SleepScholar.com editor Dr John Viviano has been moderating a discussion group on Linkedin called Sleep Disorders Dentistry. In his forum he moderates discussions related to dental therapies and sleep apnea. Tips, Tricks and points of view with opinions drawn from experienced clinicians and thought leaders in the field. Once each discussion runs for a few weeks Dr Viviano writes a consensus document that highlights points of agreement and areas where agreement was lacking. Following is an excerpt from a recent consensus document with a link to the full document that was originally posted on the American Sleep and Breathing Academy website.- ed
(Steve Lamberg, Harry Ball, Steve Carstensen, Christopher Kelly, Mark Collins, Barry Glassman, Erin Elliott, Kent Smith, Shouresh Charkhandeh, Rob Burwell, Todd Morgan, Daniel Klauer, Dennis Marangos, Tim Mickiewicz, Gina Pepitone-Mattiello, Stephen Gershberg, Tony Soileau, Richard Reichman, Dan Tache, John Viviano)
The LinkedIn Discussion Group, “SleepDisordersDentistry” has just completed an open discussion on establishing an Oral Appliance Starting Position. Here is a consensus for all to ponder.
What was asked,
“Our next discussion will be “Establishing Oral Appliance Starting Position”. We’ve already heard a great deal from both the Phonetic and George Gauge Groups, but there are many other approaches and ideas such as the Apnea Guard, Airway Metrics, Andra Gauge, MATRx etc. I have even heard of clinicians using a “Golf Tee” to establish their initial bite registration!
There is very little in the literature about “Establishing Oral Appliance Starting Position”; so it would be very interesting to hear about various techniques and methods, and what works for clinicians around the world…”
What was said,
Our discussion on “Establishing an Oral Appliance Starting Position” confirms much agreement amongst our peers that there is no universal “Evidenced Based”, or “Anecdotally Based” starting point that will assure the best outcome; most clinician’s relying on the only Evidenced Based Data, “Jaw Advancement” while keeping “Vertical to a Minimum”. However a scattering of very unique ideas were also discussed, including some new Evidence Based technologies that provide valuable information regarding both efficacy and starting position. Our longest discussion to date included some very heated posts, that were at times entertaining, at other times insightful and occasionally could be considered an outright “cyber” fistfight. I encourage you to take the time to review the following synopsis on the many ideas expressed by clinicians that actually do this work on a daily basis in their clinics.
The majority of discussion revolved around some degree of mandibular advancement (the only Evidence Based approach). As a starting point, most clinicians advance the mandible approximately 60-70 % of the protrusive range, and then make various “Consideration Adjustments” from that position which results in the final “Starting Position”. The various “Consideration Adjustments” mentioned were:
- Patient comfort (trumps all)
- Results of muscle, ligament and joint palpation exams
- Appliance design, (ensuring that the selected position still enabled the patient to reach their maximum protrusive position when considering the chosen appliances unique adjustment range, keeping in mind that for some patients, protrusive range increases with appliance wear)
- Apnea Severity (less advancement for less severe apnea)
- Urgency to obtain optimum outcome
Once a position is established, Barry Glassman discussed having the patient clench their teeth in the George Gauge, and then go to each lateral position and have the patient clench again, looking for tenderness or tightness in the contralateral joint. If this tests positive, a less (or more) protruded position would be established, followed by retesting.
It was pointed out that this 60-70% of protrusive position has little science behind it, so it makes more sense to work back from maximum protrusive based on the unique adjustment range of the chosen appliance as a start position, and then make the “Consideration Adjustments”. I found the drama over this part of the discussion quite entertaining. When one considers what 60-70% of a “typical” range of motion is, and how it compares to the position you end up with when you work back from maximum protrusive by the amount of adjustability of a “typical” appliance (approximately 5mm), the two positions of course vary, but are somewhat similar, yet this resulted in so much debate! What made this part of the discussion even more entertaining was that pretty well everyone agreed that this final position would be tweaked further, based on the “Consideration Adjustments”. Quite frankly, especially once you consider the “Consideration Adjustments ”, I don’t see any material difference between these two approaches for the majority of people. Just do the math and you’ll see what I mean. Just sayn’;). Kent Smith said it best and with the most honesty, “Hey, it’s all a guess anyway!”
So, in the end, it seems clinicians in this group advance the mandible using a set formula (which often results in a similar position for all) and then adjust that position forward or back based on certain “Consideration Adjustments” to establish the Starting Position. It was also pointed out that some patients experience maximum benefit by simply preventing the jaw from falling back, with no forward protrusion at all. However, the bite position should be advanced a minimum of 1 to 2 mm from “centric” to prevent translation/rotation out of appliance as advancement decreases the opening potential (particularly useful with the dorsal design).
For patients overly concerned about possible bite changes, it was suggested that less advancement be considered. A study conducted by Doff et al. March 2013 “Long Term OA Therapy in OSAS”, documented the following, “Linear regression analysis revealed that the decrease in overbite was associated with the mean mandibular protrusion during follow-up [regression coefficient (beta) = -0.02, 95 % confidence interval (-0.04 to -0.00)]”; suggesting that this type of tooth movement could be minimized with less advancement.
Although there are various tools available to facilitate taking a mandibular advancement bite registration (George Gauge, Pro Gauge, Andra Gauge etc), it seems that the George Gauge with the 2 mm bite fork was the most common tool used. The 5 mm bite fork was recommended when an increased vertical was sought. Modification to the George Gauge was also mentioned; placing wax in the “V” groove to increase the vertical and drilling out the “V Groove” so it better accommodates misaligned teeth. Whichever tool is used, it was recommended that the patient not clench into it when taking the bite registration.
(John Viviano, Steve Lamberg, Harry Ball, Steve Carstensen, Christopher Kelly, Mark Collins, Barry Glassman, Erin Elliott, Kent Smith)