What Causes an Orofacial Myofunctional Disorder?

There are many causal factors so it may difficult to point to one.  Research has demonstrated that any obstruction to the airway (such as a thumb/finger/pacifier sucking habit, enlarged tonsils or adenoids, deviated septum, nasal polyps etc) or an upper respiratory disorder (chronic colds, asthma, allergies) may contribute to the development of an Orofacial Myofunctional Disorder.  

These causal factors include but are not limited to :

  • vigorous digit (thumb/finger) or pacifier sucking for a prolonged period of time or beyond an appropriate age 
  • enlarged tonsils and/or adenoids 
  • shortened lingual (tongue) or labial (lip) frenum (a cord-like soft tissue)
  • chronic allergies, sinus infections and/or nasal congestion
  • neurological, structural, muscular or other physiological abnormalities
  • hereditary conditions 

When one or many of these causal factors are identified during the initial evaluation, the patient is referred to the appropriate professional such as an ENT or an oral surgeon. 


Digit or Pacifier Sucking:

Prolonged thumb, finger or pacifier sucking keeps the tongue low in the oral cavity. The thumb is pushed up against the hard palate, over-time creating a dent in the roof of the mouth.  The hard palate changes into a high and narrow palatal vault.  The dental arch changes from wide and rounded to V-shaped. Dental crowding can be observed along with an open bite. Desired lingual/palatal contact can't be achieved. The oral system becomes weak over time. 

This anterior open bite is the result of thumb sucking for prolonged periods of time. It gives the tongue an opportunity to rest in between the front teeth which keeps the bite open.  This undesirable tongue resting posture can cause a saliva, liquid and solid tongue thrust swallowing pattern to develop.  


Tonsils and Adenoids:

In this picture you can see that the swollen tonsils are taking up a lot of room in the back of the mouth.  The enlarged tonsils pushes the tongue forward and out of the mouth. The jaw is forced to hinge open, the lips are parted and the tongue sits against or between the teeth at rest. Obligate mouth breathing rather than consistent nasal breathing occurs.  A referral to an ENT or an oral surgeon is warranted.

Any situation that forces the tongue forward and low in the oral cavity with lips-apart mouth-open posture, can cause an orofacial myofunctional disorder.     

Tonsils are graded based on size.  If the tonsils are a grade 3 or grade 4 then extraction of the tonsils is warranted.  Removal of the tonsils will allow for repositioning of the tongue in the oral cavity with lips resting together.  This ensures consistent nasal breathing.   


Lingual and Labial Frenums:

This shorted cord under the tongue tethers the tongue to the bottom of the mouth, making it difficult to lift and contact the roof of the mouth.  As a result of the tongue's absence, the hard palate doesn't develop into a wide arch form because the tongue, when up against the roof of the mouth, provides 'scaffolding'. Instead, a high and narrow palatal vault develops.  As the palate becomes more narrow, it leaves little room for the tongue to fit up against the hard palate where it belongs.  Once the frenum is released, the patient needs to tone the muscles of the tongue and learn the appropriate tongue resting posture. This will avoid orthodontic relapse.  

You can see how the lingual frenum restriction could interfere with proper licking, chewing and swallowing along with typical articulation development.  

Release of the frenum can be done using a scalpel or a laser.  It doesn't require hospitalization and only takes 5 minutes with no pain or bleeding. Post-op exercises are prescribed twice daily to eliminate scarring.  

A restricted lip frenum can prevent the infant from obtaining a good latch / seal and can also cause damage to the mother while breastfeeding.  A poor lip seal causes gas, reflux and fussiness to occur; as a result, the baby is switched to bottle feeding too early.

When the permanent teeth drop and the labial frenum isn't released, the cord can pull upwards on the gingival surface, causing the teeth to rotate and move apart. This cosmetic concern is called a diastema. Once the labial frenum is released, the teeth should drift back together naturally.  


Allergies and Nasal Congestion:

 An obligate mouth breather is most likely due to breathing problems caused by allergies, asthma, enlarged tonsils/adenoids or a structural issue such as a deviated septum.  The lips are parted, the jaw is hinged open and the tongue is laying low in the oral cavity.  The short upper lip causes lip incompetency.   

Children do not outgrow ANY OF THESE causal factors.  

Remember that the function of the tongue responds to the space and the shape available in the oral cavity.  Once these opened spaces are closed using orofacial myofunctional therapy and the dental freeway space is normalized, the thrusting swallowing pattern can be eliminated.  Commonly, if the thrust is not eliminated in childhood it will be present in adulthood.  Therefore, addressing these structural concerns as early as possible is the best way to go.  

Check out the video Finding Connor Deegan - a family's journey to save their son.