Effective Oral Appliances; By Definition and Design

by Mark T. Murphy, DDS, D.ABDSM

The American Academy of Dental Sleep Medicine (AADSM) recently issued an important update to their 2013 definition that helps shape Oral Appliance Therapy (OAT) use for Dental Sleep Medicine (DSM) providers, “Definition of an Effective Oral Appliance for the Treatment of Obstructive Sleep Apnea and Snoring: An Update for 2019”.¹ The paper states that “An Oral Appliance can be an effective treatment option for those with OSA and snoring.”

The key word in the title that makes this so vital to practitioners is “Effective.” To promote consistency and best treatment practices, the AADSM has updated its definition of an effective oral appliance to reflect current scholarly literature and clinical practice. The new generation of devices is demonstrating greater effectiveness and efficiency than older artisanal products have enjoyed. As dental sleep technology and materials rapidly change, new and effective appliances have emerged. As further updates in science, technology, and practice develop, future edits to this definition may be necessitated. The recommendations provide an excellent matrix for helping providers decide what is the best appliance for each patient.

One of the key components of the definition is that an effective oral appliance stabilizes the mandible. What does this mean in clinical practice? Do devices with elastomeric straps or fulcrum wires adequately stabilize the mandible? Or do those styles of devices introduce too much play to satisfy the definition of stabilize? That’s a decision the prescriber ought to consider. Another key component of the definition is that the device protrudes the mandible. What does this mean for devices that might lose their protrusive setting as the jaw opens?

The definition states that devices ought to be made from biocompatible materials. Though all devices are made with materials that are cleared by the FDA, clinical practice and research alike have demonstrated the different types of material are associated with different degrees of staining and biomass buildup. The electron micrographs below show the relative porosity of common materials still used today compared to precision milled, control cured, medical grade, PMMA.

As material science, manufacturing methods, and precision engineering design continue to evolve, so should our selection criteria. One would be remiss if they chose a mono-block, non-adjustable device when adjustable choices abound. When biocompatible materials are readily available, they should be preferred. Precision designs and components are more favorable than devices that do not hold the mandible in the prescribed position. With well over one hundred FDA approved devices, loosely fitting into a few design categories (Herbst, Dorsal, Anterior Hinge, Iterative, Fulcrum Strap, Bilateral Strap, etc.) the material and manufacturing have a much greater impact today. FDA clearance alone, does not connote “best choice” for the patient. One of the most recent device designs with a counter balancing titration strap, stretches up to 3.0mm.² That is not consistent with the definition of an acceptable, effective device in the AADSM update.

Kudos are due to the AADSM for defining designs, materials, conditions and use for OAT that is more patient centric and effective. Efficacy and compliance combine to create the patient experience. One of my DSM mentors told me that, “the best therapy for each patient is the one that they will use that helps their condition.”

Not considered on this discussion are additional design attributes that impact side effects. During the OAT selection process, consideration should also be given to tooth movement, bilateral symmetry, tongue space, hygienic nature of materials, and overall profile size. Today’s modern engineering and manufacturing of precision medical devices has allowed great improvements over previous generations of appliances. Below are some truisms that you should weigh when evaluating your next patient for an effective OAT.

• Milled devices are less porous, easier to clean and accumulate much less
• A study done by the University of Alberta and the University of the Pacific using control cured PMMA platforms have been shown to not allow for tooth movement.³
• Device designs today, should wrap the distal molars and prevent drifting and open contacts.
• Precision engineered symmetry that CAD embraces can be designed to prevent TMD issues.
• The size advantages of milled materials increase tongue space without compromising strength.

Patient experiences and physician expectations are strengthened when effectiveness is prioritized and side-effects are minimized. Today’s innovative materials, design, and manufacturing processes are delivering robust improvements to these device characteristics.