The Link between Airways, Obstructive Sleep Apnea and Faces By Juan-Carlos Quintero, DMD, MS, and Stefan Zachar IV (guest author)

                According to the American Association of Orthodontists (AAO) glossary, Orthodontics and Dentofacial Orthopedics is the specialty which includes the diagnosis, prevention, interception, guidance, and correction of mal-relationships of the developing or mature oral and facial structures (figure 1). Orthodontics is actually more about overseeing and managing facial development and jaw relationships, and less about aligning crooked teeth. This article will discuss the vital role the orthodontist plays, for better or for worse, in understanding, screening and managing the patency of the human airway and the long term effects of that management on sleep disordered breathing (SDB) such as obstructive sleep apnea (OSA) when this information is considered (or not considered) in orthodontic treatment.

Figure 1

Figure 1

                Since the early 19th century, the relationship between airways and facial structure has been studied1. 2. 3. People became interested, because breathing is a function of craniofacial anatomy (Figure 2).

Figure 2

Figure 2

                One of the most famous theories in craniofacial biology is The Functional Matrix Theory postulated in the 1960’s by Dr. Melvin Moss4. It states that soft tissue and airway guide hard tissue, because the need to breathe supersedes all other factors which may influence growth. As 3D imaging technology continues to improve, the research is becoming increasingly clear and abundant, that the way we breathe during our growing years deeply affects how our face grows and conversely, our facial patterns and shapes produce our airway anatomy, thus influencing the way we breathe. It’s a bit of the chicken-or-the egg(?) scenario. Which came first? The truth is the 2 are tightly intertwined and as owners of craniofacial anatomy, no one is better positioned to manage airway development than orthodontists.

                The upper human airway is known as the pharyngeal airway or pharynx (figure 3) , divided into thirds:  the laryngopharynx positioned inferiorly, the oropharynx in the middle and nasopharynx right above (figure 4) .

Figure 3

Figure 3

Figure 4

Figure 4

                Several investigators have recently studied the relationship between pharyngeal airway shape and different facial patterns using cone beam computerized tomography (CBCT), a highly accurate method for airway assessment. The results are changing the landscape of orthodontics as we know it. Recently, Drs Dan Grauer and William Proffit  at the University of North Carolina compared non-growing patients, categorizing their facial types into convex profiles (Class  II), straight profiles (Class I), and concave profiles (Cl III), and then measured the pharyngeal dimensions to see if a possible correlation exists between the 3 different facial categories and airway size.  The results of the study concluded that there was a statistically significant difference between airway dimensions and the facial type: Cl II (receded lower jaws) patients had the smallest airways, followed by the CL I (straight profiles), and then CL III faces (strong lower jaw) had the largest airways. In other words, small mandible correlate to small airways, and large jaws correlate to large airways5.

                A similar study by Abdelkarinm, et al, found even stronger correlations between facial patterns and minimal cross sectional areas (MCA) of pharyngeal airways. MCA is important because it represents the “bottle neck” of the airway and thus the risk for an airway obstruction problem such as obstructive sleep apnea.  This study was particularly important because it correlated facial pattern with risk factors for obstructive sleep apnea (OSA). Abdelkarim concluded the following6:

  • Pharyngeal airway volume was largest in the Cl III patients those with the strongest mandibles or most forward lower jaw position, followed by Cl I patients – normal mandible posture, and then the last or worst were the Cl II patients with the weakest lower jaw position, known as mandibular retrognathism
  • These results indicate that the anteroposterior (front-back) dimension of the oropharyngeal airway space is affected by different skeletal patterns of the mandible. In conclusion, the mandible seems to be the biggest determinant of the airway size.
  • The pharyngeal airway should be evaluated in patients with mandibular retrognathism (small lower jaws), especially in severe cases
  • If relevant snoring or OSA symptoms are present, consideration of a sleep study, including polysomnography (PSG), can be beneficial for specific Class II malocclusion patients with noticeable mandibular retrognathia

                A recent study conducted at Case Western Reserve University by Dr. Martin Palomo reached similar conclusions7.

                 Various methods exist for the treatment of obstructive sleep apnea. They include from weight loss (the least invasive, but arguably the most difficult), positional therapy (sleeping on one’s side, not one’s back), nasal decongestants, CPAP, oral appliances, soft tissue ENT surgery known as UPPP, hard tissue jaw surgery in the form of orthognathic surgery known as maxillomandibular advancement (MMA) or mandibular advancement (MA) surgery and finally, as a last resort, a tracheotomy or tracheostomy.  Several controlled institutional based studies have compared the efficacy of some of these above mentioned methods and have found that MMA has the best outcomes for OSA when compared to CPAP and oral appliances. A few studies have even found success rates of 100% using MMA as measured through sleep studies and looking at AHI (Apnea Hypopnea Index) compared to CPAP and oral appliances8, 9, 10, 11 (figure 5 & 6).

Figure 5

Figure 5

Figure 6

Figure 6

                MMA/ MA move the jaws forward and consequently enlarge the airway. It should not come as a surprise that MMA/MA are considered the end-all, cure-all of obstructive sleep apnea because it is the only therapy which makes permanent changes on anatomy in non-growing patients. The studies discussed above regarding the relationship between airway size and jaw position explain why this is so5,6,7.  Corrective jaw surgery to enlarge airways can be a positively life altering procedure. Not only is life expectancy drastically increased, but also the quality of life can drastically increase as overall health improves/ What’s more, these patients become “CPAP liberated”. However, having one’s facial skeleton repositioned through corrective jaw surgery is invasive, comes with risks, and is by no means a “cake walk”.

                All of the above mentioned alternatives to the treatment of obstructive sleep apnea have limitations. What has not been mentioned is perhaps the least invasive, least expensive and most effective approach to OSA (obstructive sleep apnea): PREVENTION in children. Knowing that airways correlate with dento facial patterns, how can we as orthodontists not look at children differently and consider minimally invasive orthodontic therapies during the growing years of the face to help promote forward facial growth consistent with airway development? Just as important how can we continue to design orthodontic treatment plans which violate airways or worse, not consider airway in our orthodontic evaluations?

                What this means to orthodontists and patients seeking or undergoing orthodontics is that airways can and should be managed, manipulated or enlarged and orthodontic treatment plans should be designed with this in mind not only to treat to airways, but also, more importantly, to prevent airway obstructive related issues such as obstructive sleep apnea later in life. Figure 7 shows such an example of a pediatric patient suffering from OSA and who through early phase I orthodontic treatment had his airways enlarged and is now sleeping better, breathing better and living better. I know this because not only is he my patient, but also he is my son (figure 7)12.

Figure 7
Figure 7


  1. Linder-Aronson S. Adenoids. Their effect on mode of breathing and nasal airflow and their relationship to characteristics of the facial skeleton and the dentition. A biometric rhino-manometric and cephalometro-radiographic study on children with and without adenoids. Acta Otolaryngol Suppl 1970;265:1 – 132.
  2. Linder-Aronson S. Woodside DG, Lundstrom A. Mandibular growth direction following adenoidectomy. Am J Orthod 1986; 89: 273-84.
  3. McNamara, JA. Influence of Respiratory pattern on Facial Growth. Angle orthod; 1981;51: 269 – 300.
  4. Moss ML. The Functional Matrix. Functional Cranial Components.
  5. Grauer D, Cevidanes LH, Styner MA, Ackerman JL, Proffit WR. Pharyngeal airway volume and shape from cone-beam computed tomography: relationship to facial morphology. Am J Orthod Dentofacial Orthop. 2009 Dec;136(6):805-14.
  6. Abdelkarim, A. A cone beam CT evaluation of oropharyngeal airway space and its relationship to mandibular position and dentocraniofacial morphology. Journal of the World Federation of  Orthodontists. . 16 July 2012.
  7. El H, Palomo JM. Airway volume for different dentofacial skeletal patterns. Am J Orthod Dentofacial Orthop. 2011 Jun;139(6):e511-21
  8. Holty JEGuilleminault C. Surgical options for the treatment of obstructive sleep apnea. Med Clin North Am. 2010 May;94(3):479-515.
  9. Prinsell JR. Maxillomandibular advancement surgery in a site-specific treatment approach for obstructive sleep apnea in 50 consecutive patients. Chest. 1999 Dec;116(6):1519-29.
  10. Riley RWPowell NBGuilleminault C, Stanford University Medical Center, CA. Obstructive sleep apnea syndrome: a surgical protocol for dynamic upper airway reconstruction. J Oral Maxillofac Surg. 1993 Jul;51(7):742-7; discussion 748-9.
  11. White PD,  Wooten V, Lachner J, Guyette RF: Maxillomandibular advancement surgery in 23 pts with OSA syndrome. J Oral Maxillofac Surg  47: 1256, 1989.
  12. Quintero, JC. (Case Report) Unlocking King Airway, TMJ and Growth with  CBCT as the key.  OrthoTown, September 2011, Page 70.

About Dr. Juan-Carlos Quintero

Dr. Juan-Carlos Quintero (AKA Dr. “Q”) received his Dental Degree from the University of Pittsburgh in Pennsylvania and Degree in Orthodontics from the University of California at San Francisco (UCSF). During this time he also received a Master’s of Science Degree in Oral Biology. This optional degree requires an extra year of formal education and research. Before moving to Florida, Dr. Quintero was in private practice in San Diego, California for one year, where he practiced with, and mentored under world-renown orthodontist Dr. Ron Roncone.

Dr. Quintero has served as National President of the American Association for Dental Research- SRG, won numerous National research competitions, published over 14 articles in peer reviewed scientific journals and currently lectures extensively both nationally and internationally. Dr. Quintero is a faculty member at the prestigious The L.D. Pankey Institute and an attending professor at Miami Children’s Hospital, Department of Pediatric Dentistry.

Dr. Quintero is immediate past-president of the South Florida Academy of Orthodontists (SFAO). He has also been featured on several television news shows, including the Discovery Channel. He is in private practice and took over the orthodontic practice of the late Dr. Lindsey Pankey, Jr. in South Miami, Fl. His academic interests include technology in orthodontics and 3D craniofacial imaging.

3 thoughts on “The Link between Airways, Obstructive Sleep Apnea and Faces By Juan-Carlos Quintero, DMD, MS, and Stefan Zachar IV (guest author)

  1.  avatar Dr Bill Thomas

    Love your blog and information! I’ve linked your site and blog on my own web site and find its a great reference. Awesome job!

    Bill Thomas

  2. JC…We just “met” today and I’m already a fan of your blog (and your point of view).

    So about this article…I went through some of the references which looked at correlations between facial morphology and airway size. It occurs to me that looked a means of a group misses the point. What would be more interesting is to look at the individuals in that group and ask, “What does THIS individual have to do with his body to keep his airway open enough to breathe comfortably?” Does the head sit forward? Does the mouth hang open? Does the cervical spine adjust to open up the narrow spots?

    And then we have to ask, “How did that maneuver to keep the airway open affect how THAT person’s face grew from the moment they started making those compensations?” Did the tongue fail to support the growth of the palate? Did the tongue have to keep forward so as not to clog the airway? Did the facial muscles become more active to compensate for the tongue posture? The questions that can be asked are numerous and fruitful.

    We saw the same thing in Harvold’s monkey studies. Taking averages only masked the fascinating differences in the way each individual created compensations for the inability to breathe through the nose. All different forms. All different Angle classes. And yet all with the same etiology.

  3. G-d Bless! JC, I believe you saved your son’s life. I truly do.
    When we, as orthodontists, come to understand the power of what we can do to help children relinquish their compensations and start to function competently as nature intended, then we will all have great stories to tell.

    Great work!

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