ABDSM FINAL EXAM – DENTAL SLEEP MEDICINE
AMERICAN BOARD OF DENTAL SLEEP MEDICINE | 2026
CERTIFICATION
Complete Exam Preparation Material | 120 Questions with Detailed
Rationales
NB: Answers and Rationales are at the end of the Questions.
DOMAIN 1: SLEEP MEDICINE FUNDAMENTALS (Questions 1-20)
1. During a normal sleep cycle in a healthy adult, sleep architecture typically progresses from N1
to N2, then to N3, followed by REM sleep. Which of the following statements accurately
describes the distribution of N3 (slow-wave) sleep?
A. N3 sleep is predominant in the later cycles of the sleep period.
B. N3 sleep is predominant in the first third of the sleep period.
C. N3 sleep accounts for approximately 50% of total sleep time.
D. N3 sleep increases in duration as the night progresses.
2. Which neurotransmitter is primarily responsible for promoting wakefulness and is deficient in
patients with narcolepsy?
A. Gamma-aminobutyric acid (GABA).
B. Adenosine.
C. Orexin (Hypocretin).
D. Melatonin.
3. According to the AASM scoring manual, a hypopnea is scored if there is a decrease in airflow
by
,≥30%
for how many seconds?
A. 5 seconds.
B. 10 seconds.
C. 15 seconds.
D. 20 seconds.
4. [Sleep Study Interpretation] A patient undergoes a polysomnogram (PSG). The total recording
time is 420 minutes. The total sleep time is 360 minutes. The number of apneas is 120 and the
number of hypopneas is 60. What is the patient’s Apnea-Hypopnea Index (AHI)?
A. 15 events/hour.
B. 20 events/hour.
C. 30 events/hour.
D. 25 events/hour.
5. Which of the following is the primary distinguishing feature of Rapid Eye Movement (REM)
sleep?
A. High muscle tone.
B. Synchronous EEG activity.
C. Atonia of skeletal muscles.
D. Low heart rate variability.
6. Under the ICSD-3 classification, which category includes "Obstructive Sleep Apnea Adult"?
A. Central disorders of hypersomnolence.
B. Sleep-related breathing disorders.
C. Circadian rhythm sleep-wake disorders.
D. Parasomnias.
,7. What is the clinical significance of the Respiratory Disturbance Index (RDI) compared to the
Apnea-Hypopnea Index (AHI)?
A. RDI includes Respiratory Effort-Related Arousals (RERAs), while AHI does not.
B. RDI only includes obstructive events, while AHI includes central events.
C. RDI is used for pediatric patients only, while AHI is for adults.
D. There is no difference; they are interchangeable terms.
8. Which of the following is a limitation of Home Sleep Apnea Testing (HSAT) compared to in-
lab Polysomnography (PSG)?
A. HSAT overestimates the severity of OSA.
B. HSAT does not monitor EEG to determine sleep stages.
C. HSAT cannot be used for Medicare reimbursement.
D. HSAT requires a technician to be present.
9. A patient presents with excessive daytime sleepiness but denies snoring or witnessed apneas.
The sleep study reveals frequent arousals associated with increased respiratory effort, but no
significant decrease in oxygen saturation. This clinical picture is most consistent with:
A. Central Sleep Apnea.
B. Obstructive Sleep Apnea.
C. Upper Airway Resistance Syndrome (UARS).
D. Cheyne-Stokes Respiration.
10. According to AASM guidelines, what is the recommended threshold for diagnosing
Obstructive Sleep Apnea in an adult?
A. AHI
≥
5 events/hour.
B. AHI
≥
, 10 events/hour.
C. AHI
≥
15 events/hour.
D. AHI
≥
20 events/hour.
11. Which physiologic change occurs during N3 (slow-wave) sleep that differentiates it from
REM sleep?
A. Decreased blood pressure.
B. Increased cerebral blood flow.
C. Parasympathetic dominance with stable heart rate.
D. Sympathetic activation with irregular heart rate.
12. The suprachiasmatic nucleus (SCN) is responsible for:
A. Regulating the drive for sleep.
B. Generating the circadian rhythm.
C. Controlling the muscles of respiration.
D. Triggering the start of REM sleep.
13. Which of the following ICSD-3 diagnoses is characterized by a recurrent pattern of sleep
disruption due to a misalignment between the endogenous circadian rhythm and the external
environment?
A. Insomnia Disorder.
B. Circadian Rhythm Sleep-Wake Disorder.
C. Central Disorder of Hypersomnolence.
D. Sleep-Related Hypoventilation Disorder.
AMERICAN BOARD OF DENTAL SLEEP MEDICINE | 2026
CERTIFICATION
Complete Exam Preparation Material | 120 Questions with Detailed
Rationales
NB: Answers and Rationales are at the end of the Questions.
DOMAIN 1: SLEEP MEDICINE FUNDAMENTALS (Questions 1-20)
1. During a normal sleep cycle in a healthy adult, sleep architecture typically progresses from N1
to N2, then to N3, followed by REM sleep. Which of the following statements accurately
describes the distribution of N3 (slow-wave) sleep?
A. N3 sleep is predominant in the later cycles of the sleep period.
B. N3 sleep is predominant in the first third of the sleep period.
C. N3 sleep accounts for approximately 50% of total sleep time.
D. N3 sleep increases in duration as the night progresses.
2. Which neurotransmitter is primarily responsible for promoting wakefulness and is deficient in
patients with narcolepsy?
A. Gamma-aminobutyric acid (GABA).
B. Adenosine.
C. Orexin (Hypocretin).
D. Melatonin.
3. According to the AASM scoring manual, a hypopnea is scored if there is a decrease in airflow
by
,≥30%
for how many seconds?
A. 5 seconds.
B. 10 seconds.
C. 15 seconds.
D. 20 seconds.
4. [Sleep Study Interpretation] A patient undergoes a polysomnogram (PSG). The total recording
time is 420 minutes. The total sleep time is 360 minutes. The number of apneas is 120 and the
number of hypopneas is 60. What is the patient’s Apnea-Hypopnea Index (AHI)?
A. 15 events/hour.
B. 20 events/hour.
C. 30 events/hour.
D. 25 events/hour.
5. Which of the following is the primary distinguishing feature of Rapid Eye Movement (REM)
sleep?
A. High muscle tone.
B. Synchronous EEG activity.
C. Atonia of skeletal muscles.
D. Low heart rate variability.
6. Under the ICSD-3 classification, which category includes "Obstructive Sleep Apnea Adult"?
A. Central disorders of hypersomnolence.
B. Sleep-related breathing disorders.
C. Circadian rhythm sleep-wake disorders.
D. Parasomnias.
,7. What is the clinical significance of the Respiratory Disturbance Index (RDI) compared to the
Apnea-Hypopnea Index (AHI)?
A. RDI includes Respiratory Effort-Related Arousals (RERAs), while AHI does not.
B. RDI only includes obstructive events, while AHI includes central events.
C. RDI is used for pediatric patients only, while AHI is for adults.
D. There is no difference; they are interchangeable terms.
8. Which of the following is a limitation of Home Sleep Apnea Testing (HSAT) compared to in-
lab Polysomnography (PSG)?
A. HSAT overestimates the severity of OSA.
B. HSAT does not monitor EEG to determine sleep stages.
C. HSAT cannot be used for Medicare reimbursement.
D. HSAT requires a technician to be present.
9. A patient presents with excessive daytime sleepiness but denies snoring or witnessed apneas.
The sleep study reveals frequent arousals associated with increased respiratory effort, but no
significant decrease in oxygen saturation. This clinical picture is most consistent with:
A. Central Sleep Apnea.
B. Obstructive Sleep Apnea.
C. Upper Airway Resistance Syndrome (UARS).
D. Cheyne-Stokes Respiration.
10. According to AASM guidelines, what is the recommended threshold for diagnosing
Obstructive Sleep Apnea in an adult?
A. AHI
≥
5 events/hour.
B. AHI
≥
, 10 events/hour.
C. AHI
≥
15 events/hour.
D. AHI
≥
20 events/hour.
11. Which physiologic change occurs during N3 (slow-wave) sleep that differentiates it from
REM sleep?
A. Decreased blood pressure.
B. Increased cerebral blood flow.
C. Parasympathetic dominance with stable heart rate.
D. Sympathetic activation with irregular heart rate.
12. The suprachiasmatic nucleus (SCN) is responsible for:
A. Regulating the drive for sleep.
B. Generating the circadian rhythm.
C. Controlling the muscles of respiration.
D. Triggering the start of REM sleep.
13. Which of the following ICSD-3 diagnoses is characterized by a recurrent pattern of sleep
disruption due to a misalignment between the endogenous circadian rhythm and the external
environment?
A. Insomnia Disorder.
B. Circadian Rhythm Sleep-Wake Disorder.
C. Central Disorder of Hypersomnolence.
D. Sleep-Related Hypoventilation Disorder.
