What is the role of a bite block (mandibular advancement device) in treating obstructive sleep apnea (OSA)?

Role of Mandibular Advancement Devices in Treating Obstructive Sleep Apnea

Mandibular advancement devices (MADs) are recommended as first-line therapy for patients with mild to moderate obstructive sleep apnea (OSA) and as an alternative therapy for patients with severe OSA who are intolerant to or refuse CPAP therapy. 1

Effectiveness of MADs in OSA

• MADs reduce the apnea-hypopnea index (AHI), arousal index, and daytime sleepiness while improving quality of life measures in adult patients with OSA 1
• Treatment success rates (defined as ≥50% reduction in AHI) with MADs are approximately 52% overall, with higher success rates in moderate (52%) and severe (63%) OSA compared to mild OSA (25%) 2
• Complete resolution of OSA (AHI reduced to <5/hr) occurs in approximately 40% of patients using MADs 3
• Although CPAP is superior to MADs in normalizing respiratory parameters (AHI, oxygen desaturation index, and minimal oxygen saturation), both treatments demonstrate comparable effects on symptoms and health-related quality of life measures 1, 4
• Long-term effectiveness has been demonstrated, with over 50% of patients maintaining treatment success after 5 years of MAD use 2

Patient Selection Criteria

• Ideal candidates for MAD therapy include:

  • Patients with mild to moderate OSA with no comorbidities 1
  • Patients with severe OSA who are intolerant to CPAP or request an alternative therapy 1
  • Patients with primary snoring (without OSA) 1

• Factors associated with better treatment success:

  • Younger age and female gender 1, 3
  • Lower BMI and smaller neck circumference 1, 3
  • Position-dependent OSA (supine-predominant) 1
  • Lower baseline AHI 1
  • No previous CPAP use 2

Device Characteristics and Implementation

• An effective MAD should be:

  • Individualized and titratable 1
  • Made of biocompatible materials 1
  • Engaging both maxillary and mandibular arches 1
  • Stable and retentive to teeth, implants, or edentulous ridge 1
  • Capable of advancing the mandible in increments of 1mm or less 1
  • Adjustable with a protrusive range of at least 5mm 1
  • Reversible in advancement if needed 1

• Recommended protocol:

  • Initial titration should start at approximately 50% of maximum mandibular advancement 1, 4
  • Custom-made devices are more effective than prefabricated ones 1
  • Follow-up sleep testing is essential to verify treatment efficacy 1

Adherence and Patient Preference

• Adherence with MADs is typically better than with CPAP in OSA patients 1
• Long-term adherence data shows 93.3% of patients use their MAD ≥4 hours/night on ≥4 days/week after 5 years 2
• Patient satisfaction is high, with 96.5% of patients wanting to continue MAD therapy after 5 years 2

Potential Side Effects and Monitoring

• Initial side effects are common but generally minor and transient:

  • Jaw discomfort, tooth tenderness, excessive salivation 1
  • Temporary occlusal changes 1

• Long-term dental changes may occur but are typically subclinical for most patients 3

• Regular follow-up is recommended to monitor treatment efficacy and potential side effects 1, 4

Clinical Pitfalls and Considerations

• MADs are less effective than CPAP in reducing AHI, but similar effectiveness in clinical practice may result from better compliance with MADs 3
• Not all patients will respond to MAD therapy despite improvement in symptoms 3
• A multidisciplinary approach involving sleep physicians and qualified dentists is essential for optimal patient outcomes 1
• Re-evaluation with sleep testing is necessary after MAD titration, as improvement in symptoms alone is an imprecise indicator of treatment success 1

Treatment Algorithm

1. Diagnose OSA severity through polysomnography or home sleep apnea testing
2. For mild to moderate OSA: Consider MAD as first-line therapy
3. For severe OSA: Recommend CPAP as first-line therapy; offer MAD if CPAP is refused or not tolerated
4. Refer to a qualified dentist for oral examination and MAD fitting
5. Begin with 50% of maximum mandibular advancement and titrate as needed
6. Conduct follow-up sleep testing to verify treatment efficacy
7. Schedule regular follow-ups to monitor side effects and treatment response