see You Tube video here
Most orthodontists take lateral skull X-rays about the age of 12 to 14 to establish the position of the maxilla and mandible in relation to the cranium as a whole. X-rays have been used for this ever since Brodie showed (1938) that the skeletal form was more or less set by that age. Treatment was not recommended before then because experienced showed it tended to relapse.
Orthotropics suggests that most skeletal malformations are due to adverse oral posture; mainly leaving the mouth open and tongue-between-tooth habits and the emphasis of diagnosis is moving to studying oral posture. This is difficult to recognise using X-rays until after the damage has occurred although photographs can be used to forecast facial growth from the age of three or four (see illustration).
With experience anyone can be taught to read the muscle posture of the tongue and lips from the face itself and their effect on developing facial form. A photograph will demonstrate this but not an X-ray. Changing oral posture can create large changes in a growing face provided the child is under the age of seven or eight, but of course the postural changes must be maintained afterwards if a permanent correction is desired (see illustration).
see YouTube video
The subject has been debated since the times of the ancient Greeks and often generates more emotion than logic. I am constantly amazed that so many orthodontists are prepared to provide treatment without a clear understanding of what has caused the particular problem they are facing. To fail to do so, risks treating the symptoms of malocclusion rather than the cause. Is it genetic, environmental or both and if the last, in what ratio? It would seem essential to answer this question before contemplating how any malocclusion should best be treated.
Gross et al (1994) found 63% of five year olds left their mouth open for long periods and that those with “High levels of open mouth posture manifested significantly smaller growth of the upper jaw (maxilla)”, this in turn restricts the growth the lower jaw resulting in too little room for the teeth.
When I ask clinicians what has caused a particular malocclusion they will often answer like this “this malocclusion is due to a combination of an undersized maxilla and a retruded mandible”, but they will not explain why this discrepancy has occurred. The inference being that it has a genetic cause. Most clinicians would agree that congenital defects and Trauma are responsible for less than 5% of all malocclusions so what causes the rest?
In 1938 Brodie measured a number of X-rays and announced “The most startling find was the apparent inability to alter anything beyond the alveolar process”. This led to a generalised belief amongst orthodontists that the facial bones are inherited and cannot be changed more than a millimetre or two. However it is known that Bones remodel considerably during growth, for instance, as the maxilla enlarges the front of the sinus moves forward while the posterior wall moves back relative to the general forward movement of the bone. As a result of this and other growth changes, the landmarks that are used to overlay consecutive X-rays move, making it impossible to make accurate superimpositions.
Modern computer enhanced X-rays show very sharp 2 dimensional images but we must remember that these are based on rather fuzzy shadows of a three dimensional skull with inevitable slight tilt, differential enlargement and rotation distorting the superimposition often by several millimetres. This strongly affects the landmarks not on the midline which is why X-rays alone must be a less than certain means of determining the movements that actually take place. Hopefully the situation will become clearer as modern scanning techniques improve.
Overall the evidence is not as conclusive as some would suggest and there are clear differences of opinion amongst accepted leaders in the field. Above all, we are left with no explanation for the fact that many mono-zygote twins have substantially different facial form. Clearly it is impossible for these to be genetic if both individuals have the same genes. See the illustration below, by permission of Tom Graber.
see YouTube video here
The Tongue: What Part does it Play?
It is hard to comprehend the full difference between the correct and incorrect action/posture of the tongue. The teeth are resistant to short-term force during biting or swallowing but they are very sensitive to light long-term force/posture, including the touch of the tongue. If you place a blob of resin on the lingual side of an unopposed molar it will move away from the light contact of the tongue because it is continuous while the strong push from the tongue during swallowing lasts barely a second and so has little influence.
The shape of the dental arch is determined primarily by the tongue but also by the cheeks and lips, all of which have far more influence than the genes. That is why the arch shape of all animals and our primitive ancestors reflects the shape of the tongue. That does not apply to people who have any malocclusion because all of them have displaced tongues. Usually children from industrialised countries rest their tongue to a greater or lesser extent between the teeth. In fact about 95% of civilised children do this, leaving the teeth and lips apart for varying periods which of course is why malocclusion is endemic.
William Profit’s research at South Carolina, showed very clearly that teeth erupt when out of contact and intrude when in contact (Proffit et al 1993). From this research it is obvious that teeth need to be in contact 4 to 8 hours a day for them all to meet evenly with the face the correct height. But if the tongue rests between the teeth this balance is distorted.
The problem has been that few clinicians who work in the mouth have realised how influential the tongue is for the growth and development of the jaws and face. This includes many Dentists, Ear Nose and Throat Specialists, Orthodontists, Speech Therapists, Orthognathic Surgeons, Oral Myologists and to some extent Beauty Specialists and Plastic Surgeons all of whom are involved in the shape and function of the facial skeleton. We could also include Anthropologists who study the historical shape of the face as well as the Cranial Osteopaths, and Chiropractors who treat internal deformation of the skull. Many of them visualise the tongue as a soft structure which adapts to the form of the tissues around it, rather than seeing it as the large powerful muscle it is.
Orthotropists believe that the natural growth and appearance of the face is largely guided by the position of the tongue, but no one has yet found an accurate way of measuring tongue posture and so this suggestion is as yet hypothetical. It is theorised that the forward growth of the maxilla (the mid face) depends to a large extent on support from the tongue but although there is incidental evidence to support this concept it is not widely accepted by orthodontists. Sadly because it can’t be measured, university researchers have shown little interest in tongue posture so we have little idea whether it is crucial or unimportant.
The illustration below shows the effect of enlarging the maxilla and taking it forward.
YouTube video here
The big majority of orthodontics in Britain is carried out with fixed appliances this achieves excellent alignment of the teeth but is often followed by relapse. I think orthodontists are embarrassed about relapse but believe that by retaining the result afterwards they remove the problem.
To prevent re-crowding, the teeth must be held in position by one of the many types of retention available, and the British Orthodontic Society has recently recommended that every orthodontic patient should be advised that they will need to wear a retention appliance for the rest of their life. This can require more work than the treatment itself. There are also concerns about food retention and gum damage with fixed wires, especially if subsequent restorative work is required. Experience suggests that removable retainers are usually dis-guarded within a decade or two. There are clearly problems ahead and who will pay for this?
Concern has recently been expressed recently by periodontists (ref if poss) about the consequences of long-term retention of expanded dental arches. Many orthodontists do this to avoid extractions. The teeth are held in position but the soft tissue forces of the tongue, lips and cheeks remain unchanged resulting in progressive clefting and fenestration of the teeth and bone. Because this type of expansion is now widespread, it is likely to become a major problem, not only for the patients but also of course for the dental insurance companies, which may be why it is rarely discussed.
Orthotropics does not need any retention hence there is little risk of gum damage.
see YouTube video here
The big majority of orthodontics in Britain is carried out with fixed appliances which achieve excellent alignment of the teeth but several scientific papers have suggested the possibility of adverse facial changes (Battagel 1996). I think orthodontists are embarrassed about this but believe that by avoiding discussing the subject, the public will not be worried.
The father of the girl shown below was a medical doctor and asked for non-extraction treatment for his daughter hoping this would avoid damage. After a year of retractive Headgear there was little change and she then had 4 teeth extracted. After another year the orthodontist said she would need jaw surgery. The picture below shows the change to her face at that point.
The next patient (below) received a nice improvement from Biobloc Orthotropic treatment but then decided to have the alignment improved with fixed appliance. See the vertical growth that followed.
You Tube Video here
ORTHODONTICS NEEDS TO CHANGE
Root Resorption – Does it Matter?
Most orthodontics in Britain is carried out with fixed appliances and is usually associated with some root resorption. I think most orthodontists are embarrassed about this resorption but accept it as unavoidable. However we are left with little idea of its consequence in old age.
Some persistent researchers are very concerned about it and when you read their figures you can understand why. Kurol for one found that “root resorption is an early and frequent iatrogenic consequence of orthodontic treatment, even after application of a force below what is often used in other clinical situations”. “93% of teeth showed some root resorption but none of this could be seen on periapical radiographs”.
Perhaps we should consider the physiological aspect, the periodontal membrane is about ⅛ mm thick and has evolved like a sling to take the load of biting. However the fibres do not withstand lateral loads very well and if a side movement exceeds ⅛ mm the narrow line of contact between the root and the socket the surrounding membrane becomes compressed and therefor ischaemic. If this lasts for any length of time the cells die causing the pain that many children suffer following adjustment of their orthodontic appliances.
Unfortunately this is routine whenever a fixed or removable spring device is adjusted. As we might expect intermittent forces are more healthy as they allow the blood flow to be re-established at intervals but orthodontists have found these difficult or impossible to apply (Kento et al 2017).
An alternative method might be to use a rigid removable appliance which applies exactly 1/16th mm movement to each side of the maxillary arch each day so that the membrane which is ⅛th mm thick is never crushed. This precise rate might provemore effective at moving teeth and bone with little or no damage.
It is known that there is little root resorption if patients are treated young before their root apices have closed so that apical resorption is unlikely to take place (Mavragani et al 2002). The illustration below shows that orthodontic treatment is sometimes associated with root resorption.