July 18, 2016

Breathe, breathe in the air: Don’t be afraid to care. A blog series on Sleep disordered breathing and orthodontic treatment: Part 1.

This post is the first of a series in which I will address the role of breathing in the aetiology of malocclusion and whether there is a role for orthodontic treatment to help reduce childhood sleep-disordered breathing (SDB).

This has recently become controversial because orthodontists and general dental practitioners are carrying out orthodontic treatment to “cure” sleep-disordered breathing and I am unsure of the evidence base of this treatment.

Orthodontic opinion is currently split on this issue. Some feel that they are providing an essential service as part of the holistic treatment of a young person. Alternatively, there are those who think that this is a newly invented “disease” that requires treatment and which can be done by orthodontists or general dental practitioners. This, of course, could be considered quackery and I have discussed this concept before in orthodontics.

Those of you who are “children of the 70s” will recognise the line from Dark Side of the Moon by Pink Floyd, and this is relevant to this series of posts. This is because practitioners who are providing orthodontic treatment for SDB feel that they are “caring” for patients in a holistic way and those who do not support this treatment suggest they are “caring” because they are not providing this treatment because of the low evidence base. So, if I move on from my adolescent and current taste in music and get on with the blog. I will start by considering “what is childhood disordered breathing and how should it be treated”? I have been joined in this blog by my colleague Professor Iain Bruce who is a Paediatric Otolaryngologist at the Royal Manchester Children’s Hospital, Manchester, North of England.


Childhood Sleep Disordered Breathing

We gathered information from several sources. This is by no means a formal systematic review, but we have used some systematic reviews as source documents.

Sleep-disordered breathing (SDB) is a general term for breathing difficulties during sleep. This may range from loud snoring to obstructive sleep apnoea (OSA), in which the airway becomes partially or completely blocked. In most cases, the “blockage” is caused by adenotonsillar hypertrophy. Airway collapse can affect the ability of the respiratory system to effectively exchange oxygen and carbon dioxide between inhaled air and the bloodstream. Subsequent fall in blood oxygen saturation and/or blood carbon dioxide rises, can be associated with changes in heart rate, blood pressure increase, arousals and sleep disturbance.

Sleep Disordered Breathing may be considered to be a spectrum from primary snoring, which is unlikely to have any potential physiological consequences, through to severe OSA with more potential significant implications (e.g. pulmonary hypertension and cor pulmonale). If a child does not get good quality sleep, they may become irritable, sleepy during the day, or have difficulty concentrating at school, with the potential for noticeable deterioration in school performance. Sleep-disordered breathing is a common condition with an estimated prevalence of primary snoring in children ranging from 8 to 27% and obstructive sleep apnoea from 1 to 5%.

 How is sleep-disordered breathing diagnosed?

The diagnosis of SDB is mainly clinical and based on a history of snoring with disturbed sleep, apneas and arousals. There are 2 main investigations commonly used in clinical practice, namely, overnight pulse oximetry and polysomnography (PSG). Both tests have drawbacks, not least because we do not have age-specific normative data, or absolute parameter changes defining ‘abnormal’ sleep, to help with interpretation. PSG may not be readily available in all hospitals and may be best reserved for children with co-morbidities, where significant diagnostic doubt exists, or apparent failure of initial treatment. Unfortunately, the correlation between clinical examination, quality-of-life scores and polysomnography are not high. ‘Positive’ overnight pulse oximetry is highly suggestive of SDB, but ‘negative’ results do not necessarily preclude the diagnosis.

As a result, current diagnostic practice tends to be based around a clinical history and examination, with possible supplementation with overnight pulse oximetry or PSG.

The diagnosis of SDB should be made by an Otolaryngologist or Paediatric Respiratory Physician. I cannot help feeling that this is outside the scope of practice of an orthodontist/general dentist.

 How is sleep-disordered breathing treated?

The most common cause of SDB due to airway obstruction is hypertrophy of the tonsils and adenoids. As a result, removing them solves the problem. Other treatments are positive airway pressure and lifestyle changes to help an obese child lose weight.

There has been a Cochrane systematic review that investigated the benefits and harms of tonsillectomy with and without adenoidectomy compared with nonsurgical management. They looked at the following PICO

  • Participants: children aged 2 to 16 years with obstructive sleep-disordered breathing
  • Intervention: Adenotonsillectomy
  • Comparator: nonsurgical management, for example, lifestyle interventions. Medical treatment, positive airway pressure and watchful waiting.
  • Outcomes: disease-specific quality-of-life

This was the usual, well carried out, Cochrane systematic review and they concluded:

“Moderate quality evidence is available that in otherwise healthy children (5-9 years old), without a syndrome, who have been diagnosed with mild-to-moderate obstructive sleep apnoea by PSG, there is moderate quality evidence that adenotonsillectomy in terms of quality of life, symptoms and behaviour and high-quality evidence in terms of overnight sleep study findings”.

They also pointed out that polysomnographic recordings of almost half of the children managed non-surgically had normalised by 7 months after the start of the studies. This is a condition that may spontaneously resolve over time. I will return to this later when we discuss treatment.

Importantly, the findings of the systematic review agreed with another analysis that underpinned the recommendations of the American Academy of Pediatrics which stated

“If a child has SDB and has a clinical examination consistent with adenotonsillar hypertrophy, and there are no contraindications to surgery, then the clinician should recommend adenotonsillectomy as the first line of treatment”.

The simple “take home” messages from this post are:

  • Sleep disorder breathing in children is a spectrum from primary snoring to obstructive sleep apnoea.
  • It is a severe problem for some children
  • The diagnosis of SDB should be made by an Otolaryngologist or Paediatric Respiratory Physician, not a dentist in isolation.
  • The most common cause of SDB due to airway obstruction is hypertrophy of the tonsils and adenoids. As a result, removing them solves the problem most of the time.

We hope that post provides good initial information on Sleep Disordered Breathing.  But does orthodontic treatment have a role in the treatment of sleep-disordered breathing? I will start to address this in the next part of this series when I discuss the evidence behind the effect of sleep-disordered breathing on craniofacial growth.

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Have your say!

  1. Thank you for starting this line of questioning on your Blog. My experience has shown that the most common sufferers of breathing disorders are mouth breathers. This is remarkably commonplace amongst our patients and is fundamental in causing a failure of the maxilla to develop normally. The causes are many and may be due to enlarged adenoids or tonsils, but are often related to habits in childhood (dummies, bottle feeding) or an untreated tongue tie. All these situations will cause the tongue to sit in the floor of the mouth rather than in the roof of the mouth. In this situation (unless it combines with a tongue thrust or excessive mentalis action) will allow the lower jaw to develop normally, and the upper jaw growth to be restricted. In turn this leads to an inability to breathe through the nose and perpetuates the problem.
    The mouth breathing habit changes the physiology (via the Bohr Effect) and these mouth breathing individuals have a lesser ability to exercise. It is consequently not remarkable to see that these children are commonly overweight. Only by correcting this mouth breathing behavior can one expect to make lasting changes. Just making orthodontic corrections will be just that and will inevitably result in relapse.

  2. Thanks for summarizing this for us Kevin.
    I would like to add that there are adjunctive screening tools that we as dentists can use to further support any management decision when faced with a children or adolescent with a potential sleep disorder. Based on available evidence the best single tool to complete such screening process is the Paediatric Sleep Questionnaire (PSQ) by Chervin et al (reference below). This tool is really good to discard paediatric sleep disorders (almost perfect negative predictive value), but only suggestive for presence of paediatric sleep disorders (only moderate positive predictive value). In other words if this test is negative we are almost certain that there is no paediatric sleep disorder issue. As mentioned in your post is the combination of physical examination and medical history (covered at least in part through the PSQ) that suggest need to address the medical issue. Finally this diagnosis process (I prefer to call it screening process) is geared to properly refer the potentially affected patient to the otorhinolaryngologist for proper diagnosis and treatment, not for us dentists to primarily treat these cases. We can help in very specific situations but that will be covered in future posts as mentioned by Kevin.

    De Luca G, Singh V, Major MP, Major PM, Flores-Mir C. Diagnostic capability of questionnaires and/or clinical examination for the assessment of SDB in children: a systematic review and meta-analysis. J Am Dent Assoc. 2014; 145:165-178. doi: 10.14219/jada.2013.26.

  3. Thank you for taking up this topic
    I would kindly suggest a slightly different perspective on a few things:
    1. SDB starts at mouth breathing. This is becoming widely accepted amongst paediatric airway specialists.
    2. In otherwise normal children, sleep studies are a waste of time as they diagnose OSA and not the other forms of SDB.
    3. The concept of primary snoring is one borrowed from adult sleep medicine and applied to paediatrics. The research indicates there is likely to be no such thing in kids.
    4. Large adenoids alone has been shown to lead to pulmonary hypertension
    5. We know that many kids will stop having airway problems in time. The research of Bonuck K Paediatrics 2012 showed this to be the case, but with no intervention, a markedly increased incidence of a range of behavioural problems in children who “got better”.
    6. Adenotonsillectomy, at best, gives about an 80% cure rate in otherwise normal kids, in the short term with longer follow up studies showing a relapse in years to come, and a decrease in that relapse with post-op myofunctional therapy.
    7. I note a comment has been made about mouth breathing being habit. The research shows that in 80% of cases there is actual some form of physical obstruction. Furthermore there is a pervasive repetition of the application of the Bohr effect in dentistry in discussing SDB. This demonstrates a poor understanding of physiology as it is the conflation of cellular respiration with pulmonary respiration.

  4. Kevin,
    Thank you for starting this conversation. I have spent the past five years learning about and teaching the concepts of SDB to orthodontists throughout North America. I will wait until your commentary on SDB is completed before weighing in with more detail, however I did want to make a few comments. The most important thing is that in the USA the laws are such that NO dentist can diagnose any form of SDB, including snoring. It is a medical diagnosis that can only be made by a physician, and in some states, only a board certified sleep physician. That being said, dentists can screen for SDB by collecting data, performing the physical exam, issue (prescribe) home sleep tests but not interpret (physician must interpret) and use other screening tools in order to make a meaningful referral to the appropriate physician who then makes the diagnosis and PRESCRIBES the treatment. Such treatment recommendations may or may not include orthodontics depending on the education and experience of the physician. Along these lines, much of the research supporting orthodontic treatment in conjunction with other treatment modalities for SDB appears in journals that most dental professionals would never have exposure to, leaving many with a limited background upon which to base their treatment decisions. There is a lot more here than making sleep appliances. I look forward to reading the upcoming posts.

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