Using Dentofacial Orthopedics to Treat Sleep Apnea

2011(1) Newsletter

How does it Work?

Modification of the craniofacial region is possible. A significant amount of growth potential resides in the craniofacial system throughout life. Dentofacial orthopedic therapies amount to growth guidance. Rapid maxillary palatal expansion in children is a common event producingchanges in maxillary size and shape which has been shown to affect the airway. Less common is slow palatal expansion in adults. The Homeoblock™ removable orthopedic/orthodontic appliance using slow palatal expansion can provide an environmental stimulation resulting in an epigenetic response, namely maxillary morphogenesis. Morphogenesis is defined as “the biological process that causes an organism to develop its shape”.

The upper Homeoblock™ appliance may reduce nasal airway resistance through induced maxillary morphogenesis. The lower Homeoblock ™ appliance can improve tongue posture and muscle tone. Both appliances have to work together to get good results.

“There are statistically significant associations between nasal cavity dimensions and peak nasal inspiratory flow. The most important structural determinant for peak nasal inspiratory flow is the minimal cross-sectional area of the nasal cavity. The narrowest point of the nasal passage, the functional nasal valve, is the most important determinant for inspiratory nasal airflow, being the main flow limiting segment of the nasal cavity.”

[Relation of Nasal Air Flow to Nasal Cavity Dimensions

Thomas Kjærgaard, MD; Milada, Cvancarova, MSc; Sverre K. Steinsvåg, MD, PhD Arch Otolaryngol Head Neck Surg. 2009;135(6):565-570]

TREATMENT WITH THE UPPER HB APPLIANCE DEMONSTRATES CHANGES IN THE NASAL VALVE AT THE MINIMAL CROSS SECTIONAL AREA.

Before After

The increased symmetry in the nares at the nasal valve in the after-photo is a result of maxillary morphogenesis (the Spatial Martrix Hypothesis)^* which reduces airway resistance and results in the left Nares becoming smaller and the right nares larger.

Before After

Before After

In the above after-photo, notice that both nares are wider and more symmetrical. This can be attributed to maxillary morphogenesis and development, producing an increase in size and improved function. The result is still less airway resistance.

We postulate that we have improved symmetry and therefore,improved function. Improved function is consistent with improved symmetry.

Improving symmetry improves biological function, a truism.

Edler cited research supporting the claim that bilateral symmetry is an important indicator of freedom from disease, and worthiness for mating.
^ Edler R. J. "Background Considerations to Facial Aesthetics", (British) Journal of Orthodontics, Vol. 28, No. 2, June 2001, pp. 159-168.

* Singh G.D., Krumholtz J.A., Epigenetic Orthodontics in Adults Selane Products Inc.,2009

The lower appliance is designed to bring the tongue upward and forward. A patient that has a good nasopharyngeal airway and a compromised oropharyngeal airway can be treated with a lower appliance only.

Red shows the improved tongue position, tone and the resulting increased pharyngeal airway size.
Note: These images have been created after registering before and after CBCT scans using Analyze 10.0 from the Mayo Clinic.

We have demonstrated a large increase in pharyngeal airway radius. Since airflow is a factor of r⁴, the radius to the fourth power, we have improved airflow considerably.

Poiseuille’s Law: ∆P= 8µLQ / πr⁴

Further research is necessary to show that these airway improvements reduce sleep apnea.