Airway Health Has Become A Popular Conversation In Orthodontics And Sleep Medicine. But Popularity Does Not Equal Precision.
“After a health crisis forced me to take my own sleep apnea seriously, I became less interested in opinion and more interested in proof.
If expansion truly improved breathing, it should show up in objective data. If it did not, we needed to know that too.
For years, I listened to colleagues talk about airway treatment. I saw enthusiasm. I saw theories. I saw case reports. What I did not see was consistent measurement.
So we began measuring every case.
Over time, six structural metrics consistently predicted meaningful physiologic change. These are the six we still use today.”
—Dr. Bret Christensen
Since 2013, we have systematically tracked airway data across hundreds of patients. Of those, more than 340 cases meet strict criteria for clean, analyzable data sets with consistent measurement timing and standardized protocols.
Key findings include:
This is not anecdotal improvement. It is structural change measured over time.
What it is:
The narrowest point of airflow in the nasal passage.
Why it matters:
Airflow resistance is greatest at the narrowest point. Even a one-millimeter increase can significantly reduce resistance and improve nasal breathing.
How we measure it:
Acoustic rhinometry: a non-radiographic tool that uses sound reflection to calculate cross-sectional dimensions.
What our data shows:
In over 340 clean, analyzable cases, pediatric expansion produced average increases of 42–46% in minimum airway size. In our top 100 cases, some nearly doubled.
What it is:
The total cubic centimeters of airspace within the nasal cavity.
Why it matters:
Volume correlates with oxygen stability, airflow efficiency, and sleep quality.
How we measure it:
Rhinometry for volumetric data, confirmed with CBCT imaging.
What our data shows:
Adults undergoing skeletal expansion commonly gain 3–8 cubic centimeters of additional nasal volume. In some cases, increases exceed 10 cubic centimeters.
To put that in perspective, one cubic centimeter is roughly the size of a dice. We often see multiple dice worth of new space created inside the nose.
What it is:
The skeletal width of the base of the nasal cavity.
Why it matters:
The roof of the mouth forms the floor of the nose. When the palate widens, the nasal cavity widens with it.
This is structural change not dental tipping.
How we measure it:
CBCT linear measurements taken at standardized anatomical landmarks.
What our data shows:
True skeletal expansion often produces 4–6 millimeters of nasal floor widening, significantly altering airflow capacity.
What it is:
The transverse width of the upper jaw (maxilla).
Why it matters:
Palatal width determines space for both teeth and tongue. A narrow palate limits tongue position and compromises airway stability.
How we measure it:
Digital calipers, CBCT measurements, and intermolar width tracking.
What our data shows:
Dental expansion that relies solely on the teeth is insufficient. Real, long-term improvements in the airway and sleep are better predicted by achieving true skeletal widening.
What it is:
The spatial relationship of the lower jaw to the upper jaw and airway.
Why it matters:
A retruded mandible pushes the tongue backward into the airway. The mandible is often the “victim” of a narrow maxilla.
How we measure it:
Cephalometric analysis and CBCT sagittal measurements. Lateral Cephalometric Analysis determines anterior posterior jaw growth vector of the maxilla and mandible. Dental compensations such as tooth tipping and flaring of anterior teeth. Frontal Cephalometric Analysis helps to determine posterior tooth inclinations and compensations along with facial imbalance and asymmetrics.
What our data shows:
When the maxilla is expanded properly, the mandible often repositions forward naturally, improving oral airway space without forcing it.
What it is:
The volumetric and positional space available for the tongue to rest against the palate.
Why it matters:
The tongue is the instrument of facial growth and airway stability. If it cannot rest fully on the palate, nasal breathing remains compromised.
How we measure it:
CBCT airway segmentation combined with clinical functional assessment and myofunctional evaluation.
What our data shows:
Structural expansion must be paired with functional adaptation. Mobility without space fails. Space without function relapses.
A child who sleeps quietly through the night. An adult who no longer wakes up exhausted.
A family that can stop worrying.
The data matters because it confirms what patients feel.
When nasal space increases, airflow improves.
When airflow improves, oxygen stabilizes.
When oxygen stabilizes, sleep changes.
Over 340 measured cases have shown us that structural change produces physiologic change.
That pattern is not accidental. It is repeatable.
