by DeWitt C. Wilkerson, DMD

In October 2017, the American Dental Association (ADA) released a policy statement addressing dentistry’s role in sleep-related breathing disorders.¹ The policy encourages dental professionals to screen their patients for Obstructive Sleep Apnea (OSA), Upper Airway Resistance Syndrome (UARS), and other breathing disorders. The ADA advocates working in collaboration with other trained medical colleagues and emphasizes the effectiveness of intra-oral appliance therapy for treating patients with mild to moderate OSA and CPAP-intolerant patients with severe OSA.

With the endorsement of the ADA, screening and treating sleep-related breathing disorders has become the newest focus of integrative dental medicine. The purpose of this article is to provide a simplified Checklist to guide the dental team in reviewing each patient’s:

• History (signs & symptoms)
• Clinical Evaluation
• Screening & Testing

History (signs & symptoms)

1. MOUTHBREATHER – +

Are you aware being a mouth breather?

Mouth breathing is considered dysfunctional breathing, because it bypasses the critical physiologic benefits of nasal breathing.² Through the nose, air is humidified, warmed, sterilized/anti-microbial effect of nitric oxide produced in the para-nasal sinuses, and the breathing rate is controlled to help maintain an optimum carbon dioxide-oxygen ratio in the bloodstream (Bohr Effect). Mouth breathing eliminates the possibility of ideal physiologic breathing, allowing “dirty air” containing microbes, pollutants, pesticides, smog, allergens, pollen, and spores, to name a few, to pass through the mouth straight to the lymphoid tissues of the adenoids and tonsils. This can result in both inflammation and infection in the posterior throat.

2. SNORE – +

Are you aware of snoring in your sleep?

Snoring is a sign of airway blockage as the tissues of the soft palate vibrate against the posterior wall of the pharynx. This can be accompanied by the tongue dropping back as well. Approximately one in three snorers also suffers from obstructive sleep apnea.

3. SLEEP APNEA – +

Have you been diagnosed with Sleep Apnea or been observed to stop breathing in your sleep?

Obstructive Sleep Apnea is a very serious breathing disorder that has significant systemic effects due to mechanical collapse of the posterior throat airway. An apneic event occurs when breathing ceases for 10 seconds or longer accompanied by drops in oxygen saturation in the bloodstream. During sleep, multiple events in intervals of several minutes or longer can mimic the experience of choking and stimulate activation of the Sympathetic Nervous System, “Fight or Flight” response. Stress hormones, including Cortisol, are released into the bloodstream, producing an acute excitation of the heart rate. The increase in blood flow is an attempt to deliver needed oxygen throughout the body. Chronic elevated cortisol levels in the blood can produce several deleterious effects including increased blood pressure, cardiac arrhythmia, insulin resistance, and leptin/ghrelin imbalance. An increased hunger drive can be stimulated by imbalances between leptin and ghrelin.

Central Sleep Apnea (CSA) is a CNS disorder in which the respiratory center in the brain fails to transmit a signal to the body to inhale. CSA frequently occurs among people who are seriously ill from other causes: chronic heart failure, diseases of and injuries to the breathing control centers in the brainstem, Parkinson’s disease, stroke, kidney failure, and even severe arthritis with degenerative changes to the cervical spine and base of the skull. It is seen among users of opiates. Idiopathic CSA is a description used when the cause is unknown.

Mixed Apnea describes the simultaneous occurrence of both OSA and CSA.

4. POOR SLEEP QUALITY – +

Do you sleep poorly or wake up during the night?

Breathing disorders during sleep disrupt the normal sleep pattern. Stimulation of the Sympathetic “Fight or Flight” response to decreased oxygen levels, the release of steroid hormone Cortisol from the Adrenal glands, and increases in heart rate are all involved in producing arousals from deeper to lighter sleep levels or even waking up. Frequent urination at night is a common side effect.

5. DAYTIME SLEEPINESS – +

Do you feel tired and sleepy during the day?

Failure to spend adequate time in deeper sleep stages produces non-restorative sleep and its consequences: daytime fatigue and sleepiness.

6. NASAL CONGESTION – +

Do you experience frequent nasal congestion or difficulty breathing through your nose?

Nasal congestion due to allergies from food or environment, nasal stenosis, deviated septum, nasal polyps, turbinate enlargement, and/or acute and chronic sinusitis, will affect breathing and often cause a conversion to dysfunctional mouth breathing. Eustachian tube blockage can produce a fullness feeling in the ears.

7. FORWARD HEAD POSTURE – +

Does your neck bother you and do you find yourself in a forward head posture?

“Mouth-breathing Syndrome” is characterized by significant nasal obstruction, whereby an effort to overcome this resistance increases the work of accessory muscles of inspiration. Furthermore, forward head posture, common among mouth breathers, facilitates the air to enter the mouth which can lead to a deterioration of the pulmonary function. Chronically, the hyperactivity of the neck muscles may be associated with cervical changes that, as a result, can influence temporomandibular disorders (TMD) and spine cervical disorders.³

8. TONGUE-TIE – +

Do you have a tongue-tie or any tongue restrictions affecting sucking, swallowing or speech?

A short lingual frenulum has been associated with difficulties in sucking, swallowing and speech. The oral dysfunction induced by a short lingual frenulum can lead to oral facial dysmorphosis, decreasing the size of upper airway support. Progressive change increases the risk of upper airway collapsibility during sleep.⁴

9. CHRONIC COUGH – +

Do you have a chronic cough, sore throat, or difficulty swallowing?

Chronic cough and similar throat issues are highly correlated with Sleep Apnea and Gastroesophageal Reflux Disease (GERD), which often occur together. It’s reported that 80% of the 60 million Americans who’ve been diagnosed with GERD report worse symptoms at night, and 3 in 4 wake up routinely from sleep.

10. DEVIATED SEPTUM – +

Are you aware of having a deviated septum or nasal deformity or damage?

A deviated septum can be present from birth, be the result of poor maxillary development, or can occur after injury. It can contribute to difficulty breathing through the nose, nasal congestion, recurrent sinus infections, nosebleeds, difficulty sleeping, snoring, sleep apnea, headaches and post-nasal drip.

Clinical Evaluation

1. NECK CIRCUMFERENCE > 16” Women, > 17” Men
It has been demonstrated, through several studies, that enlarged necks are associated with increased soft tissue volume in the throat area.⁵ Neck size can be associated with being overweight, same as waist size.

2. MALLAMPATI > 2

The Mallampati Score⁶ comprises a visual assessment of the distance from the tongue base to the roof of the mouth, and therefore the amount of space for an adequate airway. The score is assessed by asking the patient, in a sitting posture, to open the mouth and protrude the tongue as much as possible, rating in 4 classes.

• Class 1: Soft palate, uvula, fauces, pillars visible.
• Class 2: Soft palate, uvula, fauces visible.
• Class 3: Soft palate, base of uvula visible.
• Class 4: Only hard palate visible.

A higher Mallampati score is a predictor for risk of OSA and can be a helpful screening tool during the clinical examination. However, its role in predicting severity of OSA remains doubtful and needs further study.⁷ It should be noted that some individuals with a Mallampati 1 or 2 may have serious airway compromise.

3. SCALLOPED TONGUE
The presence of tongue scalloping has shown a high correlation for abnormal AHI, and nocturnal desaturation. The presence and severity of tongue scalloping has shown a positive correlation with increasing Mallampati. In high-risk patients, tongue scalloping has been found to be predictive of sleep pathology. Tongue scalloping is a useful clinical indicator.⁸

4. 40% TONGUE RESTRICTION (Tongue-tie)
A normal range of free tongue movement is greater than 16 mm.⁹ Ankyloglossia can be classified into 4 classes based on Kotlow’s assessment(10) as follows;

• Class I: Mild ankyloglossia: 12 to 16 mm,
• Class II: Moderate ankyloglossia: 8 to 11 mm,
• Class III: Severe ankyloglossia: 3 to 7 mm,
• Class IV: Complete ankyloglossia: Less than 3 mm.

Class III and IV tongue-tie category should be given special consideration because they severely restrict the tongue’s movement. Restrictions include limitations of movement protrusively, laterally and vertically.

One screening evaluation involves:

1. Have the patient open their mouth as wide as possible. Normal maximum opening is 40-50 mm.
2. While maximally open, raise the tip of the tongue, attempting to touch the incisive papilla behind the upper central incisors. Successful touching represents “normal” tongue mobility. Tongue restrictions can be visualized as a percentage of movement from rest to full extension towards the incisive papillae. 40% restriction or greater often has significant clinical implications.

5. NASAL STENOSIS
A simple observation can be made by having the patient breathe in and out through the nose. Does the nostril on one or both sides collapse during nasal breathing? This provides a visible indicator of nasal airway collapse or obstruction. It would be common that these patients struggle with upper airway resistance and default to mouth breathing.

6. SKELETAL PROFILE
Maxillary and/or mandibular skeletal underdevelopment can compromise airway volume.¹¹ Arnett’s True Vertical¹² is a useful assessment for mandibular retrusion, maxillary retrusion, and bimaxillary (maxillo-mandibular) retrusion, by observing the patient’s profile, facing to the right.

A line dropped vertically down from the nose-lip intersection (SN) relates ideally to the fully developed lower face when:

Upper Lip = 2-5 mm in front of the line

Lower Lip = 0-3 mm in front of the line

Chin Point = -4-0 mm behind the line.

Measurements less than these ranges can implicate craniofacial, mid-face underdevelopment, with increased risk for airway compromise.

Screening & Testing

Screening: High Resolution Pulse Oximetry (HRPO)
Overnight HRPO monitors two significant factors that relate to healthy or dysfunctional breathing.

1. SO2 – Oxygen saturation is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal blood oxygen levels in humans are considered 95–100 percent. If the level is below 90 percent, it is considered low (hypoxemia). Blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart. Continued low oxygen levels may lead to respiratory or cardiac arrest.¹³
2. Pulse Rate – During non-REM sleep, the pulse rate tends to slow down 14-24 beats per minute, compared with wakefulness. The average heart rate range during all 3 stages of non-REM sleep is between 60-100. Some individuals may have a normally slower or faster heart rate range. Non-REM represents roughly 75-80% of time asleep. REM sleep includes periods of dreaming and increased heart rate, with more variability. REM is often concentrated in the last few hours of sleep. HRPO can screen for disordered breathing during sleep by observing the recorded “Delta” of both SO2 and Pulse Rate. Delta involves the difference between high and low values. Large swings in both SO2 and Pulse Rate over short intervals, on multiple occasions throughout sleep, may indicate a breathing disorder. Precise interpretation is often difficult.¹⁴

Testing: Home Sleep Testing (HST)
Home sleep testing has become a standard for evaluation and diagnosis of sleep disorders in recent years. Though less information is gathered relative to polysomnography (PSG) studies, the accuracy appears comparable¹⁵. Most home testing recorders can track time of the test period, but not sleep time, which requires EEG signals. They also gather data about oximetry, pulse rate, sleep position, apnea & hypopnea episodes, snoring, and chest effort. The reports include an AHI. A new term, REI, or Respiratory Event Index, has been adopted by the American Academy of Sleep Medicine to designate results from testing when true sleep time is not measured. There is a lot of other data on even a ‘simple’ test that provides insight to the patient’s sleep.

Note: Dentists are not qualified or licensed to interpret sleep apnea. HST should be interpreted by a Board Certified Sleep Physician. Many HST manufacturers provide an interpretation service. Dentists are the ideal health professionals to screen patients and gather studies for potential airway disorders. When HST reveals significant signs of breathing dysfunction and elevated AHI, referral for an overnight laboratory PSG will analyze important additional information such as EEG and CSA. The results may significantly altar the treatment plan.

Dr. Tom Colquitt, Past President of the American Academy of Restorative Dentistry (AARD), addressed the 2016 session of that Academy with the following critical statement: “Other than emergency care, the first procedure performed by every dentist, for every patient, of any age should be a proper airway examination and evaluation of breathing function.”

Airway and breathing disorders are becoming an increasing area of emphasis in Dentistry.

Form follows function.

Properly functioning nasal breathing, tongue posture, and swallowing patterns greatly influence a properly formed dental occlusion. On the contrary, dysfunctional mouth breathing, tongue posture, and swallowing patterns greatly influence an improperly formed dental malocclusion. This may include TMD symptoms, clenching, bruxism, tooth abrasion and erosion, headaches, GERD and broad systemic effects.

Brent Bauer M.D., Internist and Editorial Board member for the Mayo Clinic Health Letter wrote an article entitled, Buzzed on Inflammation.¹⁶ “Inflammation is the new medical buzzword. It seems as though everyone is talking about it, especially the fact that inflammation appears to play a role in many chronic diseases.” One of the most important sources of systemic inflammation is related to breathing dysfunction. For example, OSA may activate the sympathetic/adrenomedullary and the hypothalamic-pituitary-adrenal (HPA) axis limbs of the neurologic stress system.¹⁷ Nocturnal micro-arousals and awakenings are associated with chronic cortisol release. Over days, months and years this can influence a number of inflammatory related problems including insulin resistance and diabetes; dysregulation of the hunger hormones, leptin and ghrelin, leading to weight gain and obesity, and OSA directly affects the vascular endothelium by promoting inflammation and oxidative stress while decreasing NO availability and repair capacity.¹⁸

The demands of clinical practice are ever-increasing. Dentists must be aware of more health concerns every day. Patients are asking about airway because they read about health effects of sleep related breathing disorders and look to their trusted dentist for direction. You can be ready to help them by using the provided Checklist to identify airway and breathing related disorders in your dental practice.