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Less Protrusion, More Tongue Space: flexTAP Vertex Technology Explained

The key to flexTAP is its new patented Vertex Technology.

Vertex Technology is the design of the post angulation in the flexTAP hardware. The post is angled at a 45-degree angle, allowing the patient to advance their lower jaw both vertically and horizontally at the same time.

The Science Behind Vertex Technology 

Anatomically, our condylar eminence is on average at a 45-degree angle. If the jaw is moved forward 10 mm, the condyle moves down 10mm. To keep the path and plane of occlusion parallel, you would have to move the symphysis down 10mm.

The design of the flexTAP post duplicates the 45-degree angle of the eminence.  As the appliance is titrated forward, it goes down the same distance, creating more room in the box for the tongue. The front of the mandible moves both vertically and horizontally at the same rate as the condyle. There is no rotation as long as the vertical increase is no greater than the protrusion. The jaw does not rotate back.


Physiologic Breathing Position

As we all learned in dental school, our mandible translates down and forward into a resting position with space between our teeth called “freeway” space. This is the usual breathing position. Freeway space varies from patient to patient and depends on the size of the tongue and oral cavity; the greater the tongue size, the smaller the oral cavity, the more forward and larger the freeway space.

Benefits of Both Vertical and Horizontal Opening

To explain why Vertex Technology makes flexTAP stand out from the growing market of custom mandibular advancement devices (MAD), we must start from the beginning.

By definition, a MAD treats snoring and obstructive sleep apnea by moving the lower jaw and tongue forward, increasing airway space and reducing throat constriction.

I first designed the TAP so that it only contacted in the front, what is called anterior guidance with no posterior contact. I wanted at least 2mm of space interocclusally. Fortunately for me and serendipitously, that is where the tongue moves. If you look at a tongue, typically you see that the tongue goes sideways in between the teeth and is where you see the scalloping. It’s a tongue size discrepancy where you see the scalloping. With a narrow palate, the only place for the tongue is between the teeth. This is where I got the concept of a big fat tongue. When I realized this and looked into the research, the success came from the devices having a fairly open vertical bite, which allowed room for the tongue.

Research Shows Vertical Opening Success in Treatment Outcomes

One of the biggest issues in managing airways is the size of the tongue. Research says that the oral cavity, or as I say “the box,” needs to be as big as the tongue and soft tissue. Two of the strongest TAP appliance studies proved that vertical adjustability and more tongue space led to better outcomes.

  1. In a TAP and continuous positive airway pressure (CPAP) Army comparison study published in Chest in 2011, researchers prescribed an oral appliance (OA) to 497 patients and outcomes proved no significant difference in mild and moderate obstructive sleep apnea (OSA) patients. In fact, 73.6% of patients were successfully treated with TAP, and this study is used as part of the American Academy of Sleep Medicine (AASM) and American Academy of Dental Sleep Medicine (AADSM) guidelines stating OA as first-line therapy.
  2. Research published in the Journal of Dental Research indicated “that oral-appliance therapy was not inferior to CPAP for effective treatment of obstructive sleep apnea.


What’s not published in either study but was later discovered by myself and Aarnoud Hoekema is that the increased vertical dimension helped with patient outcomes. More room for the tongue seems especially helpful in cases with overweight patients. You could have less room for the tongue for some people, but more room proved beneficial for everyone.

The problem with most appliances is the size of the box. The vertical is not adequate. If you have a fat tongue, you need a bigger box for it. If you have a big tongue in a small box, you have a problem. Also, most appliances fill in the space between the teeth with plastic which significantly reduces the size of the box.

Dr. Thornton Explains “Big Fat Tongues” | Part 2

Read more on “How to Manage Big Fat Tongues” on New West Dental Lab’s blog.

How Will Patients Benefit from this Technology?

By opening the box both vertically and horizontally, vs just horizontally in most oral appliances, we’ve seen patients needing less protrusion which eases joint pain or strain on the jaw and less tooth movement. flexTAP opens the box more than any custom TAP on the market and still has the key factor of patients being able to self-adjust if needed.

flexTAP comes standard with a Mouth Shield nasal breathing promoter that easily slips onto the post and increases comfort. The Vertex Technology and Mouth Shield combination may result in better outcomes with less protrusion.

flexTAP Mouth Shield