OK, I have learned a bunch about mandibular repositioning appliances since I showed this image the first time. I didn’t know what I didn’t know!! When, that happens, I do two things. Ask someone who does and go to pubmed.gov.
I called Keith Thornton in Dallas. Keith developed the TAP appliance many years ago and his practice is now limited to sleep dentistry. I asked him what he thought was going on. He provided me with a long bibliography and then I spent time on pubmed rooting out other info.
It is well documented in the literature, (Franson, 2004, Almeida, 2006 and Ghazal 2008) that mandibular repositioning appliances for sleep apnea and snoring have dental sequelae. Chen in 2008 reported these side effects: mandibular arch width increased more than maxillary arch width, crowding decreased in both arches, the curve of Spee became flat in the premolar area, the mandibular canine to second molar segment moved forward in relation to the maxillary arch, the bite opened and the overjet decreased except in some molar areas.
Net result is that the bite changes and there appear to be skeletal changes as well.
Anecdotally, Keith told me of a patient he followed for 10 years who developed a bilateral posterior open bite and protruded mandible. Upon death, they discovered he had left his body to science and a colleague of Keith’s was able to dissect the head. He reported normal joints on both sides, not the change in retrodiskal tissue one might expect.
Keith and the surgeon postulate that permanent changes occur in the fossa and the head of the condyle.
What does this mean to us as dentists? First, we are not qualified by training to treat sleep apnea and all of its complications. If we choose to do so, then we need to partner with a sleep physician for the long-term benefit of our patients. Second, when we do these kinds of appliances we need to be sure that our patients understand the risks and complications. That said, when the ramifications of true sleep apnea are understood by the patient, then it really is a no-brainer…chances of death compared to dental issues are pretty clear to most people.
Next…so, now what do I do with it now?
Great series you have going on Steve. Thanks for all of the insight.
I’ve actually been wearing the TAP III appliance for about 8 months. I’ve had some very interesting changes in my bite since then. Currently I have a very slight anterior openbite (mainly contacting only in the premolar area), and I have some serious pain in my left TMJ area (especially when chewing). At first I thought it was due to the fact that I had some interferences in the posterior when I sleep. However, about a month ago I removed all the interferences and initially the pain went away, but now it’s back and maybe worse than ever. I’m currently considering seeking some advice from a TMJ pain speacialist. If you have any insight on this I’d appreciate it. Thanks.
Hi Mike
I would contact Dr. Thornton at sleepwellsolutions.com and ask him about it. He has a repositioning device that he tells me is working well. Will talk about it in a future blog
Steve
Steve,
thanks for the kind words.
I will try to answer some of these questions with a concensus of about 30 dentists who I consider are scientists and excellent practitioners in this field. Some of the things we are finding are counterintuitive to anything we have learned in the past. We have a number of individuals in the group who have advanced training in TMD with Henry Gremillion, Parker Mahan and others. What we are discovering is that nocturnal clenching is a response to a collapsed airway and the reacton of the muscles to stiffen the pharynx to keep the airway patent. If the airway is not open enough, then the patient continues to have a sympathetic response and the concomitant muscle activation. Ron Prehn in Houston has done a retrospective study looking at esophageal menometry, which indicates inspiratory flow limitation. In this group of individuals, 80% had tmd symptoms. There are numerous studies that show other symptoms such as gerd, fibromyalgia, chronic fatigue syndrome, atrial fibrilation, atheroscelrosis, etc. All of these studies are in the medical literature.
Getting back to this specific situation, as a group, we have decided that the best way to prevent these symptoms is to add posterior stops at the time of the delivery of the appliance. The TAP was designed to have anterior guidance with posterior disclusion. However, we have found that this occlusal scheme seemed to cause more tmd problems and certainly more change in jaw relationships. We have also come up with what I call an am aligner. It is made of a very low heat polymer with kevlar. It is very tough. I take a centric relation bite with this before fitting the appliance and have the patient wear it every morning until their occlusion returns to their acquired position. With these two techniques we are getting very little occlusal changes and have eliminated most tmd discomfort. Finally, you may not have the appliance adjusted far enough forward to eliminate the muscle activity to maintain airway patency.You might want to look at the studies by Oshima, Isono, Remmers, Kuna, Kato and many others which show the tongue and closing muscles act in concert with breathing at if they were respiratory muscles.
As far as permanent changes, my orthodontist friend who I turned into a class 3 from a class 1 has really focused on this. He is the one who insisted on my adding stops. He has taken cephs on all his patients and has found very little movement if the stops are well adjusted.
Finally, you need to know how bad your apnea is. The comorbidities with this continue to amaze those of us focused on this problem. I would stop wearing the appliance until your occlusion returns to normal and you have no pain. Then add posterior stops at the initial treatment position. Adjust the appliance 1/2 turn every third day until symptoms are eliminated. Followup with some type of home monitoring to be sure your apnea is well treated.
Hope this helps.
As I always discuss in my lectures, I have a financial interest in the TAP appliance so caveat emptor.
Dr. Thornton, thank you so much for the advice. I am going to add posterior support and see how that works out.