A BRIEF HISTORY OF CLEAR ALIGNERS
For decades, orthodontists have know that if you wanted to move a single tooth a tiny bit you could design a small number of clear retainers that would gently guide that tooth into proper position. If a patient was persistent enough, they could wear the retainers one after the other until that tooth was guided into proper position.
Right around the turn of the century (1999/2000) a pair of enterprising young Stanford graduate students made the observation that if they failed to wear their clear retainer for a while and then put it back on, they could guide their tooth back into its previously straight position. It dawned on them that they could perhaps guide teeth into better position not from a tiny bit of relapse (teeth returning to their previously straight position) but perhaps from some initially crooked position. They had arrived at knowledge that other orthodontists had been using for quite some time. The difference was that they decided to tackle this idea in a much greater scope. They enlisted two other engineers who had experience in other disciplines (3D printing, etc) and together they formed a company that would be known as 'Align Technologies' and develop the 'Invisalign' appliance. After their first clinical trials (performed at Dr. Nordberg's alma mater - The Arthur A. Dugoni School of Dentistry at University of the Pacific) they begin to market and develop the idea and the appliance to a much wider audience. Fast forward to the current day and the Invisalign appliance has treated over 4 Million smiles worldwide. It is the distinct leader in the world of clear aligners.
The early appliance was rudimentary in nature. It was primarily limited to closing spaces and tipping teeth outwards to attempt to bring them back and straighten them. The early adopters of this initial appliance encountered many frustrations. The bumps used to "hold on to the aligners" were not very functional. The clear aligner plastic material was relatively stiff and while this was very good for a clear retainer which you inserted and removed 1 to 3 times per day, an aligner that you remove every time you eat or brush your teeth proved to be quite challenging. To complicate matters further, clinicians discovered that if a patient wore a set of aligners for an extended period of time, they might find spaces open up between their back teeth. These spaces would cause difficulty for the patient to bite and chew their food. It is easy to see how both patients and their treating clinicians may become dissuaded from continuing to explore this type of treatment.
Next came the research, numerous studies evaluated this and other types of appliances and routinely discovered the same thing; that for every tooth movement requested, the tooth would accomplish somewhere between 40-60% of the desired magnitude of movement. For small movements (say a rotation of 3 degrees), this may be acceptable but for very large tooth movements (say moving a molar 4mm forward), these types of clinical results could be quite disappointing. For some "early adopter" orthodontists and even dentists, these challenges proved too much to overcome and they swore off the appliance forever.
ADVANCES AND THE CURRENT STATE OF ALIGNER TECHNOLOGY
Since those early days of Invisalign, many advances have been made. While some orthodontists were turned off by the initial challenges, others persisted in trying to explore the boundaries and overcome the limitations of this appliance. They would treat patients and plan more tooth movement than what was required to ensure that the teeth in question would be able to accomplish even the more challenging movements. In addition, Align Technologies invests yearly in increasing the capabilities of this appliance. The investments cover numerous topics such as the following:
Materials - a new plastic material known as "SmartTrack". This material is much more pliable and subsequently a patient will find it much easier to insert and remove an aligner multiple times during the day. Not only that, the material also provides a more constant force that degrades less over time and ensures that teeth move smoothly and predictably toward their desired finish position.
Biomechanics - these are the study of the various forces that an orthodontic appliance introduces to the oral environment (applied to teeth primarily) and their cumulative effects in bringing about a desired treatment result. Ideally, orthodontic forces would be applied through a tooth's "center of resistance" (don't worry there won't be a test) to move that tooth in its most direct and efficient manner. Align Technology has designed entire laboratory environments to test the various forces applied by clear aligners on fake teeth with built-in force sensors (known as force transducers). From these labs, they can improve the force levels applied to teeth and provide more successful tooth-movement results.
Treatment Efficiency - ask any orthodontic patient how they're feeling one month after they start treatment and you get the same response, "I'm used to this now but when can I take these off?" Clear Aligners are much easier to wear than braces but patients still want to be done with treatment ASAP. Align technologies has been working to improve not only the success of tooth movements but also the speed at which all combined tooth movements (for a single tooth or for all teeth in the mouth) are finished.
Software - Clear Aligners aren't magic - you can't just order a pair of them to fit your teeth and presto-change-o 6 months later you're done with perfect teeth! In fact, an orthodontist or dentist must spend a fair amount of time dialing-in your own specific treatment plan of tooth movements - going back-and-forth with the Invisalign representatives (known as technicians) as well as the patient (you) when multiple courses of action are possible or when different treatment outcomes can be adopted. In these scenarios, good software helps increase the chances of good clinical outcomes and satisfied patients and loved ones.
OTHER OPTIONS IN CLEAR ALIGNER THERAPY
Invisalign isn't the only "game in town" when it comes to Clear Aligners. Please forgive the following analogy but where Invisalign is more like the "Mercedes Benz" of the Clear Aligner world, other offerings are somewhat like a Honda or even a Kia. The analogy is this - a Honda or Kia can still help you arrive at the destination albeit with a few less "bells and whistles". We are proud to offer other Clear Aligner solutions such as ClearCorrect and SureSmile aligners.