Maximum Protrusion Evaluation in Patients Wearing a Mandibular Advancement Device

Objectives: Obstructive sleep apnea (OSA) is a sleep related disorder with a high prevalence in our society. With the efficacy of continuous positive airway pressure appliance (CPAP) limited by poor compliance, there has been growing interest in the use of mandibular advancement devices (MAD) to treat mild to moderate OSA, which is exclusively for patients with minimal maximum protrusion. The purpose of this study was to determine whether patient’s maximum protrusion could increase after using the device, which would make those with a weak protrusion eligible to receive this treatment.
Methods: The experimental group included 30 patients diagnosed with OSA by polysomnography. Upon determination of their maximum protrusion, the patients were fitted with an oral appliance for the evaluation period (3 months). A control group, matched for sex and age, included 30 subjects without OSA. Both groups had to undergo baseline and post-treatment assessments of their mandibular border movements with the K7-CMS (Myotronics-Noromed Inc.) evaluation system.
Results: The studied factors (wear of the device, overbite and class of malocclusion) did not seem to have an effect on the amplitude of mandibular movements (p>0.05). However, most patients treated for OSA by oral appliances showed an increase of their maximum protrusion (n=17, μ: 0.95±0.69 mm), a decrease of their maximum opening (n=20, p=0.0987) and an increase of at least one of their lateral movements (n=26, p<0.0001). Treatment was considered successful (85.7%) in the group of patients with maximum protrusions under 10mm at baseline assessment.
Conclusions: This study is the first of many more warranted to evaluate the evolution of maximum protrusion in patients with movement limitations. It brings us a better understanding of the jaw motion with the wear of the MAD and suggests that we could use this course of treatment with patients with minimal maximum protrusion.