Specialists In Orthodontics

Deciphering the Truth on Self-Ligating Braces

 

June 8, 2015

(Self-ligating braces are braces that do not require the “color ties” to hold the wire to the braces)

A patient’s mother recently asked me about the claims made by another office with regards to their bracket system. It is an all too common question in our office so I figured I would take a moment to set the record straight.

For most of us, large corporations and their carefully manufactured marketing plans rule what we hear and see. As I sit in my family room with the television on, I only need to watch a few commercials in order to prove this statement. Unfortunately, orthodontics is not above such marketing plans and the public is none the wiser. Below I hope to dispel some myths surrounding one of the greatest product marketing teams in the history of orthodontics.

In orthodontics there are two broad types of braces/brackets. Conventional ligation is what most people identify with. Conventional brackets use either a rubber band (the fun colored rubber bands that the kids enjoy) or a tiny steel wire to hold (ligate) the wire into the bracket.

ties on typodont

Self-ligating brackets, on the other hand, use some form of door or clip to secure the wire thus eliminating the need for those colored rubber bands or tiny ligation wires. The idea of self-ligating brackets is nothing new, they were first conceived in 1935. The most popular and well known of these brackets is the Damon System, developed by Dr. Dwight Damon and made by Ormco.

Damon Braces 3MXdamon model

There are many claims coming from the companies and practices utilizing these brackets including: lower levels of friction resulting in more biological forces, fewer extractions and expanders, decreased treatment times, less discomfort, fewer broken brackets, fewer visits to the office, faster space closure, and fewer periodontal complications. These claims are great but what does the scientific literature say? Do self-ligating brackets possess some sort of magic that allows us to straighten teeth more quickly, with less pain, and better results?

Fortunately, there is a cornucopia (I love using that word) of research on self-ligating brackets because their use has skyrocketed in recent years (between 2002 and 2008 the use of self ligating brackets went from 8.7% to 42%). If you are interested in my sources I will list them at the end of the post.

  • CLAIM: Self-ligating brackets align teeth more quickly and allow for faster space closure
  • TRUTH:  Several studies have DEBUNKED this idea. In fact, at least one study has found that initial alignment of the teeth was significantly SLOWER with self-ligating brackets.
  • CLAIM: Using self-ligating brackets decreases the need for extractions and/or palate expanders.
  • TRUTH: Let’s first tackle the expander issue.  There are two types of expansion in orthodontics: 1) dental expansion where the teeth move within the bones, 2) orthopedic expansion where we move the bones themselves.  Dental expansion is something that any bracket system can do regardless of the ligation method.  All we need to do is use a wire that is wider than the teeth (the wire is the driving force behind tooth movement not the bracket).  Orthopedic expansion is what we use palate expanders for.  These are used in cases where the upper jaw is literally too narrow compared to the lower jaw.  Why would you want to widen the teeth when the bones themselves are deficient?  The expansion that brackets and wires do is NOTHING like the expansion that expanders do.  Now let’s talk extractions.  When you boil this down to the most basic idea this is a simple math question.  You have a set width of teeth and a set width of jawbone available to fit teeth.  We can modify the width a bit (with dental and orthopedic expansion) but at a certain point there is simply too much tooth structure to fit in the mouth.  There is no magic to this.  A specific type of bracket does not change simple mathematics, period.
  • CLAIM: Self-ligating brackets result in faster treatment times and fewer visits to the office
  • TRUTH: Treatment with self-ligating brackets DOES NOT reduce treatment time or the number of appointments. There is a lot of evidence showing that treatment time is NOT related to the type of bracket that is used. One thing IS true. Self-ligating brackets do seem to decrease the physical time in the chair because the doors are generally faster to close compared to putting on a rubber band, but they DO NOT reduce the total treatment time. The time reduction in the chair is relatively insignificant for any single patient (usually less than 60 seconds per appointment).  For an orthodontist who sees 100 patients a day these small numbers add up over time but you as a patient will not notice much of a difference between a self-ligating bracket system and a conventional bracket system.
  • CLAIM: Self-ligating brackets have less friction, which results in lower, more biological forces and more efficient treatment.
  • TRUTH: A recent review found that self-ligating brackets DO have lower friction; however, this is ONLY true when the teeth are already straight and small round wires are used.
  • CLAIM: Treatment with self-ligating brackets is less painful than conventional brackets.
  • TRUTH: Things are a bit unclear here. It seems that the type of bracket has much less to do with discomfort than the type of wire that is used. Studies where half of the mouth has self-ligating brackets and half has conventional brackets show that there is slightly less discomfort with the self-ligation; however, the self-ligating brackets were much slower to align the teeth. A randomized controlled trial (gold standard for research design) showed that there was no difference between self-ligation and conventional ligation when it comes to comfort/discomfort of moving teeth.
  • CLAIM: Self-ligating brackets break less often than traditional brackets
  • TRUTH:  This is a silly claim, in my mind. There is NO evidence that this is true. Getting brackets to stick to the teeth is much more related to the technique used when placing them than the bracket used.  There are many reasons why brackets break off of teeth.  One of the most common causes of broken brackets is eating the wrong foods while wearing your braces!
  • CLAIM: Self-ligating brackets are more hygienic than conventional brackets.
  • TRUTH: There is some truth to this claim. The rubber band that holds the wire in can harbor more plaque than a self-ligating bracket; however, for kids who are good brushers this is insignificant.
  • CLAIM: Self-ligating brackets result in fewer periodontal and root problems compared to conventional brackets.
  • TRUTH: There is no scientific evidence to support these claims. Studies have shown no difference between the type of bracket and the condition of the periodontal tissues and roots of the teeth.

Take Home Message:

Your teeth do now know what type of bracket is placed on them. Damon braces do not have a contract that allows doctors who use them to move teeth more quickly, with less pain, resulting in fewer treatment complications compared to traditional braces. I often compare braces to cars. This may seem like a weird comparison but it makes sense. What makes a car move? The engine. How does the car move? The wheels/tires connect it to the road. Braces are no different, the wire is the engine that moves the teeth and the bracket is what connects the wire and the tooth. The only thing the teeth feel is a force to move. This force produces inflammation around your teeth and that makes the teeth sore.

Please don’t read this and assume that I am a “hater” of self-ligating brackets.  They are great brackets.  The Damon bracket is a very well built, high quality bracket.  However, the things that many people say make these types of brackets different really do not hold up when examined scientifically.

In reality, every orthodontic system works.

What you pay for is not the type of bracket or wire system that a doctor uses but rather their expertise in using the system. I always tell people to go to the office that makes them feel the most comfortable. As long as the office and doctor are up to date on the latest technologies, the team is friendly and skilled, and the office is clean, you should have a result of straight teeth and a healthy bite. The difference lies in the doctor’s skills and interpretation of the aesthetic outcome and his or her ability to harness the technology to work for you. Our dedication to our patients is to cut through the plethora of treatments available, not be swayed by the amount of advertising dollars spent by the manufacturers, and find the treatments that truly benefit our patients. Orthodontic treatment is a short-term partnership between the patient and the doctor and if you are not comfortable with the office treatment, your treatment will not be the pleasant experience that it should be.

References

Songra G, Clover M, Atack NE, Ewings P, Sherriff M, Sandy JR, Ireland AJ. Comparative assessment of alignment efficiency and space closure of active and passive self-ligating vs conventional appliances in adolescents: a single-center randomized controlled trial. Am J Orthod Dentofacial Orthop. 2014 May;145(5):569-78.

Miles PG. Self-ligating vs conventional twin brackets during en-masse space closure with sliding mechanics. Am J Orthod Dentofacial Orthop. 2007 Aug;132(2):223-5.

Turnbull NR1, Birnie DJ. Treatment efficiency of conventional vs self-ligating brackets: effects of archwire size and material. Am J Orthod Dentofacial Orthop. 2007 Mar;131(3):395-9.

Johansson K, Lundström F. Orthodontic treatment efficiency with self-ligating and conventional edgewise twin brackets: a prospective randomized clinical trial.  Angle Orthod. 2012 Sep;82(5):929-34.

DiBiase AT, Nasr IH, Scott P, Cobourne MT. Duration of treatment and occlusal outcome using Damon3 self-ligated and conventional orthodontic bracket systems in extraction patients: a prospective randomized clinical trial.  Am J Orthod Dentofacial Orthop. 2011 Feb;139(2):e111-6.

Fleming PS, DiBiase AT, Lee RT. Randomized clinical trial of orthodontic treatment efficiency with self-ligating and conventional fixed orthodontic appliances.  Am J Orthod Dentofacial Orthop. 2010 Jun;137(6):738-42.

Miles PG, Weyant RJ, Rustveld L. A clinical trial of Damon 2 vs conventional twin brackets during initial alignment. Angle Orthod. 2006;76:480–485.

Pandis N, Polychronopoulou A, Eliades T. Failure rate of self-ligating and edgewise brackets bonded with conventional acid etching and a self-etching primer: a prospective in vivo study. Angle Orthod. 2006 Jan;76(1):119-22.

Pandis NVlachopoulos K, Polychronopoulou A, Madianos P, Eliades T. Periodontal condition of the mandibular anterior dentition in patients with conventional and self-ligating brackets. Orthod Craniofac Res. 2008 Nov;11(4):211-5.

Pandis N, Nasika M, Polychronopoulou A, Eliades T.

External apical root resorption in patients treated with conventional and self-ligating brackets. Am J Orthod Dentofacial Orthop. 2008 Nov;134(5):646-51

Chen SS, Greenlee GM, Kim JE, Smith CL, Huang GJ.Systematic review of self-ligating brackets.  Am J Orthod Dentofacial Orthop. 2010 Jun;137(6):726.e1-726.e18

T|D|R proudly providing braces, Invisalign, and orthodontics to Rochester Hills, Birmingham, Novi, Shelby, Lake Orion, Troy, Bloomfield, Royal Oak, Farmington Hills, Northville, Livonia, Walled Lake, and surrounding communities with a long list of straight teeth and happy smiles! An orthodontist receives two to three years of education beyond dental school and are the only ones allowed to call themselves “orthodontists”. Only orthodontists may be members of the American Board of Orthodontists.

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