The width of the nasal bone is directly related to the width of our upper airway!
The tongue is intimately involved in the development of the palate, which in turn is directly involved with nasal breathing. Sounds a little confusing? Well not really. If you think about the anatomy of your mouth, your palate is directly below your nose. Still confused? Let’s go deeper into the development of the mouth and nose.
As a fetus develops, it is surrounded by amnionic fluids, and in fact swallows this fluid later in development. As it swallows, the tongue gently touches the palate each time. Why does it touch the palate? Well try to swallow with your mouth completely open. It’s almost impossible. That’s because we need to create a vacuum within our mouths to swallow efficiently. As the tongue touches the palate, it pushes the developing bones upward and outward to help form the palatal bone. This movement in width is what in turn forms the floor of the nasal bone. The width of the nasal bone is directly related to the width of our upper airway!
Why do such a high percentage of premature birth infants (prior to 36 weeks) have sleep apnea? They are born before the tongue has the opportunity to properly shape the palate and many develop a very high, narrow palate. Remember above we said the top of the palate is the floor of the nose. Well a high, narrow palate is similar to the top of a triangle. It is narrow, so the floor of the nose develops very narrow, creating an underdeveloped upper airway.
Why do some full-term babies have underdeveloped palates?
What about full term birth babies? What are some of the reasons that they can have underdeveloped palates? Some are born tongue tied. That is when a very thin muscle develops attached to the base of the tongue, almost to the tip. This keeps the tongue from touching the palate and therefore hinders the palate from developing, as discussed above. Some have this tongue tied situation into adulthood. Most, though, have this muscle snipped by the pediatrician or a pediatric ENT at a very early age. This is called a frenectomy. If done within the first month of life, it is almost 100% successful. After the first month, not only does it need to be snipped, but it also needs to be cut a little more aggressively or else it has a high degree of recurrence or reconnection.
If we go back to our blog from a few weeks ago, we said that we need to be able to breathe through our noses 96% of the time and from our mouths 4%. If the nose is underdeveloped, we cannot breathe effectively from our noses and therefore are forced to mouth breathe. The more we mouth breathe, the more there are further developmental effects. With the mouth open most of the day and night to breathe, the tongue continues to fail in helping to shape the palate and the face develops longer than usual and there is the typical “long face syndrome” often noted. The nose is long and narrow, the lower jaw also becomes shorter and narrower, following the shape of the upper jaw.
This cascade of failures in facial development will have more severe consequences as we go further in depth in the coming weeks. In the next entry, we will discuss the ultimate reasons that this development most often results in obstructive sleep apnea in children and continues into adulthood.