How Orofacial Myofunctional Therapy Can Aid in the Treatment of Sleep-Disordered Breathing

There has been an increasing number of studies looking at orofacial myofunctional therapy (OMT) as a promising adjunctive treatment for obstructive sleep apnea (OSA).1 OMT essentially helps the patient to retrain the muscles around the face, mouth, and tongue to establish correct oral rest posture and functioning of the oral facial system.

OMT—comprised of isometric and isotonic exercises targeted at impacting the lip, tongue, soft palate, and lateral pharyngeal wall regions—is shown to improve the severity of the apnea-hypopnea index.2 The literature demonstrates that OMT alone decreases AHI in OSA patients by approximately 50% in adults and 62% in children.1 Current literature suggests that adding OMT to nearly any treatment approach, including positive airway pressure therapy, oral appliance therapy, surgical techniques, orthodontic treatment, and hypoglossal nerve stimulation has the potential to make that treatment approach even more effective.3-11

OMT has also been proven to assist with residual symptoms of SDB, including reducing or eliminating snoring frequency and intensity, reducing daytime sleepiness, improving sleep quality, increasing oxygenation during sleep, increasing continuous positive airway pressure (CPAP) compliance, assisting with oral appliance therapy, reducing bruxism, eliminating jaw and facial pain, and improving overall quality of life. OMT has also been shown to reduce or eliminate the chances relapse of OSA during the teenage years in children who were once considered cured post adenotonsillectomy and orthodontic expansion.1,11-13 Research suggests that given that these exercises are noninvasive with no side effects, myofunctional therapy represents a promising future treatment direction for OSA.14

This article will provide a broad overview of OMT, explore the relationship between oral-facial soft tissue dysfunction and the evolution of airway problems, and highlight how incorporating OMT can aid in the treatment and even prevention of airway-related sleep issues.

What Is Orofacial Myofunctional Therapy?

When defining OMT, it is helpful to break down the word into its components: orofacial meaning “of or affecting both the face and mouth” and myofunctional meaning “the study of the structure and function of the muscles.” In this case, function refers to the way the oral and facial muscles work for chewing, swallowing, speech, and the resting posture when these muscles are not engaged in movement. Therefore, OMT involves treating any dysfunction of the oral and facial muscles that impact their resting position and their functioning.

There is no cookie-cutter approach to OMT. It involves designing an individualized therapeutic program that first begins with a detailed evaluation of oral muscular dysfunction (OMD) that may be contributing to problems in the oral cavity. A specially trained orofacial myofunctional therapist assesses all oral structures and functions. They look for any issues that may lead to incorrect oral rest posture of the lips, tongue, and jaw positioning at rest or during functioning, such as chewing foods, swallowing foods, liquids, and saliva, and even speaking (if the therapist is a speech-language pathologist).

After a thorough evaluation of the orofacial myofunctional system, the therapist can pinpoint exercises and various techniques to help resolve any oral soft tissue problems that may be contributing to such issues. The treatment strategies they employ may include stretching, strengthening, improving range of motion, and guiding proper chewing and swallowing. In addition, the therapist helps to address other elements that may impact such oral muscular problems though teaching proper nasal hygiene, recommending sleep and body posture strategies, providing tips for sleep hygiene, and encouraging patients to address allergies and any other related medical or dental components, to name a few. Referrals to other specialists are often an important part of the treatment program.

The orofacial myofunctional therapist also works with the patient to eliminate any unhealthy oral habits that may contribute to oral problems, such as sucking habits, chewing/biting/licking habits, and bruxism (clenching or grinding of the teeth). Evidence has shown that prolonged non-nutritive sucking and chewing may be a sign of airway obstruction and/or tongue tie, so the orofacial myofunctional therapist takes this into account in the treatment of such parafunctional oral habits.15

The Importance of Good Oral Rest Posture

The clinical significance of correct oral rest posture is important to highlight, as the way the lips, tongue, and jaws rest will impact the growth of the face and ultimately, the airway when the person is awake and during sleep.

Breathing through the nose with the tongue gently suctioned to the palate has been proven to be the healthiest way for humans to breathe, as there are countless benefits to nasal breathing on facial growth, oxygen utilization, and overall health.

Correct oral rest posture includes the following components:
• the lips resting closed and completely sealed.
• the entire body of the tongue resting gently suctioned to the palate, with the sides of the tongue resting within the dental arch and not spreading across the occlusal surface of the teeth.
• the teeth being slightly apart, allowing for adequate oral cavity space to better house the tongue.

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The Visible and Clinical Impact of Early-Intervention OMT

 

Figure 1. At age 2.5, this child displayed mouth breathing, snoring, sucking habits, restricted lingual frenum, restricted maxillary frenum, drooling, low oral muscle tone, and feeding challenges. An evaluation by a speech-language pathologist trained in the early-intervention age group (under age 3) with a specialty in oral-sensory motor, feeding issues, and skills in orofacial myofunctional disorders was warranted. It is best to evaluate and treat muscle dysfunction at the first sign of dysfunction, as such issues are progressive and will typically result in more complex problems if left untreated. The signs of disorder were there, and signs typically occur before more severe symptoms are noticed.

Figure 2. By the age of 7, this child was able to grow with nice facial balance, correct oral rest posture, and resolve his SDB issues. These successful outcomes were the result of addressing the early oral muscular problems with oral sensory motor and feeding therapy (to train oral reflexes and good feeding skills), and then initiating a standard myofunctional therapy program around age 4 after the child had established baseline foundational oral motor skills.

 

 

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This correct oral rest posture—which is a goal of OMT—is shown to directly assist in better dental and facial development, as the tongue and lips are natural growth supports for proper arch development.16-18

Lip seal is extremely important from a sleep-airway perspective. When the lips open or are even just slightly apart, the tongue typically cannot remain suctioned to the palate, and it will drop low in the oral cavity. The tongue has enough weight to vertically drop the mandible and cause the lips to open further. This bidirectional relationship of lip and tongue posture cannot be overemphasized.

When the tongue rests gently suctioned to the palate, this helps with the stability of the lower jaw, especially when the person is sleeping. Good muscle tonicity and a more stable lower jaw will help to prevent the tongue from falling back and reducing the airway size, which can contribute to airway obstruction during sleep.

All skeletal muscles maintain some tone in the body, even when the muscles are not in active use during function. This passive tone of the muscles is referred to as the “resting tone” of the muscle, and can help maintain a position of the muscle without conscious effort.19 Resting muscular tone is important when considering the relationship between the oral facial muscles and SDB.

Because the upper airway lacks rigid bony support, it is susceptible to collapse due to pressure from the surrounding soft tissues that may occur during SDB. It is the upper airway dilator muscles affecting the tongue, soft palate, hyoid, and pharyngeal walls that are responsible for maintaining upper airway patency during wakefulness and sleep. These muscles drop in tone during sleep, and in susceptible individuals, this muscular hypotonia (low muscle tone and strength) can contribute to various forms of SDB.

Myofunctional therapy helps to reposition the tongue, improve nasal breathing, and increase muscle tone in pediatric and adult OSA patients.11 When the muscles of the tongue and lips are able to maintain the proper tone to hold the correct resting posture during sleep, it helps to decrease the risk of airway collapse.

An Overview of the Spectrum of OMDs

It is important to understand what a disorder of the oral facial myofunctional system is and why such issues may occur. An orofacial myofunctional disorder (OMD) entails any of the following, and, in most cases, these problems are not isolated but occur in combination:

1. Any divergence in correct oral rest posture of the lips, tongue, and/or jaw.
• Some individuals may rest with their lips open or slightly parted. This may be referred to as “open mouth posture” or “open mouth breathing” or even “mouth breathing.” When the lips are open, it has been revealed that airflow is never fully going through the nose, even if the person is not a complete “mouth breather.”
• Some individuals may rest with the tongue low, forward, or spreading at the sides of the mouth.
• Some individuals may rest with the upper and lower jaws together in a clenched position, or, on the contrary, rest with the jaws too far apart.

2. A thrusting of the tongue during chewing and swallowing or speech.
• Some people may function (chew, swallow, and/or speak) with the tongue pushing with force on or between the teeth in the front or at the side(s).

3. Noxious or parafunctional oral habits (e.g. digit sucking, tongue sucking, cheek biting, nail biting, lip licking, prolonged pacifier use, or bruxism, to name a few).

• Such oral habits may be a response to airway obstruction and/or tongue tie and may also play a role in continued muscle dysfunction and poor oral facial growth patterns.

In OMT, the primary importance is to identify the multifactorial causes and contributing factors to the OMD before determining the treatment plan to remediate such issues. All of the factors that are capable of causing or contributing to the soft tissue dysfunction must be assessed, and often this includes problems that span across the medical system, the dental system, and the myofunctional system.

Medical system
Illness, problems in the nose or sinuses, hypertrophied tonsils or adenoids, tethered frenums, enlarged nasal turbinates due to allergies, mouth breathing, deviated septum, nasal valve collapse, nasal polyps, mucus/congestion, recurrent upper respiratory illness, asthma, tongue or lip tie, etc.

Dental system
Issues with tongue placement (such as if the palate is too narrow for the tongue to rest suctioned to it, palatal appliances that may block the tongue, or a palatal torus that is too large to allow the tongue to stay suctioned upwards) or dental or orthodontic appliances that may impact proper lip and tongue placement, to name a few.

Myofunctional system
Any soft tissue or muscular dysfunction, such as problems with the lips (low muscle tone, lip incompetence where the mentalis/chin overworks to close the lips, short upper lip, and everted lower lip); tongue rest posture and tone; chewing dysfunction; swallowing patterns such as a thrusting motion; or oral habits.

A Potential Clinical Marker of SDB
Why is a knowledge of OMDs important in sleep medicine? One of the primary goals of this article series is to increase awareness and promote understanding of the concept that an OMD may be a clinical marker of SDB.2

In many cases, SDB and clinical markers for poor orofacial growth may begin in childhood and go undetected. In addition to a low arousal threshold and high loop gain, the etiology of SDB can include soft tissue and muscular components that have resulted in deficient jaw growth, reduced space for the tongue, and poor airway functioning during sleep.20In a 2022 article in International Anesthesiology Clinics, the authors suggest that “everyone with OSA has a degree of impaired pharyngeal anatomy.”21

A persistent and common problem in the treatment of SDB is hypotonia of the orofacial muscular complex and mouth breathing.20 The literature suggests that orofacial myofunctional disorders coexist in a large proportion of people with SDB and OSA.20 In fact, it has been hypothesized that most SDB cases are comorbid with an OMD, and the OMD may even be a causal factor to the onset of the anatomical and functional problems related to the collapse of the airway during sleep.21

Because of the negative short and long-term health consequences of SDB, treatment should, of course, be initiated as early as possible. Thus, OMT is an important and often necessary component in the treatment of SDB, and early identification and treatment of OMDs is paramount to successful outcomes.

A Team Effort
It’s clear that one practitioner does not hold all of the answers to the complicated series of problems that underlie the multifactorial issues with sleep and airway problems. A collaborative approach to assessing and treating patients with SDB is of utmost importance to the success of any treatment plan.

Orofacial myofunctional therapists refer patients to a variety of specialists to help assess and treat problems in any of the systems, including otolaryngologists, allergists, sleep physicians, and airway-focused dentists or orthodontists. These specialists assist in the comprehensive treatment plan to resolve such dysfunction and the sequelae of effects that such soft tissue problems can trigger.

Many referrals to orofacial myofunctional therapists from dentists, orthodontists, and other specialists will also benefit from a referral to a sleep physician to investigate SDB, as most patients with OMDs also have SDB. Because the type of oral facial soft tissue dysfunction that encompasses OMD also contributes to anatomical factors consistent with SDB (such as underdeveloped jaws), it is imperative to understand that OMDs can increase the upper airway’s collapsibility—not just due to poor muscle tone and function, but also due to the poor growth of the airway that results from such muscular dysfunction in early childhood.

Similarly, patients who are seeing a sleep physician for sleep-related breathing issues, such as snoring, upper airway resistance syndrome, or complete OSA will most likely benefit from evaluation and as-needed treatment from an orofacial myologist.

Many dentists, orthodontists, sleep specialists, otolaryngologists, and allergy doctors have found that having an orofacial myofunctional therapist on the multidisciplinary team treating SDB is an invaluable and often essential component to resolving such airway-related issues, and hopefully this collaboration will continue to grow.

Sidebar

A Brief History of the Origins of OMT

As a treatment modality, orofacial myofunctional therapy (OMT) has been in use for well over a century. Initially, OMT was developed by orthodontists as a way to assist in orthodontic outcomes.

In 1907, Edward Angle, DDS, also known as the father of American orthodontics, first published an article in which he recognized that mouth breathing and poor resting posture of the tongue can play a primary role in hindering orthodontic outcomes.²² In 1918, Alfred Rogers, DDS further advanced the field by acknowledging the role of soft tissue dysfunction on the oral skeletal system, and he developed exercises for the orofacial musculature intended to stimulate desirable growth in the maxillofacial region.²³ This was the beginning of OMT—with the primary intention to improve orthodontic outcomes, orthodontic stability, and to help achieve facial balance and better growth and development of the oral structures.

The work of Dr. Rogers over 100 years ago lay the foundation for OMT and the concept that muscular functioning has an impact on oral facial growth, development, and overall whole-body health. It is now well established that the oral and facial muscles play an imperative role in the growth of the craniofacial respiratory complex and can directly impact the development and functioning of the airway.

The field of OMT today has come a long way from its beginning. It has advanced with a variety of programs training speech-language pathologists (SLPs), registered dental hygienists (RDH), and even some physical therapists (PTs) and occupational therapists (OTs) to perform this specialized treatment modality. An orofacial myofunctional therapist is not a separate profession or licensure, but rather a health care professional who has chosen to utilize this method of treatment and obtain specialized training to provide it.

 

Nicole Goldfarb, MA, CCC-SLP, COM® has been practicing speech-language pathology and orofacial myofunctional therapy for over 20 years. She presents internationally on orofacial myofunctional therapy as it relates to sleep-disordered breathing in both children and adults, has written articles and authored chapters in medical textbooks on this topic, is on faculty for a variety of speech pathology, sleep medicine, and dental organizations, and she also hosts an airway podcast.

 

References
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