In the early 1800s the dental literature began to recognize mouth breathing and abnormal swallowing patterns and their detrimental effects on the dental structures. In 1906 the orthodontic community began to address this muscle dysfunction and the specialty of myofunctional therapy came into being. MYO means muscle. FUNCTION means the specific, natural action or activity; to perform as expected or required. THERAPY is the process of rehabilitation: to restore to a state of useful activity through exercises, instructions and control. Myofunctional therapy is applied to the 5 basic mouth functions:

Physiologic Rest Posture Saliva swallowing Chewing and swallowing food Liquid swallows Speech

Knowledge accumulated through research indicates that there is a scheme or design for each function of the mouth that is preferred and pursued because of the physical and mechanical benefits gained by that function.

Lip closure aids in the development of the muscles in the lower third of the face.

Comfortable lip closure looks attractive.

Lip closure helps keep the lips from drying out.

Lip closure helps keep the mouth moist with saliva which has many benefits: saliva provides a defensive barrier against bacteria, fungi and viruses; it has a buffering action which protects teeth against bacteria producing acids; and there is a remineralizing benefit that helps repair the early stages of tooth decay.

Lip closure helps eliminate or reduce bad breath.

The lip and cheek muscles form a band that circles the teeth which determines the dimensions of the arch and establishes the position of the teeth.

Lip closure helps to guide the anterior teeth into position and acts as a retainer to hold them in place.

Lip closure establishes nasal breathing while awake and sleeping.

Nasal breathing increases the lung’s ability to absorb oxygen from the inspired air.

Diaphragmatic breathing, as part of the physiologic rest posture, pulls air into the lowest part of the lungs where oxygen exchange is most efficient.

Diaphragmatic breathing lowers the heart rate and blood pressure, relaxes muscles, calms the mind and stops anxiety.

Nasal breathing filters the air of debris and pathogens.

Nasal breathing helps to shrink the nasal turbinates.

Nasal breathing contributes to the normal development of the nasal cavity and the maxillary sinuses.

Nasal breathing while sleeping helps reduce the dry or sore throat associated with mouth breathing.

Nasal breathing produces a pattern of airflow which helps to suck the tongue up in the palate.The proper posture of the tongue in the palate is known as the neutral position.

The neutral position aids in the normal development of the palate.

The neutral position helps to support the palatal transverse arch width.

The neutral position helps to maintain an open pharyngeal airway.

The neutral position brings the tongue up off the floor of the mouth to facilitate free flow of the sub-lingual salivary glands.

The neutral position helps support the mandible allowing the teeth to separate in freeway space.

The physiologic rest posture with freeway space helps to relax the masseter muscles.

The physiologic rest posture with freeway helps keep the temporomandibular joint ‘loose packed’ to maintain the proper disc space width.

The physiologic rest posture with freeway space stops clenching or grinding while awake or sleeping.

The physiologic rest posture helps to maintain proper head posture.

The physiologic rest posture is the starting point for the correct saliva swallowing.

Lip closure during the process of swallowing saliva seals the oral cavity so that the tongue can create the proper suction to move the saliva to the back of the mouth to be swallowed.

During the process of sucking and swallowing the saliva, specific intrinsic and extrinsic muscles in the tongue contract which helps to reinforce the correct shape and position of the tongue.

Proper muscle tonicity in the intrinsic and extrinsic tongue muscles helps to maintain the tongue in the neutral position.

Normal sucking and swallowing of saliva with the tongue in the neutral position puts the pressure of the tongue in the palate not on the teeth which is extremely important because teeth are susceptible to the guidance and influence of pressure and stimulus.

When the teeth come together or intercuspate during the saliva swallow, there is a stabilizing effect on the teeth by holding them in lateral or transverse and rotational relationship.

The biting down during the swallow also prevents the extrusion or super eruption of the teeth which helps to maintain arch stability.

Swallowing with the tongue in the neutral position causes the back of the tongue to lift up and close the airway preventing aspiration of the saliva.

Proper swallowing with the tongue in the neutral position helps to open the Eustachian tubes to the middle ear.

Correct saliva swallowing helps to correct drooling.

Correct saliva swallowing helps to correct spitting during speech.

Correct saliva swallowing helps to reinforce the correct swallowing pattern for liquids and food.

Research indicates that we are to masticate during the process of eating 1000 to 3000 times per day; therefore it is important to use the lip, tongue and jaw muscles correctly.

There are twenty pairs of muscles that are used during normal chewing and swallowing which helps to establish muscle balance between the two halves of the oral cavity.

Lip closure during chewing and swallowing strengthens and develops the lip muscles which in turn helps establish lip closure for all the mouth functions.

Lip closure during chewing and swallowing is proper etiquette.

Lip closure prevents ‘smacking’ or noisy eating.

Lip closure keeps food from spilling out or corrects the messy eater.

Lip closure while chewing limits the side to side movement of the jaw which is beneficial for the temporomandibular joint.

Thorough chewing dissolves substances in the food to make them more accessible to the taste buds.

Chewing a semi-hard to hard diet in a child helps to develop the mandible.

Proper bilateral chewing help to develop the two sides of the mandible evenly.

Proper bilateral chewing promotes bilateral muscle development in the temporomandibular joints.

Proper bilateral chewing helps distribute the force used by the chewing muscles evenly between both sides.

Proper bilateral chewing helps produce a more uniform wear pattern on the teeth.

Proper bilateral chewing contributes to facial symmetry.

Proper tongue sweeping while chewing cleans debris off the teeth prior to the swallow.

During the swallowing of food the pressure of the tongue is in the neutral position on the palate not against the teeth.

The teeth intercuspate during the swallowing of the food helping maintain occlusal stability.

Chewing correctly has many health benefits.

Proper tongue function while chewing prevents premature entry of food into the throat which prevents choking.

Thorough chewing increases saliva production which helps to digest bacteria that can lead to plaque buildup.

Proper chewing thoroughly mixes the food with saliva which is rich in digestive enzymes that begin the process of starch and fat digestion.

The more chewing, the more food is exposed to the anti-bacterial enzyme in the saliva that kills food-borne pathogens.

When food is chewed thoroughly the less work there is for the stomach and intestines reducing gas and bloating.

The intestines will have an easier time pulling micronutrients out of thoroughly chewed food.

Thorough chewing provides the body with more vitamins, minerals, antioxidants and amino acids.

Proper swallowing of food eliminates the swallowing of air reducing gas and belching.

Chewing releases serotonin, a neurotransmitter that helps us relax, go to sleep, focus or concentrate and elevates our mood.

Proper swallowing of liquids with the tongue in the neutral position allows the back of the tongue to lift up to close the airway to prevent aspiration of liquid into the lungs.

The pressure of the tongue during the liquid swallow is in the palate not on the teeth.

Normal swallowing of liquids eliminates the swallowing of air, reducing gas and belching.

Normal swallowing of liquids eliminates ‘dribbling’.

Normal swallowing of liquids stops ‘noisy’ drinking.

All speech sounds except the /th/ sounds are based in the neutral position.

Speaking within the neutral position keeps the tongue from putting incorrect pressure on or between the teeth.

Proper muscle tone in the intrinsic and extrinsic tongue muscles helps the tongue to move quickly and accurately to produce the various consonant sounds.

Proper lip development aids in the production of the labial speech sounds.

Normal jaw function during speech is produced within a ‘graded opening’ which does not stress the temporomandibular joint.

The mouth, also known as the oral cavity, is a complex organ composed of three systems: the myofunctional system, the dental system and the medical system. There is no one specific cause for myofunctional disorders. There may be multiple contributing or causative factors within these three systems that negatively influence how the 5 basic mouth functions will work. MYOFUNCTIONAL SYSTEM Conditions within this system make it difficult for the orofacial muscles to function correctly. There are different conditions that affect the function of the lips:

Short upper lip

Restricted maxillary frenum

Everted lower lip

Flaccid orbicularis oris

Tight mentalis

Tight platysma

There are different conditions that affect the function of the tongue:

Incorrect development of the intrinsic and extrinsic tongue muscles

Restricted lingual frenum

Enlarged tonsils

Restricted palate

There are different conditions that affect the function of the jaw:

Jaw muscle pain, injury, nerve damage, etc.

Disc displacement

Dental discrepancies

DENTAL SYSTEM

Conditions within this system make it difficult for the orofacial muscles to function correctly.

Shape of the hard palate

Relationship between the upper and lower arches

Alignment of the teeth

Dental appliances on the palate, on the teeth or between the teeth

MEDICAL SYSTEM

Conditions within this system make it difficult for the orofacial muscles to function correctly.

Restricted nasal airway

Enlarged tonsils

Allergies, asthma, respiratory problems, etc.

Syndromes, neurological conditions, injury, etc.

All of these systems and structures work together as a team. A dysfunction or altered functional pattern in any one of them affects the others, contributing to myofunctional disorders.

There are many different specialists that recognize myofunctional disorders and enlist the services of a Certified Orofacial Myologist.

Dental specialists

Medical specialists

TMJ specialists

Osteopath

Chiropractor

Physical therapist

Speech pathologist

Occupational therapist

The following list reflects different conditions that are referred for therapy:

Sucking habits

Parafunctional habits

Mouth breathing

Lip incompetence-the inability to close the lips without muscle strain

Drooling

Chapped lips

Red swollen gums; excess plaque

Incorrect tongue posture at rest

Sleep disordered breathing

Bruxism-clenching or grinding the teeth in other than normal function

Jaw muscle pain

Cracking or fracturing teeth

Tongue thrust-the incorrect action of the tongue while swallowing saliva, chewing and swallowing food, liquid swallows and/or during speech

Incorrect relationship between the upper and lower arches

Malocclusion

Orthodontic/orthognathic surgical relapse

Eating dysfunction

Choking or aspirating

Lazy speech muscles

Any one or a number of specialists may recognize a problem in a child, adolescent or adult and want the patient to go through myofunctional therapy.

The orofacial muscles and the functions of those muscles are capable of change with DISCIPLINE and TIME. DISCIPLINE is defined as training of the physical powers by exercises, instructions and control.

EXERCISES tone the muscles, changing their shape, strength, range of motion and their ability to coordinate with other muscles.

INSTRUCTIONS develop consistent production of the correct functions.

CONTROL of the new functions through self-monitoring and self-correction in order to habituate the correct functions.

TIME is an essential element in the process of rehabilitating the orofacial muscles and the functions.

It will take time to tone the muscles with the exercises.

It will take time to retrain the muscles to function correctly through the instructions.

It will take time to control the correct muscle functions in order to form new habits.

The principles of myofunctional therapy are the same for children, adolescents or adults: exercises, instructions on normal function and learning to control the new function.

Progress with myofunctional therapy, whether the patient is a child, adolescent or an adult depends on a number of factors:

The number of myofunctional problems that need to be corrected as determined with a diagnostic myofunctional evaluation.

Any medical condition/s that would compromise the goals of therapy.

Dental conditions affecting the palate or teeth that make it difficult for the muscles to function correctly.

Patient compliance with the myofunctional therapy exercises and the daily practice to retrain the muscles to function correctly.

Parental involvement with young patients to supervise the exercises and give guidance on proper function.

Keeping the therapy appointments.

The frequency of interruptions in the routine of doing the exercises or practicing the proper functions, i.e. holidays, vacation, illness, school issues, work situations, etc.

Controlling any parafunctional habit, action or behavior that works against the goals of therapy.

The process of myofunctional therapy is the same for children as for adults, eliminate parafunctional habits, initiate exercises to strengthen and tone the orofacial muscles, follow instructions to develop consistent production of the correct functions and learn to control the new functions through self-monitoring and self-correction in order to habituate the correct functions. Children do present more challenges in the rehabilitation process due to the following that include, but are not limited to:

Sucking habits (digits, pacifier, clothes, toys, etc.)

Parafunctional habits (i.e. nail biting, excessive licking, gum chewing, sipper cups or bottles, straws, etc.)

Medical airway conditions (colds, sore throats, tonsillitis, allergies, etc.)

Dental conditions (loose teeth, sore mouth, appliances, etc.)

Age

Motivation (20% of all children are self-motivated, 60% are other motivated and 20% are not motivated)

Patient cooperation

Parental involvement

Extracurricular activities

After school care

Frequency of school holidays which interferes with the routine of therapy

Regardless of all the challenges involved in doing therapy with children, when myofunctional problems are noted therapy should be started immediately to correct the lack of proper muscle development and improper oral function.

There are two important reasons to guide and direct children at the earliest age possible in proper oral function.

The first reason involves ontogeny. Ontogeny is the process through which a system grows and develops to perform specialized functions. The ontogeny of the oral cavity begins at birth and reaches maturity around 18 to 25 years of age. Ontogeny includes both genetics and function. According to research, 90% of babies are born genetically perfect; but the greatest stimulus to continued proper development comes from the correct functional patterns.

It is important to note that from birth to age four there is a large increase in the development of the oral cavity including the acquisition of the primary teeth and the development of the five basic mouth functions. Then from age four to age twelve 90% of the development of the oral cavity is reaching maturity.

The second reason for early intervention is that myofunctional problems tend to be progressive. If disorders in young children are not treated, the implication is that delaying treatment can result in a greater more complex problem; require more extensive, more complicated or more expensive solutions; with a possibility that delayed treatment results will not be as good as what could be achieved with early intervention.

Taking all these factors into consideration, the child will be given therapy that is age appropriate. If they are not able to comply with therapy exercises and instructions, the focus would be on eliminating any parafunctional habits that compromise the oral cavity then resume myofunctional therapy at a later date.

In children, high levels of normal function must be maintained through the process of ontogeny to stimulate the highest growth and development of the oral cavity structures, muscles and functions.

One of my patients was soon to become a new father and asked me this very question. He was determined to do everything possible for his child to avoid the myofunctional and extensive orthodontic problems he had had as a child and as an adult. Here is the information I gave him which he and his wife implemented as soon as their daughter Talia was born because normal function begins at birth. NURSE

Nurse for a minimum of 6 months to 1 year or longer if possible to help with normal muscle development and function.

Nursing at the breast is the physiologic catalyst or initiating function that sets up the specialized functions of normal nasal breathing, normal tongue posture and normal swallowing patterns that we want children to use through the process of ontogeny and into adulthood.

If there are problems nursing, check with a lactation specialist to determine if the lingual frenum or the maxillary labial frenum is restricted, making it difficult for the infant to latch on or seal their lips properly to create the proper sucking function.

If nursing is not possible use the smallest bottle nipple possible to encourage vigorous sucking then eliminate the bottle by age 1.

When a child nurses, the breast nipple conforms to the oral cavity but when a foreign object goes in the mouth, the oral cavity adapts to the foreign object.

Nursing not only helps with the normal growth and development of the oral cavity, it is also the primary source of pacification.

PACIFICATION

If an infant needs additional pacification and will accept a pacifier, use the smallest pacifier nipple possible to simulate proper tongue and lip muscle function.

A newborn cannot self sooth and relies on sucking as a primary source of pacification.

Sucking releases serotonin, a neurotransmitter that helps us fall asleep and stay asleep, calms us, elevates our mood and helps us focus or concentrate.

Around age 4 to 6 months a baby begins to roll over and wiggle their arms and legs releasing serotonin which helps to pacify them. They can now self sooth and any sucking habit whether a pacifier, digit, blanket, or toy, etc. should be eliminated.

DRINKING

Babies begin to show an interest in drinking from a cup at around age 6 months.

All drinking from this point forward should not be a sucking action but should be free flow drinking to help the lip and cheek muscles develop correctly.

The lip and cheek muscles form a band that circles the teeth which determines the position of the teeth and the dimension of the dental arches.

Normal cheek muscle pressure is 2 grams/per square centimeter to allow for the normal expansion of the dental arches which is influenced by genetics and the function of the tongue in the palate.

The use of a straw, a sipper cup, pacifier, digit or bottle is a sucking action. This sucking action is like sending the cheek muscles to the gym and working them out. The cheek muscle pressure can increase to 20 grams in the molar region and 80 grams in the cuspid region resulting in narrowing of the dental arches.

If you are concerned with spilling, use a cup with a small opening like the Playtex Coolster Tumbler and remove the valve so it is not a sucking cup but a free flow drinking cup. The small opening will minimize spilling.

EATING

Encourage the child to chew with their lips closed.

Chew small to moderate sized bites.

Encourage the use of child sized utensils to control bite size.

Chew on both sides of the mouth.

Chew and swallow the bite before putting more food in.

By age 4 the child should be able to chew a semi-hard to hard diet.

Do not use the sucking pouches that contain pureed fruits and vegetables, this is a sucking action and works the cheek muscles.

PARAFUNCTIONAL HABITS

All oral habits that fall outside the 5 basic mouth functions should be eliminated.

Eliminate all sucking habits, thumb, fingers, arm, hand, blanket, toys, clothes, etc. If you need assistance a Certified Orofacial Myologist is trained to help families eliminate sucking habits.

No excessive licking; no biting or chewing on nails or stuff; no chewing gum, etc.

No mouth breathing except for physical activity or nasal congestion. If nasal congestion is suspected, consult your pediatrician or Ear, Nose and Throat specialist.

When Talia was 3 years old her pre-school teacher came up to her father and said, “Your daughter is the only one of all the students in my class that sits with her mouth closed and chews with her mouth closed. Why is that?” The answer is that the family followed these myofunctional guidelines to help her develop the proper muscle development and proper habits!

At age 7 Talia is a nose breather, she has normal swallowing patterns for saliva, food and drinks, her speech has developed normally to date and according to her pediatric dentist she has a normal dental relationship between the upper and lower teeth. She has not required any medical, dental, speech or myofunctional services to date.

The goal in treating children is to help them reach maturity with good myofunctional habits that will last a lifetime. Proper myofunctional habits will become life-long habits when initiated at an early age and reinforced on a daily basis by the parents.