Should there be a greater emphasis on Orthotropics in the treatment of malocclusion?

Orthodontic treatment is, and has been for many years, the go-to method of dental professionals for treating malocclusion (the misalignment of teeth) whether it is through a protruding or sunken maxilla/mandible, or twisted teeth due to dental crowding. There’s no doubt that this practice is effective, since most if not all patients end up with straighter teeth, less crowding and generally a more aesthetically pleasing smile. But the process does not come without its drawbacks, such as the risk of the teeth becoming misaligned again as well as having to go through surgical procedures on multiple occasions. However, in recent years with the introduction of a new field of study called Orthotropics, it may be possible for patients to avoid having to go through serious orthodontic treatment, or even to avoid the process altogether, by correcting their oral posture. In undertaking an individual research project, I explored the potential for orthotropics to change dentists’ perceptions when it comes to treating malocclusion. Having considered the issue, I concluded that orthotropics would be most effective as a ‘supplement’, or a preventative measure to possibly avoid going through orthodontic treatment and should be given more attention to by the NHS

Orthotropics is a branch of dentistry invented by Professor John Mew and developed further by his son Doctor Mike Mew. It is a field of study that specialises in treating malocclusion mechanically by guiding the growth of the facial bones which prevents or corrects an unfavourable growth pattern of the maxilla and mandible (usually arising in the form of excessive vertical growth, and lack of horizontal growth), known as craniofacial dystrophy, by correcting oral posture, which consequently improves the oral environment. In order to understand why Dr John Mew started out approaching this issue mechanically as opposed to surgically, we must compare the evidence brought forward by our ancestors, or more specifically, our ancestors’ jaws.

The jaws of our direct human ancestors (or those of modern humans living in isolation) almost always grew correctly[1], and this trend has carried on for a long time, but in the last few decades nasal obstructions and oral malocclusions have rapidly increased[2]. If we compare the differences between us and our ancestors, there are two factors that appear to have contributed the most to this change -genetics and lifestyle. Faulty genes are likely to play a role in the deformity of jaws, however they are not thought to be the root cause for the majority of individuals with craniofacial dystrophy, since there isn’t a single change in human DNA over the last 10,000 years that corresponds with this increase[3]. This suggests that the problem is less complex than we may think, and, unsurprisingly, when we compare current lifestyles with previous ones, we notice there are a number of differences which point to this conclusion . Humans in recent times have started eating much softer foods; changing infant feeding methods by way of introducing soft weaning foods; and living indoors. The effects of our current life styles are as follows: eating softer foods weakened our jaw muscles; early weaning created abnormal tongue habits such as resting it on the floor of the mouth; and indoor living is thought to have encouraged allergies as we weren’t coming into contact with enough bacteria to populate our gut microbiota[4], causing our immune systems to incorrectly categorise harmless substances as a threat in later life.

This idea that the aetiology (the cause) of craniofacial dystrophy (and therefore malocclusion as will be explained later) is largely an environmental factor that we are able to change, and not a genetic one, is what led to Professor Mew developing Orthotropics.

There are major problems associated with our current life styles, in relation to craniofacial dystrophy. Some allergies such as those to pollen, cause nostrils to become stuffy and obstructed, thus forcing the mouth to be opened in order to breathe. The outcome may be the same even if one does not have any allergies, as weak jaw muscles are not strong enough to keep the mouth shut, and combined with the fact that the tongue rests on the floor of the mouth (instead of on the palate which would prevent air passing through the mouth), a habit of breathing through the mouth is greatly encouraged. Mouth-breathing automatically causes the mandible to hang down and backwards[5]. In addition to this, the tongue does not press on the palate to apply pressure to the maxilla to support its forward horizontal growth, so the maxilla sinks back into the skull. With both jaws not growing forward enough, all the organs housed in the maxilla and mandible including the tongue, airway, sinus, nasal passages, and teeth are compressed into a narrower space[6]. This leaves the nasal and sinus cavities congested, and the oral cavity too small for the tongue, making it more likely to rest against the back of the throat, restricting the airway, particularly during sleep. This can lead to obstructive sleep apnoea, in which the breathing is interrupted, causing the brain, and the rest of the body, to receive insufficient oxygen.[7]

Additionally, the reduced outward growth of the jaws increases the likelihood of having problems with the jaw joints, resulting in Temporomandibular joint disorders[8], in which pain is felt in the jaw, around the ear, while chewing, and aching throughout the face. There is a difficulty in opening and closing the mouth due to the locking of the joint.

Mouth-breathing during the day, even when the tongue does not significantly restrict the airway, also affects oxygenation of the brain. Breathing through the nostrils is the most natural way in which animals breathe because it regulates airflow and prevents over-breathing. Breathing through the mouth involves taking in/out more air than necessary meaning that too much carbon dioxide tends to be exhaled, leading to hypocapnia (state of reduced carbon dioxide in blood). Each  2.5% drop in the partial pressure of arterial carbon dioxide reduces blood flow to brain by 2%[9]. In other words, oxygenation of the brain significantly decreases when you breathe through the mouth too much (this may seem counter intuitive as you are taking in more oxygen than normal, but due to the Bohr effect, haemoglobin, which associate with oxygen molecules in the blood plasma, will less readily dissociate with them at respiring tissues such as the brain when there is a low surrounding concentration of carbon dioxide, which is the case when one takes frequent large breaths through the mouth compared to smaller ones taken through the nostrils, as a proportionally large volume of carbon dioxide is being exhaled and lost). Subsequently, there is a resultant lowering of vital activities generally and of the activity of the brain in particular, and studies that show that mouth breathing has a crucial role in hindering somatic, cognitive and behavioural development in children[10].

But apart from the effect on the brain, how does all of this affect our teeth? As mentioned earlier, CFD prevents the outward growth of the jaws, therefore there is not sufficient room for all thirty-two teeth to align naturally, so teeth become very crowded [11]. Also, when the tongue is forced further back towards the airway, it is not exerting sufficient pressure outwards to oppose that of the facial muscles. The face seeks growth in the path of least resistance, downwards, further contributing to crowded teeth[12].

The orthotropic treatment involves getting the patient to create a permanent habit of keeping the lips closed and the mouth shut, to prevent air being able to pass through the mouth; resting the tongue on the roof of the mouth to drive the maxilla up and forwards and  provide head support (Mewing). This is primarily achieved through appliances which are fitted in the mouth. Bioblocs are a type of orthodontic appliance used to posture forward the lower jaw. It helps the patient achieve facial balance and aids the correction of poor oral posture at rest. More importantly, it aims to redirect jaw growth anteriorly in a more horizontal direction so that a better oral posture and soft tissue facial profile is developed[13]

The level of success of this process often depends on a greater amount of work being put in by the patient (and possibly family) than by the dental professional carrying it out, especially when the patient is a child, since they may not comprehend the importance of good oral posture, and so at times will want to take the easy option

That is not to suggest that the work of an Orthotropist is a walk in the park however, as they must regularly have meetings with the patient, (perhaps even more often than an orthodontist with someone who’s is getting braces fitted) to monitor any progress and their myofunctional training (exercises involving the mouth that teaches correct swallowing and building up jaw muscles). Treatment is most effective at an early age, preferably before the age of 10 since from this point facial bones rapidly begin to stiffen, although it will still work for those that are older, albeit much slower.

The advantages of orthotropic treatment, In addition to the aforementioned conditions that it can steer the patient away from by preventing mouth-breathing, are that after creating the habit that corrects oral posture, no more treatment is required since it is dealing with the cause of malocclusion; the same cannot be said for orthodontics, which effectively treats the symptoms of  malocclusion, since it sees It purely as a teeth problem. After treatment with fixed braces, the results need to be held straight with retainers forever. There is growing evidence that permanent retention is damaging to the gingiva and bone which supports the teeth holding them out of their naturally balanced position for long periods[14].

Also, the length of treatment depends on how quickly a habit is formed. This is more often than not a strength of Orthotropics, because it is not incredibly difficult to create a chronic oral habit. On the other hand, Orthodontic treatment with braces alone can take many years.

Finally, Orthotropics circumvents the need for jaw reposition surgery or tooth extraction, which is a relatively common solution for malocclusion with Orthodontists.

The downsides to orthotropic treatment  include the fact that it is not likely to produce perfect tooth alignment, because that can also depend on diet and what types of food are eaten. Furthermore, the cost of treatment is fairly expensive, and the NHS only offer it in extreme cases, so if professional assistance is required, it can cost up to £7500 in total.

In conclusion, this dissertation has aimed to answer the question as to whether a greater emphasis should be placed on Orthotropics in the treatment of malocclusion. It can be concluded that there should be a greater awareness of the importance of oral posture, certainly in the UK since, from speaking to multiple peers and teachers, there appears to be little to no knowledge of the concept or practice of Orthotropics. (Admittedly, I did not know about it until a few months prior to writing this research project, but that only emphasises the point I’m making)

While I understand that there is currently insufficient research and knowledge (in comparison to e.g. orthodontics) on the efficacy of Orthotropics especially in terms of the growth of the lower jaw (most investigations are led solely by the Mews), leading me to believe that, as of right now, it should by no means replace orthodontics as the main method of malocclusion treatment, it would certainly be useful to at least inform the general public of the practice of Mewing, since there is at least enough evidence to suggest that it could offset the severity of malocclusions by allowing the teeth to have enough space to align naturally. As a result, less patients may have to see the doctors regarding this issue, which could save valuable time and resources for dentists.


  • Boyd, An evolutionary perspective on the etiology of malocclusion, Darwinian Dentistry part 1, 2011 p.34


  • Silveira, W. A. Simões, F. J. M. Macedo, P. Valério, The Increased Prevalence of Malocclusion in Modern Humans: An Integrative Review, 2018


  • Cramon-Taubadel, Global human mandibular variation reflects differences in agricultural and hunter-gatherer subsistence strategies, 2011


  • Bernardes, E. “Hygiene Hypothesis in Asthma Development: Is Hygiene to Blame?” Archives of Medical Research 48, Issue 8, 2018, p.717-726


  • Basheer, K. S. Hegde, S. S. Bhat, D. Umar, K. Baroudi, “Influence of mouth breathing on the Dentofacial growth of children: A Cephalometric Study” J Int Oral Health. 2014 Nov-Dec; 6(6): 50–55


  • Mehta, T. S. Vasu, B. Phillips, F. Chung, Obstructive Sleep Apnea and Oxygen Therapy: A Systematic Review of the Literature and Meta-Analysis, 2013


  • Bengt Olof Mohlin, Karen Derweduwen, Richard Pilley, Ann Kingdon, W. C. Shaw, and Pamela Kenealy (2004) Malocclusion and Temporomandibular Disorder:A Comparison of Adolescents with Moderate to Severe Dysfunction with those without Signs and Symptoms of Temporomandibular Disorder and Their Further Development to 30 Years of Age. The Angle Orthodontist: June 2004, Vol. 74, No. 3, pp. 319-327.


  • A. Godoy, A. Seifi, D. Garza, S. Lubillo-Montenegro, F. Murillo-Cabezas, Hyper ventilation therapy for control of posttraumatic Intracranial Hypertension, 2017


  • Ribeiro GC, Dos Santos ID, Santos AC, Paranhos LR, César CP, Influence of the breathing pattern on the learning process: a systematic review of literature, 2016


  • Mew, Craniofacial dystrophy. A possible syndrome? British dental journal volume 216 no.10 2014


  • v G. D. Singh, K. Y. Kim, D. Preble, Facial enhancement using biomimetric oral appliance therapy in adults, 2016


  • B. Zanatta, T. M. Ardenghi, R. P. Antoniazzi, T. M. P. Pinto, and C. K. Rösing, “Association between gingival bleeding and gingival enlargement and oral health-related quality of life (OHRQoL) of subjects under fixed orthodontic treatment: a cross-sectional study,” BMC Oral Health, vol. 12, no. 1, article 53, 2012.

Photo Credits due to:

Tohgo Kimura