Posted by sleepsurgeon on May 16, 2012 at 15:08:13:Many patients have asked me about a normal sized airway. The problem is that there is no such a thing. Different people need different sized airway. This is because breathing is a very complicated process and there is no way of knowing whether an airway is large enough. Even when an individual has a good airway and minimal sleep apnea, it doesn’t mean that sleep apnea wouldn’t develop when he or she ages. Things tend to go south as we age, unfortunately.
Sleep apnea occurs when someone is ASLEEP!!! The airway is a dynamic and collapsible tube because it is lined with muscles. Muscles lose tone when one is asleep, thus reducing the dimensions of the ENTIRE AIRWAY!!! For those who believe in sleep endoscopy, if they observe patients for a few hours (and not just a few minutes), they will discover that the entire airway-soft palate, lateral wall, tongue, epiglottis…etc are collapsing. This is why MMA is the most successful operation compared to the other procedures.
Given the above, the airway should be expanded as much as possible as long as the expansion is stable, meaning the fixation of the advanced bones do not move. The goal of MMA for sleep apnea is quite simple. The surgeon needs to advance the jaws as much as possible but still achieve stability of the jaws, minimize complications and pay close attention to occlusion and facial esthetics. Unfortunately, it is easier said than done.
To me, a typical advance is 12-15 mm while achieving the above goals. I have certainly advanced much greater distance, but the risks are greatly increased with larger advancements. The question is how does one measures advancement. One can measure on the cast, on the teeth or on the xrays. Although cephalometric radiograph is often used, I find it very unreliable and filled with biases. In my opinion, the best way to measure advancements is on a post surgical panoramic radiograph. The distance between the cut edges of the mandible is the distance of bone movement. Actually, 12-15 mm advancement on the panoramic radiograph typically translates to 18-20 mm advancement on the cast and teeth. Obviously, there are nuances with how the jaws are moved (counter clock vs clock-wise rotation) impacting on how to measure the advancements. But for all practical purposes, this is the surest way to measure.
Finally, the degree of advancement is just as important as avoiding complications. It is the determinant of how successful the operation can be, while understanding that nothing achieves a success rate of 100%.
- Re: MMA for sleep apnea arcticranger 06:15 6/15/12 (0)
- Re: MMA for sleep apnea westernjoe 19:28 5/17/12 (2)
- Re: MMA for sleep apnea sleepsurgeon 11:41 5/21/12 (1)
- Re: MMA for sleep apnea westernjoe 09:31 6/21/12 (0)