ABDSM FINAL EXAM DENTAL SLEEP MEDICINE Actual
Exam Practice Questions with Verified Solutions & Detailed
Rationales Newest Update 2026/2027 | Graded A+ | 100%
Guaranteed Pass American Board of Dental Sleep Medicine
(ABDSM) Certification Prep | Instant Download PDF
Q1. Which of the following best defines the apnea-hypopnea index (AHI) used to
classify obstructive sleep apnea severity?
A) The number of apneas plus hypopneas per hour of recording
B) The number of apneas plus hypopneas per hour of sleep
C) The number of apneas per hour of sleep
D) The number of oxygen desaturations per hour of sleep
Rationale: The AHI is the average number of apneas and hypopneas per hour of
sleep, as measured by polysomnography (PSG) or home sleep testing (HST). It is
the primary metric for diagnosing and classifying OSA severity: mild (5-14.9),
moderate (15-29.9), and severe (≥ 30). Recording time may include wake periods;
sleep time is more accurate. The oxygen desaturation index (ODI) is a separate
measure.
Q2. According to AASM guidelines, which additional parameter must be met to
diagnose OSA when AHI is in the mild range (5-14.9) on a technically adequate
study?
A) Presence of witnessed apneas
B) Oxygen desaturation index (ODI) ≥ 10
C) Excessive daytime sleepiness or relevant comorbidities (e.g., hypertension,
atrial fibrillation, type 2 diabetes)
D) AHI on HST must be confirmed by PSG
Rationale: For mild OSA (AHI 5-14.9), the diagnosis requires the presence of
symptoms (e.g., excessive daytime sleepiness, unrefreshing sleep, fatigue,
insomnia) or associated medical comorbidities (hypertension, atrial fibrillation,
type 2 diabetes, stroke, coronary artery disease). This is per AASM diagnostic
criteria to avoid overdiagnosis of asymptomatic patients.
,Q3. What is the recommended minimum number of hours of sleep required for a
diagnostic PSG to be considered technically adequate?
A) 4 hours
B) 6 hours
C) 8 hours
D) 2 hours
Rationale: A technically adequate PSG should have at least 6 hours of recorded
sleep to provide representative data. AASM guidelines recommend a minimum of
6 hours of quality sleep recording for accurate AHI calculation.
Q4. A 52-year-old female with a BMI of 28, neck circumference of 38 cm, and
ESS score of 12 undergoes a HSAT showing AHI 8. How should this result be
interpreted?
A) Normal study; no diagnosis
B) Mild OSA with symptoms and/or comorbidities
C) Moderate OSA
D) Severe OSA
Rationale: With an AHI of 8 (mild range, 5-14.9) and an ESS score of 12
(indicating excessive daytime sleepiness), the patient meets criteria for mild OSA
with symptoms. The American Academy of Sleep Medicine (AASM) criteria
require symptoms or comorbidities for the diagnosis of mild OSA.
Q5. Which sleep stage is typically associated with the most severe obstructive
respiratory events in OSA patients?
A) NREM Stage 1
B) NREM Stage 2
C) REM sleep
D) NREM Stage 3 (slow-wave sleep)
Rationale: REM sleep is associated with more severe and frequent obstructive
respiratory events in OSA patients due to muscle atonia (reduced tone of the upper
airway dilator muscles) and REM-specific changes in ventilatory control. The
,respiratory events are often longer and associated with more significant oxygen
desaturation.
Q6. What is the primary physiologic mechanism responsible for the pharyngeal
airway collapse in obstructive sleep apnea?
A) Reduced central respiratory drive
B) Decreased lung volume
C) Increased pharyngeal collapsibility due to negative pressure and
neuromuscular factors
D) Obesity-related reduction in functional residual capacity
Rationale: Pharyngeal airway collapse in OSA results primarily from increased
collapsibility of the upper airway. This occurs due to a combination of structural
factors (narrowed airway, obesity), functional factors (reduced pharyngeal dilator
muscle activity), and intraluminal negative pressure during inspiration.
Q7. According to the ICSD-3, which of the following is NOT a criterion for the
diagnosis of obstructive sleep apnea?
A) AHI ≥ 5 events per hour with symptoms (sleepiness, unrefreshing sleep,
snoring, observed apnea)
B) AHI ≥ 15 events per hour regardless of symptoms
C) Respiratory effort-related arousals (RERAs) ≥ 5 per hour
D) Oxygen desaturation < 80% on any event
Rationale: Oxygen desaturation < 80% is not a required diagnostic criterion for
OSA diagnosis. It is a severity indicator but not part of the ICSD-3 diagnostic
criteria. The criteria include AHI ≥ 5 with symptoms or comorbidities, or AHI ≥ 15
regardless of symptoms.
Q8. What is the normal percentage of REM sleep in a healthy adult?
A) 5-10%
B) 20-25%
C) 30-35%
D) 40-50%
, Rationale: In healthy adults, REM sleep typically occupies 20-25% of total sleep
time. REM sleep usually occurs in 4-5 cycles, beginning about 90 minutes after
sleep onset, with increasing duration throughout the night.
Q9. Which of the following is a characteristic finding on PSG in a patient with
obstructive sleep apnea?
A) Normal sleep architecture with preserved slow-wave sleep
B) Fragmented sleep with increased Stage N1 and decreased Stage N3
C) Increased REM latency
D) Normal arousal index
Rationale: OSA patients typically show fragmented sleep architecture, with
increased Stage N1 (light sleep) and decreased Stage N3 (deep slow-wave sleep)
and REM sleep. The arousal index is elevated due to repeated respiratory event-
related arousals.
Q10. A patient with an AHI of 25 would be classified as having what severity of
OSA?
A) Normal
B) Mild OSA
C) Moderate OSA
D) Severe OSA
Rationale: Moderate OSA is defined as an AHI of 15-29.9 events per hour. Severe
OSA is ≥ 30, mild is 5-14.9, and normal is < 5. An AHI of 25 falls in the moderate
range.
Q11. What is the definition of a hypopnea according to AASM scoring rules?
A) ≥ 30% reduction in airflow with ≥ 3% oxygen desaturation or an arousal
B) ≥ 50% reduction in airflow with ≥ 4% oxygen desaturation
C) ≥ 90% reduction in airflow for ≥ 10 seconds
D) Any reduction in airflow for ≥ 10 seconds
Exam Practice Questions with Verified Solutions & Detailed
Rationales Newest Update 2026/2027 | Graded A+ | 100%
Guaranteed Pass American Board of Dental Sleep Medicine
(ABDSM) Certification Prep | Instant Download PDF
Q1. Which of the following best defines the apnea-hypopnea index (AHI) used to
classify obstructive sleep apnea severity?
A) The number of apneas plus hypopneas per hour of recording
B) The number of apneas plus hypopneas per hour of sleep
C) The number of apneas per hour of sleep
D) The number of oxygen desaturations per hour of sleep
Rationale: The AHI is the average number of apneas and hypopneas per hour of
sleep, as measured by polysomnography (PSG) or home sleep testing (HST). It is
the primary metric for diagnosing and classifying OSA severity: mild (5-14.9),
moderate (15-29.9), and severe (≥ 30). Recording time may include wake periods;
sleep time is more accurate. The oxygen desaturation index (ODI) is a separate
measure.
Q2. According to AASM guidelines, which additional parameter must be met to
diagnose OSA when AHI is in the mild range (5-14.9) on a technically adequate
study?
A) Presence of witnessed apneas
B) Oxygen desaturation index (ODI) ≥ 10
C) Excessive daytime sleepiness or relevant comorbidities (e.g., hypertension,
atrial fibrillation, type 2 diabetes)
D) AHI on HST must be confirmed by PSG
Rationale: For mild OSA (AHI 5-14.9), the diagnosis requires the presence of
symptoms (e.g., excessive daytime sleepiness, unrefreshing sleep, fatigue,
insomnia) or associated medical comorbidities (hypertension, atrial fibrillation,
type 2 diabetes, stroke, coronary artery disease). This is per AASM diagnostic
criteria to avoid overdiagnosis of asymptomatic patients.
,Q3. What is the recommended minimum number of hours of sleep required for a
diagnostic PSG to be considered technically adequate?
A) 4 hours
B) 6 hours
C) 8 hours
D) 2 hours
Rationale: A technically adequate PSG should have at least 6 hours of recorded
sleep to provide representative data. AASM guidelines recommend a minimum of
6 hours of quality sleep recording for accurate AHI calculation.
Q4. A 52-year-old female with a BMI of 28, neck circumference of 38 cm, and
ESS score of 12 undergoes a HSAT showing AHI 8. How should this result be
interpreted?
A) Normal study; no diagnosis
B) Mild OSA with symptoms and/or comorbidities
C) Moderate OSA
D) Severe OSA
Rationale: With an AHI of 8 (mild range, 5-14.9) and an ESS score of 12
(indicating excessive daytime sleepiness), the patient meets criteria for mild OSA
with symptoms. The American Academy of Sleep Medicine (AASM) criteria
require symptoms or comorbidities for the diagnosis of mild OSA.
Q5. Which sleep stage is typically associated with the most severe obstructive
respiratory events in OSA patients?
A) NREM Stage 1
B) NREM Stage 2
C) REM sleep
D) NREM Stage 3 (slow-wave sleep)
Rationale: REM sleep is associated with more severe and frequent obstructive
respiratory events in OSA patients due to muscle atonia (reduced tone of the upper
airway dilator muscles) and REM-specific changes in ventilatory control. The
,respiratory events are often longer and associated with more significant oxygen
desaturation.
Q6. What is the primary physiologic mechanism responsible for the pharyngeal
airway collapse in obstructive sleep apnea?
A) Reduced central respiratory drive
B) Decreased lung volume
C) Increased pharyngeal collapsibility due to negative pressure and
neuromuscular factors
D) Obesity-related reduction in functional residual capacity
Rationale: Pharyngeal airway collapse in OSA results primarily from increased
collapsibility of the upper airway. This occurs due to a combination of structural
factors (narrowed airway, obesity), functional factors (reduced pharyngeal dilator
muscle activity), and intraluminal negative pressure during inspiration.
Q7. According to the ICSD-3, which of the following is NOT a criterion for the
diagnosis of obstructive sleep apnea?
A) AHI ≥ 5 events per hour with symptoms (sleepiness, unrefreshing sleep,
snoring, observed apnea)
B) AHI ≥ 15 events per hour regardless of symptoms
C) Respiratory effort-related arousals (RERAs) ≥ 5 per hour
D) Oxygen desaturation < 80% on any event
Rationale: Oxygen desaturation < 80% is not a required diagnostic criterion for
OSA diagnosis. It is a severity indicator but not part of the ICSD-3 diagnostic
criteria. The criteria include AHI ≥ 5 with symptoms or comorbidities, or AHI ≥ 15
regardless of symptoms.
Q8. What is the normal percentage of REM sleep in a healthy adult?
A) 5-10%
B) 20-25%
C) 30-35%
D) 40-50%
, Rationale: In healthy adults, REM sleep typically occupies 20-25% of total sleep
time. REM sleep usually occurs in 4-5 cycles, beginning about 90 minutes after
sleep onset, with increasing duration throughout the night.
Q9. Which of the following is a characteristic finding on PSG in a patient with
obstructive sleep apnea?
A) Normal sleep architecture with preserved slow-wave sleep
B) Fragmented sleep with increased Stage N1 and decreased Stage N3
C) Increased REM latency
D) Normal arousal index
Rationale: OSA patients typically show fragmented sleep architecture, with
increased Stage N1 (light sleep) and decreased Stage N3 (deep slow-wave sleep)
and REM sleep. The arousal index is elevated due to repeated respiratory event-
related arousals.
Q10. A patient with an AHI of 25 would be classified as having what severity of
OSA?
A) Normal
B) Mild OSA
C) Moderate OSA
D) Severe OSA
Rationale: Moderate OSA is defined as an AHI of 15-29.9 events per hour. Severe
OSA is ≥ 30, mild is 5-14.9, and normal is < 5. An AHI of 25 falls in the moderate
range.
Q11. What is the definition of a hypopnea according to AASM scoring rules?
A) ≥ 30% reduction in airflow with ≥ 3% oxygen desaturation or an arousal
B) ≥ 50% reduction in airflow with ≥ 4% oxygen desaturation
C) ≥ 90% reduction in airflow for ≥ 10 seconds
D) Any reduction in airflow for ≥ 10 seconds
