Effects of maxillomandibular advancement on the upper airway and surrounding structures in patients with obstructive sleep apnoea: a systematic review

Obstructive sleep apnoea is ideally treated by continuous positive airway pressure, but other options are needed because its clinical effectiveness is limited by poor acceptance and tolerance, which results in suboptimal compliance. Patients often prefer operation, with maxillomandibular advancement (MMA) being the most effective approach. In this systematic review we have assessed its effects on the upper airway and surrounding structures in patients with obstructive sleep apnoea. After a structured search of electronic databases and hand searching, we retrieved 104 publications. After application of inclusion and exclusion criteria, 15 studies remained. From these we extracted data on study design, sample size, patients, methods and measurement, and outcomes. The quality of each study was assessed objectively. The heterogeneity of samples and outcome measures prevented a meta-analysis. MMA was shown to be an effective treatment of sleep apnoea. Primary and secondary MMA resulted in mean reductions in the apnoea–hypopnoea index/respiratory disturbance index of 61–92% and 82–92%, respectively. The operation not only enlarges the upper airway in the anteroposterior and lateral dimensions, but also raises the hyoid. Only 7 studies reported the relations between improvement in sleep apnoea and changes in the upper airway and surrounding structures, and only one correlated it with skeletal advancement. The studies were of low or medium quality. There were insufficient data to support a relation between improvement in sleep apnoea and changes in the upper airway and surrounding structures because of the contradictory results and poor quality of most studies.     

Sleep nasendoscopy: a diagnostic tool for predicting treatment success with mandibular advancement splints in obstructive sleep apnoea

This prospective, cohort study evaluated the role of sleep nasendoscopy (SNE) with simultaneous mandibular protrusion in predicting successful mandibular advancement splint (MAS) therapy in subjects with obstructive sleep apnoea (OSA). Nineteen OSA subjects diagnosed by overnight polysomnography were referred for MAS therapy, following SNE investigation. A Herbst MAS was fabricated for each subject. Once this had been adjusted for maximal, subjective, therapeutic effect, follow-up sleep studies were undertaken with the appliance in situ. The SNE was repeated with the appliance in place to allow the effects of the original mandibular protrusion and the actual effect of the MAS to be compared. The MAS was removed and the original and current site(s) of obstruction evaluated. Pre-treatment SNE showed airway obstruction at the following levels: intermittent multi-level (16 subjects), sustained multi-level (two subjects) and tongue base (one subject). In all individuals, gentle advancement of the mandible during SNE improved airway patency and reduced snoring. When the SNE was repeated with the MAS in situ, all subjects showed improvements in snoring and airway patency. Follow-up sleep studies confirmed the efficacy of the MAS, with all patients showing a reduction in the apnoea/hypopnoea index (AHI). Median reductions in AHI (from 28.1 to 6.1, P < 0.001) and Epworth Sleepiness Scale (ESS) scores (from 9 to 6, P < 0.001) were highly statistically significant. The results suggest that SNE with concomitant mandibular advancement to mimic MAS wear, could be a valuable prognostic indicator of successful MAS treatment.     

Increased phosphatidylcholine concentration in saliva reduces surface tension and improves airway patency in obstructive sleep apnoea

Surface tension may have important role for maintaining upper airway patency in patients with obstructive sleep apnoea. It has been demonstrated that elevated surface tension increases the pharyngeal pressures required to reopen the upper airway following collapse. The aim of the study was to evaluate the associations between the concentrations of endogenous surfactants in saliva with indices of upper airway patency in obstructive sleep apnoea. We studied 20 male patients with obstructive sleep apnoea (age: 60·3 ± 10·3 years; BMI: 25·9 ± 4·6 kg m^?2; AHI: 41·5 ± 18·6 events h^?1). We obtained 100‐μL samples of saliva prior to overnight polysomnographic sleep study. The surface tension was determined using the pull‐off force technique. The concentration of phosphatidylcholine (PC) was evaluated by liquid chromatography‐mass spectrometry (LC‐MS/MS). Regression analysis between apnoea, hypopnoea and apnoea/hypopnoea indices and the ratio of hypopnoea time/total disordered breathing time (HT/DBT) with surface tension and PC were performed. P < 0·05 was considered significant. The mean saliva surface tension was 48·8 ± 8·0 mN m^?1 and PC concentration was 15·7 ± 11·1 nM. The surface tension was negatively correlated with the PC concentration (r = ?0·48, P = 0·03). There was a significant positive correlation between surface tension with hypopnoea index (r = 0·50, P = 0·03) and HT/DBT (r = 0·6, P = 0·006), but not apnoea or apnoea/hypopnoea index (P > 0·11). Similarly, PC concentration negatively correlated with hypopnoea index (r = ?0·45, P = 0·04) and HT/DBT (r = ?0·6, P = 0·004), but not with apnoea index or AHI (P > 0·08). An increase in salivary PC concentration may increase upper airway patency in obstructive sleep apnoea through a reduction in surface tension.     

Patient-reported outcome measures following maxillomandibular advancement surgery in patients with obstructive sleep apnoea syndrome

Maxillomandibular advancement (MMA) is an effective treatment for obstructive sleep apnoea syndrome (OSAS) that is refractory to conventional treatment. However, it is a highly invasive procedure with several recognised side effects, and we know of few data on its effect on important patient-reported outcome measures (PROMS). Here we describe a case series of patients selected for MMA through our joint respiratory/maxillofacial surgery clinic, detailing the effect of MMA on objective physiological measurements and important PROMS. Patients with confirmed moderate/severe symptomatic OSAS who could not tolerate continuous positive airway pressure (CPAP) or mandibular advancement devices (MAD) were assessed in the clinic for consideration of MMA. Preoperative and postoperative airway measurements, apnoea/hypopnoea index (AHI), Epworth sleepiness scale (ESS) score, and quality of life (10-point Likert scale), were recorded. A customised questionnaire was administered postoperatively to assess selected psychosocial and functional domains (sleep quality, energy levels, appearance, ability to perform daily activities, and mood) and patient satisfaction using five-point Likert scales. Over an 18 month period, 39 patients were referred for consideration of MMA. Ten patients (7 men and 3 women, mean age 49.9, mean BMI 27.5) underwent surgery, which resulted in significant improvements in ESS, quality of life, AHI, and airway diameters. All patients reported improvements in all psychosocial/functional domains except appearance, in which five reported no change or worsened appearance. All subjects felt that MMA provided better symptom control than CPAP. The most commonly reported side effects were facial/lip numbness (9/10) and affected bite (6/10). MMA resulted in significant improvements in ESS, quality of life, and a range of PROMS, with a high level of patient satisfaction.     

Upper airway stimulation as an alternative to maxillomandibular advancement for obstructive sleep apnoea in a patient with dentofacial deformity: case report with literature review

Obstructive sleep apnoea (OSA) is characterized by repeated upper airway collapse leading to oxygen desaturation resulting in cardiovascular and neurocognitive sequelae. Upper airway surgeries such as palatopharyngoplasty, tongue base surgery, and maxillomandibular advancement can improve patient tolerance of continuous positive airway pressure, quality of life, and the severity of OSA. Upper airway stimulation (UAS) of the hypoglossal nerve is a contemporary US Food and Drug Administration-approved treatment modality for OSA with a fundamentally different mechanism. We report the case of a 65-year-old male with a high body mass index, hypertension, diabetes, dentofacial deformity, and severe OSA. He presented with a respiratory distress index (RDI) of 89.1 events per hour, apnoea–hypopnoea index (AHI) of 82.7 events per hour, and minimum oxygen saturation of 75%. He chose to undergo UAS. Initially, complete concentric collapse of the velum was found during drug-induced sedation endoscopy, which was converted by palatopharyngoplasty to meet inclusion criteria for UAS. The patient achieved surgical cure with postoperative RDI and AHI of 2 events per hour with minimum oxygen saturation of 83%, and resolution of daytime somnolence. UAS is an effective surgical option to broaden the surgeon’s ability to treat OSA, especially if facial skeletal surgery is contraindicated or declined by the patient with dentofacial deformity.     

下颌前移矫治器治疗阻塞性睡眠呼吸暂停低通气综合征的研究进展

阻塞性睡眠呼吸暂停低通气综合征(OSAHS)是一种在临床上表现为睡眠中反复发生呼吸暂停或低通气的疾病,其发病率高且具有潜在致死危险。近年来该疾病日益受到重视,在众多治疗方法中,下颌前移矫治器作为一种非手术治疗方式,因其无创伤、便于摘戴、患者易于接受等独特的优点,是治疗轻、中度OSAHS的有效方法。本文就下颌前移矫治器分类、作用机制、与持续正压通气治疗的对比、对患者的影响等进行综述。     

Upper airway changes in syndromic craniosynostosis patients following midface or monobloc advancement: Correlation between volume changes and respiratory outcome

In syndromic craniosynostosis patients, respiratory insufficiency may be a pressing indication to surgically increase the patency of the upper airway by midface or monobloc advancement. In this study the volume changes of the upper airway and the respiratory outcome following midface (Le Fort I or III) or monobloc advancement in ten syndromic craniosynostosis patients are evaluated. Pre- and postoperatively, the airway volume was measured using a semi-automatic region growing method. Respiratory data were correlated to the volume measurements.In nine patients the outcome of upper airway volume measurements correlated well to the respiratory outcome. Three of these patients showed a minimal airway volume gain or even volume loss, and no respiratory improvement was found. In one monobloc patient improvement of the respiratory outcome without an evident volume gain of the upper airway was found.The majority of patients with Le Fort III advancement showed respiratory improvement, which for the greater part correlated to the results of the volume analysis. In monobloc patients the respiratory outcomes and volume measurements were less obvious. Preoperative endoscopy of the upper airway is advocated to identify the level of obstruction in patients with residual obstructive sleep apnoea.     

下颌前移式矫治器治疗鼾症和阻塞型睡眠呼吸暂停低通气综合征

阻塞型睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)的人群患病率约2%～4%,其特征是睡眠状态中反复发生上气道完全或不完全阻塞而使口鼻无气流通过,有效呼吸障碍,出现间断的低氧血症或合并高碳酸血症、睡眠结构紊乱等,被认为是高血压、心绞痛、脑血管栓塞和夜间猝死的危险因素之一.有效的治疗方法不外乎持续正压通气治疗、外科手术、戴口腔矫治器等手段.而下颌前移式口腔矫治器具有易制作、戴用后易适应及效果较好等优点受到患者和医生的普遍青睐.本文主要介绍了OSAHS的病因机制、临床特点、诊断及下颌前移式矫治器在治疗OSAHS中的临床应用.     

Maxillomandibular advancement is a successful treatment for obstructive sleep apnoea: a systematic review and meta-analysis

The primary objective of this review was to establish the effectiveness of maxillomandibular advancement (MMA) as a successful treatment modality in improving airway patency in patients with obstructive sleep apnoea (OSA). A systematic and detailed search was performed using PubMed Central, covering the period January 2000 to December 2015, with well-defined selection criteria. The authors independently conducted the study selection, data extraction, and assessed the risk of bias of the included studies. Twenty studies met the inclusion criteria. The outcome measures studied were the apnoea–hypopnoea index (AHI), respiratory disturbance index (RDI), Epworth Sleepiness Scale (ESS), lowest oxygen saturation (LSAT), and body mass index (BMI). The random-effects model was adopted for meta-analysis as moderate heterogeneity was identified. The analysis revealed significant changes in the outcome measures after the intervention. The results showed that the preoperative severity of OSA based on AHI and RDI significantly influences the outcome of MMA intervention, with a strong positive correlation between the pre MMA AHI values and the percentage change post intervention. The surgical success of MMA in patients with OSA was found to be 100% with respect to AHI and RDI scores. It is concluded that MMA is a successful treatment for OSA.     

Segmental mandibular advancement for moderate-to-severe obstructive sleep apnoea: a pilot study

Segmental mandibular advancement (SMA) consists of a combination of bilateral sagittal split osteotomy, anterior subapical osteotomy with extraction of the first premolars, and genioplasty, to allow an extended advancement of the mandible for the improvement of tongue base obstruction in moderate-to-severe obstructive sleep apnoea (OSA) and to minimize any unfavourable aesthetic change due to the large jaw advancement. The aim of this pilot study was to evaluate the surgical outcomes and complications following SMA in OSA patients. Twelve patients (nine male, three female) underwent SMA as part or whole of their skeletal advancement procedure for OSA. The apnoea–hypopnoea index (AHI) improved from a mean± standard deviation 42.4 ± 22.0/hour preoperatively to 9.0 ± 17.4/hour at 1 year postoperative. Surgical success (50% reduction in AHI) was achieved in 11 of the 12 patients (91.7%) at 1 year postoperative, while seven patients (58.3%) attained surgical cure (AHI<5/hour). The lowest oxygen saturation (LSAT) increased from a mean 73.3% preoperatively to 78.7% at 1 year postoperative. The airway volume increased from a mean 2.4 ± 1.7 cm³ at baseline to 6.7 ± 3.5 cm³ at 1 year postoperative (P < 0.001). No major complication occurred. This pilot study showed that SMA appears to be safe and effective as part or whole of the skeletal advancement surgery for moderate-to-severe OSA.     

Orthognathic surgery in the management of obstructive sleep apnoea: experience from maxillofacial surgery unit in the United Kingdom

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.     

Genioglossus muscle advancement: A modification of the conventional technique

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.     

双颌前徙术治疗阻塞性睡眠呼吸暂停低通气综合征及长期稳定性的研究

目的采用双颌前徙术治疗中度到重度的中国阻塞性睡眠呼吸暂停低通气综合征（obstructivesleepapnea-hypopneasyndrome,OSAHS）患者,评估术后效果、治病机理及长期稳定性。方法应用双颌前徙术治疗的中度到重度OSAHS患者共9人。患者分别于T1（术前3个月内）、T2（术后3～6个月）及T3（术后最长随访期,至少1年以上）分别进行多导睡眠图仪检查、拍摄头颅定位侧位x线片进行x线头影测量及三维螺旋CT上气道重建。结果9名患者睡眠呼吸暂停低通气指数（apneaandhypopneaindex,AHI）在T1为49．5次／／l,时,T2为7．8次／小时,T3为8．5次／11,时;睡眠时最低血氧饱和度（10westoxygensaturation,I。SAT）在T1为70．2％,T2为91．8％,T3为90．3％。通过术后长期随访,患者颌骨的位置及上气道各层面的测量值相对稳定,主观症状的改善也表现出很好的稳定性。结论双颌前徙术非常适用于治疗上下颌骨发育不足的OSAHS患者,术后长期随访显示双颔前徘术治疗OSAHS具有较好的长期稳宁件．     

A mandibular advancement device reduces sleep disordered breathing in patients with congestive heart failure

Sleep disordered breathing (SDB) including obstructive and central sleep apnoea/hypopnoea as well as periodic breathing (PB) is common and is believed to increase risk for mortality in patients with congestive heart failure (CHF). Mandibular advancement device (MAD) has widely been recommended for treatment of obstructive sleep apnoea but the method has never been investigated for treatment of SDB in the patients with CHF. The aim with the present study was to examine the effect of MAD intervention on SDB in patients with CHF. The study included 17 male patients, aged 68.4+/-5.7 (mean+/-SD) with stable, mild to moderate CHF due to left ventricular systolic dysfunction and with SDB, expressed as apnoea/hypopnoea index (AHI) > or = 10. The SDB was examined during a single night using an unattended, portable polysomnographic device in the patients home, prior to and following intervention with a individually adjusted MAD. The SDB was evaluated by calculating AHI, PB expressed as the percentage of the total registration time, oxygen desaturation index (ODI) and snoring time. The AHI was reduced by MAD intervention from 25.1+/-9.4 to 14.7+/-9.7 (p=0.003). ODI reduced from 21.1+/-9.0 to 10.5+/-7.8 (p=0.007) and snoring time decreased from 53+/-111 to 18+/-47 seconds (p=0.02). PB was reduced from 55.7+/-25.6 to 40.4+/-26.4 per cent without statistical significance. In conclusion, the MAD intervention may be a feasible method for reducing SDB in patients with stable, mild to moderate CHF and left ventricular systolic dysfunction.     

双侧拉杆式口腔矫治器治疗OSAHS前后上气道容积变化及相关因素分析

目的 通过计算机体层摄影观察轻、中度阻塞型睡眠呼吸暂停、低通气综合征患者戴用双侧拉杆式口腔矫治器前后上气道形态变化及其相关因素分析.方法 经夜间多导睡眠仪监测确诊为OSAHS的男性患者9名,年龄25～43岁,平均37岁（中位数）,戴用口腔矫治器治疗有效.3个月后分别行CT扫描,三维重建后行定量分析.结果 所有患者戴用矫治器后上气道各段容积及总容积均增大.总容积的增加百分比与患者体重指数成负相关（r=-0.70,P=0.03）,与患者下颌平面角（MP-SN）没有显著相关性（r=-0.43,P=0.25）.上气道容积的增加与患者睡眠呼吸障碍的严重程度及改善程度无明显相关关系（r=0.30,P=0.43;r=0.39,P=0.29）.结论 双侧拉杆式口腔矫治器使OSAHS患者上气道大小、形态趋于正常.体重指数影响气道大小改善的程度.同时气道大小改善的程度与患者的睡眠呼吸状况改善并不一致.     

Effects of orthognathic surgery on pharyngeal airway and respiratory function during sleep in patients with mandibular prognathism

The aim of this study was to determine changes in overnight respiratory function and craniofacial and pharyngeal airway morphology following orthognathic surgery. The subjects were 40 patients in whom mandibular prognathism was corrected by orthognathic surgery: a one-jaw operation in 22 patients and a two-jaw operation in 18 patients. Morphological changes were studied using cone beam computed tomography immediately before surgery and at more than 6 months after surgery, and the apnoea–hypopnoea index (AHI) was measured with a portable polysomnography system. Pharyngeal airway volume was decreased significantly after surgery, especially in the one-jaw operation group. AHI was not changed significantly after surgery in either group, although AHI in one patient in the one-jaw operation group was increased to 19 events/h. There was no significant change in pharyngeal airway morphology in that patient, but he was obesity class 1 and was 54 years old. In conclusion, some patients who are obese, have a large amount of mandibular setback, and/or are of relatively advanced age may develop sleep-disordered breathing after mandibular setback; a two-jaw operation should therefore be considered in skeletal class III patients who have such risks because it decreases the amount of pharyngeal airway space reduction caused by mandibular setback surgery.     

Effects of a mandibular advancement device on the upper airway morphology: a cephalometric analysis

Summary  The aims of this study were to assess changes in the upper airway morphology associated with an oral appliance in situ in patients suffering from the obstructive sleep apnoea–hypopnoea syndrome and to relate these changes to treatment response. Changes in upper airway morphology as a result of an oral appliance were assessed in 52 patients with obstructive sleep apnoea–hypopnoea syndrome by means of cephalometric analysis. Lateral cephalograms were taken at baseline and after 2–3 months of treatment. Baseline and follow-up cephalograms were traced twice and cephalometric variables were compared. The predictive value of changes in upper airway morphology for the treatment response was evaluated in univariate and multivariate regression analyses. Oral appliance therapy resulted in an increased posterior airway space at the level of the second vertebra, the uvular tip and the base of the tongue. The increase of the posterior airway space at the level of the second vertebra and the uvular tip were the best predictors for relative improvement of the apnoea–hypopnoea index. However, the predictive value for treatment response of these cephalometric upper airway changes should be interpreted with caution.     

Sleep bruxism in patients with sleep-disordered breathing

The aim was to test the hypothesis of a direct association between sleep-disordered breathing and sleep bruxism. The frequency of masseter contraction (MC) episodes and rhythmic jaw movements (RJM) was measured in patients with mild and moderate obstructive sleep apnoea (OSA). The diagnosis of sleep bruxism was made from a combination of questionnaire, clinical observation and all-night polysomnographic recording which included masseter electromyography. A total of 21 patients (19 males/two females, mean age 40.0 years+/-9.2 SD) were randomly selected from a provisional diagnosis of snoring and OSA by a sleep physician. In the patients with mild OSA [n=11, mean apnoea hypopnoea index (AHI)=8.0+/-4.1 SD, body mass index (BMI)=29.1+/-5.0], the diagnosis of sleep bruxism was made in six out of 11 patients (54%); similarly, four out of 10 patients (40%) with moderate OSA (n=10, mean AHI=34.7+/-19.1, BMI=30.6+/-5.0) were identified as bruxists. Although the combination of clinical, subjective estimation and nocturnal electromyographic recording of masseter muscle might provide a more solid base for the diagnosis of sleep bruxism, the result is biased by the variation in the bruxing activity. MC episodes were associated with the termination of apnoea or hypopnoea episodes in only 3.5% of the mild group and 14.4% of the moderate group (p<0.05). It appears that sleep bruxism is rarely directly associated with apnoeic events, but is rather related to the disturbed sleep of OSA patients.     

下颌适度前移矫治器治疗对阻塞性睡眠呼吸暂停及上气道容积的影响

目的:研究下颌适度前移矫治器(mandibular advancement device,MAD)治疗对阻塞性睡眠呼吸暂停(ob-structive sleep apnea syndrome,OSAS)及上气道容积的影响.方法:选择2017年6月～2018年9月经河南省中医院收治的阻塞性睡眠呼吸暂停综合征患者57例进行...     

The effect of mandibular advancement device on pharyngeal airway dimension in patients with congestive heart failure treated for sleep apnoea

Continues positive airway pressure (CPAP) is recommended for treatment of sleep apnoea (SA) in patients with congestive heart failure (CHF) but is not easily tolerated resulting in poor patient compliance. Mandibular advancement device (MAD) is designed to inhibit pharyngeal airway (PAW) obstruction and may be a valuable alternative. It has been proposed that MAD exerts its effect by increasing PAW dimensions. This has not, however, been clearly demonstrated. The aim of this study was to examine the effect of MAD on PAW dimensions and SA in patients with CHF. Seventeen CHF-patients with mild to moderate heart failure, aged 68 +/- 6 years, (mean +/- SD), range 54-75 years, with sleep apnoea-hypopnea index (AHI) > or = 10 were evaluated. PAW dimensions were studied with and without the MAD, using lateral radiographs in supine position. Nocturnal breathing patterns were studied using a portable polysomnographic device during a single night with and without MAD. A reduction of AHI > or = 30% (arbitrary level) for each individual was regarded as a successful treatment. Mean AHI was reduced from 25.1 +/- 9.4 to 14.7 +/- 9.7 (p = 0.003). The PAW increased in its inferior section in 13 patients (p = 0.0001). AHI decreased > or = 30% in 9 patients (p = 0.003) of whom 8 showed increased PAW dimensions. Reduction of AHI was not significantly related to increased PAW dimensions. In conclusion MAD increased PAW dimensions and reduced SA in patients with CHF. The results may indicate that MAD reduces SA by other mechanism than increasing PAW dimensions.