe OSAS, with respiratory disturbance index (RDI) of 22, 46, 40, 63.3, 68 and 80 (mean: 53.2). The baseline mean lowest SaO2 (LSAT) was of 76%. Patient 1 (Table 1) underwent nasal turbinate radiofrequency and an uvulopalatopharyngoplasty simultaneously to the genioglossus muscle advancement. Patient 3 had previously had nasal surgery and an uvulopalatopharyngoplasty. In patients 2 and 4, with maxillary hypoplasia, a maxillary advancement (Le Fort I and three pieces segmented Le Fort I) was performed with the genioglossus advancement. In patients 5 and 6, respectively, an uvulopalatopharyngoplasty and radiofrequency tongue reduction were performed. In all cases the genial tubercles were captured and both bellies of the genioglosssus muscle were incorporated without any
Fig. 8. Anterior and posterior view of the final result on the postoperative 3D-TC scan.
Table 1 Preoperative and postoperative polysomnographic analysis. Patient
Complementary surgery
Preoperative RDI
Preoperative LSAT (%)
Postoperative RDI
Postoperative LSAT (%)
1. LM 2. PL 3. AR
NTR þ UPFP LeFort I Previous UPFP þ Nasal surgery LeFort I UPFP RTBR
80 63.3 68
65 77 76
17 12 15
85 90 91
22 46 40
82 79 81
11 20 15
95 89 91
4. JS 5. MS 6. PG
NTR: nasal turbinate radiofrequency; UPFP: uvulopalatopharyngoplasty; RTBR: radiofrequency base tongue reduction.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
5
Fig. 9. Inferior third facial profile. Improvement of the chin projection.
It should be emphasized that our technique differed from that of Riley and Powell et al. in the reposition of the bone flap, that is pulled anteriorly and inferiorly and fixed without rotation at the basal mandibular bone. Our procedure involves a greater advancement of the bone flap and therefore significant traction of the genioglossus muscles, since the mandible at its inferior border represents the most anterior point of the mandibular symphysis (pogonion). In contrast, in the conventional technique the rotated bone segment is fixed at the most posterior point in the concavity of the mandible (B-point) (Ricketts, 1961). In an anatomic study with 10 cadaver models, the thickness of the mandible was measured at both the level of the genial tubercles and at the inferior border. The average thickness of the genial tubercles was 12.6 mm (range 9e15 mm) while at the inferior border at pogonion was 14.5 mm (range 12e18 mm) (Silverstein et al., 2000; Hendler et al., 2001). Another significant interest of the reposition on the basal mandibular border is related to the stability of the bone fixation. The inner side of the bone flap adapts suitably on the convex surface of the inferior border providing a larger overlap and bone contact surface. In contrast, when the bone flap is rotated, its curvature is opposite to the outer table of the mandibular symphysis, causing a limited bone overlap and contact surface for the placement of the screw and therefore reducing the stability. When the flap complex is rotated, the bone contact surface remains too small, the bone segment may even fracture during drilling and screw placement leading to the failure of the procedure. Moreover, this reduced surface of contact may lead to the placement of the fixation screw in an upward direction with an added risk of tooth apex injury. The use of short and narrow screws is important in these cases in order to minimize this risk. Hendler et al. reported that the internal organization of the inferior border consists of a greater proportion of dense compact bone versus cancellous bone, producing a more stable framework (Hendler et al., 2001). All of these points support the considerable advantages of the fixation at the basal mandibular bone where two long and wide screws can be used, instead of a single narrow and short one. This kind of fixation improves the stability, prevents relapse, reduces the possibility of fracture of the bone flap and the risk of tooth injury. One of the major advantages of the linear advancement of the modification we describe is that the genioglossus complex is repositioned in a passive manner, avoiding the rotation of the genioglossus muscles what can seriously impair its effectiveness. As Silverstein et al. founded in a study of 10 cadavers, the genioglossus muscle attachments can be as wide as 15 mm (Silverstein et al., 2000). This may make rotation difficult resulting in a forced and aggressive manoeuvre. The twist and tension of the
genioglossus muscles can lead to stripping of the attachment or even avascular necrosis of the muscle, resulting in failure of the procedure (Ferreira dos Santos et al., 2007; Demian et al., 2009). Mc Andrew and Strauss reported one case of spontaneous detachment of the genial musculature eleven days postoperatively. They felt that the tension produced by the rotation of the segment may have played a role in the detachment (Mc Andrew and Strauss, 2000). Our technique eliminates the rotation of the bone and muscle complex, preserving the anatomical direction of the muscles that lay passively in the groove created at the floor of the bone window avoiding muscular stress and minimizing the risk of muscle insertion detachment. In our technique, we regraft the free facial segment filling the mandibular bone defect created. This autogenous bone grafting allows for more long-term stability. Dattilo et al. in an article of a modification of the phase I technique including genioglossus advancement and hyoid suspension, reported the grafting of the harvested bone fixed to the lateral segments of the anterior mandible. They stated that with no bone growth into the defect the possibility of inadvertent fractures continues, while with any autogenous bone graft these areas can instigate osteogenesis and eventually be refilled with stable native bone stock (Dattilo and Aynechi, 2007). A controversial point of our modification of the conventional genioglossus advancement may be related to the execution of the bone groove at the mandibular thickness that might reduce the resistance of the basal bone increasing the risk of mandibular fractures. However, the basal bone is reinforced with the rigid fixation of the segment and the reconstruction of the defect with the harvested bone. Nevertheless, a semi-soft diet during three weeks following the surgery and the use of a relaxing appliance is recommended. The surgical modification described here also offers an aesthetic benefit, as fixing the lingual cortex to the basal mandibular bone and the consequent soft tissue changes increase the chin projection. This may result in a more cosmetically pleasing facial profile, especially in patients with mandibular retrognathism (Fig. 9). In the rotation technique, the final placement of the convex lingual cortex over the concave mid area of the mandibular symphysis causes unaesthetic outcome because of loss or even inversion of the mentolabial angle.
5. Conclusion Our modification of the genioglossus advancement offers the following advantages over the conventional procedure in the
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
6
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
treatment of OSAS in phase I of Riley-Powell Stanford surgical protocol: -
Increased advancement of the genioglossus muscles. Greater long-term stability. Less muscular stress with no rotation of the genioglossus muscles. Fewer complications in relation to detachment of the muscular pedicle. - Reduced risk of fracture of the bone segment and injury of the apices of the incisors. - More pleasing aesthetic outcome. For all of these reasons, we consider that this surgical modification contributes significant improvements to the conventional procedure. References Dattilo DJ, Aynechi M: Modification of the anterior mandibular osteotomy for genioglossus advancement with hyoid suspension for obstructive sleep apnoea. J Oral Maxillofac Surg 65: 1876e1879, 2007 Demian NM, Alford J, Takashima M: An alternative technique for genioglossus muscle advancement in phase I surgery in the treatment of obstructive sleep apnoea. J Oral Maxillofac Surg 67: 2315e2318, 2009 Ferreira dos Santos J, Abrahao M, Gregorio LC, Zonato AI, Gumieiro EH: Genioplasty for genioglossus muscle advancement in patients with obstructive sleep apnoea-hypopnea syndrome and mandibular retrognathia. Rev Bras Otorhinolaryngol 73(4): 480e486, 2007 Foltán R, Hoffmannova J, Pretl M, Donev F, Vlk M: Genioglossus advancement and hyoid myotomy in treating obstructive sleep apnoea syndrome e a follow-up study. J Cranio Maxillofac Surg 35: 246e251, 2007 Gasparini G, Saponaro G, Rinaldo F, Boniello R, Marianetti TM, Torroni A, et al: Clinical evaluation of obstructive sleep apnoea in children. J Cranio Maxillofac Surg 23(2): 387e391, 2012 Guilleminault C, Takaoka S: Signs and symptoms of obstructive sleep apnoea and upper airway resistance syndrome. In: Friedman M (ed.), Sleep apnoea and snoring: surgical and non-surgical therapy. Chicago: Saunders, 3e10, 2009 He J, Kryger M, Zorick FJ, Conway W, Roth T: Mortality and apnoea index in obstructive sleep apnoea: experience in 385 male patients. Chest 94: 9e14, 1988 Hendler B, Silverstein K, Giannakopoulus H, Costello BJ: Mortised genioplasty in the treatment of obstructive sleep apnoea: an historical perspective and modification of design. Sleep Breath 5(4): 173e180, 2001 Lee NR: Genioglossus muscle advancement techniques for obstructive sleep apnoea. Oral Maxillofacial Surg Clin N Am 14: 377e384, 2002 Lee NR, Madani M: Genioglossus muscle advancement techniques for obstructive sleep apnoea. Atlas Oral Maxillofac Surg Clin N Am 15: 179e192, 2007 Li KK, Riley RW, Powell NB, Guilleminault C: Maxillomandibular advancement for persistent obstructive sleep apnoea after phase I surgery in patients without maxillomandibular deficiency. Laryngoscope 110: 1684e1688, 2000
Li KK, Riley RW, Powell NB, Troell RJ: Obstructive sleep apnoea surgery: genioglossus advancement revisited. J Oral Maxillofac Surg 59: 1181e1184, 2001 Li KK: Genioglossus advancement in sleep apnoea surgery. In: Friedman M (ed.), Sleep apnoea and snoring: surgical and non-surgical therapy. Chicago: Saunders, 301e304, 2009 Mc Andrew BP, Strauss RA: Delayed muscle detachment after genial tubercle advancement in a patient with obstructive sleep apnoea. J Oral Maxillofac Surg 58: 1040e1043, 2000 Neruntarat C: Genioglossus advancement and hyoid myotomy: short-term and long-term results. J Laryngol Otol 117: 482, 2003 Oliven R, Tov N, Odeh M, Gaitini L, Steinfeld U, Schwartz AR, et al: Interacting effects of genioglossus stimulation and mandibular advancement in sleep apnoea. J Appl Physiol 106: 1668e1673, 2009 Powell NB, Riley RW, Guilleminault C: Maxillofacial surgical techniques for hypopharyngeal obstruction in obstructive sleep apnoea. Operative techniques. Otolaryngol Head Neck Surg 2: 112e119, 1991 Powell NB, Riley RW, Guilleminault C: The hypopharynx: upper way reconstruction in obstructive sleep apnoea syndrome. In: Fairbanks DNF, Fujita S (eds), Snoring and obstructive sleep apnoea (ed 2). New York, NY: Raven Press, 193e209, 1994 Powell NB, Riley RW: A surgical protocol for sleep disordered breathing. Oral Maxillofacial Surg Clin N Am 7(2): 345e356, 1995 Powell NB, Riley RW, Robinson A: Surgical management of obstructive sleep apnoea syndrome. Clinics in Chest Medicine 19(1): 77e86, 1998 Powell NB: Contemporary surgery for obstructive sleep apnoea syndrome. Clinical and Experimental Otorhinolaryngology 2(3): 107e114, 2009 Remmers JE, deGroot WJ, Sauerland EK, Anch AM: Pathogenesis of upper airway obstruction during sleep. J Appl Physiol 44: 931e938, 1978 Ricketts RM: Cephalometric analysis and synthesis. Angle Orthod 31: 141e156, 1961 Riley RW, Guilleminault C, Powell NB, Derman S: Mandibular osteotomy and hyoid bone advancement for obstructive sleep apnoea: a case report. Sleep 7: 79, 1984 Riley RW, Powell NB, Guilleminault C: Inferior sagittal osteotomy of the mandible with hyoid suspension: a new procedure for obstructive sleep apnoea. Otolaryngol Head Neck Surg 94: 589, 1986 Riley RW, Powell NB, Guilleminault C: Inferior mandibular osteotomy and hyoid myotomy suspension for obstructive sleep apnoea: a review of 55 patients. J Oral Maxillofac Surg 47: 159e164, 1989 Riley RW, Powell NB, Guilleminault C: Obstructive sleep apnoea syndrome: a review of 306 consecutively treated surgical patients. Otolaryngol Head Neck Surg 108: 117e125, 1993a Riley RW, Powell NB, Guilleminault C: Obstructive sleep apnoea syndrome: a surgical protocol for dynamic upper airway reconstruction. J Oral Maxillofac Surg 51: 742, 1993b Riley RW, Powell NB, Guilleminault C, Clerk A, Troell R: Obstructive sleep apnoea e trends in therapy. West J Med 62: 143e148, 1995 Schendel S, Powell NB, Jacobson R: Maxillary, mandibular and chin advancement: treatment planning based on airway anatomy in obstructive sleep apnoea. J Oral Maxillofac Surg 69: 663e676, 2011 Sher AE, Schechtman KB, Piccirillo JF: The efficacy of surgical modifications of the upper airway in adults with obstructive sleep apnea syndrome. Sleep 19(2): 156e177, 1996 Silverstein B, Costello BJ, Giannakpoulos H, Hendler B: Genioglossus muscle attachments: an anatomic analysis and the implications for genioglossus advancement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 90: 686e688, 2000
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
Contents lists available at SciVerse ScienceDirect
Journal of Cranio-Maxillo-Facial Surgery journal homepage: www.jcmfs.com
Genioglossus muscle advancement: A modification of the conventional technique José Ramón García Vega a, *, María Mancha de la Plata a, Néstor Galindo b, Miriam Navarro b, Daniel Díez c, Fernando Láncara a Department of Oral and Maxillofacial Surgery (Head: Dr. José Ramón García Vega), Hospital Ruber Internacional, C/La Masó n 38, 28034 Madrid, Spain Department of Otorhinolaryngology, Hospital Ruber Internacional, Madrid, Spain c Department of Orthodontics, Hospital Ruber Internacional, Madrid, Spain a
b
a r t i c l e i n f o
a b s t r a c t
Article history: Paper received 6 March 2012 Accepted 10 May 2013
Obstructive sleep apnoea syndrome (OSAS) is a pathophysiologic condition associated with fragmented sleep and arousals caused by nocturnal mechanical obstruction of the upper airway. This results in behavioural derangements, such as excessive daytime sleepiness and fatigue, and pathophysiologic derangements that cause morbidities and mortality including hypertension, arrhythmias, myocardial infarction, stroke and sudden death. The genioglossus advancement is a proven technique for the treatment of mild to moderate obstructive sleep apnoea syndrome by relieving airway obstruction at the hypopharyngeal level. In this article, we report a modification of the conventional genioglossus advancement described by Riley and Powell. The modification we describe replaces the bone segment at the mandibular basal bone rather than at the mid area of the symphysis. This means a linear movement that allows a greater advancement and avoids the rotation of the genioglossus muscle. Through this article we will describe the advantages of the surgical technique such as greater effectiveness, stability, more pleasing aesthetic outcome and the reduction of potential complications. Ó 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
Keywords: Obstructive sleep apnoea syndrome genioglossus muscle advancement
1. Introduction Obstructive Sleep Apnoea syndrome (OSAS) is a respiratory disorder of sleep characterized by recurrent episodes of obstructive breathing caused by repetitive partial or complete collapse of the upper airway (Riley et al., 1995; Guilleminault and Takaoka, 2009). It is associated with symptoms such as excessive daily sleepiness, fatigue, memory loss and limited attention span and may result in morbidity and mortality in relation to cardiovascular derangement including hypertension, arrhythmias, myocardial infarction, stroke and sudden death (He et al., 1988; Powell, 2009; Schendel et al., 2011; Gasparini et al., 2012). The pathogenesis of the decrease of upper airway patency in OSAS is complex and multifactorial, involving anatomical and physiological factors during sleep (Li et al., 2000). Dynamic
* Corresponding author. Department of Oral and Maxillofacial Surgery, Hospital Ruber Internacional, Address: C/Montesa, 14 1 -centro, 28006 Madrid, Spain. Tel.: þ34 914012681. E-mail address: [email protected] (J.R. García Vega).
diagnostic procedures show a loss of muscular activity of the pharyngeal dilators resulting in airway collapse (Powell et al., 1998). The genioglossus muscle is a major pharyngeal dilator and the main tongue protrusor, so its role in nocturnal airway obstruction has been extensively studied (Remmers et al., 1978; Li, 2009; Oliven et al., 2009). In 1984, Riley and Powell described the advancement of the genial tubercle/genioglossus muscle complex (GGC) for the treatment of hypopharyngeal obstruction in OSAS (Riley et al., 1984). The rationale of this procedure was to stabilized the hypopharyngeal airway by moving forward the GGC which places tension on the base of the tongue and, thereby, expanding the airway during sleep (Powell et al., 1998; Li et al., 2001; Lee and Madani, 2007). The initial case report described a procedure that was essentially a standard horizontal genioplasty advancement. (Riley et al., 1984) As this procedure only included the lower portion of the GGC, a superior extension was designed in order to include the entire genioglossus muscle (Riley et al., 1986; Powell et al., 1994). Riley and Powell modified the surgical procedure in 1989, with the technique involving a bicortical rectangular osteotomy to allow incorporation of the GGC. Thereby, the continuity of the inferior border of the mandible was maintained
1010-5182/$ e see front matter Ó 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jcms.2013.05.007
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
2
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
minimizing the risk of mandibular fractures (Powell et al., 1991; Powell et al., 1994; Li et al., 2001). This procedure is included with success in the phase I of Riley-Powell Stanford surgical protocol (Powell and Riley, 1995). The aim of this article is to report a modification of the conventional genioglossus advancement that is based on the rectangular osteotomy advocated by Riley and Powell, replaces the GGC on a different way and position, offering noticeable advantages. 2. Material and methods Six male patients underwent genioglossus advancement by a single surgeon (J.R.G-V). All of the patients were diagnosed with OSAS by nocturnal polysomnography. Radiographic examination consisted of standard lateral cephalogram and a panoramic radiograph. The location of the GGC and root apices of the incisors and canines was determined before surgery by 3D-TC scan in all patients. The accurate position of the rectangular window in the outer cortex of the mandibular symphysis was established on the three dimensional reconstruction as well as the inclination of the osteotomy to reach the lingual cortex and include the genial tubercles (Fig. 1a and b). The positions of the superior and inferior horizontal osteotomies were measured from a fixed point of reference which was the inferior mid alveolar ridge.
2.1. Surgical technique An intraoral approach is carried out through a mucosal incision in the gingivolabial sulcus. Dissection is performed submucoperiosteally to expose the mandibular symphysis without requiring identification of both mental nerves. A rectangular bone window, centred in the middle of the mandibular symphysis, is then drawn. The superior and inferior horizontal lines (20 mm length) were marked at the positions previously measured at the 3D-TC scan. The superior line should always be located 5 mm inferior to the apices of the mandibular incisors. Both are connected by two vertical lines positioned medial to the root apices of the canines (10 mm in height). The anterior cortical bone is then cut following the drawn rectangle. At this point of the procedure, a 14e 16 mm orthodontic traction screw is placed in the centre of the rectangular corticotomy (Fig. 2). Good care must be taken to make sure that the inclination of the drilling is the accurate to reach the genioglossus tubercles in the inner aspect of the mandibular symphysis. The orthodontic traction screw we use has a long cylindrical head which is the reference for the inclination we should follow performing the horizontal osteotomies. The head of the screw also has a hole in the middle to pass a wire through that enables the manipulation, control and advancement of the osteotomized bone segment (Fig. 3).
Fig. 1. a: Preoperative planification on the 3D-TC scan. Anterior view. b: Preoperative planification on the 3D-TC scan. Posterior view.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
Fig. 2. Bicortical screw placed in the midline of the anterior rectangular corticotomy.
3
Under direct vision, a longitudinal groove, wider at the lingual end than in the labial, is made in the floor of the bone window by means of a tungsten rotatory burr. While making this groove, a residual bone height of at least 8 mm must be kept above the mandibular basal bone (Fig. 5). At this time, the full-thickness bone segment with the attached genial tubercles and genioglossus muscles is advanced anteriorly and inferiorly, towards the basal border of the mandibular symphysis where it is adapted passively. The genioglossus muscles lies on the groove made previously without any torsion. The outer bone cortex and marrow are then removed with a reciprocating saw. The inner cortex is rigidly fixed at its lateral ends to the basal bone with two screws of 2 14 mm (Fig. 6). Finally, the harvested bone is used as an in-lay graft, fixed with wired osseosynthesis, filling the bone defect created (Figs. 7 and 8). After haemostasis has been achieved, the mentalis muscle is suspended and closure of the mucosa is performed. A pressure dressing is placed on the anterior mandible for 48 h to secure the mentalis musculature to its appropriate position. 3. Results The mean age of the six patients was of 43 years (range: 36e51 years). Only one patient had a coexisting medical problem including hypertension and a moderate ventricular hypertrophy.
Fig. 3. The bicortical screw used for control and manipulation of the bone segment.
The osteotomies are then completed using piezo surgery, oscillating and reciprocating saws under copious irrigation, encompassing the full-thickness mandibular bone. Once all the osteotomies are verified and the bone segment is freed (Fig. 4), the latter is pulled backward to expose the floor of the bone window.
Fig. 4. The bone segment is freed.
Fig. 5. The longitudinal groove in the floor of the bone window and the residual height of the mandibular basal bone are shown.
Fig. 6. Fixation of the bone flap at the mandibular basal bone with the genioglossus muscles laying passively on the groove performed.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
4
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
rotation or twist. None of them suffered spontaneous detachment of the genial musculature. There were no intraoperative complications. There was no postoperative bleeding or infection, wound dehiscence, tooth root injury, mental nerve paresthesia or loss of the fixation. There were no mandibular fractures. The postoperative evaluations consisted of a nocturnal polysomnograph (Table 1) and reassessment of the physical symptoms 6 months after the surgical procedure. The mean postoperative RDI was 15 and the baseline mean LSAT 90.2%. All patients reported improvement of physical symptoms such as snoring, daytime sleepiness and fatigue and were also very pleased with the aesthetic result.
4. Discussion The genioglossus advancement is a proven technique for relieving airway obstruction at the hypopharyngeal level (Riley et al., 1993a; Neruntarat, 2003). The American Sleep Disorders Association studied the success rate of all surgical modifications of the upper airway and noted that genioglossus advancement with or without hyoid myotomy seemed to be the most beneficial method for widening the retrolingual space (Sher et al., 1996, Foltán et al., 2007). Riley et al. in 1993 reported to be 70%e80% successful in treating mild to moderate obstructive sleep apnoea syndrome (Riley et al., 1993b). Several osteotomy designs have been used to advance the genioglossus musculature, including standard genioplasty, inferior sagittal osteotomy, circular genioplasty and mortised genioplasty (Riley et al., 1984; Riley et al., 1989; Hendler et al., 2001; Lee, 2002; Lee and Madani, 2007). The current technique advocated by Powell and Riley et al. consists on advancement of the GGC through a rectangular anterior mandibular osteotomy. The bone flap is advanced and rotated 30 a 45 to create bone overlap for a fixation screw (Li et al., 2001; Guilleminault and Takaoka, 2009; Powell, 2009). We consider that this surgical procedure presents significant limitations that we sought to overcome with our modification as well as to contribute new improvements, regarding different aspects of the GGC advancement that will be discussed below.
Fig. 7. Surgical view of the final result.
The mean body mass index (BMI) was 26.1 kg/m2 (range: 25e 30.1 kg/m2), two patients had optimal weight, three patients were overweight and one patient was obese. None of the patients had been able to tolerate nasal continuous positive pressure (CPAP). After polysomnographic analysis (Table 1) one patient was classified as moderate OSAS and five patients as severe OSAS, with respiratory disturbance index (RDI) of 22, 46, 40, 63.3, 68 and 80 (mean: 53.2). The baseline mean lowest SaO2 (LSAT) was of 76%. Patient 1 (Table 1) underwent nasal turbinate radiofrequency and an uvulopalatopharyngoplasty simultaneously to the genioglossus muscle advancement. Patient 3 had previously had nasal surgery and an uvulopalatopharyngoplasty. In patients 2 and 4, with maxillary hypoplasia, a maxillary advancement (Le Fort I and three pieces segmented Le Fort I) was performed with the genioglossus advancement. In patients 5 and 6, respectively, an uvulopalatopharyngoplasty and radiofrequency tongue reduction were performed. In all cases the genial tubercles were captured and both bellies of the genioglosssus muscle were incorporated without any
Fig. 8. Anterior and posterior view of the final result on the postoperative 3D-TC scan.
Table 1 Preoperative and postoperative polysomnographic analysis. Patient
Complementary surgery
Preoperative RDI
Preoperative LSAT (%)
Postoperative RDI
Postoperative LSAT (%)
1. LM 2. PL 3. AR
NTR þ UPFP LeFort I Previous UPFP þ Nasal surgery LeFort I UPFP RTBR
80 63.3 68
65 77 76
17 12 15
85 90 91
22 46 40
82 79 81
11 20 15
95 89 91
4. JS 5. MS 6. PG
NTR: nasal turbinate radiofrequency; UPFP: uvulopalatopharyngoplasty; RTBR: radiofrequency base tongue reduction.
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
5
Fig. 9. Inferior third facial profile. Improvement of the chin projection.
It should be emphasized that our technique differed from that of Riley and Powell et al. in the reposition of the bone flap, that is pulled anteriorly and inferiorly and fixed without rotation at the basal mandibular bone. Our procedure involves a greater advancement of the bone flap and therefore significant traction of the genioglossus muscles, since the mandible at its inferior border represents the most anterior point of the mandibular symphysis (pogonion). In contrast, in the conventional technique the rotated bone segment is fixed at the most posterior point in the concavity of the mandible (B-point) (Ricketts, 1961). In an anatomic study with 10 cadaver models, the thickness of the mandible was measured at both the level of the genial tubercles and at the inferior border. The average thickness of the genial tubercles was 12.6 mm (range 9e15 mm) while at the inferior border at pogonion was 14.5 mm (range 12e18 mm) (Silverstein et al., 2000; Hendler et al., 2001). Another significant interest of the reposition on the basal mandibular border is related to the stability of the bone fixation. The inner side of the bone flap adapts suitably on the convex surface of the inferior border providing a larger overlap and bone contact surface. In contrast, when the bone flap is rotated, its curvature is opposite to the outer table of the mandibular symphysis, causing a limited bone overlap and contact surface for the placement of the screw and therefore reducing the stability. When the flap complex is rotated, the bone contact surface remains too small, the bone segment may even fracture during drilling and screw placement leading to the failure of the procedure. Moreover, this reduced surface of contact may lead to the placement of the fixation screw in an upward direction with an added risk of tooth apex injury. The use of short and narrow screws is important in these cases in order to minimize this risk. Hendler et al. reported that the internal organization of the inferior border consists of a greater proportion of dense compact bone versus cancellous bone, producing a more stable framework (Hendler et al., 2001). All of these points support the considerable advantages of the fixation at the basal mandibular bone where two long and wide screws can be used, instead of a single narrow and short one. This kind of fixation improves the stability, prevents relapse, reduces the possibility of fracture of the bone flap and the risk of tooth injury. One of the major advantages of the linear advancement of the modification we describe is that the genioglossus complex is repositioned in a passive manner, avoiding the rotation of the genioglossus muscles what can seriously impair its effectiveness. As Silverstein et al. founded in a study of 10 cadavers, the genioglossus muscle attachments can be as wide as 15 mm (Silverstein et al., 2000). This may make rotation difficult resulting in a forced and aggressive manoeuvre. The twist and tension of the
genioglossus muscles can lead to stripping of the attachment or even avascular necrosis of the muscle, resulting in failure of the procedure (Ferreira dos Santos et al., 2007; Demian et al., 2009). Mc Andrew and Strauss reported one case of spontaneous detachment of the genial musculature eleven days postoperatively. They felt that the tension produced by the rotation of the segment may have played a role in the detachment (Mc Andrew and Strauss, 2000). Our technique eliminates the rotation of the bone and muscle complex, preserving the anatomical direction of the muscles that lay passively in the groove created at the floor of the bone window avoiding muscular stress and minimizing the risk of muscle insertion detachment. In our technique, we regraft the free facial segment filling the mandibular bone defect created. This autogenous bone grafting allows for more long-term stability. Dattilo et al. in an article of a modification of the phase I technique including genioglossus advancement and hyoid suspension, reported the grafting of the harvested bone fixed to the lateral segments of the anterior mandible. They stated that with no bone growth into the defect the possibility of inadvertent fractures continues, while with any autogenous bone graft these areas can instigate osteogenesis and eventually be refilled with stable native bone stock (Dattilo and Aynechi, 2007). A controversial point of our modification of the conventional genioglossus advancement may be related to the execution of the bone groove at the mandibular thickness that might reduce the resistance of the basal bone increasing the risk of mandibular fractures. However, the basal bone is reinforced with the rigid fixation of the segment and the reconstruction of the defect with the harvested bone. Nevertheless, a semi-soft diet during three weeks following the surgery and the use of a relaxing appliance is recommended. The surgical modification described here also offers an aesthetic benefit, as fixing the lingual cortex to the basal mandibular bone and the consequent soft tissue changes increase the chin projection. This may result in a more cosmetically pleasing facial profile, especially in patients with mandibular retrognathism (Fig. 9). In the rotation technique, the final placement of the convex lingual cortex over the concave mid area of the mandibular symphysis causes unaesthetic outcome because of loss or even inversion of the mentolabial angle.
5. Conclusion Our modification of the genioglossus advancement offers the following advantages over the conventional procedure in the
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007
6
J.R. García Vega et al. / Journal of Cranio-Maxillo-Facial Surgery xxx (2013) 1e6
treatment of OSAS in phase I of Riley-Powell Stanford surgical protocol: -
Increased advancement of the genioglossus muscles. Greater long-term stability. Less muscular stress with no rotation of the genioglossus muscles. Fewer complications in relation to detachment of the muscular pedicle. - Reduced risk of fracture of the bone segment and injury of the apices of the incisors. - More pleasing aesthetic outcome. For all of these reasons, we consider that this surgical modification contributes significant improvements to the conventional procedure. References Dattilo DJ, Aynechi M: Modification of the anterior mandibular osteotomy for genioglossus advancement with hyoid suspension for obstructive sleep apnoea. J Oral Maxillofac Surg 65: 1876e1879, 2007 Demian NM, Alford J, Takashima M: An alternative technique for genioglossus muscle advancement in phase I surgery in the treatment of obstructive sleep apnoea. J Oral Maxillofac Surg 67: 2315e2318, 2009 Ferreira dos Santos J, Abrahao M, Gregorio LC, Zonato AI, Gumieiro EH: Genioplasty for genioglossus muscle advancement in patients with obstructive sleep apnoea-hypopnea syndrome and mandibular retrognathia. Rev Bras Otorhinolaryngol 73(4): 480e486, 2007 Foltán R, Hoffmannova J, Pretl M, Donev F, Vlk M: Genioglossus advancement and hyoid myotomy in treating obstructive sleep apnoea syndrome e a follow-up study. J Cranio Maxillofac Surg 35: 246e251, 2007 Gasparini G, Saponaro G, Rinaldo F, Boniello R, Marianetti TM, Torroni A, et al: Clinical evaluation of obstructive sleep apnoea in children. J Cranio Maxillofac Surg 23(2): 387e391, 2012 Guilleminault C, Takaoka S: Signs and symptoms of obstructive sleep apnoea and upper airway resistance syndrome. In: Friedman M (ed.), Sleep apnoea and snoring: surgical and non-surgical therapy. Chicago: Saunders, 3e10, 2009 He J, Kryger M, Zorick FJ, Conway W, Roth T: Mortality and apnoea index in obstructive sleep apnoea: experience in 385 male patients. Chest 94: 9e14, 1988 Hendler B, Silverstein K, Giannakopoulus H, Costello BJ: Mortised genioplasty in the treatment of obstructive sleep apnoea: an historical perspective and modification of design. Sleep Breath 5(4): 173e180, 2001 Lee NR: Genioglossus muscle advancement techniques for obstructive sleep apnoea. Oral Maxillofacial Surg Clin N Am 14: 377e384, 2002 Lee NR, Madani M: Genioglossus muscle advancement techniques for obstructive sleep apnoea. Atlas Oral Maxillofac Surg Clin N Am 15: 179e192, 2007 Li KK, Riley RW, Powell NB, Guilleminault C: Maxillomandibular advancement for persistent obstructive sleep apnoea after phase I surgery in patients without maxillomandibular deficiency. Laryngoscope 110: 1684e1688, 2000
Li KK, Riley RW, Powell NB, Troell RJ: Obstructive sleep apnoea surgery: genioglossus advancement revisited. J Oral Maxillofac Surg 59: 1181e1184, 2001 Li KK: Genioglossus advancement in sleep apnoea surgery. In: Friedman M (ed.), Sleep apnoea and snoring: surgical and non-surgical therapy. Chicago: Saunders, 301e304, 2009 Mc Andrew BP, Strauss RA: Delayed muscle detachment after genial tubercle advancement in a patient with obstructive sleep apnoea. J Oral Maxillofac Surg 58: 1040e1043, 2000 Neruntarat C: Genioglossus advancement and hyoid myotomy: short-term and long-term results. J Laryngol Otol 117: 482, 2003 Oliven R, Tov N, Odeh M, Gaitini L, Steinfeld U, Schwartz AR, et al: Interacting effects of genioglossus stimulation and mandibular advancement in sleep apnoea. J Appl Physiol 106: 1668e1673, 2009 Powell NB, Riley RW, Guilleminault C: Maxillofacial surgical techniques for hypopharyngeal obstruction in obstructive sleep apnoea. Operative techniques. Otolaryngol Head Neck Surg 2: 112e119, 1991 Powell NB, Riley RW, Guilleminault C: The hypopharynx: upper way reconstruction in obstructive sleep apnoea syndrome. In: Fairbanks DNF, Fujita S (eds), Snoring and obstructive sleep apnoea (ed 2). New York, NY: Raven Press, 193e209, 1994 Powell NB, Riley RW: A surgical protocol for sleep disordered breathing. Oral Maxillofacial Surg Clin N Am 7(2): 345e356, 1995 Powell NB, Riley RW, Robinson A: Surgical management of obstructive sleep apnoea syndrome. Clinics in Chest Medicine 19(1): 77e86, 1998 Powell NB: Contemporary surgery for obstructive sleep apnoea syndrome. Clinical and Experimental Otorhinolaryngology 2(3): 107e114, 2009 Remmers JE, deGroot WJ, Sauerland EK, Anch AM: Pathogenesis of upper airway obstruction during sleep. J Appl Physiol 44: 931e938, 1978 Ricketts RM: Cephalometric analysis and synthesis. Angle Orthod 31: 141e156, 1961 Riley RW, Guilleminault C, Powell NB, Derman S: Mandibular osteotomy and hyoid bone advancement for obstructive sleep apnoea: a case report. Sleep 7: 79, 1984 Riley RW, Powell NB, Guilleminault C: Inferior sagittal osteotomy of the mandible with hyoid suspension: a new procedure for obstructive sleep apnoea. Otolaryngol Head Neck Surg 94: 589, 1986 Riley RW, Powell NB, Guilleminault C: Inferior mandibular osteotomy and hyoid myotomy suspension for obstructive sleep apnoea: a review of 55 patients. J Oral Maxillofac Surg 47: 159e164, 1989 Riley RW, Powell NB, Guilleminault C: Obstructive sleep apnoea syndrome: a review of 306 consecutively treated surgical patients. Otolaryngol Head Neck Surg 108: 117e125, 1993a Riley RW, Powell NB, Guilleminault C: Obstructive sleep apnoea syndrome: a surgical protocol for dynamic upper airway reconstruction. J Oral Maxillofac Surg 51: 742, 1993b Riley RW, Powell NB, Guilleminault C, Clerk A, Troell R: Obstructive sleep apnoea e trends in therapy. West J Med 62: 143e148, 1995 Schendel S, Powell NB, Jacobson R: Maxillary, mandibular and chin advancement: treatment planning based on airway anatomy in obstructive sleep apnoea. J Oral Maxillofac Surg 69: 663e676, 2011 Sher AE, Schechtman KB, Piccirillo JF: The efficacy of surgical modifications of the upper airway in adults with obstructive sleep apnea syndrome. Sleep 19(2): 156e177, 1996 Silverstein B, Costello BJ, Giannakpoulos H, Hendler B: Genioglossus muscle attachments: an anatomic analysis and the implications for genioglossus advancement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 90: 686e688, 2000
Please cite this article in press as: García Vega JR, et al., Genioglossus muscle advancement: A modification of the conventional technique, Journal of Cranio-Maxillo-Facial Surgery (2013), http://dx.doi.org/10.1016/j.jcms.2013.05.007