April 03, 2014

To extract or not: The orthodontist’s endless dilemma?

The orthodontist’s dilemma

This blog follows on from my post last week on the “unanswered questions in orthodontics” and is concerned with my interpretation of the extraction/non extraction dilemma that we face on daily basis.

As we all know this is not a new debate in orthodontics and we have been discussing this issue for many years. We also know that from time to time somebody “rediscovers” non extraction treatment.  Strangely, this discovery tends to coincide with the development of a new technique that then becomes a new philosophy or paradigm.  This is then packaged up, clinician advocates give up their time, airport hotels are booked up, courses are run, general practitioners become interested, everyone thinks that it is great and then the research is published that shows that the new treatment is no better than the traditional techniques….

However, if we put my deep cynicism of non extraction treatment philosophies aside. It is clear that we should have a discussion on the need for extractions as part of orthodontic treatment.

 The extraction decision

Firstly, we need to go back to basics and remember that it is completely logical for us to assume that the position of the teeth is influenced by muscular pressure. If you need convincing about this reads Proffits “Equilibrium Theory revisited”, it is here.  This paper and many others have provided information that we should continue to use and it is clear to me that we should not be moving teeth out of the neutral zone, too much….and we, therefore, need space.

 Other ways of gaining space?

If we look at other ways of gaining space.  We know that distal movement with headgear only gives us 2-3mm of space.  I am not so keen on removing enamel in “thin slivers” from all the contact points, because I think that contact points are there for a reason.  We genuinely do not know if this causes harm.  We all think that we can procline the lower incisor, but by how much?  We do not know.

 Do extractions do harm?

The simple answer is there is no evidence of harm.  The important point here is that we need to consider that it is more likely to be poor treatment mechanics that “dish in” faces rather than the extractions.

 What about non-extraction?

This, of course, involves some expansion and flaring of arches. It also means that treatment is simpler and faster. Hence the adoption by the “speedy braces disciples”.  We can argue that we should only treat mild crowding on a non-extraction basis. However, we need to consider what is considered to be mild crowding in contemporary orthodontics.  It has been pointed out in the comments on this blog that cases that we now consider to be borderline extraction/non-extraction would have been clear extraction cases 10 years ago.  This is because we are currently in a non extraction phase of orthodontic thinking, this may or may not continue.  As a result, we are flaring and expanding with abandon. Is this correct? The answer is that we do not know.  It is, therefore, becoming good practice to not extract teeth if we honestly feel that we do not know whether to extract or not.

 When should we extract?

I cannot, honestly, give you solid answers to this question, we do not really know. There is no science to call upon, apart from years of clinical experience that is passed down from generation to generation of orthodontists, like myths and legends.  I think that I only extract in severely crowded cases. But I am worried about moving teeth out of the alveolar bone, but I have never consistently seen this type of harm.  As a result, my extraction philosophy is driven by my clinical experience and those who taught me.  On reflection, in todays evidence based era, is this right? I am not 100% certain.

 Solutions?

The answer to this is do a trial!  I would happily be an operator in a trial of extraction vs non extraction treatment, as I feel that I am in equipoise. Nevertheless, one obstacle is patient consent. When we need to consent patients, we need to explain to them that we do not know which is best, so the conversation will go

 

Orthodontist- “I would like you to think about your child being in a trial of having orthodontic treatment with some of their adult teeth being taken out or not being extracted. I do not know which is best”

Parent- “ If you do not know then we will have treatment without the extractions”.

I know that I would say this and then we have recruitment problems

 

Summary

I will try and wrap this discussion up.  We need to consider if there is a problem with either approach to treatment?  We occasionally see case reports illustrating “damage” done by extraction and/or non-extraction, but research tends to show no real differences.  We are told that if we treat non-extraction then we need to retain, but lifetime retention is a clear oxymoron.  Perhaps the problem is us and our competing groundless philosophies.  As a result, the extraction whirlpool keeps going round forever….

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Have your say!

  1. Avatar

    Thank you for this blog. Can I just ask a few questions/make a few points:

    “we should not be moving teeth out of the neutral zone, too much….and we, therefore, need space.”

    What makes you think that teeth are not moved out the neutral zone with extraction therapy? Incisor angulations are altered with extraction mechanics too. If the neutral zone is the answer to our problems then why don’t we measure it/find out where it is in every case and base or extraction decision on that?

    Interesting comment: “We are told that if we treat non-extraction then we need to retain”

    Question: do you not retain your extraction cases?

    “it is more likely to be poor treatment mechanics that “dish in” faces rather than the extractions.”

    Poor mechanics are possible with both extraction and non-extraction mechanics are they not?

    • Avatar

      Thanks for the comments. In answer to your points, while there may be some movement of the teeth into the neutral zone with extraction therapy, the main reason for extracting is to relieve crowding etc without moving the teeth out of the neutral zone, so this risk is reduced but not eliminated by extraction therapy. As I said it depends on mechanics.

      Yes, I retain my extraction cases and yes poor mechanics are possible with both non ext and extraction mechanics and this is why the mechanics are important

  2. Avatar

    1) How many times we apply non-extraction protocol BUT at the end of the treatment we extract thirds molars??? Too many!!!! So the case becomes finally an extraction case.
    2) Can we avoid the extraction of third molars when the bicuspids already extracted??? I am not sure….

    • Avatar

      Yes, the impaction of third molars does not help this discussion! I remember from some time ago there was a study that looked at third molar extraction following orthodontic treatment with extractions and this found that there was no effect on the third molar eruption, but I cannot remember much more about it.

  3. Avatar

    Hi Kevin,

    You’d better sit down, because I find myself totally agreeing with the overall message and analysis of your blog 🙂

    I also think it is very ‘mature’ of you to admit bias – it is something we all need to do reflectively and not necessarily see it as a bad thing in of itself, it’s just human nature and hard-wired in, but we do need to acknowledge it and cope with it as best we can, whether it comes from ourselves, other colleagues or patients.

    I appreciate as a researcher, science compensates for this by ‘randomising’ and ‘double-blinding’ etc. This is necessary for science to show even when told something doesn’t work (null hypothesis), it has such a differential effect that it’s outcomes cannot be denied (be they positive or negative compared to controls) and then we can say (hopefully) XYZ does ABC whoever uses it with whatever bias they may have!

    However……..

    We do not limit patient choice in the same way and guess what, patients are emotional beings, many decisions they make are ENTIRELY BIASED and opinion-based whatever the evidence says, be it led by costs or timescales or cosmetic rather than function/health priorities. Indeed ethically, we are told patient choice and autonomy is paramount in Medicine and Dentistry.

    Thus people can tattoo themselves from head to toe, they can have Butt/Breast/Cheek implants for ‘cosmetic’ reasons and even the amputation of healthy limbs in some cases.

    So what has this got to do with Extract vs Non-extraction evidentially?

    It has everything to do with the patient and operator and their Rapport – that rapport does influence patient choice, because it’s an emotional interaction between human beings !!!

    When patients are given ALL the choices (price/speed/operator/outcomes/evidence) but discover, in the main, scientific evidence is relatively poor for many things, then other aspects are more critical, more influential.
    Again we should not be in denial about that (it’s difficult because we all think we are scientific/logical first, emotional second) but openly acknowledge it.

    It may not surprise you to learn that ‘speed’ is an important factor for many and patients often say, if it takes months to just be seen for an opinion, then years to have Ortho treatment which may involve extractions of teeth anyway, I’ll have the (quicker and less destructive) Veneers or Crowns instead in weeks then – however IF there is offered a middle option, one that can straighten teeth in Months and done by the person they already have ‘rapport’ with and it results in a more cosmetic/functionally favourable outcome that is FAR less destructive of tooth tissue by avoiding prepping or extractions AND can be started (and finished) soon etc, then many patients ARE choosing that ‘middle’ option.

    As a restorative dentist mainly, I find it strange that I am doing more Ortho every year – as you know I favour FastBraces as a short-treatment ortho system MAINLY because despite it’s shorter timescales, it follows all the main Orthodontic scientific principles, has a long track record of success and starts with a square wire and is FOCUSSED upon 3D correction of root position using light forces and mainly non-extraction based cases (in other words, it’s relatively safe and reversible) and has evidence to support it’s claims. We’d like more evidence of course, but it’s not new or experimental, it is proven safe and effective!
    Now, I know you may not necessarily agree with all the above Kevin and that’s fine, but please humour me another paragraph or two.

    My point is, by more patients being offered Ortho on the frontlines instead of restorative options (or as I had this week a lady in tears unhappy with appearance and came to me for clearance and dentures!!!) or in combination to minimise tooth loss and prepping, that can only be a GOOD thing, where the majority of those people would have (and do!) refuse Traditional ortho referral options outside of the Practice.

    Now let’s just accept for now, we can agree to disagree about FastBraces being able to achieve Comprehensive results to the same degree as standard Straightwire systems but in less time in less complex ways etc – of all the alternative Ortho systems out there, can you appreciate WHY I prefer a system based upon square-wire 3D torque rather than just round-wires or tipping-only options when treating for months only?

    I hope you can, because more patients are saying YES to those options when they otherwise would have said NO or gone elsewhere to someone elses drill or forceps – indeed even the lady above has agreed to a short course of Ortho, some Restorative work and a bit of whitening and bonding if done before September – it’s a tough call, but I need those roots as parallel as possible as fast as possible and tipped-teeth would just look awful or need excessive prepping or removal anyway. Now her second choice is extractions and dentures which for me, is my ethical boundary and would not do, but patient autonomy means she has the right to get that done somewhere, as she wishes!

    So when it comes to GDPs doing Ortho, I feel there is something intrinsically safe about the default-position being non-extraction and like all other dentistry disciplines, a friendly Specialist can help out and if necessary, or in extremis, more easily take over because there has been some wasted time but no irreversible harm, as a worst-case scenario – for an extraction Ortho. case that would be a completely different story of course!

    So in conclusion – I think it’s a good thing GDPs are gaining more interest in Ortho ,offering more Ortho and doing more Ortho – some caution is advisable of course – however the orthodontic establishment must take some of the blame for not making Ortho more accessible and supportive for GDPs to do more easily on the front lines for years – remember when clinical attachments for Ortho were readily available in every area?
    That ‘approach’ has created an increasing vacuum and that is now been filled-in by external sources which are ‘variable’ in their technology, teaching and ongoing support, so DUE DILIGENCE is important – but make no mistake about it, routine Ortho is returning to frontline GDPs one way or another and bodies like the BOS can either be part of the solution or part of the problem, in helping that to happen as constructively as possible.

    There is a rebalancing taking place now Kevin – the old mantra of ‘Specialist knows best’ so don’t you do any Ortho, just refer, simply isn’t going to wash any more.

    Yours evidently,

    Tony.

    • Avatar

      This is a very interesting comment you made about GDPs making a move towards more ortho Tx in the UK.
      I studied a Master course in orthodontics, and received training on the hands of 4 good consultants. Each adopted a Tx philosophy (s)he was fond of.
      My conclusion was that the more you make of expert opinion along side EB, the more you feel relaxed regarding decisions on exo or non-exo.

      Kind regards,
      Hany

  4. Avatar

    Thank you Kevin. I arrived here obviously via GDPUK link. Could I ask your thoughts on relative level of stability conferred by extraction treatments. Lifelong retention, especially if it needs to involve buccal segments can be quite onerous. A patient may be willing to exchange 4 premolars for a far less onerous retention regime if they could be assured there would be a reasonable level of stability with extraction treatment. If I recall correctly Little’s work mostly demonstrated lower incisor irregularity relapse.
    With the relapsed case I posted on GDPUK I feel that if 4 premolars had been extracted the lower incisors could have remained upright and a good overbite established. This in turn might have provided solid lifelong “natural” retention for the upper labial segment. And of course the non existent lower premolars would not have leapt buccally into cross bite. Given an identical retention regime that the patient was able to cope with I am fairly certain she would not have re-presented 3 years later in tears. It is also interesting that this case was initially probably only a mild to moderate crowding case. I am absolutely not a confirmed “extractionist” but I feel each individual case needs careful diagnosis and treatment planning with consideration given to stability among other things.

    • Avatar

      Yes, I agree with you we need to plan the treatment for the individual patient and one of the dangers of being a follower of one of the “camps’ is that this is not being done. I think that most orthodontists know that we cannot treat everyone the same way, orthodontic treatment is not a “kit” that comes out of a box

  5. Avatar

    Kevin, I have just re-logged on to your blog and noticed multiple comments. I would not want your blog to become a tiresome repeat of GDPUK forum. Please ignore my previous comment and do not feel under any obligation to reply. Your blog itself is sufficient comment for me on the topic. Kind regards Peter Ollivere.

  6. Avatar

    Hi Kevin; I enjoyed your Blog as always. I wanted to bring up one point where you state; “I think that contact points are there for a reason” – what reason and what evidence do you have for this statement? I am playing the Devil’s advocate so a little bit of pot stirring going on but have you thrown the baby out with the enamel dust? Best wishes, Peter.

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