A Study Comparing Two Mandibular Advancement Devices in the Treatment of Sleep Apnea

A mandibular repositioning appliance (MRA) is the primary treatment option for patients with mild to moderate obstructive sleep apnea (OSA), as well as for those with severe OSA who are intolerant to continuous positive airway pressure (CPAP) therapy or for whom surgical interventions are not viable. MRAs function by advancing the mandible, thereby increasing the volume of the upper airway and reducing its tendency to collapse during sleep. Various types of MRAs are available, and multiple classification systems can be employed to distinguish between these different types.

Mandibular repositioning appliances (MRAs) can be either custom-made or universal. Custom-made devices, which are typically more expensive, are fabricated in a dental laboratory using dental impressions. In contrast, prefabricated devices, often thermoplastic MRAs, are generally less costly and readily available over the counter.

Mandibular repositioning appliances (MRAs) can be classified as non-titratable, also known as monoblock devices, which have a fixed position, or titratable devices, which allow for gradual adjustment of the mandibular position until the desired therapeutic effect is achieved. Current guidelines recommend the use of titratable MRAs.

Titratable mandibular repositioning appliances (MRAs) can be further categorized into two types: midline traction devices, where the upper and lower components are connected at the front of the device, and bilateral thrust devices, where the upper and lower components are linked in the lateral or (pre-)molar regions.

Within the latter category, various designs exist, including devices that are adjustable on both sides using Hyrax screws and 3D-printed devices equipped with a series of lower components that allow for adjustments in mandibular position.

An example of an MRA adjustable with Hyrax screws is the SomnoDent® device (SomnoMed, Denton, Texas, USA). An example of a device utilizing a series of lower components for titration is the OrthoApnea appliance (ORTHOAPNEA S.L., Málaga, Spain), which features a specific attachment mechanism.

Although studies have already been published comparing different types of "bilateral thrust" devices, no studies to date have directly compared the categories mentioned above. The hypothesis of the investigators is that both appliances have similar effectiveness in the treatment of mild-to-moderate obstructive sleep apnea.

Primary objective:

Improvement of AHI, measured by polygraphy before treatment and after treatment with each MRA.

Secondary objective;

• Peripheral oxygen saturation, measured by polygraphy before treatment and after treatment with each MRA

• Average saturation
• Lowest saturation
• Oxygen desaturation index >3% (events/h)
• Total duration with saturation < 90%
• Epworth Sleepiness Scale, taken before treatment and after treatment with each MRA
• Patient experience questionnaire, taken before treatment and after treatment with each MRA
• Patient final choice of preferred MRA

Endpoints:

The investigators assess the objective improvement in OSA by comparing polygraphy results taken before and after treatment with each MRA. To evaluate the subjective effects of the MRA, the investigators compare the scores from the Epworth Sleepiness Scale. The participants subjective experience with each MRA type is measured using a patient experience questionnaire, along with noting the final preference for device type of the participants.

Study design:

• Randomized, controlled cross-over study
• Study population: Patients referred to the Department of Oral and Maxillofacial Surgery at ZOL Genk for Mandibular Repositioning Appliance (MRA) therapy, aged 18 years or older diagnosed with an Apnea-Hypopnea Index (AHI) between 5 and 30 events per hour.

Inclusion criteria

In order to be eligible to participate in this study, a subject must meet all of the following criteria:

• Provide signed and dated informed consent
• Males or females aged 18 and above
• Apnea-Hypopnea Index (AHI) between 5 and 30 events per hour diagnosed by a polysomnography

Exclusion criteria

A potential subject who meets any of the following criteria will be excluded from participation in this study:

• Previous surgery on the upper airways
• Prior treatment of OSA (CPAP or MRA)
• Presence of unstable cardiovascular conditions, neurological, mental, or psychiatric disorders
• Insufficient dental or periodontal condition for a mandibular repositioning appliance (MRA)
• Presence of temporomandibular joint dysfunction

In order to be eligible to participate in this study, a subject must meet all of the following criteria:

• Provide signed and dated informed consent
• Males or females aged 18 and above
• Apnea-Hypopnea Index (AHI) between 5 and 30 events per hour diagnosed by a polysomnography

A potential subject who meets any of the following criteria will be excluded from participation in this study:

• Previous surgery on the upper airways
• Prior treatment of OSA (CPAP or MRA)
• Presence of unstable cardiovascular conditions, neurological, mental, or psychiatric disorders
• Insufficient dental or periodontal condition for a mandibular repositioning appliance (MRA)
• Presence of temporomandibular joint dysfunction