Mandibular Advancement Splints (MAS)

What are Mandibular Advancement Splints?

Oral devices have been used in the investigation and management of snoring and mild forms of Obstructive Sleep Apnoea (OSA) for a number of years. The technology has been based on experience in the field of Orthodontics. The idea for Mandibular Advancement Splint (MAS) devices is a development of functional appliances which have been used in orthodontic treatment for many years. They look vaguely like the plastic dental-guards the contact sports players (eg rugby players use)

How do they work?

A MAS consists of two parts, (an upper and a lower) fitting over the teeth in such a way as to allow the lower jaw (“Mandible”) to be maintained in a forward posture. The forward posture in turn allows for a more forward position of the tongue and an increase in the airway flow behind the tongue to decrease the vibration of the palate and throat muscles which contribute to snoring. The MAS is custom-made in a dental laboratory and requires impressions of the upper and lower teeth.

What’s the evidence?

MAS devices worn at night have been shown in controlled trials to help mild to moderate OSA and some aspects of snoring, (Stradling et al, 1998). This study of a group of people who snore reported a significant reduction in snoring from 193 to 20 snoring episodes per night. Reduced respiratory effort was also noted. At this time research is on-going to determine which appliance is most likely to
improve symptoms for a given patient. The literature suggests that MAS’s have place in the management of snoring and mild/moderate OSA. The general opinion is that these patients should have a specific assessment from a physician or surgeon which may include information from overnight sleep studies. Off-the-shelf “DIY” MAS’s are available, but their success rates are poor, as they seldom fit properly. Custom made MAS’s, made by an experienced orthodontist are much more likely to work effectively.

Which MAS is best for me?

There are a number of different designs of MAS. It is sometimes necessary to try out more than one design type, depending on a number of factors. It will be necessary to check the state and health of the teeth and gums. In some cases, an MAS may not be a feasible option due to adverse factors in the mouth. These will be discussed at the consultation appointment.

Are there any side-effects?

Oral devices are cost-effective and can be an alternative to other treatments. In a small number of cases, patients noted an alteration in the bite and some reported symptoms due to jaw joint tenderness, (temporomandibular joint discomfort or pain). These effects are usually minor in nature.