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Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom
YBJOM-4238; No. of Pages 5
ARTICLE IN PRESS Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx
Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom Shofiq Islam ∗ , Nosa Uwadiae, Ian W. Ormiston Department of Maxillofacial Surgery, Leicester Royal Infirmary, Infirmary Square, Leicester, East Midlands LE1 5WW, UK Accepted 2 April 2014
Abstract In the United Kingdom, maxillofacial techniques are underused in the treatment of obstructive sleep apnoea (OSA). We retrospectively analysed the details and relevant clinical data of consecutive patients who had operations for OSA at the maxillofacial unit in Leicester between 2002 and 2012. They had been referred from the local sleep clinic after investigation and diagnosis, and in all cases treatment with continuous positive airway pressure (CPAP) had failed. We compared preoperative and postoperative apnoea/hypopnoea indices (AHI), scores for the Epworth sleepiness scale (ESS), and lowest oxygen saturation to measure surgical success (AHI of less than 15 and a 50% reduction in the number of apnoeas or hypopnoea/hour) and surgical cure (AHI of less than 5). We identified 51 patients (mean age 44 years, range 21–60) with a mean (SD) body mass index (BMI) of 29 (3.4). Most patients had bimaxillary advancement with genioplasty (n = 42). Differences in mean (SD) preoperative and postoperative values were significant for all 3 outcome measures (AHI: 42 (17) to 8 (7) p < 0.001; ESS: 14 (4) to 5 (4) p < 0.001; lowest oxygen saturation: 76% (11%) to 83% (7%); p = 0.006). On the postoperative sleep study 85% of patients met the criteria for surgical success. Our experience has confirmed that bimaxillary advancement results in a high rate of success in patients with OSA. The operation has a role in the management of selected patients in the UK who do not adhere to CPAP. © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Obstructive sleep apnoea; Orthognathic surgery; Maxillofacial surgery; Maxillomandibular advancement; Success rate; Cure rate; UK
Introduction Obstructive sleep apnoea (OSA) is characterised by the cessation of respiration during sleep secondary to obstruction of the upper airway. It has an estimated prevalence of 4% in men and 2% in women.1 The main symptoms are snoring and daytime sleepiness but more importantly, it is also associated with premature death, cardiovascular disease, type 2 diabetes, depression, cognitive impairment, and road traffic accidents.1,2,3
∗
Corresponding author. Tel.: +44 0300 303 1573. E-mail address: [email protected] (S. Islam).
Since its introduction 30 years ago, continuous positive airway pressure (CPAP) has become the treatment of choice for OSA. Unfortunately, patients often find compliance difficult as they need to wear a tight-fitting mask during sleep, and the overall rate of compliance has been reported to be about 60%.4,5 Consequently, a substantial number of patients are not being treated and there is a need to develop alternative options for those who cannot use CPAP. Some patients with mild to moderate OSA are successfully managed with custom-made mandibular advancement splints, but some will not tolerate them. Several operations, which include tracheostomy, uvulopalatopharyngoplasty, hyoid advancement, midline glossectomy, and lingualplasty, have been described for the
http://dx.doi.org/10.1016/j.bjoms.2014.04.002 0266-4356/© 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
YBJOM-4238; No. of Pages 5
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management of OSA with variable results.6,7 However, a Cochrane review in 2005 concluded that there was insufficient evidence to support the widespread use of surgical treatment.7 A growing number of publications now report that the upper airway can be modified using conventional orthognathic techniques, and several studies have shown that simultaneous advancement of the maxilla and mandible results in an appreciable anteroposterior and lateral enlargement of the retrolingual and the retropalatal airways.8,9,10 Internationally, the use of maxillomandibular advancement for OSA is increasing10 but in the United Kingdom it is rarely considered, and currently we know of no published clinical data from UK centres that relate to such management. We report the operative experience from the maxillofacial unit in Leicester where orthognathic surgery has been used to treat patients with refractory OSA for nearly a decade, and analyse the outcomes of the patients treated over this period.
The Epworth sleepiness scale (ESS) is a validated questionnaire that subjectively assesses the degree of daytime sleepiness in patients with OSA. Eight questions, which involve 8 different situations are rated, and possible total scores range from 0 to 24. The score can be used to subdivide patients into the normal range (score less than 10), those with mild to moderate symptoms (score 11–18), and those with severe daytime sleepiness (score over 18). We sought to assess the rates of surgical success and surgical cure in our group. In previous publications the threshold used to define surgical success has included 2 criteria: a 50% reduction in the number of breathing events/hour, and no more than 15 breathing events/hour (AHI less than 15).10 This cut-off was used in the present study. We defined surgical cure as a postoperative AHI of 5 or under. Data were analysed with SPSS for Windows. Patients’ characteristics were assessed using descriptive statistics. A paired t test was used to compare continuous data and the chi square test was used for categorical data. A p-value of less than 0.05 were considered significant.
Method We retrospectively analysed a consecutive group of patients who had orthognathic surgery for OSA between 2002 and 2012. Most had been referred from the local sleep clinic in Leicester and OSA had been confirmed. They had been managed primarily with noninvasive conventional methods but remained symptomatic, and most had exhausted all other options for treatment. In some, CPAP had been successful initially, but they had refused to accept it as a life-long treatment. We retrieved data from patients’ medical records and recorded their details, relevant medical history (comorbidities, smoking, and alcohol consumption) and clinical characteristics (body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, preoperative skeletal profile, and operative data). They were followed up and a repeat 6-month sleep study was recommended to assess their response to treatment. We compared apnoea/hypopnoea indices (AHI), Epworth sleepiness scores (ESS), and lowest recorded oxygen saturation before operation with those after operation. These variables have been used as outcome measures in previous reports.10 Complications that arose from the operation were also recorded. Variables The apnoea/hypopnoea index (AHI) is an objective measure of the severity of OSA based on the number of periodic partial obstructions (hypopnoea) or complete cessations (apnoea) of breathing secondary to obstruction of the upper airway. OSA can be classed as mild (AHI 5–14/h), moderate (AHI 15–30/h), or severe (AHI over 30/h).
Results We identified 51 patients (46 men and 5 women) who had orthognathic surgery for OSA (mean age 44 years, range 21–60). The median BMI was 28 (range 23–37), and in 26 patients it was less than 30. Nineteen patients (37%) had a serious coexisting condition. A total of 44 patients (86%) had used CPAP for a mean duration of 24 months. The remainder either declined outright, or failed to tolerate it for a meaningful duration (more than 4 weeks). The baseline characteristics of the group are summarised in Table 1. Most of our patients underwent bimaxillary advancement with an advancement genioplasty (n = 42). The advancement is typically done without orthodontic involvement and maintains the pre-existing dental occlusion. Bimaxillary operations consisted of Le Fort I osteotomy with maxillary advancement and bilateral sagittal split osteotomy for mandibular advancement. Genial advancement was done using a horizontal sliding osteotomy of the mandibular symphysis. A further 4 patients had bimaxillary advancement alone. The remaining 5 patients opted for single jaw surgery, which involved bilateral sagittal split advancement osteotomies with an anterior subapical (Hofer) setback procedure. Only 2 had preoperative orthodontic treatment: both had a severe class II occlusion with increased overjet. The mean (SD) maxillary advancement was 8 (2.1) mm, whilst the mean (SD) mandibular advancement was 8.3 (2.2) mm. Lateral cephalograms taken before and after operation showed significant widening of the posterior airway space from a mean (SD) of 6.6 (2.4) mm to 11.7 (3.1) mm (SD 3.1) (p < 0.001). Table 2 shows the mean preoperative and postoperative scores for the AHI and ESS, and for lowest recorded oxygen saturation. The mean (SD) preoperative and postoperative
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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S. Islam et al. / British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx Table 1 Patients’ baseline characteristics. Data are number (%) except for age and body mass index, which are mean (SD). Mean (SD) age (years) Mean (SD) body mass index Sex Male Female Smokers Alcohol consumption Comorbidities Cardiovascular Respiratory Other Continuous positive airway pressure (CPAP) Trialled Not trialleda Previous operation Nasal surgery UPPP Both ASA grade 1 2 3 Skeletal profile Class 1 Class 2 Edentulous Mallampati scores I II III IV
44 (8) 29 (3.4) 46 (90) 5 (10) 14 (28) 40 (78) 11 (22) 6 (12) 2 (4) 44 (86) 7 (14) 15 (29) 4 (8) 2 (4) 9 (18) 36 (71) 5 (10) 33 (65) 17 (33) 1 (2) 11 (22) 23 (45) 13 (26) 3 (6)
a Declined CPAP or used it for under 4 weeks; ASA: American Society of Anesthesiologists’ physical status classification; UPPP: uvulopalatopharyngoplasty.
Table 2 Comparison of preoperative and postoperative outcome measures. Data are mean (SD). Preoperative Postoperative p value Apnoea/hypopnoea index 42 (17) Epworth sleepiness scale 14 (4) Lowest recorded oxygen saturation 76 (11)
8 (7) 5 (4) 83 (7)
<0.001 <0.001 0.006
BMI was 29 (3.4) and 28 (3.1), respectively; the difference was not significant. AHI scores before and after operation, were available for 39 of the 51 patients. In all 39 the postoperative AHI and ESS scores had improved from baseline values. Of these, 33 (85%) met the criteria for surgical success (AHI less than 15), and 23 (59%) had a postoperative AHI score of less than 5, which we defined as surgical cure. The mean (SD) follow-up period for this group was 25 (11) months. Complications are shown in Table 3. Twenty patients had 2 or more complications and 13 had one. The most common complication was transient nerve morbidity. Long-term ‘permanent’ partial numbness was noted in 11 subjects at 12 month review. Eleven patients had minor occlusal discrepancies after operation, and postoperative orthodontic treatment
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Table 3 Complications after operation (20 had 2 or more complications). No. (%)(n = 51) morbiditya
Nerve Transient Permanent Plate removed Infected Exposed Occlusal derangement Anterior open bite Posterior open bite Temporomandibular joint symptoms Oroantral communication Sinus infection Deviation of nasal septum Voice changes
27 (53) 16 (31) 11 (22) 5 (10) 3 (6) 2 (4) 11 (22) 6 (12) 5 (10) 3 (6) 2 (4) 1 (2) 1 (2) 1 (2)
a Nerve morbidity relates to upper or lower lip/chin. Hypoaesthesia or paraethesia.
was required by 3 who developed an anterior open bite which subsequently failed to resolve with elastics alone. In 5 patients the mini plates had to be removed.
Discussion To our knowledge we present the first UK series of patients who have undergone orthognathic surgery for OSA. Our data show that maxillomandibular and mandibular advancement are highly effective in the treatment of these patients when 3 of the most commonly cited outcome measures are considered. Our data highlight significant improvements in objective and subjective outcome measures. Follow-up sleep studies showed a marked reduction in postoperative AHI and ESS scores, and an improvement in minimum lowest oxygen saturation. It remains unclear which outcome variable best reflects the benefits of treatment for OSA.10 Many clinicians consider subjective symptoms to be the most important as patients typically seek treatment because of daytime sleepiness and a poor quality of life.11 However, the correlation between changes in objective measures with subjective symptoms is weak.12,13 In our series, all patients except one reported subjective improvement in symptoms after operation and 87% had a postoperative ESS score of less than 10. The observed surgical success rate based on objective criteria was 85%. Our definition of surgical “success”, is perhaps a more rigorous criteria when compared to studies quoting surgical success rate using a purely 50% AHI reduction alone. This latter criterion has the potential to increase the overall success rate in a given study examining surgical outcomes in OSA patients. Allowing for differences in the interpretation of the AHI between the UK and other countries, our percentage success rate compares favourably with others published, which range from 65% to 100%.10,14–17 A recent meta-analysis, which evaluated surgical outcomes after maxillomandibular advancement and which used similar criteria for success and
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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cure to those in our study, reported pooled success and cure rates of 86% and 43%, respectively.18 It is noteworthy that 2 patients in our series, who would be described as surgical failures on the basis of a reduction in the AHI alone, had considerably lower ESS scores postoperatively, indicating that their OSA “syndrome” (presence of daytime somnolence in conjunction with obstructive apnoea’s during sleep) had been successfully treated. Paradoxically, one patient in the series required further CPAP after operation despite the fact that postoperative AHI suggested surgical success (in this case the ESS had remained abnormal at 16/24). This represented an ongoing impairment in the sleep quality in this patient despite reduction in the rate of apnoea. As mentioned previously the ESS is well validated as a subjective screening tool and useful in monitoring progress after treatment. The AHI is objective measure derived from a sleep study, and does not always correlate with the patients reported ESS. Our findings show a significant improvement in the mean lowest recorded oxygen saturation from baseline to the sleep study 6 months after operation. Conventionally, outcome measures in surgical studies relating to OSA have tended to focus on the AHI with or without use of the ESS. It is well known that chronic intermittent hypoxaemia is a serious risk factor for the development of significant morbidity. In a recent longitudinal study of more than 10 000 patients with OSA, multivariate analysis showed that low nocturnal oxygen saturation was a strong independent risk factor for sudden cardiac death. The researchers reported that below a threshold of 78% for lowest oxygen saturation, the risk of sudden cardiac death is increased by 80%.19 In our series the mean lowest oxygen saturation improved from 76% preoperatively to 83% postoperatively (p = 0.006). Historically, uvulopalatopharyngoplasty with or without nasal surgery was the operation most commonly performed to treat OSA.6 In 21 of our patients (41%) previous operations had failed to resolve the condition. Recently, a study that directly compared uvulopalatopharyngoplasty with orthognathic procedures concluded that maxillomandibular advancement was significantly more effective than uvulopalatopharyngoplasty in reducing the AHI in patients with OSA. The researchers also noted that uvulopalatopharyngoplasty combined with maxillomandibular advancement was no more effective than the orthognathic procedure alone.20 They concluded that maxillofacial orthognathic techniques should be the surgical treatment of choice in patients with moderate to severe OSA who cannot adhere to CPAP. Given that the previously published Cochrane review predominantly analysed ear, nose, and throat-based operations, it seems that an updated analysis with a greater focus on maxillofacial operations is warranted. Complications in older patients who have orthognathic operations are not well reported. The mean (SD) age of patients in our series was 44 (8) years. The most common complication in our group was partial sensory nerve deficit around the lip and chin, and roughly half of our sample
Fig. 1. Intraoperative image of patient undergoing anterior subapical setback (Hofer) with bilateral sagittal split osteotomy for obstructive sleep apnoea. Significant overjet achieved with segmental osteotomy/midline mandibulotomy and extraction in the premolar region before mandibular advancement of 8 mm (width of one premolar) to re-establish the pre-existing occlusion.
had some degree of sensory disturbance. Most had transient symptoms, but 11 (22%) reported persistent sensory disturbance beyond one year, which would reasonably be described as a permanent partial deficit. Eleven patients had occlusal derangements postoperatively, most of which were minor in nature and resolved with the use of short-term elastics. Three patients with a persistent anterior open bite required formal orthodontic treatment. The rate and type of complication seen in this group, typically older adults, highlight the importance of thorough preoperative assessment and the need for patients to be fully informed when they give their consent. However, we have found that the partial neurosensory deficit was well tolerated and patients feel that the potential benefits of surgery sufficiently outweigh the risks. Another important consideration is that orthognathic surgery can alter the facial profile. The advantage of single jaw surgery (bilateral sagittal split osteotomy with anterior subapical (Hofer) setback) is that it avoids mid-facial advancement (bimaxillary protrusion and changes to the nasiolabial angle), which is particularly important in cases with an acute angle (Figs. 1 and 2). Most of our patients, however, underwent bimaxillary osteotomy with genioplasty, as it affords maximal enlargement of the velo-orohypopharyngeal airway. Anecdotally, we found that most of our patients were satisfied with their facial aesthetics postoperatively; some reported an improvement with a reduction in the laxity of facial soft tissue. We will explore this topic in greater detail in a subsequent paper. A small number of studies that have explored facial aesthetics in surgically treated OSA patients, have reported high levels of satisfaction with their facial profile postoperatively, and with the overall perception of treatment.21,22 The retrospective nature of our study and the fact that AHI scores before and after operation were obtained from only 39 of the 51 patients are its primary limitations. Data were missing from the medical records, particularly in the
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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Fig. 2. Postoperative cephalometric radiograph after anterior subapical setback (Hofer) with bilateral sagittal split osteotomy advancement for obstructive sleep apnoea.
postoperative period, and a small number of patients did not attend follow-up. Although our sample was numerically conservative our results correspond with those in previously published studies. A number of confounders may have influenced our outcome measures, not least factors that affect lifestyle such as alcohol consumption and the potentially fluctuating weight of patients. However, at the time of the follow-up sleep study the difference between the mean BMI values before and after operation was not significant. Conclusion A recent European Respiratory Society working group concluded that young people with OSA whose lifestyles cannot readily be modified, would potentially benefit from maxillofacial intervention.23 They also concluded that maxillomandibular advancement was as effective as long-term CPAP. Our results has confirmed that a high rate of surgical success is achievable and supports the increased use of orthognathic techniques in selected patients with OSA in the UK. References 1.
Lurie A. Obstructive sleep apnea in adults: epidemiology, clinical presentation, and treatment options. Adv Cardiol 2011;46: 1–42.
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2. Drager LF, Togeiro SM, Polotsky VY, Lorenzi-Filho G. Obstructive sleep apnea: a cardiometabolic risk in obesity and the metabolic syndrome. J Am Coll Cardiol 2013;62:569–76. 3. Vijayan VK. Morbidities associated with obstructive sleep apnea. Expert Rev Respir Med 2012;6:557–66. 4. Waldhorn RE, Herrick TW, Nguyen MC, O’Donnell AE, Sodero J, Potolicchio SJ. Long-term compliance with nasal continuous positive airway pressure therapy of obstructive sleep apnea. Chest 1990;97:33–8. 5. McArdle N, Devereux G, Heidarnejad H, et al. Long-term use of CPAP therapy for sleep apnea/hypopnea syndrome. Am J Respir Crit Care Med 1999;159:1108–14. 6. Sher AE, Schechtman KB, Piccirillo JF. The efficacy of surgical modifications of the upper airway in adults with obstructive sleep apnea syndrome. Sleep 1996;19:156–77. 7. Sundaram S, Bridgman SA, Lim J, Lasserson TJ. Surgery for obstructive sleep apnoea. Cochrane Database Syst Rev 2005;(4):CD001004. 8. Lin CH, Liao YF, Chen NH, Lo LJ, Chen YR. Three-dimensional computed tomography in obstructive sleep apneics treated by maxillomandibular advancement. Laryngoscope 2011;121:1336–47. 9. Abramson Z, Susarla SM, Lawler M, Bouchard C, Troulis M, Kaban LB. Three-dimensional computed tomographic airway analysis of patients with obstructive sleep apnea treated by maxillomandibular advancement. J Oral Maxillofac Surg 2011;69:677–86. 10. Hsieh YJ, Liao YF. Effects of maxillomandibular advancement on the upper airway and surrounding structures in patients with obstructive sleep apnoea: a systematic review. Br J Oral Maxillofac Surg 2013;51:834–40. 11. Siccoli MM, Pepperell JC, Kohler M, Craig SE, Davies RJ, Stradling JR. Effects of continuous positive airway pressure on quality of life in patients with moderate to severe obstructive sleep apnea: data from a randomized controlled trial. Sleep 2008;31:1551–8. 12. Weaver EM, Kapur V, Yueh B. Polysomnography vs self-reported measures in patients with sleep apnea. Arch Otolaryngol Head Neck Surg 2004;130:453–8. 13. Weaver EM, Woodson BT, Steward DL. Polysomnography indexes are discordant with quality of life, symptoms, and reaction times in sleep apnea patients. Otolaryngol Head Neck Surg 2005;132:255–62. 14. Hochban W, Brandenburg U, Peter JH. Surgical treatment of obstructive sleep apnea by maxillomandibular advancement. Sleep 1994;17:624–9. 15. Prinsell JR. Maxillomandibular advancement surgery in a site-specific treatment approach for obstructive sleep apnea in 50 consecutive patients. Chest 1999;116:1519–29. 16. Riley RW, Powell NB, Li KK, Troell RJ, Guilleminault C. Surgery and obstructive sleep apnea: long-term clinical outcomes. Otolaryngol Head Neck Surg 2000;122:415–21. 17. Bettega G, Pépin JL, Veale D, Deschaux C, Raphaël B, Lévy P. Obstructive sleep apnea syndrome. Fifty-one consecutive patients treated by maxillofacial surgery. Am J Respir Crit Care Med 2000;162:641–9. 18. Holty JE, Guilleminault C. Maxillomandibular advancement for the treatment of obstructive sleep apnea: a systematic review and meta-analysis. Sleep Med Rev 2010;14:287–97. 19. Gami AS, Olson EJ, Shen WK, et al. Obstructive sleep apnea and the risk of sudden cardiac death: a longitudinal study of 10,701 adults. J Am Coll Cardiol 2013;62:610–6. 20. Boyd SB, Walters AS, Song Y, Wang L. Comparative effectiveness of maxillomandibular advancement and uvulopalatopharyngoplasty for the treatment of moderate to severe obstructive sleep apnea. J Oral Maxillofac Surg 2013;71:743–51. 21. Li KK, Riley RW, Powell NB, Guilleminault C. Patient’s perception of the facial appearance after maxillomandibular advancement for obstructive sleep apnea syndrome. J Oral Maxillofac Surg 2001;59:377–80. 22. Li KK, Riley RW, Powell NB, Guilleminault C. Maxillomandibular advancement for persistent obstructive sleep apnea after phase I surgery in patients without maxillomandibular deficiency. Laryngoscope 2000;110:1684–8. 23. Randerath WJ, Verbraecken J, Andreas S, et al. European Respiratory Society task force on non-CPAP therapies in sleep apnoea. Non-CPAP therapies in obstructive sleep apnoea. Eur Respir J 2011;37:1000–28.
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
ARTICLE IN PRESS Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx
Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom Shofiq Islam ∗ , Nosa Uwadiae, Ian W. Ormiston Department of Maxillofacial Surgery, Leicester Royal Infirmary, Infirmary Square, Leicester, East Midlands LE1 5WW, UK Accepted 2 April 2014
Abstract In the United Kingdom, maxillofacial techniques are underused in the treatment of obstructive sleep apnoea (OSA). We retrospectively analysed the details and relevant clinical data of consecutive patients who had operations for OSA at the maxillofacial unit in Leicester between 2002 and 2012. They had been referred from the local sleep clinic after investigation and diagnosis, and in all cases treatment with continuous positive airway pressure (CPAP) had failed. We compared preoperative and postoperative apnoea/hypopnoea indices (AHI), scores for the Epworth sleepiness scale (ESS), and lowest oxygen saturation to measure surgical success (AHI of less than 15 and a 50% reduction in the number of apnoeas or hypopnoea/hour) and surgical cure (AHI of less than 5). We identified 51 patients (mean age 44 years, range 21–60) with a mean (SD) body mass index (BMI) of 29 (3.4). Most patients had bimaxillary advancement with genioplasty (n = 42). Differences in mean (SD) preoperative and postoperative values were significant for all 3 outcome measures (AHI: 42 (17) to 8 (7) p < 0.001; ESS: 14 (4) to 5 (4) p < 0.001; lowest oxygen saturation: 76% (11%) to 83% (7%); p = 0.006). On the postoperative sleep study 85% of patients met the criteria for surgical success. Our experience has confirmed that bimaxillary advancement results in a high rate of success in patients with OSA. The operation has a role in the management of selected patients in the UK who do not adhere to CPAP. © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Obstructive sleep apnoea; Orthognathic surgery; Maxillofacial surgery; Maxillomandibular advancement; Success rate; Cure rate; UK
Introduction Obstructive sleep apnoea (OSA) is characterised by the cessation of respiration during sleep secondary to obstruction of the upper airway. It has an estimated prevalence of 4% in men and 2% in women.1 The main symptoms are snoring and daytime sleepiness but more importantly, it is also associated with premature death, cardiovascular disease, type 2 diabetes, depression, cognitive impairment, and road traffic accidents.1,2,3
∗
Corresponding author. Tel.: +44 0300 303 1573. E-mail address: [email protected] (S. Islam).
Since its introduction 30 years ago, continuous positive airway pressure (CPAP) has become the treatment of choice for OSA. Unfortunately, patients often find compliance difficult as they need to wear a tight-fitting mask during sleep, and the overall rate of compliance has been reported to be about 60%.4,5 Consequently, a substantial number of patients are not being treated and there is a need to develop alternative options for those who cannot use CPAP. Some patients with mild to moderate OSA are successfully managed with custom-made mandibular advancement splints, but some will not tolerate them. Several operations, which include tracheostomy, uvulopalatopharyngoplasty, hyoid advancement, midline glossectomy, and lingualplasty, have been described for the
http://dx.doi.org/10.1016/j.bjoms.2014.04.002 0266-4356/© 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
YBJOM-4238; No. of Pages 5
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management of OSA with variable results.6,7 However, a Cochrane review in 2005 concluded that there was insufficient evidence to support the widespread use of surgical treatment.7 A growing number of publications now report that the upper airway can be modified using conventional orthognathic techniques, and several studies have shown that simultaneous advancement of the maxilla and mandible results in an appreciable anteroposterior and lateral enlargement of the retrolingual and the retropalatal airways.8,9,10 Internationally, the use of maxillomandibular advancement for OSA is increasing10 but in the United Kingdom it is rarely considered, and currently we know of no published clinical data from UK centres that relate to such management. We report the operative experience from the maxillofacial unit in Leicester where orthognathic surgery has been used to treat patients with refractory OSA for nearly a decade, and analyse the outcomes of the patients treated over this period.
The Epworth sleepiness scale (ESS) is a validated questionnaire that subjectively assesses the degree of daytime sleepiness in patients with OSA. Eight questions, which involve 8 different situations are rated, and possible total scores range from 0 to 24. The score can be used to subdivide patients into the normal range (score less than 10), those with mild to moderate symptoms (score 11–18), and those with severe daytime sleepiness (score over 18). We sought to assess the rates of surgical success and surgical cure in our group. In previous publications the threshold used to define surgical success has included 2 criteria: a 50% reduction in the number of breathing events/hour, and no more than 15 breathing events/hour (AHI less than 15).10 This cut-off was used in the present study. We defined surgical cure as a postoperative AHI of 5 or under. Data were analysed with SPSS for Windows. Patients’ characteristics were assessed using descriptive statistics. A paired t test was used to compare continuous data and the chi square test was used for categorical data. A p-value of less than 0.05 were considered significant.
Method We retrospectively analysed a consecutive group of patients who had orthognathic surgery for OSA between 2002 and 2012. Most had been referred from the local sleep clinic in Leicester and OSA had been confirmed. They had been managed primarily with noninvasive conventional methods but remained symptomatic, and most had exhausted all other options for treatment. In some, CPAP had been successful initially, but they had refused to accept it as a life-long treatment. We retrieved data from patients’ medical records and recorded their details, relevant medical history (comorbidities, smoking, and alcohol consumption) and clinical characteristics (body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, preoperative skeletal profile, and operative data). They were followed up and a repeat 6-month sleep study was recommended to assess their response to treatment. We compared apnoea/hypopnoea indices (AHI), Epworth sleepiness scores (ESS), and lowest recorded oxygen saturation before operation with those after operation. These variables have been used as outcome measures in previous reports.10 Complications that arose from the operation were also recorded. Variables The apnoea/hypopnoea index (AHI) is an objective measure of the severity of OSA based on the number of periodic partial obstructions (hypopnoea) or complete cessations (apnoea) of breathing secondary to obstruction of the upper airway. OSA can be classed as mild (AHI 5–14/h), moderate (AHI 15–30/h), or severe (AHI over 30/h).
Results We identified 51 patients (46 men and 5 women) who had orthognathic surgery for OSA (mean age 44 years, range 21–60). The median BMI was 28 (range 23–37), and in 26 patients it was less than 30. Nineteen patients (37%) had a serious coexisting condition. A total of 44 patients (86%) had used CPAP for a mean duration of 24 months. The remainder either declined outright, or failed to tolerate it for a meaningful duration (more than 4 weeks). The baseline characteristics of the group are summarised in Table 1. Most of our patients underwent bimaxillary advancement with an advancement genioplasty (n = 42). The advancement is typically done without orthodontic involvement and maintains the pre-existing dental occlusion. Bimaxillary operations consisted of Le Fort I osteotomy with maxillary advancement and bilateral sagittal split osteotomy for mandibular advancement. Genial advancement was done using a horizontal sliding osteotomy of the mandibular symphysis. A further 4 patients had bimaxillary advancement alone. The remaining 5 patients opted for single jaw surgery, which involved bilateral sagittal split advancement osteotomies with an anterior subapical (Hofer) setback procedure. Only 2 had preoperative orthodontic treatment: both had a severe class II occlusion with increased overjet. The mean (SD) maxillary advancement was 8 (2.1) mm, whilst the mean (SD) mandibular advancement was 8.3 (2.2) mm. Lateral cephalograms taken before and after operation showed significant widening of the posterior airway space from a mean (SD) of 6.6 (2.4) mm to 11.7 (3.1) mm (SD 3.1) (p < 0.001). Table 2 shows the mean preoperative and postoperative scores for the AHI and ESS, and for lowest recorded oxygen saturation. The mean (SD) preoperative and postoperative
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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S. Islam et al. / British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx Table 1 Patients’ baseline characteristics. Data are number (%) except for age and body mass index, which are mean (SD). Mean (SD) age (years) Mean (SD) body mass index Sex Male Female Smokers Alcohol consumption Comorbidities Cardiovascular Respiratory Other Continuous positive airway pressure (CPAP) Trialled Not trialleda Previous operation Nasal surgery UPPP Both ASA grade 1 2 3 Skeletal profile Class 1 Class 2 Edentulous Mallampati scores I II III IV
44 (8) 29 (3.4) 46 (90) 5 (10) 14 (28) 40 (78) 11 (22) 6 (12) 2 (4) 44 (86) 7 (14) 15 (29) 4 (8) 2 (4) 9 (18) 36 (71) 5 (10) 33 (65) 17 (33) 1 (2) 11 (22) 23 (45) 13 (26) 3 (6)
a Declined CPAP or used it for under 4 weeks; ASA: American Society of Anesthesiologists’ physical status classification; UPPP: uvulopalatopharyngoplasty.
Table 2 Comparison of preoperative and postoperative outcome measures. Data are mean (SD). Preoperative Postoperative p value Apnoea/hypopnoea index 42 (17) Epworth sleepiness scale 14 (4) Lowest recorded oxygen saturation 76 (11)
8 (7) 5 (4) 83 (7)
<0.001 <0.001 0.006
BMI was 29 (3.4) and 28 (3.1), respectively; the difference was not significant. AHI scores before and after operation, were available for 39 of the 51 patients. In all 39 the postoperative AHI and ESS scores had improved from baseline values. Of these, 33 (85%) met the criteria for surgical success (AHI less than 15), and 23 (59%) had a postoperative AHI score of less than 5, which we defined as surgical cure. The mean (SD) follow-up period for this group was 25 (11) months. Complications are shown in Table 3. Twenty patients had 2 or more complications and 13 had one. The most common complication was transient nerve morbidity. Long-term ‘permanent’ partial numbness was noted in 11 subjects at 12 month review. Eleven patients had minor occlusal discrepancies after operation, and postoperative orthodontic treatment
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Table 3 Complications after operation (20 had 2 or more complications). No. (%)(n = 51) morbiditya
Nerve Transient Permanent Plate removed Infected Exposed Occlusal derangement Anterior open bite Posterior open bite Temporomandibular joint symptoms Oroantral communication Sinus infection Deviation of nasal septum Voice changes
27 (53) 16 (31) 11 (22) 5 (10) 3 (6) 2 (4) 11 (22) 6 (12) 5 (10) 3 (6) 2 (4) 1 (2) 1 (2) 1 (2)
a Nerve morbidity relates to upper or lower lip/chin. Hypoaesthesia or paraethesia.
was required by 3 who developed an anterior open bite which subsequently failed to resolve with elastics alone. In 5 patients the mini plates had to be removed.
Discussion To our knowledge we present the first UK series of patients who have undergone orthognathic surgery for OSA. Our data show that maxillomandibular and mandibular advancement are highly effective in the treatment of these patients when 3 of the most commonly cited outcome measures are considered. Our data highlight significant improvements in objective and subjective outcome measures. Follow-up sleep studies showed a marked reduction in postoperative AHI and ESS scores, and an improvement in minimum lowest oxygen saturation. It remains unclear which outcome variable best reflects the benefits of treatment for OSA.10 Many clinicians consider subjective symptoms to be the most important as patients typically seek treatment because of daytime sleepiness and a poor quality of life.11 However, the correlation between changes in objective measures with subjective symptoms is weak.12,13 In our series, all patients except one reported subjective improvement in symptoms after operation and 87% had a postoperative ESS score of less than 10. The observed surgical success rate based on objective criteria was 85%. Our definition of surgical “success”, is perhaps a more rigorous criteria when compared to studies quoting surgical success rate using a purely 50% AHI reduction alone. This latter criterion has the potential to increase the overall success rate in a given study examining surgical outcomes in OSA patients. Allowing for differences in the interpretation of the AHI between the UK and other countries, our percentage success rate compares favourably with others published, which range from 65% to 100%.10,14–17 A recent meta-analysis, which evaluated surgical outcomes after maxillomandibular advancement and which used similar criteria for success and
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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cure to those in our study, reported pooled success and cure rates of 86% and 43%, respectively.18 It is noteworthy that 2 patients in our series, who would be described as surgical failures on the basis of a reduction in the AHI alone, had considerably lower ESS scores postoperatively, indicating that their OSA “syndrome” (presence of daytime somnolence in conjunction with obstructive apnoea’s during sleep) had been successfully treated. Paradoxically, one patient in the series required further CPAP after operation despite the fact that postoperative AHI suggested surgical success (in this case the ESS had remained abnormal at 16/24). This represented an ongoing impairment in the sleep quality in this patient despite reduction in the rate of apnoea. As mentioned previously the ESS is well validated as a subjective screening tool and useful in monitoring progress after treatment. The AHI is objective measure derived from a sleep study, and does not always correlate with the patients reported ESS. Our findings show a significant improvement in the mean lowest recorded oxygen saturation from baseline to the sleep study 6 months after operation. Conventionally, outcome measures in surgical studies relating to OSA have tended to focus on the AHI with or without use of the ESS. It is well known that chronic intermittent hypoxaemia is a serious risk factor for the development of significant morbidity. In a recent longitudinal study of more than 10 000 patients with OSA, multivariate analysis showed that low nocturnal oxygen saturation was a strong independent risk factor for sudden cardiac death. The researchers reported that below a threshold of 78% for lowest oxygen saturation, the risk of sudden cardiac death is increased by 80%.19 In our series the mean lowest oxygen saturation improved from 76% preoperatively to 83% postoperatively (p = 0.006). Historically, uvulopalatopharyngoplasty with or without nasal surgery was the operation most commonly performed to treat OSA.6 In 21 of our patients (41%) previous operations had failed to resolve the condition. Recently, a study that directly compared uvulopalatopharyngoplasty with orthognathic procedures concluded that maxillomandibular advancement was significantly more effective than uvulopalatopharyngoplasty in reducing the AHI in patients with OSA. The researchers also noted that uvulopalatopharyngoplasty combined with maxillomandibular advancement was no more effective than the orthognathic procedure alone.20 They concluded that maxillofacial orthognathic techniques should be the surgical treatment of choice in patients with moderate to severe OSA who cannot adhere to CPAP. Given that the previously published Cochrane review predominantly analysed ear, nose, and throat-based operations, it seems that an updated analysis with a greater focus on maxillofacial operations is warranted. Complications in older patients who have orthognathic operations are not well reported. The mean (SD) age of patients in our series was 44 (8) years. The most common complication in our group was partial sensory nerve deficit around the lip and chin, and roughly half of our sample
Fig. 1. Intraoperative image of patient undergoing anterior subapical setback (Hofer) with bilateral sagittal split osteotomy for obstructive sleep apnoea. Significant overjet achieved with segmental osteotomy/midline mandibulotomy and extraction in the premolar region before mandibular advancement of 8 mm (width of one premolar) to re-establish the pre-existing occlusion.
had some degree of sensory disturbance. Most had transient symptoms, but 11 (22%) reported persistent sensory disturbance beyond one year, which would reasonably be described as a permanent partial deficit. Eleven patients had occlusal derangements postoperatively, most of which were minor in nature and resolved with the use of short-term elastics. Three patients with a persistent anterior open bite required formal orthodontic treatment. The rate and type of complication seen in this group, typically older adults, highlight the importance of thorough preoperative assessment and the need for patients to be fully informed when they give their consent. However, we have found that the partial neurosensory deficit was well tolerated and patients feel that the potential benefits of surgery sufficiently outweigh the risks. Another important consideration is that orthognathic surgery can alter the facial profile. The advantage of single jaw surgery (bilateral sagittal split osteotomy with anterior subapical (Hofer) setback) is that it avoids mid-facial advancement (bimaxillary protrusion and changes to the nasiolabial angle), which is particularly important in cases with an acute angle (Figs. 1 and 2). Most of our patients, however, underwent bimaxillary osteotomy with genioplasty, as it affords maximal enlargement of the velo-orohypopharyngeal airway. Anecdotally, we found that most of our patients were satisfied with their facial aesthetics postoperatively; some reported an improvement with a reduction in the laxity of facial soft tissue. We will explore this topic in greater detail in a subsequent paper. A small number of studies that have explored facial aesthetics in surgically treated OSA patients, have reported high levels of satisfaction with their facial profile postoperatively, and with the overall perception of treatment.21,22 The retrospective nature of our study and the fact that AHI scores before and after operation were obtained from only 39 of the 51 patients are its primary limitations. Data were missing from the medical records, particularly in the
Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002
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Fig. 2. Postoperative cephalometric radiograph after anterior subapical setback (Hofer) with bilateral sagittal split osteotomy advancement for obstructive sleep apnoea.
postoperative period, and a small number of patients did not attend follow-up. Although our sample was numerically conservative our results correspond with those in previously published studies. A number of confounders may have influenced our outcome measures, not least factors that affect lifestyle such as alcohol consumption and the potentially fluctuating weight of patients. However, at the time of the follow-up sleep study the difference between the mean BMI values before and after operation was not significant. Conclusion A recent European Respiratory Society working group concluded that young people with OSA whose lifestyles cannot readily be modified, would potentially benefit from maxillofacial intervention.23 They also concluded that maxillomandibular advancement was as effective as long-term CPAP. Our results has confirmed that a high rate of surgical success is achievable and supports the increased use of orthognathic techniques in selected patients with OSA in the UK. References 1.
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Please cite this article in press as: Islam S, et al. Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2014.04.002