OMDOROFACIAL MYOFUNCTIONAL DISORDERS: Assessment, Prevention and Treatment

By Licia Coceani Paskay, MS, CCC-SLP, COM

identified in older children, orthodontist might be frustrated by rofacial Myofunctional teenagers and adults, a multidisci- an unstable occlusion, stubborn Disorders (OMDs) are plinary approach of their treatment anterior open bites or unexpected disorders pertaining to would ensure the best care results, treatment relapses. The natural the face and mouth and by involving the orthodontist, the bridge is Orofacial Myology or the Omay affect, directly and indirectly, orofacial myologist, the dental study of orofacial myofunctional chewing1, swallowing2, 3, speech4, 5, 6, hygienist and other professionals disorders and its application, orofa- occlusion7, 8, 9, 10, temporomandibu- cial myofunctional therapy, which lar joint movement11, 12, oral such as ear-nose-throat specialists, has been around in various forms hygiene13, 14, stability of orthodontic allergists and osteopathic physi- for many decades. 15, 16, 8, 17 18, 9 cians to name a few. treatment , facial esthetics , What are OMDs? The most 19, 20 With the unprecedented expan- and facial skeletal growth . common are: Orofacial Myofunctional Disorders sion of medical knowledge and the may have an impact on treatment need to become highly specialized, b Oral breathing or lack of habit- by orthodontists, dentists, dental medical and health professionals ual nasal breathing; are often unaware of the contribu- hygienists, speech-language pathol- b Habitual open mouth posture tions offered by another disciplines ogists and other professionals work- and lack of lip seal with patent in the treatment of patients with ing in the same anatomical and nasal passages; physiological area. multiple disorders. For instance, a Most OMDs can be easily speech pathologist might find it b Reduced upper lip movement, assessed by dentists and orthodon- difficult to address the correction of with or without a restricted tists and, in many cases, they can certain speech sounds like /s, z/ or labial frenum; be prevented, especially in young /ch, j, sh/ when the child has no b Restricted lingual frenum, from children with deciduous dentition habitual nasal breathing, no lip borderline to ankyloglossia; still in place, thus promoting a competence, has an excessive ante- more harmonious growth of the rior overjet or wears a bulky oral b Anterior or lateral tongue thrust orofacial complex. When OMDs are appliance. Conversely, an at rest (static posture); 34 March/April 2012 JAOS b Low and forward tongue posi- the air are lost in oral breathing. Although orthodontists or tion at rest, usually accompanied Nasal breathing is positively corre- dentists can easily identify hyper- by an increased vertical dimen- lated to lip seal, the appropriate trophic or enflamed tonsils sion; development of the orofacial struc- restricting the airways, an ENT is tures21, 22, 23, 24 and a correct tongue the proper professional to evalu- b Inefficient chewing related (or position20. Nasal breathing also ate and manage the oral airways. not) to temporomandibular joint contributes to a more desirable Hypertrophic tonsils may drasti- (TMJ) disorders or malocclusion; facial outlook9. Even a cursory visit cally reduce the posterior oral to any art or history museum can b Atypical swallowing, with or space, therefore affecting breath- attest that through history people without a tongue thrust ing and promoting the anterior have been represented in classic (dynamic posture); position of the tongue at rest paintings or statues with a proper (“tongue thrust”), which is often b Oral habits, like excessive or lip seal at rest. related to malocclusion26, 27. non-age appropriate sucking Nasal patency can be easily (bottles, sippy cups, pacifiers, the assess by the following: tongue, fingers or clothes), Rosenthal Test: The patients biting (lips, the tongue, cheek, are asked to close their mouth fingernails, cuticles or pens) and and breath nasally for one chewing (gum or gummy minute (or 20 breaths), if the candies); nose is patent the task should be easily accomplished. b Oro-facial habits like touching Gudin Test: The examiner one’s face, mouthing of fingers pinches the patients’ nose for or objects, licking lips or leaning one second and then lets go of on one’s hand; one nostril at the time, observ- b Forward position of the head at ing whether or not there is a rest, during chewing and spontaneous flaring of the nares. during swallowing. People who breathe orally tend to have a depressed or absent Just like in orthodontics the ideal Fig. 1 flaring of the nares. dentition should be in Class I, with Nasal mirror: This allows a gross perfect occlusal interlocking, smooth Lip seal, determined by proper estimation of nasal patency, but protrusion, retrusion and lateraliza- nasal breathing, is useful to requires at least a basic understand- tion, with the temporomandibular orthodontists as lips, along with ing of nasal breathing physiology. joint (TMJ) in an optimal centric cheeks, form the natural retainers A person with restricted or no 25 position. So, from the functional for the dental arches . A lack of nasal breathing tends to exhibit perspective of an Orofacial Myolo- lip seal may therefore be identified head postural changes28, a lowered as an OMD that needs to be gist, the ideal situation is: optimal mandible, a high palatal vault and addressed (Fig.1). nasal breathing, therefore an appro- constricted maxillary vault, a Not all instances of a lack of a priate lip seal, an appropriate verti- forward and low tongue position, lip seal indicate a nasal problem. In cal space between the dental arches, increased vertical dimension, many cases patients are able to the tongue usually resting against reduced facial muscle activity or a comfortably breathe through the the palate, relaxed facial muscles, hyperactive mentalis muscle and nose but, at some point in the past, correct chewing and age appropriate grimaces during swallowing. they developed a habit of breathing swallowing. Once the “norm” is Often the patient presents a orally, maybe after a prolonged established it’s easier to determine noticeable forward head posture, period of nasal congestion. Now a variations and abnormalities. that is an attempt by the body to necessity has become a habit and create more pharyngeal space for unless the habit is replace by AIRWAYS FIRST AND FOREMOST breathing. A forward head posture, another habit (lip seal), there is less Obstruction of the nasal airways although it provides a better chance that the nasal breathing is the most important etiological breathing situation, in the long pattern is re-established. factor in OMDs. Healthy children run is usually linked to postural Although there are some easy who develop normally tend to keep changes, muscle pain29 and assessment tools and techniques, their lips closed at rest, breathing occlusal alterations30. it’s always a good policy to have a nasally. Mouth breathing becomes a patient with oral breathing, or a necessity when the nose is UPPER LIP FRENUM habitual open mouth posture, to congested or anatomically compro- The lack of a lip seal is usually undergo a full ENT evaluation to mised. However, the benefits of linked to a habitual open mouth ascertain the patency of the ante- nasal breathing, such as humidifica- rior and posterior nasal passages. posture or oral breathing, but during tion, filtration and the warming of a growth and development phase it www.orthodontics.com March/April 2012 35 Fig. 2 Fig. 3 Fig. 4 LOW TONGUE REST POSITION Although the “normal” rest posi- tion of the tongue is still somewhat controversial, from a therapeutic standpoint, it is accepted that the tip should rest against the incisal papilla and the back of the tongue should rest against the posterior portion of the palate. In a minority of people the tip of the tongue lays b Optimal speech down, below the lower incisors, b Optimal chewing with no repercussion to surround- b Optimal swallowing ing structures. There are some exceptions to the most common b Social activities (playing musical instruments, kiss- position of the tongue tip up, ing, etc) notably in the presence of TMJ pain, in which keeping the tongue A tongue-tie is one of those low could actually induce excessive 36, 37 OMDs easily overlooked and yet masticatory muscles activation . it may be involved in puzzling The correct tongue rest posture delays in achieving orthodontic (a static position) against the palate implies nasal breathing, as it is not Fig. 5 or orofacial myofunctional ther- apy results33, 34, 35 (Figs. 2-4). In conducive to effective oral breath- severe tongue-tie cases (anky- ing. When the body needs more may be related to a still-developing air, however, the tongue is kept or underdeveloped upper lip. The loglossia) (Fig.5) the tip of the tongue assumes a heart shape, or low in the jaw and the jaw is more upper lip grows until about age 12 likely to be pushed forward. A low 31 the tongue is unable to touch the in girls and about age 17 in boys , tongue rest posture is another so a lack of a lip seal in a 7-year-old upper or lower molars, or it “bunches up” in protrusion by OMD that is easy to identify and child is not necessarily pathological, often comes accompanied by other although the lips may still need to relying heavily on the transverse issues. Proffit 38, 39 found that a low be “trained” to stay closed together. muscles and less on the superior longitudinal muscles. However, intensity pressure but with a long The lip seal means that there duration, as in the case of a tongue should be no space between the lips it’s easier to miss a short frenum with posterior attachment thrust at rest, may affect the denti- at rest, in fact there should be a tion and impact orthodontic treat- saliva seal between them. When because the tip of the tongue looks fine, but the dorsum of the ments, when constant pressure is there is a noticeable space (like 5+ exerted by the tongue within the mm), apart from habit and lip tongue does not lift adequately for a normal swallow. mandible, as opposed to within the growth, there is the possibility that palate and maxilla. the upper central labial frenum is An easy way to assess the sever- ity of a tongue-tie is to measure the A low tongue at rest in pre- too restricted and that the upper lip schoolers and school-age children is prevented from reaching its full maximum aperture of the mouth, from the edge of the upper incisors (Figs. 6-8) is often accompanied motion and providing a comfort- with speech misarticulations mostly able seal. A restricted upper lip to the edge of the lower incisors, and then ask the patient to place affecting the sibilants /s, z/ as they frenum may also be thick enough or are then produced with the tongue attached low enough to contribute the tip of the tongue against the incisors papilla and take the same between the teeth as in /th/ (think, to central incisor diastema. More- 40, 41, 42, 2 measurement. If the second this) . Finally, a low tongue over, a lack of a lip seal has been rest position is also accompanied linked to air exposure gingivitis32, 13. measurement is less that 50% of the first measurement then either a with increased vertical dimension LINGUAL FRENUM therapeutic “stretch” (which is and changes in the craniofacial dentoskeletal structures43, 44, 45, 46. In the last decade, there has actually a re-patterning of the been an emphasis in properly tongue muscles) or a surgical release should be considered. More “TONGUE THRUST” assessing the lingual frenum and to The very concept of a “tongue determine at what point the restric- comprehensive protocols to assess the severity of the tongue-tie and thrust” has been controversial for tion (tongue-tie) is significantly decades, probably because of affecting functions like: the functions it affects have been 33, 34, 35 misunderstandings and different b developed by Marchesan and Breastfeeding are recommended for their accu- nomenclature used by profession- b Oral clearance of food racy and ease of consultation. als, as opposed to the nomenclature (buccal cleaning) used by parents and patients. A

36 March/April 2012 JAOS tongue thrust is very easy to iden- tify, both during swallowing and during speech (dynamic tongue pattern). The ease with which this OMD is identified led to the belief, Fig. 6 Fig. 7 Fig. 8 in the past, that a tongue thrust was the cause of open bites, although studies indicated the opposite8, 9, 47, 48 that the tongue finds an open space and occupies it, often preventing the teeth from erupting properly. An anterior tongue thrust is a natural occurrence in babies and in Fig. 9 Fig. 10 young children and tends to natu- rally disappear with the emergence suspected sleep disorders the tongue into the esophagus. Normal chewing of the permanent dentition. The thrust would not be the object of is with the lips closed to prevent infantile type of swallowing, with a therapy but would be regarded as a spills of liquids and chewed food, forward direction of pressure, symptom of something more seri- while the food is soaked and amal- should evolve into a more mature ous, which would require proper gamated by saliva, crushed by teeth swallow pattern in which the direc- referrals to be addressed. and prevented from prematurely tion of the pressure is upward, A tongue thrust may be related to falling into the pharynx by the toward the palate. However, in a posterior crossbite (unilateral or gentle contact between the soft many individuals this shift does bilateral) or posterior open bite palate and the tongue. not occur naturally (Figs.9 & 10), (unilateral or bilateral). Once again, Good chewing also implies due to several factors, the most the tongue may find a space created good nasal breathing. In presence important of which are the absence by mixed dentition and with its own of reduced or absent nasal breath- of proper habitual nasal breathing intrinsic tone prevents or delays the ing, chewing becomes a struggle as and the presence of hypertrophic eruption of the permanent teeth, breathing always take precedence tonsils and adenoids49. When creating or maintaining a posterior over anything else. Because breath- tonsils are so hypertrophic that the open bite53, 8, 9. In the case of a cross- ing is a struggle, the food is not airways are drastically reduced, the bite, the tongue may not be resting properly chewed, it’s not soaked by child has no alternative but to keep up against the palate, but instead saliva properly and it’s not prop- the tongue low and forward to be exerting lateral constant pressure erly swallowed. Anecdotally, able to breathe more comfortably against the mandible and lower teeth. patients who cannot chew prop- (obligatory tongue thrust). The natural pressure of the erly tend to drink lots of liquids to The presence of an anterior cheeks, accompanied by the wash down the food. Also, because tongue thrust is indeed linked to an absence of a counter presence of of the poor chewing and the larger anterior open bite and/or an exces- the tongue at rest, may be enough food fragments ingested, patients sive overjet47, 48, 43, 44, speech misar- to cause a transverse collapse of often exhibit texture aversion, in ticulations affecting /s, z/, poor the maxilla and the emergence of which they refuse to eat certain Eustachian tubes clearance (there- a crossbite. In some cases, when foods and tend to prefer foods that fore the insufficient aeration of the the tongue exhibits an asymmetric are soft and with uniform consis- middle ear)50, the instability of tone (one side significantly tency (like fast food). swallowing mechanisms3 and stronger than the other half), it’s Some chewy foods with tough TMJD11, 12. possible to see also a unilateral consistency are thought to aggra- However, in some cases, a tongue crossbite, on the stronger side of vate existing a TMJD. Dysfunctions trust may be one of the signs and the tongue. of the TMJ, like a reduced mouth symptoms of a sleep disorder, when opening, reduced lateral movement the body tries to keep the tongue CHEWING DISORDERS and reduced anteroposterior move- out of the way and therefore open- Chewing is a highly complicated ment, clicking or pain, also affects ing up the posterior airways. The function involving several soft and chewing. Sometimes asking proper distinction between a devel- hard structures, cranial nerves and patients about their chewing (and opmental tongue thrust and an muscular valves. It’s the perfect chewing habits) can reveal unsus- adaptive tongue thrust is the co- coordination between the jaw, chew- pected problems with the TMJ. presence of other signs and symp- ing muscles, cheeks, lips, tongue and Also, chewing can be temporarily toms of sleep disorders, such as soft palate, all moving in timed impaired after orthognathic tongue scalloping, nocturnal brux- concert, moving the food (bolus) surgery, until the range of motion ism, daytime sleepiness among between the teeth, preparing it for and strength of motion of the many others51, 52. In cases of propulsion through the oropharynx mandible is restored.

www.orthodontics.com March/April 2012 37 ATYPICAL SWALLOWING achieve “optimal” swallowing or a 11), force the mandible into unnat- Along the continuum of swal- “normal range”, as the concept of ural positions for a prolonged lowing there is: what constitutes a “normal” swal- period of time or with great force lowing is still controversial. (as is nail biting). Oral habits are b Normal swallowing comforting to patients therefore (or optimal swallowing) they create (and maintain) a crav- b Atypical swallowing (affect- ing for such unhealthful behaviors. ing oral preparation and the Eliminating or greatly reducing oral phase of swallowing) these orofacial habits takes specific skills of applied behavior modifica- b Dysphagia tion and the purpose of therapy is (disodered swallowing) to replace an old habit, like thumb- sucking, with a new habit, like lips b Aphagia (absence of swal- lowing). closed and tongue resting on the palate. Treating OMDs in general Aphagia is a life-threatening requires a specific set of skills and medical condition managed specific knowledge, usually the mostly by physicians. Dysphagia, Fig. 11 purview of orofacial myofunctional or dysfunctional swallowing, may therapists65, 66, 9. be temporary or permanent and is usually treated by specially PREVENTION trained speech pathologists work- NOXIOUS OROFACIAL HABITS Preventing OMDs has a positive ing with a team with physicians Not everything that goes in the effect in both micro-economies and dieticians. mouth is necessarily noxious or bad. (people) and in macro-economies Children undergoing orthodontic It depends on frequency, duration (countries). In terms of a micro-econ- treatment might present atypical and intensity. The higher these three omy it’s easier to eliminate noxious swallowing. The patient is usually factors are, the more likely the habit habits or pathological conditions well nourished, therefore the swallow- has deleterious consequences for the earlier on and to assist in the harmo- ing is functional (or it would be classi- growth and development of the nious growth of the orofacial fied as dysphagia) but it’s not yet orofacial complex and for the posi- complex of patients2, 42, 67. The orofa- “optimal”. Atypical swallowing is tive outcome of the orthodontic or cial complex grows to its full poten- fairly easy to detect, as the tongue orofacial myofunctional treatment. tial when there are no interferences tends to push forward to create a seal Sucking one’s fingers may not be along the way68 and it’s comforting with the lips, the teeth are not in significant unless it’s done daily, for to see that multiple organizations, occlusion and the face presents a hours at time and with enough including the American orthodontic grimace by contracting the mentalis intensity to often cause an abnor- Society or the American Academy of muscle, or the orbicularis oris or the mal growth of the finger. Situations Pediatric Dentistry are drawing atten- buccinator in the cheeks. Often the in which identification and modifi- tion to prevention of OMDs. lips are also open and the tongue cation of intensity, duration and These disorders require a multi- pushes outside the lips. frequency are crucial are: thumb disciplinary intervention where the 58, 59, 60, 61, 62 Malocclusions are often present and finger sucking , prop- pediatrician, the ENT, the pedodon- 63 in patients with atypical swallowing ping the jaw on one’s hand , in tist, the orthodontist, and the orofa- addition to excessive gum chewing 3, 8, 9, 2 because the tongue pressure is cial myologist work together to and nail biting64, to name a few. exerted forward or laterally, as ensure that the growth and develop- Lip licking is also a significant opposed to upward, toward the ment of the orofacial complex takes oral habit. When lips get dry palate. The palate has a shape place naturally and appropriately. In (because of dehydration or oral designed to accommodate the some cases, other professionals may breathing) patients feel the need to tongue at rest and during swallow- be needed to complete the team, lick them, thus getting short-term ing, therefore, when the tongue is such as a speech-language patholo- relief but causing long-term lip and secured against the palate and the gist, a dental hygienist, an osteo- perioral skin irritation due to the teeth are in occlusion, the orofacial pathic physician, a nutritionist, a acids present in the saliva. This muscles exerts the proper tension to gastroenterologists and/or allergist, habit can trigger a spiral of chapped implement a swallow that is fast and so that the real causes of an orofa- lips, lip licking, more chapped lips efficient56. A proper swallow against cial myofunctional disorder are and more lip licking. If the patient the palate also activates the muscles identified and corrected as soon as is already exhibiting an anterior that twists open the Eustachian they develop40, 41, 69. A team of tongue thrust, adding the lip lick- tubes, contributing to the aeration professionals who understand and ing habit is certainly unhelpful. and drainage of the middle ear57, 50. appreciated one another’s contribu- Oral habits usually preserve an The purpose of orofacial myofunc- infantile pattern of movement (Fig. tion to the patient’s wellbeing may tional therapy is to help the patients be able to arrest and reverse the 38 March/April 2012 JAOS cascading effect that certain situa- b Eliminating or drastically ing, eating, speaking, exploring etc. tions may cause. reducing orofacial noxious and those functions are imple- For instance, an allergy that has habits by modifying their dura- mented by changing the position or not been addressed may cause nasal tion, frequency and intensity. shape of the muscles. However, congestion, which may cause a even the most skilled therapist b chronic open mouth posture, which Changing orofacial muscle might face some OMDs that cannot is linked to poor palatal develop- movements to the desired and be eliminated by orofacial myofunc- ment and TMJ instability, which is optimal pattern. tional therapy alone, but may linked to less than ideal orthodontic b Ensuring the generalization require a coordinated intervention results, prolonged use of retainers of a correct pattern and function by the orthodontist first, as in the and even sleep disorders and (same optimal behavior in differ- case of a restricted palate (a maxil- surgery. Parental involvement and ent contexts) lary transverse deficiency), an exces- the patient’s preferences and values sive overjet or an open bite. are crucial variables, as often some b Ensuring the habituation of A visit to an oral surgeon may dietary and life-style changes are a correct pattern and function also be the first step in treatment, in needed to arrest the noxious (same optimal behavior in differ- the case of a restricted lingual cascade, and these changes need to ent times) frenum, while other times the first be implemented by the patient. All these principles are imple- step might be the need to see the Preventing OMDs benefits mented through motivational allergist, the ENT or the osteopathic patients, orthodontists, and third techniques73 customized by the physician. Therefore a multidisci- party payers because it intercepts therapist and honed by profes- plinary approach is absolutely 97 situations that could derail the sional experience74, 75. Some tech- necessary as the timing of the vari- normal growth and development of niques imply self-awareness and ous therapies needs to be decided as a harmonious orofacial complex. patient education76, 77, 78 while a team, after a full evaluation of the Preventing OMDs also makes sense other techniques derive from the patient is completed and a list of in the global health discourse, field of dysphagia treatment79, 56 or goals has been approved by the because millions of people are speech articulation treatment80, 5. patient. Myofunctional therapy may emerging from poverty world-wide From a neurophysiological stand- occur before orthodontics, during and they are exposed to the same point, the patients need to inter- orthodontics or after orthodontics. perks of more affluent countries and nalize the correct pattern of orofa- Just like form and function influ- therefore they may develop OMDs cial movements, and keep approx- ence each other, orthodontics and at an unprecedented number, imating to that behavior through orofacial myofunctional therapy although the economic ability to repetition over time, for the also influence each other. take care of the consequences is not results to be stable81, 82, 83, 84, 85, 86. Identifying OMDs, striving to growing on par with the disorders. In recent years studies have been prevent them or treating them in a Finally, in cases where an orofa- conducted on the minimum multidisciplinary approach should cial myologist is not available, an number of therapy sessions neces- be a part of the standard of care in a array of oral appliances and habit sary to cause a physiological change dental or orthodontic office, in trainers have been employed for in orofacial muscles and on the orofacial myology and in speech years70, 71. However, in cases where need to build in follow-ups in the pathology as the anatomical multiple OMDs are present or undi- therapy cycle to identify and correct changes brought forth by the agnosed, results have been mixed at possible functional relapses87. There orthodontist’s treatment are more best62, 72, as the habit tends to persist are very specific neurophysiological stable when muscles and function once the appliance is removed and principles behind the process of patterns are optimized. Conversely, the patients have not been taught acquisition of a correct muscle appropriate functions happen in the correct tongue posture. pattern, its generalization and habit- appropriate spaces and so speech uation88, 89, 90, 91, 92, 93, 94, 95. Interrupting pathologists or orofacial myologists TREATMENT OF OMDs therapy too soon may cause a need to work closely with orthodon- Just like when orthodontic treat- regression and disappearance of the tists as they are expanding palates or ment is dictated by anatomical and newly acquired functional pattern96, reducing excessive overjets before physiological constraints, so too is 87, just like interrupting orthodontic starting myofunctional therapy. orofacial myofunctional therapy treatment too soon may invalidate By being aware of the intricate because the changes in functions the gains to date. relationship between orofacial are dictated by anatomical Orofacial myofunctional therapy structures and orofacial functions constraints (like a restricted palate requires specific skills because the orthodontist and other professional shape or a restricted lingual muscles of the face and mouth are working within the same area can frenum) and by physiological different, anatomically and physio- coordinate care with an orofacial constraints (like the absence or logically, from muscles of the limbs myofunctional therapist for the reduction of nasal breathing). and the trunk. Orofacial muscles benefit of the patient and treat- The principles of therapy are: share multiple functions like breath- ment success and stability. 40 March/April 2012 JAOS