August 12, 2019

Is interceptive orthodontics a possibility?

August tends to be a holiday month, and I have decided to revisit some of the most popular posts as we all relax on holiday. This first one is on the concept of interceptive orthodontics. We would all like to do this, but does it work?

I published this post in 2014, and I feel that it still is relevant.

The effectiveness of interceptive orthodontics is one of the “great unanswered questions” in orthodontics.  This is the long-standing issue of whether it is possible to provide interceptive orthodontics and either “cure” orthodontic problems before they develop or make any eventual treatment easier. This process of interception is closely allied to the concept of screening. Because if we intend to intercept a disease, this needs to be done via screening.

So the right place to start would be with the effectiveness of screening.  This is classically carried out to detect disease early and “cure” disease by providing treatment when it has not done harm or can be treated easily. There is an excellent summary of screening in “Testing Treatments” by Evans et al.  They point out that screening for a disease is not always as effective as we may hope. They also suggest that screening should only be done under certain circumstances. I have adapted this for orthodontics.

These are the relevant principles:

  1. The condition being screened is essential in terms of public health. Malocclusion affects large numbers of people, so this could qualify.
  2. There is a recognizable early stage of the condition. Again, we can identify the early development of malocclusion
  3. There is a valid and reliable test for the disease. We know that IOTN can detect malocclusion that requires treatment.
  4. There is an effective and acceptable treatment for the condition so that screening is likely to have an effect on its outcome. This is where we run into problems for orthodontic treatment because can we intercept malocclusion?
Can we intercept malocclusion?

To address this question, I would like to start with considering our history as orthodontists. Before the advent of the widespread use of fixed appliances, orthodontists used to treat Class I crowding cases by removal of first premolar teeth and allow spontaneous alignment. The advantage of this treatment was that the teeth aligned and may have ultimately been placed in the “zone of stability”. Over the years we have discarded this form of therapy because we were concerned that residual features of malocclusion remained and that the posterior occlusion was not always corrected. However, it is undoubtedly worth us considering whether this treatment, which aligns the “social six” should be explored further and in many ways may be a reasonable treatment for any patients who are not so concerned with the attainment of a “six key occlusion”. But, I hear you say “where is the science behind your statement”? There is none, and perhaps we need to investigate this further.

What about discussing scientific evidence?

If I now turn to evidence-based practice and address the features of malocclusion that we intercept. The first is the interception of palatally displaced permanent canines. I have covered this in a previous blog post and concluded that there some evidence that removal of the primary canine can intercept the impaction of a palatally displaced canine.

What about children with increased overjets? Again this is covered in a previous post that reviewed the findings of a Cochrane Systematic Review. There is evidence that early overjet reduction is of benefit, but the level of uncertainty about this treatment is still high.

We know that we can correct crossbites “early” and that this treatment is effective.

However, when we consider the statements on screening, we should remember that we are screening to intercept a disorder that affects a large number of people and it is clear to me that the examples that I have given above do not fall into this category. However, I have become very interested in some work carried out by two research teams, and I will go into this in more detail.

Orthodontic intervention in the early mixed dentition: A prospective controlled study on the effects of the eruption guidance appliance

This was a fascinating study carried out in Finland. The investigators screened a sample of children in two towns and included 315 children in their research and they started treatment with an eruption guidance appliance for 255 children. These were then compared to a randomly selected sample of children from another town who did not receive treatment.

They showed that interceptive treatment with the appliance resulted in a significant improvement in the occlusion. These findings look encouraging. However, we need to interpret them with some caution. Firstly, this was not a trial, it was a cohort study, and there may be biases present between the groups. Secondly, they reported that 33% of the patients who were given the interceptive treatment did not wear the appliance and were excluded from the analysis. The results of this study are, therefore, only applicable to the patients who co-operated and this raises doubts about the overall effectiveness of the treatment. Nevertheless, I still feel that these results are exciting, and while they have not found the solution, this study may provide a direction of future research.

Randomized Clinical Trial of interceptive and comprehensive orthodontics.

This was carried out in Washington State, USA, This was a trial in which patients who were eligible for funded orthodontic treatment were randomly allocated to receive comprehensive treatment or to interceptive therapy, such as space management, strategic extractions, correction of crossbites etc. At follow up, they showed that the patients who had comprehensive treatment had better PAR scores by approx. 4 points, which is just about clinically significant. However, both groups achieved a substantial reduction in PAR, suggesting that both treatments were effective. They concluded that interceptive treatment provided significant short-term benefits. Importantly, the interceptive treatment is likely to be accompanied by a reduction in costs.

This paper suggested interceptive may effective, but it does not result in perfect occlusions. However, we need to consider if all our patients require perfect occlusions and whether some (or many) may be happy to “trade-off” a less ideal occlusion for a shorter course of treatment. Perhaps the next step is to develop this concept further and ask our patients what they want?

I have found revisiting this conceptfascinating and I am becoming more convinced that this is one of the “unanswered questions” that should be answered.

 

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Have your say!

  1. Avatar

    Hi Kevin,
    A thoughtful piece as ever. Could I add there is often “added value” in interceptive orthodontics that may justify it beyond the evidence base of clinical outcome. There is the patient management advantage of “doing something” for those families that want to be active in the management of their child’s malocclusion (e.g. crowding or overjet). There may be the social advantage of improving aesthetics early and, in my experience, compliance with removable appliances in a young child is often better than the early teenager as they begin to define “self”. Lastly clinicians should be mindful in those who may not be able to access complex orthodontic appliances or management for whatever reason (social, medical, psychological) simplifying problems or reducing the orthodontic need by early interception (e.g. early extraction of first premolars to allow ectopically positioned crowded canines to come into the line of the arch) can make significant differences.
    Keep up the good work and enjoy your summer

  2. Avatar

    Hi Kevin,
    The last section. in particular, sounds like a good justification for “DIY” orthodontics. Trade off a quality result (hopefully) for a cheap fix? Just line up the “social six”. We don’t need orthodontists for that. Don’t even need dentists!

  3. Avatar

    Interceptive orthodontics is already wrong in the choice of words. Orthodontists who do not do early treatment will always consider the symptom to be the disease to be corrected.

    However, the disease is a lack of development of oral functions and not enough tonic children with too little movement and a chewing apparatus that wants to be occupied.

    This can only be seen when children from the tender age of six months to the ripe milk teeth receive support. Then it becomes obvious what influence the oral functions have on growth and development.

    Even in children who are treated functionally (therapist) in alternating dentition, if they do not have limiting devices in their mouth, the enormous influence of improved oral functions (lip closure / swallowing pattern) on development becomes visible. You have to close your eyes if you don’t see it.

    But at the age at which the orthodontist sees and treats children, he must consider the symptom to be the disease. The misdevelopments are irreversible and he confuses the creation of a useful occlusion with the healing of diseases.

    Translated with http://www.DeepL.com/Translator

  4. Avatar

    Thank you again for another thought provoking post.

    Some interceptive interventions appear to be worthwhile, but may not change the treatment required later. Extraction of upper primary canines is a good example. If they are extracted and the permanent canines erupt, fixed appliances are then required to align them. This also applies if they don’t erupt. But, if they are not extracted and space is opened, they are even more likely to erupt without needing to be surgically exposed. This can be done early and reduces the risk of resorption of lateral incisors and the need for surgery. This interception is far more beneficial than primary canine extraction as fixed treatment will always be required.

    We also know that we can correct crossbites early. The real question should be, why correct them early rather than later with the fixed phase? Do crossbites cause asymmetrical facial growth or TMJ problems? Evidence? Benefit to patients or their wallets?

    Space maintenance is another interesting interception. It can be done routinely when a primary molar is lost. If a maintainer can prevent the need for treatment later, then it may be beneficial. If further treatment is likely to be needed later, then one must question their use. Opening space can easily be done during the fixed phase without any additional cost or discomfort, or the increased risk of caries.

    It is easy to “intercept”, but there has to be a significant benefit for the patient, not just the practitioner. It is far too easy to see everything as a problem, when we hold an appliance in our hand.

    Interceptive treatment should perhaps only be done when damage is likely. For example, only correcting an anterior crossbite if wear is occurring.

    Everything seems to work. We don’t know what is beneficial to the patient, until we stop doing it. Only then do we see normal development and realise that most of our interceptions are of little value to the patient.

  5. Avatar

    Thanks Kevin. For me, a key concept is an informed consent. If we clearly and unbiasedly lay down to our patients what we know (limited) compared to what we do not know (unlimited) regarding the certainty of any proposed early treatment approach and then explain to them the associated costs with early intervention (i.e., is likely more expensive than doing everything in one phase), then its up to the families to make the call. If they value an early benefit and are willing to pay for it then I have no conceptual problem. The key again is that we are unbiased in how we present the facts. Can we consistently do it when we wear two hats (oral health provider and business owner)?

    • Avatar

      Carlos,
      I love this conversation. Kevin is familiar with our work. We have made our sample available to him too. I totally agree that early treatment is not worth it unless you are doing growth guidance and changing the oral habits.
      I could not think of a better researcher than you to look at our 200+ consecutively treated cases. Keep us posted!

  6. Avatar

    Impacted canines may not affect a large population but the interception would probably prevent a moderately inconvenient/morbid procedure that requires expensive skilled time and resources. Can you do the sums on the benefit of avoiding this V the inconvenience of screening all the patients that clinically test negative for displaced canines (ie seem to have normally placed canines).

    If you were doing it military style, perhaps you could screed 30+ patients per hour, 1000 in a week. If you’re being pleasant to them, it might take 6 weeks. If 20 patients in that 1000 had displaced canines, and 16 of them were spared surgical exposure by an interceptive intervention removal of primary canines, would that be a fair trade off. Bearing in mind you’re likely to see a few displacing crossbites in that number too, or abnormal eruption patterns that might mean there’s a tooth missing etc, and early loss of deciduous molars that might be an indication for space maintaining (does that count as interceptive treatment?)

  7. Avatar

    Does this concept apply to assisting the erupting and alignment of the 3rd molars?

  8. Avatar

    If a study does not definitively provide evidence based proof that early tx correction of anterior crossbite, posterior crossbite, A-P improvement, archlength management, habit correction, gingival display reduction, occlusal plane improvement, symmetry establishment, growth optimization, etc…maybe there are more inadequacies in the capacity to measure the effects of interceptive ortho than the interceptive ortho itself…..We need good science but sadly it is largely absent in Dentistry in general , and in Orthodontics in particular IMO. Isn’t it common sense that some Ph I tx is essentially useless while other Ph I tx can make a significant improvement in tx outcomes? Or result in fewer extractions? Maybe a grad student can do a study to determine this?

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