An occasionally irregular blog about orthodontics

Does sleep disordered breathing influence facial form

By on September 21, 2015 in Clinical Research, Recent posts with 9 Comments
Does sleep disordered breathing influence facial form

Does sleep disordered breathing influence facial form?

One of the most controversial areas in orthodontics is the relationship between craniofacial form and breathing. This is very relevant because we do not  know how much the environment (e.g. breathing) influences the aetiology of malocclusion.  This area of research is becoming increasingly important as we search for treatments that correct functional problems. This recent, open access, paper sheds some light on this interesting area.


Screen Shot 2015-09-21 at 11.58.03The influence of snoring, mouth breathing and apnoea on facial morphology in late childhood: a three-dimensional study

Ala Al Ali et al

British Medical Journal Open. On line DOI: 10.1136/bmjopen-2015-009027




One of the lead investigators is Prof Stephen Richmond from Cardiff University, Wales. I had the pleasure of working with him in Manchester from 1984 – 1993. His major work has been in the development of measures and he has refined the index of orthodontic treatment need and invented the PAR index. I shared an office with him for  several years and his area of our office was always covered in piles of dental casts, papers and measuring devices, while mine had a completely clear desk. I still miss those vibrant days, but I do not miss the untidy office!

In this paper, they investigated the relationship between the prevalence of sleep disordered breathing (SDB) and face shape in a large sample of 15-year-old young people. They wanted to investigate this problem because SDB is a subtle disorder of childhood and it may have serious consequences. The prevalence varies between 2 to 16%. They provided an excellent literature which covered the subject very well and this is well worth reading.

They defined SDB as “an abnormal respiratory pattern during sleep that includes snoring, mouth breathing and pauses in breathing”.

What did they do?

The children who took part in the study were part of that Avon Longitudinal Study of Parents And Children (ALSPAC). This is a cohort study of 13,988 newborn children who have been following prospectively since the early 1990s. Further details are here. A large amount of research data has been collected on these young people. This included SDB data that they collected at six, 18, 30, 42, 57, 69 and 81 months of age. This was based on symptoms reported by the parents.

During 2006 and 2007 they recalled the children  when they were 15 years of age and they scanned their faces with paired optical scanners to generate three-dimensional facial images. They then constructed the average faces of the children with SDB (1724) and healthy children (1862).

They used the relevant sophisticated statistical analysis and I was really pleased, and impressed, to see that they avoided presenting and analysing a mass of cephalometric data by combining their main measurements into five dimensions.

What did they find?

Their main finding was that the odds of a child having SDB increased with respect to mandibular angle and increasing face height and decreased with face width. In general, healthy children tended to have bigger noses, more prominent mandibles and cheeks and forehead.

They stated that one advantage of this study, over previous investigations, was the large sample size of children who were all of the same age, they were demographically equivalent and they controlled for the confounding variables of body mass index and gender.

They concluded that SDB was associated with an increase in face height, retrusive mandible and decrease in nose prominence.

What did I think?

I thought that this was an interesting paper and I’ve thought about its clinical significance. I think that it is important for us to consider that we do not know whether the facial features were caused by the SDB, or was the SDB a result of the facial morphology? As a result, we cannot assume that we can treat SDB by attempting to change skeletal pattern. Furthermore, we also know that we cannot influence the skeletal pattern with orthodontic appliances. Nevertheless, we cannot discount attempting to treat SDB when the child is young to try to change a skeletal pattern. But before the myofunctional orthodontists get excited and start promoting this concept, I would like to see someone carry out a trial in this area.

What this discussion is  somewhat academic. It is worth pointing out that the differences in facial morphology between the SDB and healthly children were very small (in the order of less than 1mm or 1 degree). Finally, they collected the SDB data when the children were 7 years old and the facial form data was recorded when the children were 15 years old. A lot has happened between these two-time points and I think that the authors have assumed that the SDB continued from 7 to 15 years old. This was not really addressed in the discussion.

In summary, even though I have ended on a critical note, I think that this  study has interesting findings and I feel this it is an addition to the literature.

Perhaps there is a relationship between SDB and facial form? The clinical relevance of this could be addressed in a trial early functional appliance treatment for Class II malocclusion? This made me wonder whether the early class II treatment studies should be repeated with SDB as an outcome. Now that would be a good study!

There may not be a blog next week, as I will be at the WFO 2015 Congress in London. I hope to see many of the followers of this blog there!

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There Are 9 Comments

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  1. Benny Soegiharto says:

    always enjoy your review Prof! Hope to see you soon in London WFO!

  2. How could the myofunctional orthodontist fail to jump on this evidence? We’d be abandoning our mission if we did not give a little elbow nudge at this one. But Kevin, I honor your role as the eternal skeptic in keeping us honest…

    Regarding the “which came first” question of facial morphology vs OSA (or any flow limitation for that matter, including snoring), there is no benefit in asking that question. Much like the chicken and egg quandry, the appropriate form and function question is really this: “What comes NEXT?”. Form and function is an eternal spiral and it is either proceeding to health or proceeding toward illness. As clinicians we need only decide in which direction the spiral is headed and how to reverse its trajectory.
    So if a child has OSA, UARS, or snoring, you can rest assured that the current trajectory is not toward good health. Now the question is how to intervene: Addressing Form or addressing Function. (But doing nothing does nothing).

  3. David Mcintosh says:

    As an ENT, I find this topic very interesting. I also find it very concerning.
    My concern is that whether SDB in kids is related to craniofacial form is the least of concerns when it comes to a child’s health. There is, however, a cohort of practitioners that dismiss mouth breathing as an issue as they feel it has nothing to do with orthodontics. By doing so, the child’s SDB is not assessed, and hence not treated.
    In many ways the arguments have been all misguided from a patient point of view.
    There is so much that a child benefits from when they are able to breathe properly, if it helps orthodontics as well, then that is a great bonus but hardly the greatest benefit.

  4. Brian Bourke says:

    Hi Kevin,
    Very interesting paper and I enjoyed reading your opinion thank you. I would be very interested in reading what Dr. David Macintosh as an ENT specialist recommends as a care pathway for these SDB-affected children following his comments. I was fascinated by the content of his linked slide presentation. This is clearly an enormous “new” area as we learn more about a very old and vexing problem. There are potentially very great implications arising for many areas across the patient care spectrum as awareness and understanding in this area expands.
    Thanks as ever,
    Brian Bourke

  5. great info, Dr. OBrien. Please see my post on LinkedIn regarding this article and your blog!

  6. Kevin Boyd says:

    Dear Kevin

    In response to your posting of this article I sent a note to a colleague who was a co-author:

    Congratulations to you and your co-authors on this BDJ paper that was recently discussed on Kevin O’Brien’s, (cc’d- a British academic orthodontist who is largely visible per his blog

    Anyway, it would be interesting to see if data could be extracted from this particular AVON cohort of 15 yr-old ‘children’ that might indicate the presence of predisposing craniofacial phenotypes (e.g., high-vaulted/narrow hard palates, lack of adequate space for the tongue, cross-bites, open bites, retrognathic mandibles and/or maxillae, excessive overjets, obtuse nasio-labial angles, enlarged tonsils and/or adenoids, steep mandibular plane angles, gummy smiles, deep overbites, etc.) from when they actually were indeed ‘children’ and first present/detectable; and thus correctable, whilst they were still in their complete primary/early mixed dentition stage of dental (i.e., under 6 yrs old). This would lend support to our (testable) hypothesis that certain physical/craniofacial and behavioral phenotypes that are known (evidenced) to be associated with increased risk for later malocclusion and associated airway and neurological/neurobehavioral disease, are often initially detectable, and treatable, in very early life; this would also support our speculation that most orthodontic Dx/Tx is begun much to late relative to protecting children from increased risk for SDB/OSA, ADD/ADHD,etc.

    My colleague replied that this would indeed be a good investment of time and energy, but lack of funding for such an endeavor would likely preclude it.

  7. Thanks for sharing this, Kevin O’Brien! We have postulated for years that upper (nasal) and lower (tongue base) airway obstruction during growth and facial development can lead to developmental jaw deformities, especially long-face syndrome and anterior open bites. We know that the lower jaw is the primary determinant of vertical and transverse growth of the upper jaw. It follows that children who can’t breathe through their noses and habitually mouth-breathe develop adverse vertical growth patterns which, if not corrected early, may require surgical correction after growth has ceased.

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