Sunday, December 2, 2012

Invisalign Summit 2012 Review: Invisalign G4

I recently had the pleasure of attending the Invisalign Summit, which is held every other year and offers orthodontists and their team members an opportunity for continuing education time along with updating all of us on the current changes and innovations that Invisalign is making to improve their product.  I saw a variety of case presentations where Invisalign was effectively used to treat cases that were complex, and in many cases most orthodontists would not have considered Invisalign as an option.  In addition, I am becoming more and more comfortable with Invisalign as an option for teenagers instead of braces with the Invisalign Teen product.  The biggest news out of the conference was the future implementation of Invisalign G4.  Whenever Invisalign makes an innovation that is big enough to warrant calling it a new generation for the product, they give it a "G" tag and thus this is considered the 4th generation of the product.

Here is a video explaining  the new approaches to some of the tooth movements that have been more difficult to achieve with Invisalign versus braces.

Invisalign G4 should thus allow:

1.  Greater root tip control for upper central incisors and canines
2.  Improved predictability for upper lateral incisors
3.  Better clinical outcomes for anterior open bite treatment

All three of those categories of tooth movement were by far the most unpredictable with Invisalign treatment in the past, so I am looking forward to being able to offer the Invisalign option to patients who have those tooth movement needs to achieve a nice result.

Finally, the news I was most excited about was to hear that Invisalign has been very active in researching ways to improve the properties of the plastic used for the aligners.  Invisalign suffers in comparison to braces in that the force levels are fairly high with the initial placement of the new trays and they then decay over the typical two week period a set of trays is worn.  Not to get too technical, but this is the opposite of the properties of the initial wires we place to start the alignment and leveling process in a braces patient.  The initial wires are made of nitinol and deliver a low, almost constant force throughout the period that they are in the mouth.  These wires were obviously a huge advancement a few decades ago for the profession.  As this chart shows, the plastic they are working on should allow force levels more in line with the most ideal for efficient tooth movement and I feel it could be a major game changer for clear aligner treatment versus braces.



Friday, September 28, 2012

Case of the Month, September 2012

This month's case will illustrate an impressive improvement of a patient's overbite due to the lower jaw being positioned too far back or posterior to the upper jaw.  This is a common problem that orthodontists have to correct and not only does it result in a more functional bite, it can greatly improve lip and facial balance.  There are many methods of correction of these types of bites and this case will demonstrate a non-surgical correction that avoids the use of headgear.

The patient was 12 years old at the start of treatment and the initial photos below illustrate the large overbite (vertical), overjet (front-back discrepancy of the front teeth) and class II occlusion (lower back teeth a full tooth behind where they should be versus the upper teeth).

The cephalometric radiograph shows the poor soft tissue profile and proclined incisor positions.

The method of bite correction used in this case was an appliance called Forsus Springs.  Once the teeth were well aligned and leveled (about 6 months), the Forsus springs were placed and worn for 6 months.  This is a great appliance when methods such as rubber band wear alone would not be expected to achieve desired treatment results and the patient does not desire to wear headgear or other less patient friendly appliances.  Patients actually do quite well with the springs, as they are flexible and allow a wide range of jaw movements, making eating almost normal.  They are also not too large and sit on the sides of the mouth and thus are not highly noticeable.  The force the springs apply is also at at low, constant level, so the discomfort is not a bad as one might think. 

Illustration of the Forsus Springs appliance.  We placed springs on both sides, but they can also be very effective placed on one side when the bite is asymmetrical and off on one side only.  The springs are not removable (probably another reason for their high effectiveness).

The results of our treatment are shown below.  The bite was fully corrected to an ideal overbite and overjet and a marked improvement in lip and facial balance can be seen on the lateral radiograph (actual facial photos of the patient are not shown for patient privacy).  The total treatment time was right at 2 years with a few months added on because we had to wait on a few teeth to finish erupting near the beginning of treatment.  Our young patient did a wonderful job and all in all we are very proud of the finished product.

Friday, August 17, 2012

Case of the Month

This 11 year old patient presented with the following main orthodontic problems:

1.  Insufficient space for the upper canines to erupt fully
2.  Class II bite (posterior teeth not interdigitating well)
3.  Moderate crowding in the upper arch, mild in the lower

The summarized orthodontic treatment plan was to shift the upper posterior teeth back into proper bite position while creating room for the canines to erupt fully and align.  We utilized a very patient friendly appliance called a Carrier Distalizer as shown in the next photos.  More traditional methods might have included the wear of a headgear.  The patient wore rubber bands from the lower molar (back tooth) up to the upper first premolars where you see the little hook to accomplish the shift of the back teeth and the space creation.  Below are pictures of the appliance showing treatment progress.

 The patient did an excellent job with rubber band wear and the final pictures showing the treatment results are below.  The alignment of the teeth and the bite both look excellent and we were able to achieve our goals without extracting teeth.  The total treatment time was 16 months.

Saturday, August 4, 2012

Common Bite Problems Seen in Children

The following is a video from the American Association of Orthodontists that discusses the common bite problems we see in children in the mixed dentition (children between the ages of 7 and 11 that have a combination of permanent and primary (baby) teeth present).

Saturday, July 7, 2012

What in the world is the orthodontist looking at when he or she evaluates my teeth?!?!

Orthodontists usually have the basic goal of achieving Angle's Six Keys of Occlusion in any of our comprehensive orthodontic cases.  Dr. Edward Angle is considered the "father" of modern orthodontics and essentially created the orthodontic specialty by opening the first school focused on orthodontics only in 1900.  He noted that function (the way the bite works) and form (the way the teeth and bite look) go hand in hand and wrote a paper on the aspects of tooth positioning that resulted in the most ideal form and function.  While there have been a few modifications to the original Six Keys since, Dr. Angle was remarkably accurate in his descriptions.

So, when an orthodontist evaluates a person's bite and tooth positions, he or she is comparing the current positioning versus the Six Keys of Occlusion.  Occlusion basically means the way the teeth fit together.

Angle's Six Keys to Occlusion
bulletKey I – Molar Relationship
bulletKey II – Crown Angulation (tip)
bulletKey III – Crown Inclination (torque)
bulletKey IV – Rotation
bulletKey V – Spacing
bulletKey VI – Curve of Spee

The photo above illustrates dental casts with ideal occlusion (inter-digitation of teeth) and ideal overbite/overjet.  

 The following link provides a great explanation and pictures for each of the Six Keys:

So, when many patients think they should be finished with treatment when their teeth are straight, just remember that orthodontists are specially trained to go the distance and achieve both a great looking smile and a bite that fits together and functions in the most ideal way.  Orthodontists also evaluate jaw relationships, anterior/posterior and vertical positioning of the teeth relative to the face, and soft tissue form (lips especially), but the Six Keys truly are the key to the best orthodontic treatment in most cases.

Saturday, June 23, 2012

AcceleDent: The Future for Faster Tooth Movement?

The FDA has recently approved a device that has been tested for the last few years at my residency program in San Antonio called AcceleDent.  AcceleDent works through the application of pulsating, low magnitude forces (cyclic forces) to the dentition and surrounding bone as a means of accelerating orthodontic tooth movement through enhanced bone remodeling.  Teeth move as bone is resorbed in the direction the roots are moving and built behind the roots after the movement.  The forces the AcceleDent device apply to the teeth are very low in magnitude and do not cause any discomfort.  We have known for years that teeth move faster in younger patients because their bone biology adapts more quickly to the forces being placed on the teeth, so this system is just a new way to cause any patient's response to orthodontic forces quicken.

Here is a picture of the device:

The current recommendations are to bite into the mouthpiece 20 minutes per day while in orthodontic treatment.  This can be easily accomplished while doing normal daily activities like watching TV, reading, or surfing the internet. 

I fully believe in the strong scientific evidence supporting the device's effectiveness coming out because fields such as orthopedic medicine have been using similar methods for decades to heal bone fractures faster, for example.  I plan to offer it to patients at Avery Orthodontics but the current price point may result in it being used by adult patients for the most part until the pricing may drop (it costs about $900 to order each unit from the manufacturer and this amount would just be applied to the overall orthodontic fee).  I believe most orthodontists who will offer it would essentially sell it to the patients at cost because faster treatment times is a bonus for both the patients and doctors.  The group of patients I am especially excited about AcceleDent would be Invisalign patients.  Invisalign is a series of clear trays that move the teeth in little increments.  The current protocol is to change the Invisalign trays once every 14 days, but the use of AcceleDent would certainly allow us to change trays every 10 days and possibly just every 7 days, thus having the potential to reduce the Invisalign treatment time in half.  The situation with patients in braces is a little different because many of our wires need plenty of time to work and express themselves, but braces patients who elect to use AcceleDent in my practice would be seen at quicker appointment intervals to change the wires a little faster than we would in traditional treatment.  I would expect treatment time in braces patients to be reduced about 30%, but that is definitely dependent on the type of case.

Here is a nice video on the AcceleDent system and if you would like to consider its use, be sure to ask us at our consultation appointment.

Wednesday, May 9, 2012

Seven Common Questions Parents Have About Orthodontic Treatment

Today, nearly four million children in the United States and Canada are receiving treatment from members of the American Association of Orthodontists (AAO). And while parents know that orthodontic treatment results in a healthy, beautiful smile, many don’t realize the important long-term health benefits.

As part of its commitment to education, the AAO provides parents with this list of answers to commonly asked questions about orthodontic care.

1.    Why is orthodontic treatment important?
A: Straight teeth and properly aligned jaws contribute to good dental health as well as overall physical health. Orthodontic treatment can boost a person’s self-image as teeth, lips and jaws move into position and improve appearance.

2.    How do parents know if their child needs orthodontic treatment?
A: The best way is to visit an orthodontist. The AAO recommends that all children get a check-up with an orthodontist no later than age seven.

3.    What if my child still has baby teeth at age seven? Should they still see an orthodontist?
A:  Yes.  By age 7, enough permanent teeth have arrived for orthodontists to evaluate how the teeth and jaws meet, and to identify current or developing problems.  If a problem is detected, the orthodontist and parents can discuss when treatment may be necessary.

4.    How does a child’s growth affect orthodontic treatment?
A: Treatment and growth often compliment each other. In some cases, the orthodontist takes advantage of a child’s growth to guide jaws and teeth into their ideal positions.

5.    How often do you visit your orthodontist while in orthodontic treatment?
A: Typically a child will see the orthodontist every 6-12 weeks throughout the course of treatment.

6.    If you currently don’t have an orthodontist, what is the best way to find someone to treat orthodontic problems?
A: To find an orthodontist near you, ask for a referral from your family dentist, your pediatrician or your child’s school nurse. Or you can visit and click on the Find an Orthodontist service. It is important to choose an orthodontist who is a member of the AAO.  Orthodontists receive an additional two to three years of specialized education beyond dental school to learn the proper way to align and straighten teeth.  Only those with this formal education may call themselves “orthodontists,” and only orthodontists may be members of the AAO.

7.    What is the average cost of orthodontic treatment?
A: Fees will vary, depending on the treatment needed.  Most orthodontists offer convenient payment plans, making treatment more affordable than ever.  Most orthodontists will work with you to find a plan that fits your family budget.  In addition, many patients have dental insurance that includes orthodontic benefits. Check with your employer’s human resources department to learn about your coverage.

Tuesday, April 24, 2012

Invisalign is Continuing to Improve and Evolve with G4

The Invisalign method of moving teeth has actually been around for much longer than many people realize.  Clear plastic trays or aligners used to be fabricated by making a series of stone models and resetting the teeth in the lab in small increments.  Invisalign redefined the clear plastic tray method of tooth movement about 20 years by incorporating computer scanning technology to create a virtual model of the patient's teeth and then perform the movements on a computer prior to tray fabrication, thus greatly improving accuracy.

While the product was a great advancement 20 years ago, Invisalign continues to evolve and improve as much more experience and data is gathered and analyzed regarding this type of tooth movement.  The product of today is far more predictable in achieving a wider range of tooth movements that orthodontists thought were nearly impossible with plastic trays a couple decades previously.

I do not like the tagline "clear braces" because simply put, nothing is more precise in achieving desired tooth movement than the use of braces and wires in the hands of an experienced orthodontist and thus equating Invisalign to that is a bit misleading.  That said, I have never felt more confident in the Invisalign product and I am starting to change my mind about the tagline because nearly any type of orthodontic case can be effectively treated with the system now.  Invisalign recently made a series of scientifically based treatment protocol changes (called Invisalign G4), which should continue to increase the types of cases with which orthodontists will feel comfortable treating.  The protocols have changed the default rates of different types of tooth movement and also the shape and position of attachments that are placed on the teeth to allow better force application.

In addition to the clinical Invisalign G4 changes, Invisalign now offers orthodontists more options to be able to present their patients.  The new options are as follows:

Invisalign 5:  This low-cost option is for simple cases involving minor crowding (often the result of relapse of previous orthdontic treatment due to not wearing retainers).  This is great for people who would like to see their teeth as perfectly straight as they once were but want to avoid a large treatment fee associated with longer, more comprehensive treatment needs.  Patients who qualify for Invisalign 5 could be treated with 5 or fewer total aligners (about 3-4 months total treatment time).

Invisalign 10:  This is another low-cost option for patients with mild to moderate crowding and whom can be treated with 10 or fewer aligners.  This option results in treatment times of about 6 months typically.

Invisalign Full:  This is the comprehensive treatment option for any case requiring more than 10 trays and includes a broad range of treatment types.  The fee is usually similar to the fee for comprehensive orthodontic treatment with braces and the treatment times vary from about 9 months to up to 2 years.  Treatment times depend on the specific case and typical case types Invisalign Full is used for include crowding, deep bite, excess overbite or overjet, class II, class III and even open bites.  Essentially patients whose treatment needs are more than just anterior crowding will fall under this category and I would determine the expected length of treatment and if Invisalign is truly an option at the consulatation.

Invisalign Teen:  Invisalign Teen is a new category of Invisalign treatment designed with the unique needs of teenagers in mind.  It is essentially the same as Invisalign Full or comprehensive Invisalign, yet has a few special features.  The special features include compliance indicators (color tabs that tell the orthodontist and parents if the trays are truly being worn for the prescribed period of time), eruption tabs for second molars (a tab that extends at the end of a tray if the second molars are not fully erupted yet), and the ability to replace trays at no extra charge if they are lost.  More and more teenagers are desiring the Invisalign method of orthodontic treatment and I always discuss if it is a realistic option during the consultation.