Position-dependent obstructive sleep apnea and its influence on treatment success of mandibular advancement devices.

Purpose: Depending on the severity of pre-treatment obstructive sleep apnea (OSA) and the criteria used to define treatment success, the efficacy of mandibular advancement devices (MADs) ranges from 30 to 69%. Identifying suitable candidates is the key to increasing the efficacy of a MAD. Positive predictors include a low body mass index, a low apnea-hypopnea index (AHI), and low age. Another consideration is whether or not a patient's OSA is position dependent. To evaluate the effect of such dependency on MAD treatment success, we studied the following: treatment success across the patient's total AHI and in the supine and non-supine sleeping positions; the influence of pre-treatment position dependency on MAD treatment success; and the effect of MAD treatment on post-treatment shifts in position dependency.

Methods: This is a single-center retrospective study of patients with OSA. Patients were diagnosed through an overnight polysomnography and treated with a MAD between February 2015 and January 2018. They were defined as being positional if the AHI in supine sleeping position was at least twice as high as in the non-supine position.

Results: Complete treatment success was achieved in 32% of study population (n = 96) and partial success in 54%. Complete treatment success was significantly higher (p = 0.004) when a patient was sleeping in the non-supine position. Treatment success did not differ significantly between patients who were position dependent and those who were not. When treated with a MAD, patients did not spend significantly more time in supine position. Neither did we find any post-treatment shifts in position dependency.

Conclusion: A MAD is an effective treatment modality that may significantly reduce the total AHI, supine, and non-supine AHI. Since position dependency has no impact on MAD treatment success, it does not determine whether or not a patient is a suitable candidate for MAD treatment.