Examination for Dental Sleep Medicine

Abstract

The dentist is looked upon as a vital player in oral conditions and diseases in patient’s well-being. Many times, they are the frontline in identifying potential patients with some form of systemic disease. When adequately trained, dentists can treat those who have been diagnosed with obstructive sleep apnea (OSA) using a dental sleep appliance (DSA) also known as an oral appliance. The term DSA is used because it is worn in the mouth during sleep to maintain a patent oropharyngeal airway to manage OSA and/or snoring, whereas in the field of dentistry, the term oral appliance is generic for many kinds of appliances.

Practicing dentists with some knowledge of sleep disorders are just as likely to recognize potential patients who may have a sleep disorder. Physicians are properly trained to evaluate for a sleep disorder or to obtain a sleep history; the possibility of uncovering a sleep disorder has been shown to be more likely. The same applies to a dentist and hygienist who sees patients on a regular basis. This chapter will cover how to do a dental sleep examination and documentation.

1 Introduction

The dentist is looked upon as a vital player in oral conditions and diseases in patients well-being. Many times they are the frontline in identifying potential patients with some form of systemic disease. The dentist and hygienist are well-positioned in the screening and recognition of potential health-related conditions, including sleep disorders, and then to inform the patient of the possible presence of the condition and direct the patient accordingly. When adequately trained, they can treat those who have been diagnosed with obstructive sleep apnea (OSA) using a dental sleep appliance (DSA) also known as an oral appliance. The term DSA is used because it is worn in the mouth during sleep to maintain a patent oropharyngeal airway to manage OSA and/or snoring, whereas in the field of dentistry, the term oral appliance is generic for many kinds of appliances. The increased awareness of sleep disorders in dentistry is acknowledged by the increasing numbers of articles related to sleep disorders that appear in publications for the dental profession and its related specialties. The same can be said for the dentist who sees patients on a regular basis.

According to American Dental Association statistics, there are just over 181,700 professionally active dentists in the USA (annual survey ADA) and approximately 300,000 US dental patient visits per year [1], seeing patients on a routine, rather than a medical crisis basis. This is an ideal environment to apply sleep-related breathing disorders (SRBD) and wellness screening to large numbers of the population, possibly catching many before serious medical consequences are manifested. In one study, it was found that 75.5% of responding US dental schools reported some teaching time in sleep disorder in their predoctoral dental program [2]. The average number of educational hours was 3.92 h for the schools with curriculum time. The most frequently covered topics included sleep-related breathing disorders (32 schools) and sleep bruxism (31 schools). Although 3.92 h is an improvement from the mean 2.5 h last reported [3], the absolute number of curriculum hours given the epidemic scope of sleep problems still appears insufficient in most schools to achieve any competency in screening for SRBD or sufficient foundation for future involvement in treatment.

Practicing dentists with some knowledge of sleep disorders are just as likely to recognize potential patients who may have a sleep disorder. The average dentist along with the dental hygienist may see just as many patients on a daily basis as a family practitioner or an internist. Physicians are properly trained to evaluate for a sleep disorder or to obtain a sleep history; the possibility of uncovering a sleep disorder has been shown to be more likely [4]. The same applies to a dentist and hygienist who sees patients on a regular basis.

2 Medical History

Vitals should be recorded for the patients. This should include blood pressure, pulse, weight, height, and neck circumference. Body mass index (BMI) should be calculated using height and weight. The association between obesity and SDB is substantial, with high BMI contributing to moderate to severe SRBD in 58% of affected persons [5]. Also note that around 50% of patients with the sleep apnea/hypopnea syndrome are not obese: BMI < 30 kg/m² [6]. Cross-sectional observation studies have shown a prevalence of arterial hypertension in subjects with OSA ranging from 35 to 80% [7]. When focusing on hypertensive patients, however, OSA prevalence has been reported to be around 40%, increasing to nearly 90% in patients with resistant hypertension [8]. Measurement of neck circumference has become a standard part of physical examination of patients suspected of having sleep apnea [9]. Neck circumference is reflective of parapharyngeal fat deposits. A short and fat neck in patients with sleep apnea, both men and women, is a very characteristic sign of this disease [10].

In addition, a review of the patient’s health history should be completed. OSA brings many adverse consequences, such as hypertension, obesity, diabetes mellitus, cardiac and encephalic alterations, and behavioral alterations, among others. A study of 100 patients with OSA (84 men and 16 women) with a mean age of 50.05 years (range 19–75 years) found prevalence of comorbidities, which were hypertension (39%), obesity (34%), depression (19%), gastroesophageal reflux disease also known as GERD (18%), diabetes mellitus (15%), hypercholesterolemia (10%), asthma (4%), and no comorbidities (33%) that were present. Comorbidities occurred in 56.2% patients diagnosed with mild OSA, 67.6% of patients with moderate OSA, and 70% of patients with severe OSA [11].

3 Dental History

During a consultation, the treating dentist should obtain information from the patient to see whether he/she will be a good candidate for dental sleep appliance therapy (DSAT) also known as oral appliance therapy. Information obtained by the dentist or dental team should be the following:

• 1. When was the last dental examination and if dental treatment was necessary?

• 2. Is the patient aware of any soreness when eating, tooth sensitivity (what area?), jaw joint noise (present or past), gingival bleeding, jaw locking/limited opening, sensitive gag reflex, and facial pain?

• 3. Is the patient aware of parafunctional activity such as clenching, grinding, cheek biting, tongue biting, or biting on objects?

• 4. Is the patient aware of breathing from their mouth, nasal obstructions, and waking up with a dry mouth?

• 5. What position does the patient prefer to sleep, on their back, side, stomach, not sure, or all positions?

4 Screening

First step for the dental team is to be able to screen for a sleep breathing disorder. This can be achieved with the utilization of a very basic and simple questionnaire to an existing health questionnaire. These questions may not only uncover an individual who is at risk for snoring or having OSA, but they may also assist in the identification of someone who has been previously diagnosed with SRBD.

Some basic questions that the dentist may include in the initial patient history questionnaire are the following

• 1. Do you have difficulty falling asleep or staying asleep?

• 2. Do you or have you been told you snore when sleeping?

• 3. Are you frequently tired during the day?

• 4. Are you aware or have you been told that you stop breathing during sleep?

• 5. Is your sleep unrefreshing?

• 6. Are you drowsy when driving?

• 7. Do you fall asleep in inappropriate situations such as meetings, at movies, at church, or in social situations?

• 8. Do you have headaches in the morning?

If the response to these questions is positive, then additional questioning should be implemented. This will allow a more comprehensive understanding of any potential sleep disorders that may be present.

In the adult population, the Epworth Sleepiness Scale (ESS), Berlin, and STOP-BANG questionnaires are examples of questionnaires that collectively focus on subjective and objective criteria and are valuable tools for the initial screening process. The EES questioner (Fig. 8.1) identifies patients who are experiencing symptoms related to daytime sleepiness, which may suggest the risk for OSA [12]. The scored result of the ESS is a common means of communication within the sleep medicine field regarding the risk of OSA. If the total approaches 9, the risk of OSA increases. Note that an elevated score is not always definitive for OSA and is not necessarily indicative of its severity. Excessive daytime sleepiness can also be caused by other medical conditions (cancer, Parkinson’s disease, anemia), mental health (depression), certain medications (antihistamines, antidepressants), and drug and alcohol use. The Berlin questionnaire includes a question on hypertension, which is of value when correlated with the number of medications for hypertension [13].

Fig. 8.1

Epworth sleepiness scale (ESS). (Adapted from [12])

Another simple questionnaire is based on four questions represented by the acronym STOP (Fig. 8.2). Positive response to two or more of the questions represents an increased risk for sleep apnea. An expanded version of the four questions to eight is represented by the acronym STOP-BANG. The use of these eight questions has been shown to be predictive of sleep apnea. A score between 3 and 5 increased the probability of identifying a potential sleep apnea patient. If the score was greater than 5, then the patient had a larger risk for having moderate/severe sleep apnea [14, 15].

Fig. 8.2

STOP-BANG questionnaire. (Adapted from [14])

The Berlin questionnaire (Fig. 8.3) incorporates questions about snoring (category 1), daytime somnolence (category 2), and hypertension and BMI (category 3) which provide a summary score that correlates with a high likelihood of a sleep-disordered breathing condition. Clinicians should not exclude patients on the basis of a low score on a questionnaire. The physical examination may show structural evidence for airway obstruction.

Fig. 8.3

Berlin questionnaire. (Adapted from [13])

Reviewing the health history and gathering information from the ESS, Berlin, and/or STOP-BANG questionnaire, a detailed clinical examination should be performed to identify the potential risk of sleep apnea. Recognizing clinical findings which will be detailed later in the chapter, dentists and dental hygienists may not connect their findings with the risk for SRBD due to inadequate training or awareness. Understanding these clinical findings should lead to a more detailed discussion about a potential SRBD with your patient. At that point, a referral should be made to a sleep physician for the diagnosis of your clinical suspicion of SRBD.

Other common sleep disorders may be uncovered by the dentist, such as those patients who present with orofacial pain or complaints of headaches and who may be at risk for insomnia. Dentists often treat patients for sleep bruxism using splints. The presence of bruxism may be indicative of an increased risk for restless legs syndrome [16].

5 Radiographic Evaluation

There needs to be radiographic imaging and evaluation of all dentition to rule out any dental pathology, as the DSA will be fitting onto the teeth and using the teeth as an anchor to provide a patent oropharyngeal airway. There should be at least eight teeth per arch for the DSA to anchor on. With a minimum of eight teeth per arch, the DSA can be fabricated like a partial denture. Otherwise, the DSA can be fabricated like a full upper and lower denture, but these authors do not recommend it due to a high failure rate based on our experience. Fabricating a DSA will place too much pressure on the gingival tissues that may cause pain.

6 Nasal Evaluation

The nose produces two-thirds of total airway resistance [17]. Any reductions in nasal cross-sectional area by allergic, infectious, or chronic nonallergic (idiopathic) rhinitis or mechanical obstruction predispose to upper airway collapse by amplifying the pressure differential between the atmosphere and the thoracic cavity [18]. Nighttime nasal congestion was associated with a 1.8 odds ratio for an AHI greater than five versus no congestion [19].

When looking at the nares (nostrils), note the size of the passage (small, medium, large). Also, ask the patients if they have a hard time breathing through their nose and if they have any nasal obstructions. Have the patients close one naris at a time and breathe. If they have any obstructions, you can perform the Cottle’s maneuver. This maneuver is a test where one or two fingers are placed on the cheek next to the nose, and gentle pressure is placed by pulling the tissue laterally. It is used to determine if there is nasal obstruction at the nasal valve or deeper inside the nose.

7 Evaluation of the Temporomandibular Joint

To evaluate the temporomandibular joint (TMJ) effectively, one must have a sound understanding of the anatomy in the region. The TMJs are examined for any joint sounds, joint tenderness or pain, and any dysfunction with mandibular movement. The fingertips are placed over the lateral aspects of both joints simultaneously. If you are uncertain about finger placement, you may ask the patient to open and close a few times to determine position. Once the position of the fingertip over the lateral pole has been verified, medial force is applied to the joint area (Fig. 8.4a). Each side may be evaluated independently to allow the patient to react more appropriately to the pressure being applied. The patient’s response to pain is placed in one of four categories (Table 8.1). The patient is asked to report any pain experienced and recorded on your examination form, which will assist in diagnosis and later in the evaluation and assessment of progress. Once recorded, have the patient open maximally, and the fingers should then be rotated slightly posteriorly to apply force to the posterior (dorsal) aspect of the condyle (Fig. 8.4b). Pain felt on the lateral aspect of the condyle would suggest capsulitis, and the palpation posterior to the condyle would suggest retrodiscitis.

Fig. 8.4

Finger placement for a TMJ evaluation. (a) Lateral pole palpation. (b) Posterior joint space

Table 8.1 Pain rating

Furthermore, joint loading manipulations can be used during the examination process to get additional information regarding inflammation. As the examiner is facing the patient, have the patient open his/her mouth slightly and relax the jaw. The examiner can place his or her right thumb on the occlusal surface or the patient’s left lower molars while placing the fingers under the ramus. As the jaw is relaxed, the examiner will push the jaw back toward the skull to see if the patient complains of tenderness or pain on the dorsal aspect of the condyle. Then, while the jaw is relaxed, push the jaw upward to load the superior aspect of the joint to check for inflammation (Fig. 8.5). With the left hand, the examiner can load the patient’s right joint to check for inflammation on that side.

Fig. 8.5

Finger placement for joint loading of left TMJ

7.1 Joint Sounds

These are either a click or crepitation sound that is heard and at times felt on your fingertips as the patient opens and closes their jaw (Fig. 8.6). A click is considered as a single sound of short duration and often loud. Sometimes this is referred to as a “pop” by patients. Crepitation is a multiple gravel-like sounds heard on opening and closing. This sound is commonly associated with osteoarthritic changes of the articular surface of the joint which can also be verified by imaging of the joints. A stethoscope or a joint sound recording device can be utilized in the evaluation for joint sounds. Clinicians should appreciate that these methods are more sensitive and will detect many more sounds than mere palpation.

Fig. 8.6

Evaluation of joint sounds. (a) Finger placement over lateral pole. (b) Have the patient open and close multiple times

It is not wise to examine the joint for sounds by placing the fingers in the patient’s ears. It has been shown that this method can actually produce joint sounds that are not present during normal function of the joint [20]. The presence of joint sounds gives some level of insight regarding disk position. One needs to be aware that the absence of sounds does not always mean normal disk position. Asking the patient on any past history of joint sound that may have resulted in a period of limited opening should be noted.

7.2 Jaw Movement

Normal range of mouth opening when measured interincisally is considered greater than 40 mm [21]. Being less than 40 mm of mouth opening seems to represent a reasonable point at which to designate restriction, but one should always take into consideration the patient’s age and face type (brachiocephalic, mesocephalic, and dolichocephalic). When factoring interincisal opening, the overbite should be taken into consideration (Fig. 8.4a). For example, if the interincisal opening is 36 mm, however the patient’s overbite is 6 mm, then the opening should be recorded as 42 mm. If the overbite is not taken into consideration, then the previous example may suggest limited opening.

When observing vertical opening, the patient should be observed for deviation or deflection. Deviation is defined as a discursive movement of the mandible that ends in the centered position. This is usually due to disk derangement in one or both joints and is a result of condylar movement that is necessary to get past the disc during translation. Once this is achieved, the straight midline path is resumed. Deflection is an eccentric displacement of the mandible on opening away from a centered midline path without correction to midline on full opening. This is typically due to restricted movement in one joint. Lateral and protrusive movements need to be observed and recorded as well.

Deflection with limited opening can also indicate muscle spasm. This can be checked by doing an end-feel stretch. For example, if a patient has a limited interincisal opening, with a deflection to one side, by placing your thumb against the upper incisors and index finger against the lower incisors, gently try to stretch the jaw open. If the range of motion increases, this indicates muscle spasm.

When documenting jaw movements, one should document protrusive and lateral movements also (Fig. 8.7b–d). The protrusive movement is measured by adding the overjet to the millimeters the patient advances the mandibular teeth past the upper incisors. For example, if there is 3 mm of overjet and the patient can advance the mandibular incisors 7 mm past the maxillary incisors, that patient has a 10 mm of protrusion. This is great information to have, in order to know how much the oral appliance can be titrated. It is acceptable that greater than 7 mm in lateral and 6 mm protrusive movements are considered normal [21].

Fig. 8.7

Range of motion measurements. (a) Maximum opening, (b) protrusive movement, (c) right lateral movement, and (d) left lateral movement

Lateral excursions can be measured looking at how the patient’s upper and lower midlines correlate when biting in centric occlusion, and then have the patients move their jaw as far as they can to one side and then to the other side. This information is good to have, indicating whether there is stiffness or laxity of the opposing joint. For example, if the jaw moves 4 mm to the right and 14 mm to the left, this indicates stiffness of the left TMJ and laxity of the right TMJ.

A simple, quick method of assessing normal mandibular motion during mouth opening is by the ability to position three fingers in the mouth during dental examination. Using this method, clinicians may be able to more accurately distinguish “normal” from “restricted” mouth opening (Fig. 8.8) [22]. Opening to lateral movement ratio in a healthy TMJ is generally 4.4:1 [23].

Fig. 8.8

Mouth opening

8 Muscle Examination

Generally pain is not associated with normal function or palpation of a healthy muscle. Mechanisms behind masticatory muscle pain include overuse of a normally perfused muscle or ischemia of a normally working muscle, sympathetic reflexes that produce changes in vascular supply and muscle tone, and changes in psychological and emotional states [24]. Palpation of the muscle is performed by the palmar surface of the index finger. Soft but firm pressure is applied to the designated muscle with a single firm thrust of 1–2 s. The patient is then asked to report any pain experienced (Table 8.1) and recorded on your examination form which will assist in diagnosis and later in the evaluation and assessment of progress.

A muscle examination should identify not only general tenderness and pain but also any localized firm hypersensitive bands of the muscle tissue (trigger points) indicative of myofascial pain. To locate these bands, the examiner must palpate the entire body of the muscle. In myofascial pain when these trigger points are palpated, there is a pattern of pain referral. Pressure should be applied to the trigger point for 4–5 s and the patient is then asked if the pain is felt locally or radiated in any direction.

Muscles that should be considered for examination are all those that are responsible for supporting and functioning with the mandible. They include temporalis (anterior, middle, and posterior fibers), masseter (deep and superficial fibers), anterior and posterior digastric, lateral pterygoid, and sternocleidomastoid. Having a baseline on the health of the muscles is important, because these muscles may become painful if an oral appliance is used in the future. See Fig. 8.9 for finger placement for the muscles mentioned above. Functional manipulation method needs to be utilized when examining the lateral pterygoid muscle because it is nearly impossible to palpate it intraorally. This examination is performed by having the patient protrude the mandible against resistance provided by the examiner or by having them open against resistance (Fig. 8.10).

Fig. 8.9

Finger placement for muscle palpation. (a) Anterior temporalis, (b) middle temporalis, (c) posterior temporalis, (d) superficial masseter, (e) deep masseter, (f) anterior digastric, (g) posterior digastric, and (h) sternocleidomastoid

Fig. 8.10

Hand position for provocation of the lateral pterygoid muscle. (a) Protrude against resistance, and (b) open against resistance

9 Intraoral Examination

9.1 Tongue Assessment

This includes observation for tongue scalloping on the lateral borders, size, coated, redness, fissured, geographic, and ankyloglossia (tongue-tie). A Mallampati scoring assesses tongue position relative to the soft palate as well as visualization of the oropharynx [25,26,27]. To determine the score, the mouth is held open with the tongue at a rest position (referred to as Friedman tongue position) as compared to the version utilized by the anesthesiologist where the tongue is protruded (referred to as Mallampati classification). In either case, the position is graded from I to IV (Fig. 8.11, Table 8.2). It has been shown that as the degree of obstruction of the oropharyngeal airway and the soft palate increases, the risk for OSA also increases. For each one-point increase in the Mallampati score, odds of having OSA were more than twice likely, and the apnea-hypopnea index (AHI) may increase more than five events per hour (Table 8.3).

Fig. 8.11

Mallampati classification

Table 8.2 Difference between Mallampati classification and Friedman tongue position (adapted Mallampati index)

Table 8.3 Mallampati score on OSA and AHI [26]

9.2 Tonsil Assessment

Upper airway obstruction due to enlarged tonsils results in limited airflow. Such limitation is caused by a mechanical blockage that obstructs airflow, leading to mouth breathing.

Tonsils were classified by degree according to hypertrophy as follows: grade I, tonsils inside the tonsillar fossa lateral to posterior pillars; grade II, tonsils occupying 25% of oropharynx; grade III, tonsils occupying 50% of oropharynx; grade IV, tonsils occupying 75% or more of the oropharynx, almost meeting in the midline; and grade 0, previous tonsillectomy (Fig. 8.12).

Fig. 8.12

Tonsil grades

9.3 Tori

The size and appearance of mandibular tori vary considerably, ranging from small knobs to bulky protuberances with a smooth surface or with bony projections. A torus may appear in single, multiple, or fused form.

9.4 Nasal Evaluation

When evaluating the nose, observe if the alar rims collapse during forced inspiration through the nose. Inspect the nose from the front and side and stand behind the patient; note the presence of humps, broadness, unusual length, drooping tip, nostril size, scars, pits, or any deviation in the nasal bones or cartilage (this is best done by standing behind the patient with his/her head tilted slightly back) (Fig. 8.13). The nasal valve is the narrowest segment of the nasal cavity and plays an essential role in breathing. The Cottle’s maneuver is a test in which the cheek on the side to be evaluated is gently pulled laterally with one to two fingers to open the valve. This test is used to determine if the most significant site of nasal obstruction is at the valve or farther inside the nasal cavity. If results are positive, then some type of nasal airway dilator may be helpful (see adjunct therapies in Chap. 12).

Fig. 8.13

Nasal passages. Left figure arrow points to turbinate. Middle figure a deviated columella and depression of the ala. Right figure demonstrates collapsed nasal passage collapse and deviated septum

9.5 Airway Evaluation

The following should comprise the oral airway evaluation:

Mallampati

• Grade 1.

• Grade II.

• Grade III.

• Grade IV.

Tongue

• Coated.

• Scalloped.

• Enlarged.

• Fissured.

• Geographic.

• Ankyloglossia (tongue-tie).

• Tongue posture above occlusal plane.

• Retracts into airway on opening.

• Protrusion on opening.

Uvula

• Normal.

• Swollen (see Fig. 8.14).

• Elongated.

• Obstructs airway.

• Absent.

Soft palate

• Firm.

• Loss of tone.

• Appears to obstruct the airway.

• Swollen.

Gag reflex

• Absent.

• Diminished.

• Exaggerated.

• Normal.

Tonsils

• Grade 0.

• Grade 1.

• Grade 2.

• Grade 3.

• Grade 4.

Fig. 8.14

Swollen and elongated uvula

9.6 Dentition

It is important to examine and document the patient’s current health status. Components of documentation for the dental and supporting structures include the following:

• Dental caries.

• Loose teeth.

• Periodontal health (includes periodontal probing).

• Dental classification of occlusion (I, II, Div 1, Div 2, III).

• Crossbite.

• Wear facets.

• Abfraction.

• Erosions.

• Tori (mandibular or palatal).

• Narrow maxilla or mandible.

• Exostosis (maxilla/mandibular).

• Vaulted palate.

• Mandibular midline position (dental or frenum).

• Gingival recession.

• Missing teeth.

• Teeth needing to be restored.

• Dental implants.

• Overbite.

• Overjet.

• Relation of dental midlines.

• Protrusive movement.

• Lateral movements.

Examination Form