Extracting teeth to relieve crowding - is there an alternative?
Sparkle Dental | 31/08/2014
The extraction of healthy permanent teeth to relieve crowding before braces is a controversial and fiercely debated topic within the orthodontic community.
The removal of healthy body tissue in the fields of dentistry and medicine is unique to orthodontics, and it is no wonder that many people are questioning if there are alternatives.
In this post, Dr Shereen Lim shares her philosophy on extraction of adult teeth to relieve crowding.
Why extract for crowding?
In traditional orthodontics, teeth are removed to alleviate crowding and then to align the upper and lower teeth to fit together in a more normal relationship.
It can be helpful to camouflage underlying jaw discrepancies and orthodontists have been successful in achieving straight teeth and perfect bites for many years using this approach.
What are the limitations of extracting for crowding?
The most regarded limitation is the impact on facial profile, although this is not universally accepted amongst orthodontists.
In many cases, patients who are advised to have teeth removed have a moderate degree of crowding in the range of 5-8 millimetres. Whilst the width of a typical premolar is on average 8mm, removal of two creates a space of 16mm in the dental arch, far more than is necessary to resolve the crowding.
To close the spaces, retractive orthodontics is performed. This involves pulling the front teeth back into the spaces (which is far easier than moving the large molar teeth forwards into the gaps).
Considering that the front teeth support the lips, there is a tendency for extractions and retractive orthodontics to flatten the facial profile and reduce facial balance. It is something that I have observed in patients over the years, and this has been demonstrated in small identical twin studies where the genetic variation has been minimised between pairs of subjects who have been treated either with or non-extraction.
Does retractive orthodontics affect the airway and breathing during sleep?
In addition there is now growing support for the idea that retractive orthodontics can contribute to reduced tongue space, narrowing of the airway space behind the jaws, and increased risk of problems with the jaw joint, muscle and facial pain in some patients.
Proving this concept in large scientific studies is a very difficult thing to do because of the difficulty in having identical “control” subjects, and therefore it is not considered “evidence based”.
However there are many case reports emerging that demonstrate on 3D volumetric imaging an increase in airway size following the re-opening of extraction spaces with orthodontic appliances in patients with sleep-disturbed breathing and pain symptoms. Reduction in these symptoms and a reduction in obstructive breathing (measured with overnight sleep studies) has also been reported.
Based on current standards, this alone should not be the reason to avoid orthodontic extractions aimed at relieving crowding. However based on my experience managing people with sleep-disordered breathing and the knowledge I have gained through my post-graduate diploma in that field, it is something that influences my philosophy on this topic, and my reluctance to remove healthy permanent teeth to relieve crowding.
For more information on this topic, watch this video
by US orthodontist Bill Hang who is involved with reopening extraction spaces in patients with headaches on obstructive sleep apnoea.
What are the alternatives to tooth extraction?
Since a major study concluded that the majority of crowded teeth are caused by underdeveloped jaws rather than having teeth that are too large, for most people it makes sense to increase the size of the dental arches through arch development.
This is ideally done at an early age, usually starting at the age of 7-9 years.
Beyond that time, it is still possible to create some dental expansion using a passive self-ligating system of braces like Damon Braces that moves teeth very gently and slowly, and best allows formation of new bone as the teeth move.
If the tooth and jaw size discrepancy is more severe, one possibility is to use slow expansion devices in the upper jaw to increase the width of the jaw and create the additional space for the teeth.
The upper jaw is key because it forms the template for normal forward growth and positioning of the lower jaw. When the upper jaw is too constricted, the lower jaw can be trapped behind and prevented from sliding forward, similar to a foot not sliding all the way into a narrow shoe. The lower teeth will meet far behind the upper teeth. This is how many “overbites” result.
Getting a second opinion
Whilst it may not be possible to treat every single patient non-extraction, it can make sense to have a second opinion before the irreversible removal of healthy teeth if this is a concern.
Ultimately every provider of orthodontic care wants what is best for their patients, but each will have different philosophies based on their training, experience and continuing education.
Dr Derek Mahony is one of Australia’s most prominent orthodontists and he is reknown for successfully treating a high volume of patients non-extraction after they presented to him for second or third opinion. He is also a well sought after presenter who lectures extensively around the world. I am currently completing a 2 year Mini-Residency in Orthodontics based in Sydney and taught by Dr Mahony. This has now allowed me to offer non-extraction treatment at the practice.
To find out more about his “full face” philosophy and non-extraction orthodontics, please view Dr Mahony’s interview on 60 minutes here.
Our practice You Tube channel also has a playlist of similar videos as a resource to patients who want further information. Visit here
If you would like a second opinion to determine if non-extraction orthodontics could be an option, please call our practice for an appointment.
Related blog categories: braces, extractions, orthodontic
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