The Impact of Varying Vertical for Oral Appliance Therapy Outcomes

I truly appreciate Todd Morgan posting his insights regarding "Vertical" on the SleepDisordersDentistry LinkedIn Discussion group. He has provided us with research that he has participated in to review, that support these insights. I highly recommend taking a look at them. Click on the links below to download them.

Assessing changes in the apnea/hypopnea index resulting from increased vertical dimension of occlusion of mandibular repositioning devices

Comparison of Mandibular Repositioning Device outcomes for the Treatment of Obstructive Sleep Apnea Using Alternative Approaches for Determining the Optimal Jaw-Forward Position

Initial Evaluation of a Titration Appliance for Temporary Treatment of Obstructive Sleep Apnea

I will let Todd tell his story on how he came to work with Vertical variation,

“You may recall my previous contribution describing how I have evolved with vertical and when/why I apply it based on gender. We were very intrigued to discover how added VDO in much smaller amounts (3.5-8.5 mm in our studies) than those seen in Pitsis and Cistulli’s study (15mm @ incisal) from 2002 can be helpful. As a reminder, in the later 2000s we were testing a developing the ARES HST monitor and positioning it to be used by dentists for appliance calibration purposes. During that time Keith Thornton made a change in design in moving from TAP II to TAP III hooks. We wound up splitting our 130 patients between the two designs. And, unaware of the added VDO in TAP II our outcomes shifted from better in men to better in women. Once we discovered this difference we crossed a sample of those same subjects to the other design and re-tested.

From that point forward I was either adding or reducing vertical using cold cure acrylic (BTW, post-menopausal women like vertical, too) chairside to appliances when results were less than ideal and saw consistently better outcomes, both in lowering AHI and comfort. Theoretically, adding VDO may improve upper airway dynamics by one or two routes: 1) By putting the hyoid sling musculature under additional tension, primarily via the stylohyoid and styloglossus muscles, or 2) By increasing a phenomena known as tracheal tug. My assumptions are based on the dynamic interaction of the infra and supra hyoid muscles and observation on lateral imaging that demonstrates a “smoothing” of the pharyngeal mucosal outline. Whatever the mechanism, we have found in clinical practice that VDO acts as a surrogate to further protrusion in bringing down the supine AHI.

The spawn of our conviction with vertical is the Apnea Guard System for bite registration and immediate OSA Tx. For anyone interested, I suggest taking a look and I can provide a sample to you. BTW- I do not benefit from the sales of Apnea Guard kits. One of our most significant findings in another study comparing George Gauge technique to AG was the savings of time, overhead and appointments. (see above). The AG bite takes the patient directly to the predicted efficacious jaw position based on the correct VDO and 70%. Almost all patients do very well at this position out of the gate since we are pacifying pharyngeal airflow right away and muscles go quiet.

The most recent development with vertical are ourV-tabs that fit onto the Narval appliance. In case we get the vertical wrong at the start or in cases of discomfort we can add 1,2 or 3mm vertical increments at a time and, as we all know, nothing can be added to that nylon polymer... I can also provide a sample of the tabs to others in the blog if they wish to try them. I look forward to any comments from the group.”

Below you see a picture of the Apnea Guard used to mount the patients models.


Below you see the mounted models and resulting bite from using the Apnea Guard as a bite registration.


Thanks for this information Todd.

John Viviano DDS D ABDSM

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