According to the 2021 Oral Health Barometer, released by the Portuguese Dental Association, it is estimated that 61 % of Portuguese visit a dental doctor at least once a year for professional oral hygiene procedures or other therapies,17,25 in accordance with the published data. These conditions set dentists in an ideal position to perform OSA screening.

A medical dentist can participate in screening, treating, and managing adults with SBD7,17,18,23,26 and can provide a more streamlined and cost-effective model of care.18,23 Special training or experience is required to deliver informed care. Dentists should be educated according to the AADSM-defined requirements to be a “Qualified Dentist” in dental sleep medicine.7 AADSM advocates that dentists should have a valid state license and proof of liability coverage and possess additional training or experience in this area of care.7 Dentists should use objective data according to their scope of practice and as defined by their state dental practice acts.27

In Portugal, the competence in dental sleep medicine was framed in December 2021 in the Regulation Document for Sectorial Competences.28 However, the specific criteria to be recognized as a dentist qualified in dental sleep medicine in Portugal are not well defined yet.

When faced with a patient with snoring, the dentist must investigate whether it is isolated snoring or associated with other symptoms that suggest sleep-related respiratory pathology.19,23,29 Dentists should screen patients for SBD, starting with the partner's perception of both sleep and awake symptoms (snoring, witnessed apneas, gasping, sleepiness) and by evaluating the upper airway.23,26 Clinical history should be oriented to seek OSA risk factors, like the presence of excess weight, smoking habits, alcohol drinking history, sedative drugs, and family history of OSA.30 Finally, questionnaires should be applied like the Berlin Questionnaire, the STOP-BANG score to assess OSA probability, and the Epworth Sleepiness Scale (ESS)23 to assess daytime somnolence.19,23,26

The prevalence of OSA is higher in specific populations, namely the obese, people diagnosed with congestive heart failure, atrial fibrillation, hypertension, type 2 diabetes, pulmonary hypertension, or who had a stroke; therefore, it is fundamental to evaluate the clinical history.

There are certain professionals who, due to the nature of their work, are more at risk of the effects of OSA in sleep privation, namely people whose work involves heavy driving, like professional truck drivers, airline pilots, and heavy machinery operators.31

The qualified dentist should carry out a physical examination of the identified at-risk patients in the screening phase. Baselines should be recorded for each patient to monitor future changes. Features to be evaluated that may suggest the presence of OSA include increased neck circumference (>43 cm in men, >40 cm in women), body mass index (BMI) >30 kg/m2, a Modified Mallampati score of 3 or 4, lateral peritonsillar narrowing, macroglossia, tonsillar hypertrophy, elongated/enlarged uvula, high arched/narrow hard palate and nasal abnormalities.24 The presence of retrognathia and/or overjet should be noticed23.In some cases, the patient should be referred for an ear, nose, and throat evaluation.23 When OA can be indicated, it should be noticed that the number of teeth included in the appliance framework can compromise the retention and efficacy of the device or even the loss of teeth in the future.23 Also, the location and morphological integrity of teeth and periodontal health should be accessed to orientate OA selection. TMD and orofacial pain should be screened. Occlusal analysis and intraoral and extraoral photographs are mandatory and recommended to access any future variations. A retrognathic mandible, shorter soft palate, and low positioning of hyoid bone have all been associated with favorable outcomes. However, these associations are weak and, again, cannot be relied on for clinical decision-making.21 A cephalometric evaluation is not always required for patients who will use an OA, although it is recognized that appropriately trained professionals should perform this examination.24 This evaluation is considered as an option, and not as a guideline, for physical examination.32

SBD diagnosis should always be made in a multidisciplinary team including the qualified dentist, the sleep unit and the sleep doctor, as recommended by the international guidelines. As for screening the role of dentists, family doctors, pulmonologists and ear–nose–throat (ENT) doctors as well as others healthcare professionals that compose the multidisciplinary seep team including the qualified dentist, the sleep unit and the sleep doctor, as recommended by the international guidelines.24

Overnight polysomnography (PSG) or a home sleep apnea test (HSAT) should be prescribed, aimed at collecting objective data to determine if the patient suffers from an SBD. HSAT portable monitors may be indicated for the diagnosis of OSA in patients for whom in-laboratory PSG is not available or possible due to immobility, safety, or critical illness.32 Sleep tests can be divided into four types:32

Type 1: in laboratory full attended PSG (≥ 7 channels) in a laboratory setting

Type 2: ambulatory full unattended PSG (≥ 7 channels)

Type 3 (HSAT): limited channel devices (usually using 4–7 channels)

Type 4: 1 or 2 channels usually using oximetry as one of the parameters

A PSG (type 1 or 2) uses a 7 channel minimum recording system with an electroencephalogram (EEG), electrooculogram (EOG), chin electromyogram, airflow, oxygen saturation, respiratory effort, and electrocardiogram (ECG) or heart rate.24 A type 3 HSAT includes, at a minimum, the record of airflow, respiratory effort, and blood oxygenation. The type of biosensors used to monitor these parameters for in-laboratory PSG are also recommended to use in type 3 HSAT and include an oronasal thermal sensor to detect apnea, a nasal pressure transducer to measure hypopneas, oximetry, and, if possible, calibrated or uncalibrated inductance plethysmography for respiratory effort.24

PSG can provide the Apnea Hypopnea Index (AHI) and respiratory disturbance index (RDI). AHI can be fixed as the number of apnea and hypopneas per hour of sleep.7 RDI measures the number of apnea, hypopneas and RERA.33 The severity of OSA can be determined using the AHI: mild OSA (5≤AHI<15/h), moderate OSA (15≤AHI<30/h) and severe OSA (AHI≥30/h).24 However, other surrogate parameters like hypoxic burden, hypoxia load, obstruction severity, or phenotypes based on symptoms and comorbidities, should be considered together with AHI in the disease management and treatment decision-making processes.34,35

PSG is routinely indicated for the diagnosis of sleep disorders, while type 3 HSAT should be used as part of a comprehensive sleep evaluation in patients with a high pre-test likelihood of moderate to severe OSA. However, they are not indicated in patients with major comorbid conditions, for instance, cardiorespiratory disease, neuromuscular condition, suspected hypoventilation, chronic opioid medication use, stroke or insomnia.24 When PSG is not available or possible (immobility, safety or critical illness), HSATs can also be used for OSA diagnosis and to monitor response to non-CPAP therapies.24

Even though AASM and AMA have previously published recommendations stating that HSAT should be ordered by a physician,23,26 nowadays it is considered that the qualified dentist also has the training and education necessary to order this exam.18,36 The diagnosis of medical diseases and verification of treatment efficacy remains the responsibility of the sleep physician, as the PSG prescription.18,36

Type 4 tests are not considered a diagnostic exam for OSA.

Sleep-disordered breathing tends to get worse and not to cure spontaneously.16 The treatment option for moderate to severe symptomatic OSA (OSA syndrome) is CPAP therapy, considered the gold-standard treatment.18,37 This therapy should be used considering OSA risk factors and, therefore regarding behavioral and positional therapies.37,38

Behavioral treatment options include weight loss, ideally to a BMI of 25 kg/m2 or less; weight reduction surgery in selected cases; physical exercise; positional therapy when indicated; and avoidance of alcohol and sedatives before bedtime.24,37 The patient should be aware that weight reduction in obese patients with OSA is associated with a trend of improvement in breathing pattern, quality of sleep and daytime sleepiness, and that is recommended to reduce these important risk factors.16,24

Supine position can also affect airway size and patency with a decrease in the area of the upper airway, particularly in the lateral dimension.24 Positional therapy can be initiated by positioning devices (e.g., alarm, pillow, backpack, tennis ball) and keeping the patient in a non-supine position, with better patency, which can improve AHI.32,37

In selected adult patients, hypoglossal nerve stimulation and myofunctional therapy can be considered for specific cases seeking alternative treatments, although both constitute conditional recommendations.37

Videotapes, handouts, websites, and brochures can be used as resources for patient education.24 Medical treatment of ENT diseases with pharmacological treatment should also be considered.

For specific cases, other treatment options include surgery, such as maxillofacial surgery (maxillo-mandibular advancement) or otolaryngologic surgery.23,26,39

Treatment options should always be discussed by a multidisciplinary team including the qualified dentist, the sleep unit and the sleep doctor.24

The candidates for treatment with OA are adult patients who request treatment of primary snoring (without obstructive sleep apnea) or patients with mild to moderate OSA with no comorbidities. OA is an accepted alternative therapy for patients with severe symptomatic OSA who are intolerant to CPAP therapy or request an alternative therapy.7,19,29 In fact, adherence with OA is better in patients with OSA.20 Oral appliances reduce the AHI, the arousal index, daytime sleepiness as well as to improve quality of life measures in adult patients with OSA.3 It also improve nocturnal oxygenation (oxygen desaturation index and minimal oxygen saturation).7,20,40

Although CPAP is superior to OA in terms of normalizing respiratory parameters, AHI, oxygen desaturation index and minimal oxygen saturation37,40–42 CPAP and OA demonstrate comparable effects in symptoms and health-related quality of life measures. We found in multiple RCTs and meta-analyses similar improvements on daytime sleepiness, general physical and mental health, driving simulation assessment and nocturia.41,43–45

Younger age, lower BMI, and smaller neck circumference have been related to successful treatment, as well as the female gender. Evaluation of nasal patency and function should also be done to reduce the risk of non-responders. Low AHI indicated by PSG and position-dependent OSA have been proposed as predictors of success. As described above, other factors can favor or compromise the outcomes, namely, the number of teeth included in the appliance framework the characteristics of the mandible, the palate, and the hyoid bone, and non-anatomical traits such as a sensitive respiratory control system and a low arousal threshold.23,46,47 However, none of these factors is essential for successful treatment, which can be achieved in overweight patients and those with more severe disease.21

To orientate OA selection, the teeth location and morphological integrity should be accessed as should the periodontal health. To access any future variations, it is mandatory and recommended to perform an occlusal analysis and intraoral and extraoral photographs.

More recent research has focused on titrating mandibular advancement during sleep studies to assess the potential efficacy and determine optimal mandibular protrusion. Early prototypal studies have been promising, but these methods are resource-expensive and seem unlikely to be widely adopted.21

An effective OA should be individualized and titratable, made of biocompatible materials and engage both the maxillary and mandibular arches (Fig. 1).19,23 It should maintain a stable retentive relationship to the teeth, implants or edentulous ridge and retain the prescribed setting during use.19 The OA should allow the mandible to be advanced in increments of 1 mm or less with a protrusive adjustment range of at least 5 mm and have the possibility of reversing the advancement.19

Fig. 1.

Example of adjustable mandibular advancement devices: Narval CC device, Resmed (A); BTI DIA device (B).

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Qualified dentists with appropriate training in the field should provide the devices.18,23,26 An ideal device should have anatomical evidence that supports maintaining airway patency during sleep (Fig. 2).19

Fig. 2.

Schematic diagram of the working mechanism of a mandibular advance dispositive (MAD) (A) advancement and forward positioning of the mandible during sleep. (B) Corresponding upper airway volumes in relation to the anatomical structures without (left panel) and with (right panel) mandibular advancement.

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Studies employing sleep endoscopy enabled direct observation of a patent airway upon mandibular advancement in sleeping patients who respond favorably to oral appliance therapy.19

There are several OAs in the market, with different features, being MAD the most accepted by the scientific academies. A custom-made OA is fabricated using impressions or a scanner of mouth and bite from an individual patient's oral structures; in contrast, non-custom OAs are primarily pre-fabricated, also known as “boil and bite devices”.7 OAs can also be classified as titratable or non-titratable.7 During the titration procedure, which is only adjustable during treatment in titratable devices,7 the mandible is gradually positioned and stabilized in a more anterior position to achieve a maximum therapeutic effect on opening the upper airway.33 The concept of a custom-made MAD has evolved from the ‘mono-bloc’ type of device where upper and lower parts are rigidly connected towards the current ‘duo-bloc’ types or titratable MAD. The rigid mono-bloc MAD can restrict mandibular movements, sometimes producing discomfort, and there is evidence suggesting significant improvements with ‘dual-block’ when compared with ‘mono-block devices’, namely the possibility of titling, which is an unequivocal advantage (Fig. 3).48,49

Fig. 3.

Schematic overview of titratable, duo-bloc MAD designs used in current clinical practice: (A) MAD with an anteriorly articulating component that allows the MAD for adjustment of the appliance; (B) MAD with attachments for adjustment of mandibular protrusion in the frontal teeth area; (C) MAD with two lateral positioning attachments that permit incremental protrusion of the mandible; (D) MAD with lateral telescopic rods that force the mandible into an anterior position.

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The qualified dentist will need to determine an appropriate endpoint for the MAD advancement, usually between 50 % to 80 % of the patient's maximum protrusive range.21 A dose dependency seems to be a frequent finding in the literature, although a larger protrusion is not always associated with a corresponding reduction in AHI.33

Smaller increments of advancement can allow the evaluation of subjective parameters while minimizing potential temporomandibular discomfort.19 Progressive mandibular advancement performed during the clinical titration of the dispositive was shown to decrease AHI and oxygen desaturations,19 and the ability to titrate protrusion according to efficacy and tolerance is the key advantage of these devices.21

In the absence of an optimal titration strategy many possible titration protocols have tried to achieve this target protrusive position.33

Titration can be multiparametric, combining the evolution of subjective symptoms and objective measurements of the severity of SBD. Objective parameters can be obtained by using a single-channel measurement (generally measuring nasal airflow or oximetry) with a portable monitoring device type 4, a portable monitoring device type 3 (monitoring ventilation or airflow, heart rate or electrocardiogram and oxygen saturation), or full polysomnography (7 channel). Since no laboratory facility or night-time technician is needed, a major cost of traditional polysomnography is removed. Portable monitoring device type 3 is in general an easy and reproducible tool to assess the evolution of SBD in response to treatment.33

There is no consensus in the literature regarding the definition of a successful treatment outcome, or which combination of objective and subjective criteria should be used to determine if a titration protocol is successful or not.33 For patients with OSA, the desired outcome of treatment includes the resolution of the clinical signs and symptoms of OSA, and the normalization of the apnea-hypopnea index and oxyhemoglobin saturation.29

Considering the vertical adjustability of MAD, several studies suggested that increased vertical dimension decreased patient acceptance and had no consistent impact on efficacy.19 In the absence of valid research data, one should keep the vertical opening and dimension to a minimum during the gradual titration of the mandibular protrusion.10

Outcome indicators to monitor therapy include evaluation of the resolution of sleepiness, patient quality of life and satisfaction assessment, adherence evaluation, and evaluation of presence of protective and absence of worsening risk factors.18

As titrating MAD during sleep studies is expensive,21 titration is still determined with “trial and error”.33 This reinforces the importance of a final sleep test equal to the initial diagnosis (always interpreted by the sleep physician), to allow comparison with baseline indicators.18,36 Some authors support that a type 3 test, including polysomnography or an attended cardiorespiratory sleep study, should be performed to ensure satisfactory therapeutic benefit from OAs, with the oral appliance in place after final adjustments of fit are made.18,29 If the treatment is sub-therapeutic, the physician and dentist should collaborate to discuss calibration or other treatment possibilities - for instance, combining CPAP therapy with the treatment with OA.50

An annual follow-up performed by the sleep specialist is required regarding sleep apnea treatment, i.e. suppression of breathing disturbances and improvement of quality of life. The sleep specialist should regularly evaluate the breathing disturbances with PSG and HSAT. Additionally, regular evaluation of the dental and oral cavity situation should be performed by the dentist.37

Those on chronic therapy (CPAP, OA, positional therapy) should have regular follow-ups, and those with the elimination of OSA (weight loss, surgery) should be monitored for continued risk factor modification and to look for the eventual return of symptoms.24

Follow-up protocol after the final calibration should include a patient evaluation every six months for the first year and at least annually thereafter.50 Patients diagnosed with primary snoring may be treated without objective follow-up data; however, they should be re-evaluated at least annually.50 Follow-up sleep testing is not indicated for patients with primary snoring.29

Besides evaluating patients’ requirements for treatment with oral appliances, the qualified dentist should also proceed with the necessary follow-ups.17If the patient's annual assessment reveals symptoms of worsening OSA or the potential need for additional adjustments to the device, the dentist shall communicate this information to the patient's physician.50

Most complications of MAD therapy are mild and temporary. Short-term side effects of OAs utilization in the stomatognathic system usually occur during the adaptation period in the first few weeks of therapy. They can include hypersalivation, dry mouth, damage to teeth or restorations, dental pain, gingival irritation, myofascial pain and TMD discomfort.21,23

Adherence to OAs declines over time, mostly due to appliance intolerance and TMD issues.29 TMD disorders can be a true obstacle to using these appliances, although they are usually transient, and any pain appears to decrease in intensity with continued use.21 During the patient adaptation, mandibular exercises may improve discomfort and allow continuity of treatment; this can be softened with a physiotherapy professional.21

Long-term dental side effects are also identifiable, namely decreases in overbite and overjet, proclination of the lower incisors, retroclination of upper incisors and occlusal alterations in posterior teeth.21 Appropriate planning and monitoring may avoid these dental effects, and the benefits are assumed to compensate for the inconvenient effects.21 Additionally, bite changes can influence the maintenance or alteration on the degree of advancement of the device and this situation should be controlled in patients’ follow-ups.51

If the device is lost or broken, a new comprehensive evaluation should be completed to enable replacement.23 In case of relapse or worsening of initial signs and symptoms, weight gain and changes in overall health, the patient should also be examined by a qualified dentist.

Fig. 4 presents a proposed flowchart of OSA screening, treatment, and follow-up between multidisciplinary teams.

Fig. 4.

Flowchart between multidisciplinary teams.

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Bidirectional referral patterns are recognized, with the qualified dentist referring to the physician and the physician referring to the qualified dentist, always sharing relevant clinical information.18,23,26

The dentist must have a role in screening patients with snoring or OSA and establishing diagnosis together with a sleep physician.17,18 The main purpose of SBD risk patient management protocols is to establish the communication flow between the multidisciplinary team; qualified dentists should screen sleep apnea but diagnosis and treatment efficacy should be verified by physicians, even when the screening, the OA selection and the positioning and consequent follow-ups are made by the qualified dentist.18