Obstructive sleep apnea (OSA) is a condition that develops from the obstruction of the upper airway during sleep and necessitates awakening to resume breathing. Recently developed oral appliances, fabricated to maintain upper airway patency during sleep, are proven to be effective when treating patients with OSA. This article outlines the role of the dental professional in the diagnosis and treatment of OSA, including patient education on the use of oral appliances, as well as intervention strategies to prevent dental diseases from occurring during oral appliance therapy.
Obstructive sleep apnea (OSA) is
caused by reduced upper airway size and altered upper airway muscle activity,
which leads to an obstruction and cessation of breathing for longer than ten
seconds. The primary symptoms of OSA are snoring, nocturnal awakenings, failing
to feel refreshed in the morning, and feeling excessively sleepy during the
day. The patient's spouse or partner often reports apneas, choking, and gasping
for breath. In general, the patient is unaware of these events, but may
complain of dry mouth on awakening, which can be an indication of repeated
episodes of gasping and mouth breathing. The impact of OSA on daytime function
(eg, excessive daytime sleepiness, consequent increased risk of motor vehicle
accidents, and cardiovascular complications) has been associated with
morbidity. Premature mortality is also increasingly evidenced in OSA patients,
but may be a result of obesity and/or cardiovascular disease, which is often
present in these individuals. Although snoring is a key symptom of the
condition, not all snorers have OSA. Significant snoring is most prevalent in
10% to 40% of overweight, middle-aged men, and approximately half as many
women. The more common "primary snoring," however, is not accompanied
by apnea, hypoventilation, or excessive sleepiness. Snoring may also be
associated with hypertension, ischemic heart disease and stroke, although its
etiologic role in these conditions is controversial.
Diagnosis of OSA
The presence or absence of OSA
must be determined before treatment is initiated. The condition is considered
"obstructive" when there is absence of airflow despite continuing
respiratory effort; "central" when both airflow and respiratory
effort cease; and "mixed" when there is an initial period of central
apnea that becomes obstructive within the same episode (Figure 1). Documentation
of OSA identifies those patients at risk of complications of sleep apnea and
provides a baseline to evaluate the subsequent treatment. Polysomnography is
used to record EEG, EMG (of chin and legs), airflow, chest and abdominal
movement, oximetry, and EKG. The severity of OSA is categorized by the
apnea-hyponea index (ie, the frequency of apneas and hyponeas per hour of sleep
related to blood oxygen saturation during sleep), and some measure of oxygen
desaturation, such as the minimum oxygen saturation during the sleep period.
Other indices have been developed to evaluate the effect of OSA on sleepiness
and daily functions (eg, the Epworth Sleepiness Scale-a questionnaire used to
aid in evaluation of sleepiness).
Treatment of Snoring and OSA
The treatments of snoring and OSA
are directed at the upper airway and include nasal continuous positive airway
pressure (CPAP) (eg, sleeping with an oxygen mask and tank by the bedside), and
various surgeries (eg, tracheostomy, uvulopalatopharyngoplasty, [UPPP]),
reconstructive surgery of the facial skeleton, medication, and weight
reduction). Some treatments are limited by a low and unpredictable success rate
(ie, UPPP, medication, weight reduction), inconvenience (ie, tracheotomy, CPAP,
patient expense [reconstructive surgery]) and/or patient noncompliance (CPAP).
While CPAP is the most effective and widely used treatment, many patients do
not accept this solution or use it optimally.
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Types and Mechanisms of Oral Appliances
In response to the recent interest
in OSA, various types of oral appliances have been designed and investigated to
treat snoring and sleep apnea. The goal of oral appliance therapy is to modify
the position of upper airway structures to enlarge the airway or reduce its
Among the appliances
devised are mandibular-advancing devices and tongue- retaining devices (Table 1). Mandibular devices use traditional dental techniques to attach the
appliance to one or both dental arches and to advance the mandibular posture
(Figure 2). Tongue retainers are designed to keep the tongue in an anterior
position during sleep by means of negative pressure in a soft plastic bulb.
Recent research has indicated that this device shows minor success rates.
of the oral appliance requires impressions and bite registration to be
recorded, and study models and appliances to be fabricated in a dental
laboratory. A thermoplastic device is now available in a prefabricated form,
however, and can be adapted to the patient's teeth in the clinician's office
(Figure 3). Several appliances allow readjustment of the mandibular position
after initial construction, but other devices require prefabrication of the
entire apparatus. Some bi-arch appliances may restrict mouth opening by means
of clasps and elastic bands, whereas others allow relatively unhindered mouth
opening. Some designs include tubes for breathing or pressure relief.
Effectiveness of Oral Appliances
have demonstrated that snoring and OSA are reduced when oral appliance therapy
is utilized. In addition, most patients have reported an improvement in daytime
adverse effects of wearing an oral appliance include TMD and tooth discomfort,
which may be alleviated with further occlusal adjustment by a dentist.
Initially, most patients experience pain, excessive salivation, and occlusive
changes for the first month of appliance use, which may lead to a
discontinuation in therapy. Analysis
by the American Academy of Sleep Medicine has suggested
that oral appliances are a useful alternative to more aggressive approaches,
especially for patients with no medical complications linked to snoring
("simple snoring") and those with moderate OSA who cannot tolerate
nasal CPAP. Additional clinical studies are necessary, however, to better
define the efficacy of oral appliance therapy across the spectrum of OSA
Effects on the Periodontium
the oral appliance is worn for many hours each day, it seems feasible that this
type of therapy may have a deleterious effect on an individual's periodontal
health. A randomized crossover study has recently been conducted on the oral
appliance's effect on the periodontium. Over an eight-month period, the
researchers conducted an evaluation made at the baseline and following
treatment with each appliance. This study suggested that the use of oral
appliances has no effect on periodontal diseases or occlusion. Since patients
may use OSA appliances for longer periods, however, further studies are required
to determine long-term efficacy.
The Practice’s Approach to Oral
the dental hygienist is a primary provider of dental care, she or he is often
the first practitioner to discuss the patient's health history. Consequently,
the dentist and the dental hygienist should have a thorough understanding of
OSA and a predetermined protocol by which they will engage such patients. Questions
about snoring and sleeplessness can alert the hygienist and patient to the need
for assessment by a physician (Table 2). In many cases, the dental hygienist
may not gather information about OSA symptoms during a health history, but
rather during a subsequent conversation. In fact, since OSA-afflicted patients
may receive repeated hygiene care, it is possible that patients may more
readily discuss the socially embarrassing symptoms of OSA (eg, snoring and
sleeplessness) with dental hygienists, rather than with other healthcare
In addition, the dental hygienist can play an important
role in the fabrication of the oral appliance by making impressions, performing
bite registration, and pouring and trimming models during a routine dental
hygiene appointment. The dentist is then responsible for making necessary
occlusal adjustments to the oral appliance. The
most important function of the dental hygienist, however, is patient education.
Patients receiving oral appliance therapy will need customized oral hygiene
techniques designed to clean the appliance and prevent dental diseases. The
utilization of a toothbrush and nonabrasive toothpaste is recommended. The
entire appliance and any retention screws should be brushed thoroughly and
rinsed well with cool water. Although it is not necessary to store the oral
appliance in water or mouthwash, soaking solutions are currently available and
are proven to be safe and effective.
OSA is a common condition caused by reduced upper airway size and altered upper airway
muscle activity. The relationship between the dental hygienist and the patient
is crucial in the diagnostic formulation and treatment of OSA. With a thorough
understanding of this condition, the hygienist can educate the patient about
the benefits of an oral appliance and whether or not a referral is necessary.
In addition, the hygienist can instruct the patient on the proper techniques to
prevent periodontal diseases during oral appliance therapy to ensure optimal
*Associate professor; University of New Mexico. Graduate Program Director
and Clinic Manager; UNM Division of Dental Hygiene. Coordinator; UNM Division
of Dental Hygiene.
**Associate Professor and Director, Division of Dental Hygiene, University of New Mexico.
***Associate Professor of Medicine Emeritus, University of New Mexico,
Sleep Medicine Institute, Presbyterian
Hospital, Dallas, Texas,
and President, American Sleep Disorders Association.
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