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.
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
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….
Emeritus Professor of Orthodontics, University of Manchester, UK.