Efficacy of Oropharyngeal Exercises for Patients With Obstructive Sleep Apnea Using Mandibular Advancement Device

Background:

Obstructive Sleep Apnea (OSA) refers to recurrent upper airway blockages during sleep, leading to symptoms like snoring, 2 interrupted breathing causing micro-awakenings, daytime sleepiness, impaired concentration, and various chronic conditions. The Mandibular Advancement Device (MAD) is a treatment method for OSA, suitable for mild to moderate cases and CPAP noncompliance. However, clinical use of MAD sometimes falls short in comprehensively alleviating the clinical symptoms of obstructive sleep apnea. Therefore, oropharyngeal muscle training has emerged as a novel adjunctive treatment approach, involving training of the swallowing muscle group and tongue muscles to prevent tongue collapse, reduce tongue base volume during sleep, and strengthen muscle tension. This training aims to increase overall respiratory tract rigidity and improve muscle responsiveness during reduced blood oxygen levels.

Given that some patients do not achieve the expected outcomes after MAD therapy, whether oropharyngeal muscle training can enhance treatment effects becomes a research focus. Thus, this study aims to apply oropharyngeal muscle training to patients who have not achieved the anticipated results following MAD treatment. The objective is to assess changes in oropharyngeal muscle strength, ultrasonographic tongue morphology, severity of sleep related breathing interruptions, clinical symptoms, and correlations among these factors.

Methods:

Fifty diagnosed OSA patients using MAD and consenting to participate are recruited. Patients agreeing to undergo 12 weeks of oropharyngeal muscle training form the treatment group, while those not agreeing form the control group. The treatment group undergoes 12 weeks of training, with weekly in-person follow-ups for treatment intensity adjustment and home-based sessions (30 mins, 1-3 times/day, 3-5 days/week) for a total of 12 weeks. The control group continues MAD therapy. Both groups undergo evaluations of muscle strength and endurance, various sleep physiological tests, ultrasonographic imaging of the tongue and oropharynx, and sleep questionnaire tests before and after the 12- week training period.

Expected Outcomes:

• Oropharyngeal muscle training may increase muscle strength and endurance.
• Oropharyngeal muscle training may reduce the severity of sleep-related breathing interruptions.
• Oropharyngeal muscle training may decrease clinical symptoms.
• Oropharyngeal muscle training may improve tongue morphology.

Inclusion criteria

• OSA patients
• Aged over 20 years
• Wearing MAD (The amount of MAD is at least 50% of the maximum amount that the patient can achieve.)

Exclusion criteria

• Body Mass Index (BMI) ≧ 35
• Pregnancy
• Severe obstructive or restrictive lung disease
• Exercise with high-risk cardiovascular disease
• History of central or peripheral neurological disease resulting in an inability to perform exercise prescriptions
• Musculoskeletal or psychological disorders that prevent the performance of exercise prescriptions
• Chronic illnesses that are ongoing or not yet controlled