Sleep Apnea Diagnosis & Testing

Why Proper Diagnosis Matters

Sleep apnea affects an estimated 30 million Americans, yet the vast majority of cases remain undiagnosed. Without a formal sleep study, it is impossible to know whether your snoring, daytime fatigue, or restless nights are caused by obstructive sleep apnea, central sleep apnea, or another sleep disorder entirely. Guessing is not enough — an accurate diagnosis determines the type and severity of your condition, which directly shapes the treatment approach that will be most effective for you.

A proper diagnosis also establishes a baseline that your healthcare providers use to measure treatment success over time. If you have been experiencing signs and symptoms of sleep apnea — chronic snoring, witnessed breathing pauses, morning headaches, or excessive daytime sleepiness — getting tested is the essential next step. At Glendale Dental Wellness, Dr. Ivan Chan guides patients through the diagnostic process and collaborates closely with sleep physicians to ensure you receive the right diagnosis and the right care.

Types of Sleep Studies

There are two primary types of sleep studies used to diagnose sleep apnea. Your physician will recommend the appropriate test based on your symptoms, medical history, and the level of detail needed to make an accurate diagnosis.

Home Sleep Test (HST)

A home sleep test is a simplified, portable diagnostic tool that you use in the comfort of your own bed. The device is typically a small unit that clips to your finger and includes a nasal cannula and chest belt. It records key data points including airflow through your nose and mouth, blood oxygen saturation levels, chest and abdominal movement, and heart rate throughout the night.

Home sleep tests are the most commonly prescribed option for patients with a moderate to high probability of obstructive sleep apnea. They are less expensive than in-lab studies, more convenient, and covered by most medical insurance plans. Because you sleep in your own environment, some patients find that the data better reflects their typical sleep patterns. However, home sleep tests have limitations — they do not measure brain wave activity, so they cannot detect sleep stages or differentiate between obstructive and central sleep apnea as precisely as an in-lab study.

In-Lab Polysomnography (PSG)

In-lab polysomnography is the gold standard for sleep apnea diagnosis. This comprehensive overnight study takes place in a sleep center or hospital under the supervision of a trained sleep technician. Multiple sensors are placed on your scalp, face, chest, abdomen, and legs to record a wide range of physiological data.

A polysomnography measures brain wave activity (EEG) to identify sleep stages and arousals, eye movements (EOG) to track REM sleep, muscle activity (EMG) in the chin and legs, airflow through the nose and mouth, respiratory effort of the chest and abdomen, blood oxygen levels via pulse oximetry, heart rate and rhythm (ECG), body position and limb movements, and snoring intensity. This level of detail makes PSG essential for patients with suspected central sleep apnea, complex sleep apnea, or other coexisting sleep disorders such as periodic limb movement disorder or narcolepsy. Your physician may also order an in-lab study if a home sleep test produces inconclusive results.

What Sleep Tests Measure

Regardless of whether you undergo a home sleep test or an in-lab polysomnography, the core data being collected focuses on how well you breathe during sleep. The two most important events that a sleep study records are:

• Apneas — complete cessations of airflow lasting at least 10 seconds. During an apnea event, the airway is fully blocked (in obstructive sleep apnea) or the brain fails to signal the breathing muscles (in central sleep apnea), and no air enters the lungs.
• Hypopneas — partial reductions in airflow of at least 30% lasting at least 10 seconds, accompanied by a drop in blood oxygen saturation of 3-4% or an arousal from sleep. These are less severe than full apneas but still disrupt sleep architecture and reduce oxygen delivery.

In addition to these respiratory events, sleep studies track oxygen desaturation patterns, heart rate variability, time spent in each sleep stage, total sleep time versus time in bed, body position correlations, and snoring frequency and volume. This comprehensive data set allows your sleep physician to identify not only whether you have sleep apnea, but how severe it is, what positions make it worse, and whether other sleep disorders may be contributing to your symptoms.

Understanding Your Results: AHI Scores

The primary metric used to diagnose and classify sleep apnea severity is the Apnea-Hypopnea Index, or AHI. This number represents the average number of apnea and hypopnea events you experience per hour of sleep. Your AHI score places you into one of four categories:

• Normal: AHI below 5 — fewer than 5 breathing disruptions per hour. This is considered within the normal range, though some patients with an AHI between 1 and 5 may still benefit from treatment if they have significant symptoms.
• Mild sleep apnea: AHI 5 to 15 — 5 to 15 events per hour. Many patients with mild sleep apnea experience noticeable daytime fatigue, disruptive snoring, and reduced concentration. Oral appliance therapy is often the first-line treatment recommended for mild cases.
• Moderate sleep apnea: AHI 15 to 30 — 15 to 30 events per hour. At this level, the health risks of untreated sleep apnea become significantly more pronounced. Both CPAP therapy and oral appliance therapy are effective treatment options.
• Severe sleep apnea: AHI above 30 — more than 30 events per hour. Severe sleep apnea carries the highest cardiovascular, metabolic, and cognitive risks. CPAP is typically the primary recommendation, though oral appliance therapy may be considered for patients who cannot tolerate CPAP.

Beyond the AHI score, your sleep physician will also evaluate your lowest oxygen saturation level during sleep, the percentage of time spent below 90% oxygen, and how your breathing events correlate with body position and sleep stage. All of these factors inform the treatment plan that will work best for you.

The Role of the Dentist vs. Sleep Physician

Sleep apnea care involves a team approach, and it is important to understand the distinct but complementary roles that your sleep physician and your dentist play in the diagnostic and treatment process.

What the Sleep Physician Does

A board-certified sleep physician is the medical professional who orders and interprets your sleep study, makes the formal sleep apnea diagnosis, determines the severity of your condition, and prescribes treatment. If CPAP therapy is recommended, the sleep physician manages the prescription, equipment setup, and ongoing titration. The sleep physician is also responsible for monitoring your condition over time and ordering follow-up studies as needed.

What Dr. Chan Does as Your Dental Sleep Medicine Provider

Dr. Chan serves as your dental sleep medicine provider, working within the framework established by your sleep physician. His role includes screening for sleep apnea risk factors during your routine dental examinations — evaluating your airway, jaw position, tongue size, and soft tissue anatomy for indicators of obstruction. When sleep apnea is suspected, Dr. Chan facilitates referrals to qualified sleep physicians for testing.

Once a diagnosis is confirmed and oral appliance therapy is prescribed, Dr. Chan designs, fits, and adjusts your custom oral appliance to ensure optimal jaw positioning and airway opening. He also screens for TMJ disorders that may affect appliance selection or comfort, monitors your dental health throughout treatment, and coordinates follow-up sleep testing to verify that the appliance is effectively treating your sleep apnea.

What Happens After Diagnosis

Receiving your sleep apnea diagnosis is not the end of the process — it is the beginning of your treatment path. After your sleep physician reviews your results and confirms a diagnosis, the next steps depend on your AHI score, the type of sleep apnea, your symptoms, and your personal preferences.

For patients with mild to moderate obstructive sleep apnea, oral appliance therapy is frequently recommended as an effective and comfortable alternative to CPAP. Dr. Chan will take detailed impressions and bite records to fabricate a custom mandibular advancement device that holds your lower jaw in a slightly forward position during sleep, preventing airway collapse.

For patients with severe obstructive sleep apnea, CPAP therapy is typically the first-line recommendation. However, if you have tried CPAP and cannot tolerate it — a common challenge — Dr. Chan can work with your sleep physician to determine whether an oral appliance is an appropriate alternative. Studies show that while CPAP is more effective at reducing AHI in severe cases, oral appliances often achieve better real-world outcomes for CPAP-intolerant patients because of higher nightly compliance.

Regardless of which treatment path is chosen, follow-up testing is an essential part of the process. A repeat sleep study — typically a home sleep test — is performed after your treatment has been initiated to verify that your AHI has been reduced to a healthy range and that your oxygen levels have stabilized during sleep.

Insurance Coverage for Sleep Apnea Testing

Sleep apnea testing is a medical procedure, and most medical insurance plans provide coverage when testing is deemed medically necessary by your physician. Here is what you should know about coverage:

• Home sleep tests are generally covered with lower out-of-pocket costs because the equipment is less expensive than an in-lab facility. Many plans cover HST at 80-100% after your deductible is met.
• In-lab polysomnography is also covered by most plans, though it typically costs more and may require prior authorization. Some insurers require that a home sleep test be attempted first before approving an in-lab study.
• Referral requirements vary by plan. Most insurers require a referral from your primary care physician or sleep specialist before they will authorize a sleep study.
• Oral appliance therapy following diagnosis is often covered under medical insurance rather than dental insurance, since it is treating a medical condition. Coverage varies by plan, and our office can help verify your benefits.

Our team at Glendale Dental Wellness can help you navigate the insurance process, from obtaining the necessary referrals to verifying your coverage for both testing and treatment. We want to remove as many barriers as possible so you can get the diagnosis and care you need. Contact our office to get started.