An observational study in Obstructive Sleep Apnea (OSA) and Mandibular Advancement Device, sponsored by University Hospital, Antwerp. Completed at 6 sites in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-02-24.
Sponsored by University Hospital, Antwerp · Observational
Study Objectives: To retrospectively study mandibular advancement treatment efficacy using apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), in a large cohort of patients, in 'real world' settings across 6 general hospitals.
Methods: Diagnosis at 6 Belgian recognised OSA sleepcenters with type-1 polysomnography. After drug-induced sleep endoscopy by Ear-Nose-Troat-specialist, patients with positive effect of mandibular protrusion on reopening the upper airway were referred. The mandibular advancement device (MAD) was fitted in 'maximal comfortable protrusion' minus 2mm. A type-3 home polygraphy with MAD followed titration.
Methods Patients were diagnosed at conventionalized Belgian OSA sleep centers, in alphabetical order: AZ Monica (Antwerpen), AZ Sint-Maarten (Mechelen), AZ Voorkempen (Malle), Heilig Hart Ziekenhuis (Lier), Imelda Ziekenhuis (Bonheiden), and VITAZ (Sint-Niklaas), with a type 1 polysomnography. The apnea-hypopnea index (AHI; number of events/h sleep), oxygen desaturation index (ODI; number of desaturations/h sleep) and body mass index (BMI; kg/m2) were calculated.
The Ear-Nose-Troat-specialist at the OSA sleep center performed an awake examination of the upper airway, followed by a drug-induced sleep endoscopy (DISE). Patients with positive effect of mandibular protrusion on reopening of the upper airway were referred to the dental sleep professional (DSP) for dental clinical and/or radiological examination. The DSP registered the mandibular protrusive trajectory with a bite registration device (The BiteFix, Scheu-Dental, Iserlohn, Germany) and a hard bite registration paste (Futar Fast, Kettenbach, Germany), as to achieve a stable fit on both tooth arcs. Next, the 'maximal comfortable protrusion' (MCP, mm) of the mandible was determined, being the most forward mandibular protrusion still tolerated by the patient and tested during DISE.
At the time of fitting, the patients received full explanation on the MAD titration schedule and were instructed to titrate after fitting of the MAD till resolution of the snoring symptoms or upon reaching physiological limits. A 1-month follow-up was performed by telephone. Next, a type 3 home polygraphy with the MAD was organized between 3 to 5 months after treatment start, recording identical parameters as at baseline, making each patient to serve as the own control.
Inclusion In Belgium, the reimbursement criterion for MADt leaves out central apneas in the calculation of AHI and requires this 'obstructive AHI' (OAHI) to be ≥ 15 events/h. In the absence of any central event, the OAHI = AHI, whereas in the presence of central events OAHI \< AHI. Patients with OAHI ≥ 15 events/h and therefore AHI ≥ 15 events/h were included on the condition that the full clinical pathway as described before was followed and that the MAD was self-reportedly used at least 4 hours per night. Further reporting is done on AHI, for reasons of comparison with other studies.
Parameters Age (years) and gender (Male/Female, M/F) were noted. Questionnaires were used at baseline and controls for the quantification of snoring using a visual analogue score on loudness (VAS-snore) with a Likert-scale from 0 (no snoring) up to 10 (partner sleeps in other room). A VAS-snore > 3/10 represents socially disturbing snoring. The Epworth sleepiness score (ESS) quantifies daytime sleepiness with ESS ≥ 11/24 representing increased propensity to fall asleep during daytime.
Mandibular advancement device The starting position of the MADt was set at MCP minus 2mm (MCP-2, mm). Digital imprints of both tooth arcs were taken (Trios, 3Shape, Copenhagen, Denmark) as well of the bite-registration in the MCP-2 position. The selected MAD (EVO, ProSomnus Sleep Technologies, Pleasanton, CA, USA) uses a Class IV resin (United States Pharmacopeia and National Formulary) which is the highest grade of material currently available. Its design is characterized by perpendicular rectangular posts to protrude the mandible. Such design could preserve mandibular advancement even during limited mouth opening while asleep. The fully digital manufacturing pathway, starting from the digital intra-oral scans up to the 3D milling, favors accuracy-of-fit on the dental arcs.
2,263 studies on the registry are indexed under Sleep Apnea, Obstructive; 465 are open to participants now.
This study's enrollment of 182 is above the median of 105 across 666 observational studies indexed under Sleep Apnea, Obstructive.
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patients referred by sleep physicians and after ear-nos-troat-specialist examination, for mandibular advancement treatment in routine clinical settings.
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Exclusion Criteria:
Results of clinical trials on MADs are regularly published in the international literature but are generally very strongly controlled studies, still far away from being applied in routine daily clinical practice. The current retrospective study evaluates real-world data to determine the extent to which MAD improves both symptoms in patients with OSA. It is estimated that about 3% of newly diagnosed OSA patients are treated with MAD. In the light of new future treatment conventions, health government departments are increasingly demanding real-world data to stimulate knowledge of the relative effectiveness and value of treatments in the management of patients in routine clinical settings.
Respiratory index "apnea-hypopnea index" (AHI)
The first primary outcome is an expected improvement in apnea-hypopnea index (AHI; number of apneas and hypopneas per hour of sleep; a higher AHI means more severe obstructive sleep apnea) upon MAD treatment (MADt). Functional objective outcome measure is the quantification of the effect of MADt on AHI. "Success" is defined as treatment AHI≤15 events/h following the Belgian threshold for reimbursement, and any decrease in baseline AHI.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
Respiratory index "oxygen desaturation index" (ODI)
The second primary outcome is an expected improvement in respiratory parameter oxygen desaturation index (ODI; number of desaturations per hour of sleep; a higher ODI means a more severe condition) upon MAD treatment (MADt). Functional objective outcome measure is the quantification of the effect of MADt on ODI. "Success" is defined as treatment AHI≤15 events/h following the Belgian threshold for reimbursement, and any decrease in baseline AHI.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
Obstructive sleep apnea severity
The third primary outcome is an expected improvement in OSA severity category upon MAD treatment (MADt). Categories are defined as AHI 5-14.9/hour = mild OSA; AHI 15-29.9/hour = moderate OSA; and OSA ≥30/hour = severe OSA.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
Visual analogue score for snoring
The fourth primary outcome is an expected improvement in snoring as reported by the patient. This functional subjective outcome measure quantifies the snoring using a questionnaire with a visual analogue score on loudness of snoring (VAS-snore) with a Likert-scale from 0 (no snoring) up to 10 (partner sleeps in other room). A VAS-snore \> 3/10 represents socially disturbing snoring. The higher the VAS-snore score the louder the snoring is.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
Epworth Sleepiness Scale
The fifth primary outcome is an expected improvement in daytime sleepiness as reported by the patient. This functional subjective outcome measure quantifies the propensity to fall asleep during daytime activities, using a questionnaire with with the Epworth Sleepiness Score-scale (ESS) from 0 (no propensity to fall asleep) up to 24 (extremely high propensity to fall asleep). An EES-score ≥ 11/24 represents a pathological increased daytime sleepiness. The higher the ESS-score the more pronounce the daytime sleepiness is.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
Titration
The sixth primary outcome is the amount of titration required at the moment when the control home-polygraphy (HPG) is recorded. The starting position of the MADt was set at the maximal comfortable protrusion (MCP) minus 2mm: first the mandibular maximal protrusive trajectory was measured in millimeters. Next, MCP was determined, being the most forward mandibular protrusion still tolerated by the patient. The actual protrusive position of the MAD at the time of the HPG minus the start position quantifies the amount of protrusion. This result cannot be interpreted in terms of a 'higher' protrusion as a 'better' protrusion since this is a patient specific characteristic, as is the range of mandibular protrusion.
Time frame: From enrollment to the control home polygraphy at 3 to 5 months after fitting the MAD
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