Can procedures such as drug-induced sleep endoscopy tell sleep professionals in advance whether patients will respond to mandibular advancement for obstructive sleep apnea?
If you ask Eric Kezirian, MD, MPH, a sleep surgeon and professor in the University of Southern California (USC) Caruso department of otolaryngology – head and neck surgery at USC’s Keck School of Medicine, how he treats his patients with obstructive sleep apnea, his approach differs with each patient. He doesn’t believe in taking “cookie cutter” approaches to treating patients who do not tolerate or respond well to CPAP.
One treatment alternative is oral appliance therapy. The most common type of oral appliance is a mandibular advancement device (MAD), which is designed to position the lower jaw slightly forward and down to open up the airway.
Several researchers have found that oral appliance therapy is an effective and reliable alternative to CPAP for patients with obstructive sleep apnea (OSA). In a 2-year randomized trial involving 103 patients that was published in SLEEP, oral appliance therapy was found to work well among patients who aren’t morbidly obese and to effectively reduce the risk of fatal cardiovascular events among patients with severe OSA.1
Challenges with Oral Appliance Therapy
One of the biggest barriers for patients seeking oral appliance therapy is often the cost of these customized dental appliances. When you count the number of office visits, the cost of the device, and other adjustments that need to be made, the costs for oral appliance therapy can really add up.
The financial burden is not just on the patient, it’s also an investment for the dentist, who has to continuously tweak and adjust the custom-fitted dental device.
“A historical challenge that both patients and dentists had to deal with is figuring out whether or not oral appliance therapy will work for a specific patient—it usually takes a couple of months to figure out how the patient is exactly responding to the device,” says Shouresh Charkhandeh, DDS, chief dental officer of Zephyr Sleep Technologies. “The last thing you want is to realize oral appliance therapy actually doesn’t work for the patient a few months after starting the treatment.”
In an attempt to solve this issue, some dentists use transitional oral appliances as a less costly, temporary solution to determining if mandibular advancement works for a patient. But as researchers have pointed out, a premade non-custom transitional oral appliance doesn’t achieve the same level of efficacy as a custom appliance so the implications of transitional oral appliance trials are limited.
Finding New Ways to Predict Oral Appliance Outcomes
Today there are several devices available to dentists to predict oral appliance efficacy. One is the MATRx by Zephyr Sleep Technologies, a FDA-approved medical device system that helps dentists not only identify successful candidates for oral appliance therapy, but also determine the amount of protrusion that’s required to effectively treat a patient with OSA.
Using the trays that come with the MATRx device, the dentist takes a patient’s dental impressions, which the patient then brings to the sleep lab. In the sleep lab, the trays in the patient’s mouth are attached to a remotely controlled mandibular positioner that moves the patient’s mandible back and forth without disturbing his/her sleep, according to Zephyr Sleep Technologies. “The MATRx device allows sleep technicians to do a mandibular titration that’s comparable to adjusting CPAP titration pressure, but in this process we’re interested in gathering information on how much protrusion of the mandible is required to eliminate sleep apnea,” says John Remmers, MD, co-founder and chief medical officer of Zephyr Sleep Technologies.
A study published by the Journal of Clinical Sleep Medicine surveyed 254 patients with OSA and concluded that remotely controlled mandibular positioners like MATRx are effective in predicting oral appliance therapy outcomes and identifying the amount of mandibular advancement that’s needed.2
Can Oral Appliance Therapy Success Be Predicted During Drug-induced Sleep Endoscopy?
Drug-induced sleep endoscopy (DISE) is best known for being an anesthesia procedure that gives sleep physicians an opportunity to see the dynamic airway in a sleep patient. It helps sleep physicians identify the site of the obstruction (by viewing three dimensions: anteroposterior, transverse, and circumferential) and is frequently used prior to sleep surgeries. Studies like one published in Laryngoscope find that drug-induced sleep endoscopy helps predict outcomes of upper airway surgery among OSA patients.3
Considering that this technique gives surgeons an edge to achieve precise results, you would wonder why it’s not used more to predict the outcome of other treatment methods like oral appliances.
That’s exactly the question researchers sought to answer in a recent study published in a supplement to the journal Sleep that concludes that drug-induced sleep endoscopy does help dentists predict the success of oral appliance therapy for patients with OSA.4 Another study found DISE to be helpful in identifying patterns of residual collapse in patients with OSA who didn’t fully respond to oral appliance therapy.5
“Drug-induced sleep endoscopy can be very helpful for people who are thinking about different choices besides CPAP, whether surgery or oral appliances,” Kezirian says. “It can point someone in the right direction to determine what kind of surgery might be helpful or whether they would be more likely to respond to an oral appliance. In addition, if they have not had success with previous surgery or an oral appliance, it can help us understand why and how to reach our goal of addressing their obstructive sleep apnea fully.”
DISE can be a costly procedure and not every sleep lab or dentist’s office has the ability to offer drug-induced sleep endoscopy, especially in North America.
“Although a very useful and effective clinical tool, drug-induced sleep endoscopy requires special expertise and training and the outcome can vary based on a clinician’s level of experience,” Charkhandeh says. “That can pose a challenge in whether it’ll be widely used in North America, but it’s frequently used in countries like Belgium, Netherlands, Germany, and other European countries.”
One recent study suggests it is feasible to use remotely controlled mandibular positioning (such as the MATRx) during drug-induced sleep endoscopy.6 But Remmers sees two important takeaways: 1) assuming that drug-induced sleep is analogous to natural sleep, the MATRx approach should identify favorable candidates for oral appliance therapy, and 2) DISE gives physicians better insight on how to treat patients who didn’t respond well to oral appliance therapy (since it gives them an inside look into the pharynx where there are residual sites of obstruction).
While it is unclear whether DISE will become a clinically widespread practice among dentists, Charkhandeh says tools that can predict the accuracy of oral appliance therapeutic outcomes and target level of protrusion position may soon become widespread in use for treating patients. He adds that Zephyr is working on the MATRx “Plus,” a home sleep study-compatible version of its computer-controlled mandibular positioner.
“Right now a lot of dentists are taking a trial-and-error approach to oral appliances, and in my opinion, if we continue with that model it will take us a long time to get oral appliances as the front line treatment option,” Charkhandeh says.
Yoona Ha is a freelance writer and digital strategist.
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2. Kastoer C, Dieltjens M, Oorts E, et al. The use of remotely controlled mandibular positioner as a predictive screening tool for mandibular advancement device therapy in patients with obstructive sleep apnea through single-night progressive titration of the mandible: a systematic review. J Clin Sleep Med. 2016;12(10):1411-21.
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6. Kastoer C, Dieltjens M, de Beeck SO, et al. Remotely controlled mandibular positioning during drug-induced sleep endoscopy towards mandibular advancement device therapy: feasibility and protocol. J Clin Sleep Med. 2018;14(8):1409-13.