Treatments for Obstructive Sleep Apnea

Oral Appliances

Similar to OPT, oral appliances (OAs) attempt to prevent upper airway collapse. OAs either stabilize the tongue, advance the mandible, or lift the soft palate to increase the volumes of the upper airways to avert OSA [16, 51]. The OAs, like the mandibular advancement device, for example, have the added benefit of being fitted specifically for the OSA patient. The mandible for a patient can be advanced to alleviate obstructive apneas, but can also be pulled back if the OA is too uncomfortable or painful. However, there is still dispute on how exactly to titrate these OAs [52]. A meta-analysis recently published looked at all clinical trials of OAs through September 2015. After meeting strict exclusion/inclusion criteria, 17 studies looking at OAs were included in the meta-analysis. There were robust decreases in AHI and in symptoms of sleepiness in OSA patients that used OAs compared to control groups. However, due to the strict inclusion/exclusion criteria of the meta-analysis, all the studies except one used mandibular advancement appliances; one study used a tongue-retaining appliance. The authors concluded that there is sufficient evidence for OAs to be effective in patients with mild-to-moderate OSA [51]. Since the meta-analysis, 6 new studies have been published about OAs. In 4 of the studies (all using mandibular advancement), OAs significantly decreased AHI by 50% or more in the majority of OSA patients [53–56]. The other 2 studies looked at long-term efficacy and compliance. In both studies, there were drastic decreases in AHI when OAs were applied [57, 58]. In one study, about 40% of OSA patients stopped using the OAs. When the change in AHI was stratified between users and non-users, the users group was significantly higher that the non-user group, suggesting that the non-user group were not compliant due to less of an effect of the OA on AHI [57]. In the second study, OSA patients using OAs for a median of 16.5 years were evaluated for long-term efficacy of the OAs. At the short-term follow-up, AHI decreased by more than 50% with use of an OA. However, at the long-term follow-up, the OA lost any effect on AHI. One reason for this is that the OSA patients’ AHI without the OA at the long-term follow-up nearly doubled compared to AHI without OA at the short-term follow-up. The authors conclude that OSA patients using OAs for the long-term might undergo deteriorations in treatment efficacy of OAs, and that regular follow-up appointments with sleep apnea recordings should be implemented [58].

A similarity in all these studies is that adherence was higher for OAs compared to CPAP [51]. The caveat is that most studies have relied on self-reports for adherence rates [12]. However, there were 3 studies that implemented a sensor that measured adherence and compared those results to self-reported OA adherence. All 3 studies showed a strong relationship between self-reports and sensor adherence; patients were honest about adherence to OAs [59–61]. Studies have also been conducted to predict compliance with OAs: higher therapeutic CPAP pressure, age, OSA severity [62], decreased snoring [63], and lower BMI [64, 65] predicted compliance, while dry mouth [63], oropharyngeal crowding [65], and sleeping in a supine position [66] predicted noncompliance. Though adherence rates are high, OAs do not decrease AHI as much as CPAP [67], and a recent study showed that long-term adherence rates might not be different to CPAP adherence rates [68]. OAs, due to their higher adherence rates, are a potential second choice over CPAP. However, they are less efficacious than CPAP at decreasing AHI. That may not be as important since a recent meta-analysis comparing the effects of CPAP or OAs on blood pressure showed that both treatments significantly decreased blood pressure [69]. More studies need to be conducted over long-term efficacy of OAs compared with CPAP.