sleepwell summary data

NOTE : The clinical name for Sleepwell ™ is MDSA.

This page contains a summary of the published data on the most comprehensively tested MAS to date. In addition the full research findings are available as a download from the menu.

This section includes related clinical data on the analysis of OSA and research conducted into wider medical conditions associated to OSA.

Efficacy of Positive Airways Pressure and Oral Appliance in Mild to Moderate Obstructive Sleep Apnoea.

Maree Barnes, R. Douglas McEvoy, Siobhan Banks, Natalie Tarquinio, Christopher G Murray, Norman Vowles, and Robert J Pierce Am. J. Respir. Crit. Care Med. published 16 June 2004, online article.

Abstract:

The efficacy of currently recommended treatments is uncertain in patients with mild to moderate obstructive sleep apnoea (apnoea - hypopnoea index 5-30). A group of 114 sleep clinic patients with apnoea- hypopnoea index 5-30 have participated in a randomised controlled crossover trial of 3 months treatment with each of nasal continuous positive airways pressure, a mandibular advancement splint and a placebo tablet. Outcomes were sleep fragmentation and hypoxemia, daytime sleepiness, quality of life, neurobehavioral function and blood pressure.

Both active treatments improved sleep outcomes, but positive pressure had a greater effect.

Quality of life, symptoms and subjective but not objective sleepiness improved to a similar degree with both treatments, however many of the improvements seen in the neuropsychological function and mood were no better then the placebo effect.

Some aspects of nocturnal blood pressure were improved with the splint but not with continuous positive airway pressure.

This study has shown that although both continuous positive airways pressure and mandibular advancement splint effectively treated sleep-disorder breathing and sleepiness, the expected response in neurobehavioral function was incomplete. This may be due to the splint having a lesser therapeutic effect, and the continuous positive airways pressure being poorly tolerated and therefore used less in this patient group. (Products used; CPAP Resmed Australia. Oral Appliance Sleepwell ™ supplied by RJ & VK Bird Pty Ltd)

What the paper specifically states about the Sleepwell™

Patient Selection:

Patients were excluded if they did not have at least 2 teeth in the upper and lower jaws on both left and right sides to enable adequate retention of the Sleepwell ™ ... only 5 patients out of 99 could not be fitted with a Sleepwell ™

Patient Fitting:

The goal of the Sleepwell ™ advancement was maximum comfortable protrusion. At the initial fitting, the Sleepwell ™ was advanced maximally as tolerated by the subject. Subjects were reviewed weekly and the Sleepwell ™ advanced further (wash in period for the Sleepwell ™ was 1-3 weeks). When no further advancement was possible, the screw was, sealed, advancement measured, and 3 month treatment period commenced. No subjects required an extra dental visit.

Patient Advancement:

Mandibular advancement with the Sleepwell ™ was 10.3 ± 0.3mm. And ranged between 1-13mm. Seventy five percent of subjects required at least 75% of maximum possible protrusion.

Patient Acceptance:

...only one subject was unable to tolerate CPAP and two were unable to use the Sleepwell ™

Effectiveness of the Sleepwell ™ design:

...There has been concern that vertical dimension opening of an oral appliance may result in posterior movement of the tongue and soft palate with consequent reduction of the posterior airway space and worsening of sleep disordered breathing. The AHI increase in uncontrolled oral appliance trials has attributed to a problem with the design of the oral appliance, ... however we found that significantly fewer subjects had an AHI increase with Sleepwell ™¬ than with placebo.

Treatment adherence:

CPAP - Sleepwell ™

Nights per week: 4.2 ± 0.3 5.3 ± 0.3

Hours per night: 3.6 ± 0.3 5.5 ± 0.3

...It has been proposed that effective CPAP treatment of OSA requires usage for at least 4 hours per night on at least 70% nights. 43% of subjects treated with CPAP received adequate treatment, 71% with Sleepwell ™

...suggesting that the CPAP response extends to low usage levels.

Response to Sleepwell ™:

...In addition to the primary analysis, we measured the improvement in sleep disordered breathing with the Sleepwell ™ using response definitions that have been used in similar studies. A complete response is defined as a reduction in the AHI to below 10, and partial response is a fall of at least 50% in the AHI but not below 10, with an improvement in symptoms; the remainder of subjects are classified as treatment failures. By this criteria 49.1% subjects had a complete response to the Sleepwell ™, and a further 6.1% had a partial response. (55.2% in total)

Quality of life:

...Both treatments (CPAP-Sleepwell ™) were more effective than placebo in improving quality of life symptoms and subjective not objective sleepiness, with neither treatment being better than the other.

Blood Pressure:

...There was no response in blood pressure to CPAP, however Sleepwell ™ improved the nocturnal diastolic blood pressure and significantly increased the proportion of subjects with a normal nighttime dip in blood pressure.

The blood pressure response to Sleepwell ™ was greater than that to CPAP, and raises the possibility that some aspects of CPAP treatment may mitigate against a lowering of blood pressure in the mild OSA severity range. To our knowledge, there have been no other published controlled trials of the effect on blood pressure of treating OSA subjects with CPAP, and none with an oral appliance.

Reported Side Effects:

Subjective Effectiveness:

Further Clinical Data:

Evaluation of Variable Mandibular Advancement Appliance for Treatment of Snoring and Sleep Apnoea* (Chest. 1999;1 16:1511-1518.) @ 1999 American College of Chest Physicians.

JEFFREY PANCER, DDS; SALEM AL-FAIFI, MD; MOHAMED AL-FAIFI, MD AND VICTOR HOFFSTEIN, PhD, MD, FCCP.

* From the Department of Medicine, Respiratory Division, St. Michael's Hospital, University of Toronto, Ontario, Canada.

Correspondence to: Victor Hoffstein, PhD, MD, FCCP, St. Michael's Hospital, 30 Bond St, Toronto, Ontario, Canada M 5 B I W8; e-mail: victor.hoffstein@utoronto.ca

Objective: To evaluate an adjustable mandibular positioning appliance for treatment of snoring and sleep apnoea.

Methods: One hundred and thirty-four patients with baseline apnoea / hypopnoea index (AHI) of 37 ± 28 events/h (mean ± SD) received the appliance. The efficacy of the appliance was assessed by the following investigations, performed at baseline and with the appliance: polysomnography, Epworth sleepiness scale, bedpartners' assessment of snoring severity, patients' assessment of side effects, and overall satisfaction.

Results: Thirteen patients were lost to follow-up. Additional 46 patients had no follow-up polysomnography, but answered the questionnaires. A total of 75 patients had polysomnography at baseline and with the appliance. We found a significant reduction in AHI from 44 ± 28 events/h to 1 2 ± 1 5 events/h (p < 0.0005) and a reduction in the arousal index from 37 ± 27 events/h to 1 6 ± 1 3 events/h (p < 0.05). Epworth scores fell from II ± 5 to 7 ± 3 (p < 0.0005). Bedpartners' assessment revealed marked improvement in snoring. For example, at baseline 96% of patients were judged to snore loudly "often" or "always" by their bedpartners, whereas only 2% were judged so while using dental appliance. The most frequent side effect was teeth discomfort, present "sometimes" or often" in up to 32% of patients. Follow-up clinical assessment in 121 patients conducted on the average 350 days after the insertion of the appliance revealed that 86% of patients continued to use the appliance nightly; 60% were very satisfied with the appliance, 27% were moderately satisfied, 11% were moderately dissatisfied, and 2% were very dissatisfied.

Conclusion: We conclude that the adjustable mandibular positioning appliance is an effective treatment alternative for some patients with snoring and sleep apnoea.

Effect of Oral Appliance Therapy on Upper Airway Collapsibility in Obstructive Sleep Apnoea.

Andrew T Ng, Helen Gotsopoulos, Jin Qian and Peter A Cistulli.

Department of Respiratory and Sleep Medicine, St. George Hospital, University of New South Wales, Sydney, Australia.

Correspondence: Correspondence and requests for reprints should be addressed to Peter Cistulli, M.D., Ph.D., Department of Respiratory Medicine, St. George Hospital, Belgrave Street, Kogarah, NSW 2217, Australia. E-mail: p.cistulli@unsw.edu.au

Oral appliance therapy is emerging as an alternative to continuous positive airway pressure for the treatment of obstructive sleep apnoea (OSA). However, its precise mechanisms of action are yet to be defined. We examined the effect of a mandibular advancement splint (MAS) on upper airway collapsibility during sleep in OSA. Ten patients with proven OSA had a custom-made MAS incrementally adjusted during an acclimatization period until the maximum comfortable limit of mandibular advancement was reached. Polysomnography with the splint was then performed. After a 1-week washout period, upper airway closing pressures during sleep (with and without MAS) were determined. Significant improvements with MAS therapy were seen in the apnoea/hypopnoea index (25.0 ± 3.1 vs. 13.2 ± 4.5/hour, p < 0.03) and upper airway closing pressure in Stage 2 sleep (Æ1.6 ± 0.4 vs. Æ3.9 ± 0.6 cm H2O, p < 0.01) and in slow wave sleep (Æ2.5 ± 0.7 vs. Æ4.7 ± 0.6 cm H2O, p < 0.02) compared with no therapy. These preliminary data indicate that MAS therapy is associated with improved upper airway collapsibility during sleep. The mediators of this effect remain to be determined.

The effect of body posture on sleep-related breathing disorders: facts and therapeutic implications.

Sleep Medicine Reviews 1998;2(3):139-162

OKSENBERG A, SILVERBERG DS.

The aggravating effect of the supine body position on breathing abnormalities during sleep was recognized from the earliest studies on sleep breathing disorders. Most of the anatomical and physiological correlates of this phenomenon appear to be due to the effect of gravity on the upper airway. Although few articles have been published on this topic, it has been shown in a large population of obstructive sleep apnoea (OSA) patients that more than half of them are Positional Patients, i.e. they have at least twice as many apnoeas/hypopnoeas during sleep in the supine posture as in the lateral position. This positional phenomenon is influenced by factors such as Respiratory Disturbances Index (RDI), Body Mass Index (BMI), age and sleep stages. The sleep supine posture not only increases the frequency of the abnormal breathing events but also their severity. This sleep posture also has a detrimental effect on snoring, -as well as on the optimal CPAP pressure. Positional Therapy, i.e. the avoidance of the supine posture during sleep, is a simple behavioural therapy for many mild to moderate OSA patients. Unfortunately, only a few studies, including only a few patients, have investigated this form of therapy. Although the results of these studies are promising, the lack of a reliable long-term evaluation of its efficacy is perhaps an important reason why this form of therapy has not been widely accepted. Since mild to moderate OSA patients are the majority of the OSA patients and since without treatment, a large percentage of them will develop a more severe form of the disease, a thorough evaluation with a major emphasis on the long-term effectiveness of this form of therapy is urgently needed. Copyright 1998 W. B. Saunders Company Ltd. All rights reserved.

Clinical data courtesy of MDSA Pty Ltd.