The jaws grow and develop as a result of even pressure from the lips, cheeks and tongue. Any disruption in this equilibrium can result in not only facial and skeletal changes, but also changes in airway health.
Infant airways are divided into three parts: the nasopharynx (the portion of the airway associated with the nose), the oropharynx (the portion of the airway associated with the mouth and throat), and the hypopharynx (the pharyngeal airway space below the mouth). The nasopharynx develops as an infant breathes through his or her nose consistently. Therefore, mouth-breathing babies and small children will not fully develop their nasal passages.
Chronic mouth-breathing can be correlated with large tonsils and adenoids. The nose is a natural filtration system. If it is not being used, the tonsils and adenoids are being exposed to more allergens and bacteria, causing them to be inflamed. Once this tissue becomes inflamed, the child is then forced to bring the tongue forward and/or breathe with an opened mouth posture – further exacerbating the inflamed tonsils and/or adenoids. An anterior tongue posture can lead to flaring of the front teeth and/or a dental open bite.
Consistent open mouth postures and mouth-breathing will change the way a jaw will grow and develop. An open mouth posture allows for supra-eruption of the posterior maxilla and downward and backward (clockwise) growth.
This can lead to a long face, flaccid musculature, vertical maxillary excess, and muscle strain to keep lips together. This facial pattern is often correlated with airway and breathing problems. If not addressed early, the only way to correct this jaw pattern is bimaxillary surgery combined with orthodontics.
The tongue is directly linked with the oropharynx. The back of the tongue makes up the front wall of the oropharynx. As the tongue moves forward and fills the oral cavity, it is moved out of the back of the throat, opening up the airway.
Problems associated with the tethered tongue
If the tongue is tethered (tongue tied), the tongue movement is restricted. A restricted tongue, therefore, can have the following effects on skeletal growth and development as well as airway development:
If the tongue is tethered, it cannot rise to the palate and cannot put pressure on the upper jaw. This can lead to narrow upper jaws and upper jaws that do not grow forward enough.
Tethered tongues have been correlated with small lower jaws. If the tongue is tethered, it holds back the forward growth potential of the mandible (the lower jaw).
If the upper jaw is narrow and small and/or if the lower jaw is small or set back, the tongue will fill the oropharynx (the airway space in the back of the throat) and compromise airway.
Tethered tongues are seen correlated with dental and skeletal open bites. If the child is trying to open his or her airway and the skeletal structures are blocking the airway, the child is forced to bring his or her tongue forward in order to breathe better. This will result in an open bite. Once there is space between the front teeth, the tongue will always rest there. If the underlying airway issue is not resolved, it is unpredictable to correct the open bite long-term.
Infant airway development
How is breastfeeding linked to airway and skeletal/facial growth and development?
Proper latching, swallowing, digestion and breathing are dependent on a tongue that is not restricted. A tethered tongue will not allow an infant to latch properly. Tethered tongues can also be disruptive to proper swallowing, can be linked with poor weight gain, reflux, and inadequate feedings.
Proper breastfeeding forces an infant to breathe through his or her nose, helping form and develop the nasal passages. The tongue and lower jaw muscles work very hard during breastfeeding. The activation of these muscles and the pressure of the tongue are what form the jaws. A tethered tongue may potentially be the underlying cause of a feeding problem that causes a mother to give up breastfeeding early.
In older children, a tongue tie can restrict tongue movement, leading to improper swallowing. Children may be more likely to gag because the tongue is held in a more backward position and the upper jaw may have not developed entirely. If there is a small distance between the back of the tongue and the soft palate, the gag reflex is more likely to get triggered.
If the tongue is restricted, the child cannot process and move food through his or her mouth efficiently. Food can therefore get caught in the mouth and cause gagging. Food can also get stuck behind upper teeth and the child will not be able to move his or her tongue to clear the food. The child may learn to favor certain foods and will manifest as a “picky eater.”
The tongue's effect on speech and pronunciation
Speech and pronunciation are affected by a tethered tongue. Children with tongue ties may have difficulty with l, r, t, d, n, th, sh, and z sounds. Some children are able to compensate for this, so it may or may not be a problem for all children.
Seek medical and dental treatment if you notice any of the following in a child:
Chronic mouth breathing
Chronic allergies, rhinitis, and/or asthma
A narrow upper jaw
A noticeable underbite or overbite