If you are a fan of our BLOGs, and have read the prior postings, you are likely to notice a significant amount of familiar material as we discuss the difference between Braces and CAT (Clear Aligner Therapy, commonly known as Aligners or Invisalign). This is because much of what will be used to compare braces to aligners has been covered in BLOG #4 (Why Do I Need Attachments with My Aligners?) and BLOG #6 (What Are Traditional Braces and What Do They Do?). When compared to each other, braces have some advantages over aligners but also pose some disadvantages. Aligners also have some advantages over braces but present some disadvantages in comparison as well.
Each system excels or improves upon the other systems’ disadvantages. Where one is weak the other is stronger, so they tend to complement each other. Since each system is generally capable of achieving a very acceptable result, whether one chooses treatment with braces or aligners is more of a personal choice rather than a result driven choice.
From BLOG #4 on Aligners and Attachments:
Several years ago, as a new company, Invisalign completely changed the world of orthodontic treatment. The concept, and method of moving teeth sequentially was not new. This form of treatment had been used for decades, but it was woefully complicated and required a lot of time and effort in the lab to complete the process. With the technological advances seen in the world of CAD/CAM and 3D digital imaging, it finally became feasible to do this method of treatment in an economical and comfortable way for the patient.
The technology that made it possible is a combination of 3D imaging and the ability to print the captured image in a 1:1 life-size physical object, coupled with the ability to manipulate the digital image. Once it was possible to scan the teeth, or make a super accurate impression of the teeth, then print the digital image from the scan or impression, then manipulate the image without distorting it, it becomes possible to automate the process and make it feasible to do on a large scale. Invisalign was the first company to successfully adapt this CAD/CAM technology to orthodontics and leverage the ability to mass produce the clear aligners that were in common use as retainers.
Backed by technological and manufacturing advances, it became possible to mass produce the clear retainers used as aligners. The initial digital images were manipulated to reflect minor incremental tooth movements from the initial tooth positions to a digitally projected norm or ideal tooth position. Depending on the amount of individual tooth movement needed, and how the cumulative tooth movements were coordinated, a series of models were produced for the fabrication of the clear plastic retainers that would fit each respective model. Although this path from digital models of teeth to actual models of the teeth that could be used to fabricate the series of retainers, now called aligners, made it feasible; it was not quite ready for implementation as the individual retainers/aligners still required manual trimming and polishing. When it became possible to mechanize the process of producing the aligners, everything came together to allow this process to be completely automated and without the restrictions of requiring manual labor in the process. This is what ultimately made it a viable treatment option that could be made available to patients on a large scale.
If the incremental tooth movements were small enough, and the plastic could get sufficient grip on the teeth so the aligner could exert enough force to create tooth movement, treatment with aligners could be successful. One of the major difficulties encountered early on in aligner treatment was that the aligners had a difficult time getting a grip on the teeth that was significant enough to allow the teeth to move an appropriate distance between aligners. If the increments were too small, it would take way too many aligners and too much time to complete the treatment. The solution was to use attachments on the teeth to allow the plastic to be effective in moving the teeth and achieving the treatment result in a reasonable number of aligners.
The attachments perform the same function for the aligners as the braces do for the wires in traditional treatment. Just like braces, or brackets, the attachments provide a handle for the plastic to grab the teeth and exert a force to move the teeth in the desired direction. The attachments are made of the same special bio-compatible composite that adheres the braces to the tooth structure. Both the bond or adhesion, as well as the composite material itself, are strong enough to withstand the forces necessary to move the teeth, the forces generated when chewing, and the significant pressures placed on the attachments when the aligners are inserted and removed.
Attachments have been developed and refined over the years so that there are several shapes, orientations, and sizes used to provide optimal leverage for the plastic to accomplish the desired individual tooth movements. Some tooth movements are accomplished very effectively with a single attachment on the tooth, while other movements require multiple attachments on the same tooth so they can work in concert with each other to efficiently move the tooth and position the root as desired. Attachments have become an integral part of clear aligner treatment, and a necessary component for achieving excellent treatment results.
Although the bonding adhesives used to form the attachments are strong and durable, they may wear, chip, fracture, or dislodge and fall off during treatment. If an attachment becomes worn or chipped, it will be less than optimally effective in accomplishing the desired tooth movements. If an attachment falls off, the aligner may be unable to accomplish further tooth movement, depending on the tooth involved and what movements remain in treatment. Because the loss of an attachment can has an adverse effect on treatment, it is important to report any loss of attachments to the orthodontist as soon as possible. It is helpful if you can tell them what teeth are missing from their attachments. The orthodontist will be in a better position to understand how urgent it is to repair the breakage, and what else may need to be done in conjunction with replacing the missing or damaged attachments. The staff will give you an appointment to make the needed repairs or replacements.
One of the differences between the braces and aligners and how they work to straighten the teeth is that with the braces, the details of tooth position is determined by where the braces are placed on the surface of the teeth, and in relation to the brace positions on the adjacent teeth. With clear aligners, the position that the attachments are placed on the teeth has no bearing on how the teeth are moved or ultimately positioned. The attachments are usually placed to gain maximum effect for the movement they are facilitating. Typically, the attachments are placed closer to the edges of the teeth rather than closer to the gums because when they are placed close to the gums there is very little aligner material at the gum level to grip the attachment and this weakens the grip of the aligner on the attachment.
As one would expect, the bigger the attachment, the more effective it will be as a handle for the aligner to grab a hold of. Cosmetics and irritation are limiting factors to the size of the attachments. You do not want to have an attachment that is large and irritating when you can accomplish the required tooth movement with an attachment that is less intrusive. There is a balance to be had in the size and positioning of attachments.
Virtually every person who has aligners should expect to have attachments placed as part of treatment. With time, experience, and a greater number of people completing treatment with aligners; the number, size, and shape of the attachments has been refined. Currently, the AI used in treatment planning recommends attachments on almost every tooth undergoing a significant amount of movement. The attachments may be changed at different points during treatment to maximize efficiency. The customized shape and size of attachments allows treatment to be completed faster and with better results than when a minimal number of attachments are used. Customized attachments have been a substantial factor in our ability to control the cost of treatment because we are able to be more efficient and complete treatment faster and with fewer aligners. This cost control is very important in today’s world where Bidenflation is adversely impacting everyone’s budget.
Invisalign and clear aligners are a great way for the orthodontist to craft your best smile. Attachments are a big part of the treatment and should be expected. If they break off or wear significantly, they are likely to be replaced. Let your orthodontist know if you are aware that an attachment is broken or missing. Enjoy your treatment with clear aligners and the benefits this type of treatment offers!
From Blog #6 Aout Braces:
When considering all the modern types and styles of braces, one may ask “how did we get to where we are today?” With all the advancements and changes that take place routinely in the field of orthodontics, braces have certainly changed over the past few years.
There is evidence of orthodontic treatment being done well before the meridian of time, but it became more widespread and less barbaric in the mid 1800’s when Dr. Edward Angle started refining braces so the doctor could control tooth movement 3 dimensionally. He initially did this with a “Pin and Tube” type appliance that used bands, or rings, around each tooth. Each band had a tube welded vertically, and a base wire that followed the arch or semi-circle of the teeth and jaws with vertical pins soldered on the wire that corresponded to each tube welded onto a band. The bands would fit precisely to the form of each tooth, then cemented in place. The wires would be tied into place once the pins were engaged into each tube.
Dr. Angle encountered some obvious problems and complications with the “Pin and Tube” system and did a redesign. The new system was called the “Ribbon Arch” and used a rectangular wire that fit in a vertical slot that was cut into the tube from the old “Pin and Tube” system. The rectangular wire was bent around the smaller wire dimension to create an arch form for the teeth to follow, and it was pinned or tied into the tube. The “Ribbon Arch” system was better but still had some problems. It was also difficult to place and secure in the vertical tube braces. To solve this, the next generation of braces turned the slot and the wire 90 degrees. The slot became horizontal rather than vertical, which made wire insertion much easier. The wire was now bent around the short dimension of the rectangular wire and Dr. Angle called this the “Edgewise System.” To hold the wire in the braces, “tie wings” were created by placing undercuts on opposing sides of the wire slot and very fine “ligature” wires were used to ligate or tie the arch wires in place.
The edgewise system has been in place since the late 1800’s but has undergone several upgrades and design changes to the basic system. The Edgewise Appliance in one form or another is the most widely used orthodontic system in use today. It has become the worldwide standard for brace systems.
Now that we know what braces are, let’s learn what they do, how they work and what part the braces play in orthodontic treatment. For the teeth to move, pressure must be applied to the tooth. The tooth responds to the pressure by moving in harmony with the force vector, or direction of force. In the past, there was no way to secure a brace directly to the tooth, so they were welded onto bands that were fit like rings around every tooth. Bands are still used with some orthodontic appliances and on the back teeth because they are much more durable and less prone to breakage. Fortunately, in the late 70’s and early 80’s composite resins that are bio-compatible with the tooth structure were developed and started being used for dental fillings and adhesives. These composites were refined and developed to glue or bond the braces directly to the teeth. In today’s modern orthodontic practice, most of the braces are bonded directly to the teeth and bands are rarely, if ever, used on any of the front teeth.
Once the braces, or “brackets” could adhere to the teeth, treatment became much more aesthetic and the application of the braces much easier on the patients. It is important to have a good bond between the tooth and the bracket so that the bracket can transmit sufficient force to the tooth so that the tooth will respond and move as intended.
The braces, or brackets, provide a slot for the arch shaped wires to engage and exert a force to move the teeth in the desired direction. The braces are basically a handle, or stable point, that allows the wires to become effective in moving the teeth. Tooth movement is really all about the wires, not about the braces. It is the wire that produces the force to move the teeth, but it is the interface between the wire and the brace that dictates how the force will be applied and controls how the tooth will move.
How the brace and the arch shaped wire interface work together is dependent on several different variables. One variable is the position of the bracket on the tooth. For example, if the brace is placed closer to the edge of the tooth, the wire will push the tooth into the gum and make it appear shorter. If the brace is placed at an angle on the tooth, the crown of the tooth will tip to one side and the root will tip in the opposite direction. If the brace is placed off center, then it will cause a rotation of the tooth. These bracket placement errors can be overcome and compensated for by bending the arch shaped wire or repositioning the bracket. It is rare to find that every brace is placed in the exact right place on every tooth from the beginning of treatment. Often, because of the crowding, it is impossible to place the bracket in the proper position, so it needs to be repositioned later in treatment once the tooth is in a better position and there is access to the location where the brace belongs.
The braces have many variations in their design and the orientation of the wire slot. Each of the variations serves a unique purpose. One of the most significant initial changes made to braces was to build the individual root angle, root tip, and tooth thickness compensation into the brace itself, thus eliminating the need for the orthodontist to bend the arch wires to make these accommodations. Because the adjustment bends could be built into the braces rather than being bent into the wires, this advancement in design was called “Straight Wire” appliances.
With proper placement and positioning of the braces in a straight wire appliance, as the teeth move into a position that is in harmony with the form of the arch that the wire displays, the teeth will align themselves and mesh together in the proper bite. Often the bite is off, and elastics (or other traction devices) must be used to adjust the overbite and the mesh of the bite on the side teeth. When this is done and the treatment is completed, the patients’ health, bite, function and aesthetics are all improved.
One of the other fun changes with the braces happened in the 1980’s when colored ties were first made available. Previously, the arch wires were tied in using very thin wires, called ligature wires. The ligature wires were removed and replaced at every appointment. This was time consuming and at times it could be hard on the patient. Things improved when rubberized elastomeric doughnut shaped ties were made available to replace the ligature wires for general use. These rubber o-ties only came in silver or gray for many years, until someone got the brilliant idea to make them in different colors.
At first, only a few colors were available, but the ability to choose a color quickly became the highlight of the visit to the orthodontist. This was such a hit with the patients, and fun to create different color schemes, like seasonal or team colors. Thanks to the popularity of the colors, the number and variation of the colors made available multiplied very rapidly. Today, almost any color imaginable is available as an orthodontic o-tie. The colored o-ties have become the standard for tying in arch wires, and the patients love it! Some patients who are good candidates for other less visible treatment options choose to do braces, strictly because they can do the colors and have that fun as part of their treatment experience.
Without the braces, the wires could not apply the force needed to move the teeth into position. The colored o-ties and chains add fun to the treatment and perform the important function of seating the arch wire into the braces so the wire can exert a force that will move the tooth into the proper position. As the teeth are placed on the same level, aligned to a natural arch form, and mesh properly on the sides with a normal overbite, the benefits of improved aesthetics, health, bite, and function are achieved. Braces are an integral part of the magical transformation that takes place during orthodontic treatment!