Across populations, OSA is more common in males, with estimates of approximately 14% in men and 5% in women. In Australia, primary snoring alone is estimated to affect around 8% of the population, and is an important early indicator of sleep-related breathing disorders.
In adults, excess body weight is the dominant contributor, and prevalence rises sharply in the presence of cardiometabolic disease. Rates are particularly high in individuals with severe obesity, especially those undergoing bariatric assessment (70%-80%). Elevated rates are also reported among patients with cardiovascular disease, resistant hypertension, heart failure, arrhythmias, prior stroke or transient ischaemic attack, type 2 diabetes mellitus, and polycystic ovary syndrome.
Consider OSA in patients presenting with symptoms of sleep disordered breathing, non-restorative sleep, or daytime functional impairment. Suspicion is particularly warranted when symptoms are longstanding, normalised by the patient, reported by a bed partner, or occur in the presence of obesity, type 2 diabetes mellitus, resistant hypertension, or established cardiovascular disease.
Features prompting assessment for OSA include:
Early recognition enables timely referral for comprehensive sleep evaluation and facilitates informed discussion of management options, including oral appliance therapy for appropriately selected patients. Untreated OSA is characterised by recurrent airway collapse, resulting in fragmented sleep, intermittent hypoxia, intrathoracic pressure fluctuations, and heightened sympathetic activity. Over time, these pathophysiological changes increase the risk of hypertension, coronary artery disease, heart failure, arrhythmias, stroke, and impaired glucose regulation. Effective treatment improves symptoms, daytime function, quality of life, and long-term cardiometabolic outcomes.
In Australia, OSA diagnosis is typically confirmed through monitored or unmonitored (home-based) polysomnography, coordinated through general practice alongside a comprehensive sleep evaluation. Objective assessment guides treatment selection, referral planning, and ongoing monitoring.
OSA severity is defined using the apnoea-hypopnoea index (AHI), representing the average number of apnoeic and hypopnoeic events per hour of sleep. According to American Academy of Sleep Medicine (AASM) criteria, OSA is classified as mild when AHI ≥5, moderate at 15-30, and severe when >30. Hypopnoeas are defined as airflow reductions of ≥30% for ≥10 seconds, accompanied by ≥3% oxygen desaturation or arousal.
Assessment of snoring may be subjective or objective. Bed partner reports, validated questionnaires such as the OSA-50, STOP-BANG, and snoring intensity scales provide practical clinical insights. In some cases, acoustic analysis as part of the polysomnography can quantify snoring frequency and intensity, particularly when assessing the efficacy of oral appliance therapy.
Oral appliance therapy is an established treatment option for appropriately selected patients with sleep-related breathing disorders and specifically involves the use of mandibular advancement appliances (MAAs). These custom-fitted devices are worn overnight and function by advancing the mandible, thereby reducing upper airway collapse and improving airflow during sleep.
MAAs are most effective in patients with primary snoring or mild to moderate OSA. For patients with more severe disease who cannot tolerate or decline continuous positive airway pressure (CPAP) therapy, oral appliances may still provide clinically meaningful benefit, even if reductions in AHI are modest. Symptomatic improvements and quality of life gains may occur despite incomplete normalisation of polysomnography indices.
Assessment of suitability for MAA involves:
MAAs are convenient, easy to use, well tolerated and associated with good compliance. Therapy involves wearing the appliance nightly with gradual, patient directed mandibular advancement (titration). During this process, the mandible is protruded in small, adjustable increments using the appliance mechanism over successive weeks to months until an effective and comfortable mandibular position is achieved. Once the therapeutic position has been established based on the subjective report of the patient, a follow-up polysomnography under medical supervision may be required to evaluate treatment efficacy, particularly in patients with moderate to severe OSA.
Treatment efficacy has been described in several ways. These include achieving an AHI below 5 or 10, or a reduction of more than 50% with an AHI under 15. Most commonly, success is defined as a ≥50% reduction in AHI accompanied by symptomatic improvement, such as reduced snoring, tiredness on waking, morning headaches, and daytime fatigue. Maximal benefit is usually reached over several months of appliance titration.
Short term side effects
Short-term side effects of MAA therapy are common during the initial acclimatisation phase, particularly in the first few weeks. These may include excessive salivation or oral dryness, tooth discomfort, transient changes in bite upon waking, and soreness of the temporomandibular joint or masticatory muscles. These effects are typically mild and self-limiting, usually resolving within days to several weeks, and can often be managed through adjustment of the appliance by a dentist trained in dental sleep medicine.
Long term bite changes
Long-term bite changes are common with prolonged MAA use and may include reduced anterior teeth overjet and overbite, tooth movement, and posterior teeth open bite. Most patients tolerate these changes in exchange for improved symptom control. Informed consent and regular dental review, typically every 12 months are essential. Close communication and collaboration between the GP and dentist ensure that any short or long-term side effects are identified and managed promptly, optimising therapy outcomes and minimising risk. Intolerable long-term side effects warranting cessation of MAA therapy are uncommon.
Collaboration between GPs, sleep physicians, and dentist trained in dental sleep medicine supports integrated care and optimises patient outcomes in the management of snoring and OSA with MAAs. Oral medicine specialists and dentists trained in dental sleep medicine provide expertise in assessing oral and craniofacial factors relevant to therapy. Their role includes assessing patient suitability, selecting and fitting appliances, guiding titration, and monitoring for oral or temporomandibular complications.
Consider referral when:
Information to include in the referral:
1,2, Ramesh Balasubramaniam OAM1,3
1Consultant, Perth Oral Medicine and Dental Sleep Centre, West Leederville, Western Australia.
2Clinical Senior Lecturer, UWA Dental School, The University of Western Australia, Nedlands, Western Australia.
3Associate Professor, Discipline Lead in Oral Medicine, UWA Dental School, The University of Western Australia, Nedlands, Western Australia.
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