Every Breath You Take: a theory of Sleep Disordered Breathing

My introduction to Obstructive Sleep Apnea has been through the early orthodontic technique that recognizes that open mouth postures lead to deformation of the maxilla and, hence, crooked teeth.  Part of the deformity is poor forward growth of the mid-face leaving the airway smaller.  I've come to understand that these kids will be more susceptible to OSA since it will take less obstruction to stop the breath.

Mouth breathing has other effects as well.  

The theory is this: chronic open mouth posture allows  excess escape of  carbon dioxide (CO2) lowering both lung and blood CO2 levels.  Medullary breathing triggers (in the brain, stimulated by CO2)  are eventually lowered to accomodate these chronically lower levels.  Lower triggers are tripped sooner in a feedback cycle and in time breathing rate rises.  Hence, a state of chronic hyperventilation ensues.   Instead of 8-10 breaths/min, mouth breathers are 20 or more bpm.

Further, according to the Bohr phenomenon, lower blood CO2 raises blood pH and inhibits the release of O2 from hemoglobin lowering availability to tissues.

Finally, CO2 is responsible for regulating the tone of smooth muscle.  Lower levels lead to spasm in vessels and organs with multiple effects, including hypertension, behavioral effects, and more, too numerous to mention here.

 

Regarding sleep, open mouth postures are often at maximum during sleep, allowing even more CO2 escape.  Breathing may actually stop when blood levels are acutely low.  Breathing stoppage however allows a quick buildup of CO2 until the patient begins breathing with a start.  This is Centrally-mediated Sleep Apnea.

 

CPAP (continuous postive airway pressure), may be helping with OSA by physically opening the airway under pressure. But it may also be helping with CSA by preventing the excess release of CO2, allowing proper build-up and breathing triggering.  

It seems to me that this distinction has gone largely unrecognized by a burgeoning Sleep Medicine establishment.  You can see the relevance of this thinking is huge: to the extent mouth breathing is the cause of centrally mediated phenomenon, a transition to nasal breathing and a lowered breathing rate may be the FIRST line of defense against sleep disordered breathing, especially in the young.  Furthermore, mandibular advancement appliances,  airway clearing surgery, and even jaw surgery will be fruitless unless proper breathing is achieved simultaneously.

(I would like to thank Dr. John Flutter for helping me understand these concepts)

Sleep tight! (you lips, that is....)

Snake Oil?

My family is constantly chiding me on my fixation with mouth breathing.  Evidence of its importance to health seems to be everywhere I look and yet they don't have a context to understand my every mention of it.  They just roll their eyes.   Wait 'til they read this post....

I came across an ad from the 1930's, pictured here.  I saw it some time ago and sloughed it off.  Today, I read it again and it didn't seem so funny.  Read it yourself....

People on another blog were making fun of it.  So, I just had to add my two cents as follows:

"I can't believe I'm actually making this post, but after 28 years in the dental profession and now becoming fluent in the realm of sleep apnea and it's ravages, I can tell you in all seriousness that this somewhat inelegant method has merit!  Mouth breathing is still considered a deterrent to longevity.  And that's from day one of life.  

• Mouth breathing affects oxygen balance and metabolism (with lowered oxygenation of tissues).

• It allows unfiltered air to irritate the respiratory tract (hence, allergies, asthma, URT infections and swollen lymph tissue).

• It affects the tone of smooth muscle (like in blood vessels and organs).

• It leaves the upper jaw unsupported during growth (hence, crooked teeth).

• In fact, both obstructive and centrally-mediated forms of sleep apnea are aggravated by mouth breathing. 

 I've never considered selling snake oil, but I just might like to see this product make a return...."

And there you have it.  I said "snake oil".  Now they'll really think I'm off the deep end.  And, hey, at $3.00, it couldn't hurt...STEP RIGHT UP!....

What I'm telling the GP

Before I begin treatment, I write a letter to the dentist (GP, general practitioner) to explain what I'm going to do. The letter I wrote today was exemplary enough (as in: a perfect example), that I thought I might share it with you.   You may use it yourself....(p.s.: I'm using a fictitious name....)...

"Dear George,  Hi. It's Barry Raphael, orthodontist for Stephanie.   Below is a summary of my treatment plan for Stephanie and attached are copies of records.  Please review and consult with Stephanie's father and mother with your opinion.

First some background.  Before I move teeth, I like to look at the cause of the problem.  Orthodontics has long been plagued by trying to treat and maintain teeth when the etiology has not been rectified.  I particularly look at muscular habits,  especially during breathing, swallowing and sleeping.  Mouthbreathing and tongues not positioned on the palate are, I feel, responsible for many of the malocclusions we see, Stephanie included.  

Her narrow palate, posterior crossbite and anterior openbite are typical of such issues.  As such, my preliminary treatment is aimed at eliminating the harmful habits.  Once reduced, straightening the teeth become much simpler.  More importantly, however, these habits and the poor growth patterns that ensue are associated with the sleep disorders that adults are now often struggling with.  No matter the orthodontic protocol I choose, she will be predisposed to sleep disorders if the habits are not corrected.

Correcting harmful habits, unfortunately, is like giving dance lessons - many will participate but only those that are motivated and work at it will succeed, and even then to varying degrees.  Without Stephanie's and her parent's understanding and participation, the results will diminish, and she will be likely be subject to typical orthodontic regimines like extractions and retractive mechanics - something I try to avoid whenever possible.

Stephanie's treatment will begin with a removable (by her choice) expander to widen the palate and establish room for the tongue.  Then myofunctional training to 1) keep the lips closed, 2) keep the tongue on the palate, and 3) breath through the nose, especially at night, will begin.  Again, her cooperation with these exercises is paramount to success.

Should she have difficulty with the exercises I proscribe, a referral to an Oral Myologist will be made for a more specific and individualized therapy.

Finally, when she is on the way out of the mixed dentition (estimated age 11-12), I will re-evaluate for fixed appliance therapy.  If the myofunctional work is effective, only alignment will be needed.  If it is not, then more complex treatment will have to be considered.

If you are not familiar with the above approach, or would like to learn more about it out of curiosity, I will be happy to forward some links to more information. You can start here.

Sincerely,  Dr. Barry Raphael "