What is Invisalign®?
Invisalign® invisible braces are just that: invisible. The Invisalign® system utilizes clear aligners that are designed to fit discreetly over the teeth and gradually straighten them. Because the aligners are constructed from clear material, they are virtually imperceptible to the eye, no braces or wires are used.
Invisalign® vs. Traditional Orthodontics
Invisalign® is effective for mild to moderate orthodontic problems and provides the same teeth straightening benefits as traditional metal braces, they are becoming the orthodontic treatment method of choice. Dr. Bisbas is an Invisalign® Premier Provider and can determine if you are a candidate for this type of treatment.
Made to fit your lifestyle, not change it.
Because Invisalign® uses comfortable plastic aligners to move teeth, you can continue enjoying your active lifestyle even during treatment. If maintaining your professional appearance is important to you, most people won’t know you are straightening your teeth unless you tell them because Invisalign® is nearly invisible. And since Invisalign® is removable, you can always take it out for special events.
The Invisalign® Procedure
The Invisalign® procedure is extremely quick and easy. Dr. Bisbas begins by using advanced 3-D computer imaging technology to transform your impressions into a series of clear, custom-fitted aligners. There may be as many as 48 in the series or as few as 12, depending on your individual treatment plan. You will wear each set of aligners day and night for about two weeks, removing them so that you can eat, brush, and floss normally. Instead of visiting Dr. Bisbas monthly to have your brackets adjusted and tightened, you simply replace your aligner with the next in the series. Your office visits are no more frequent than with conventional braces. Invisalign® invisible braces allow patients to straighten teeth discreetly without hassle. The Invisalign® procedure straightens teeth just as effectively as traditional metal braces, provided the patient follows all of the guidelines outlined by Dr. Bisbas.
If you decide that Invisalign® is the right choice for you, we’re ready to help you take the next step toward achieving that perfect smile.
Take the Invisalign Self Assessment today.
Contact Us to Learn More about Invisalign® Invisible Braces
We are dedicated to helping our patients achieve the smile they desire. Schedule your complimentary consultation with Dr. Bisbas online or call our office at: 858.755.5363 to learn more about why Invisalign® is the clear choice for a beautiful, healthy smile.
An Overview of Invisalign® Treatment
INTRODUCTION: WHAT IS INVISALIGN®?
Invisalign® is an esthetic orthodontic treatment alternative developed by Align Technology, Inc. (Santa Clara, Calif.), for adults and teenagers who want improved tooth alignment, but do not want treatment with conventional braces. The system was introduced in the late1990s and uses Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) technology to fabricate a series of custom appliances that are esthetic and removable for patients. Depending on the malocclusion and the type of tooth movement required, Invisalign® may provide an alternative to fixed appliances for many patients.
The treatment appliance consists of a series of clear, custom-made, removable aligners created to effectively move teeth into their desired position (Figures 1a and 1b). This method of orthodontic treatment combines orthodontics, materials science, and 3-D computer graphics to project and plot tooth movement. Generally, aligners are worn on a full-time basis and are removed only for eating, drinking, brushing, and flossing. Patients usually wear each set of aligners for two-week periods.
The manufacturer, Align Technology, provides guidelines for the types of malocclusion and orthodontic problems that can be managed with Invisalign®. These problems include mild to moderate crowding (1-6 mm), mild to moderate spacing (1-6 mm), constricted arches (nonskeletal), and limited relapse cases after fixed appliance therapy.1,2 Invisalign® can perform the following orthodontic movements: space closure, tooth alignment, limited dental expansion, incisor advancement, and limited distalization of teeth. Invisalign® is not advised for treating complicated malocclusions such as severe deep bite, open- bite, Class II and Class III cases that require significant anterior-posterior corrections, severely tipped or rotated teeth, or cases that require multiple tooth extraction.
Ultimately, treatment choices are left to the clinician’s judgment. In general, cases that require significant root movement may be difficult to treat with Invisalign® solely. Approximately 40,800 orthodontists and general practitioners worldwide are Invisalign®-certified, and that number grows each year. More than 529,000 patients have started Invisalign® treatment to date. (Jennifer Olson-Wilk, manager of university programs, Align Technology; oral communication, February 2007.)
Align Technology accepts more than 98 percent of all cases it receives. The company defers to the professional judgment of the treating doctor to determine how Invisalign® can be incorporated into the treatment plan. Align Technology has manufactured more than 22.9 million unique Invisalign® aligners since its inception. (Olson-Wilk, oral communication, February 2007.) As noted previously, Align Technology has stated that Invisalign® is indicated for patients with mild to moderate crowding (1–6 mm), mild to moderate spacing (1–6 mm), nonskeletal constricted arches and those patients who have experienced relapse after fixed appliance therapy. The fact that each clinician is responsible for the treatment results achieved in every patient makes it important to conduct more clinical studies.
It has been shown that, in an orthodontist’s hands, fixed appliances produce better treatment outcomes than Invisalign® Specifically, in one study (the sample treated with the Invisalign® system), the greatest positive change measured was in the alignment of teeth, followed by closure of interproximal space. But an undesirable change was found with a decline in posterior occlusal contacts, showing that treatment with Invisalign® aligners had adverse effects on posterior occlusal contacts and positive effects on tooth alignment, buccal-lingual inclination, and interproximal spaces. Other studies, however, have shown that more complex cases managed with Invisalign® may be successfully treated, but have noted that the treatment outcome is highly dependent on the practitioner’s clinical experience and case selection.
THE INVISALIGN® SIX-STEP PROCESS
Before initiating Invisalign®, all necessary basic restorative treatment must be completed, the patient should exhibit no active periodontal disease, and the patient should have fully erupted second molars. As with fixed-appliance orthodontic treatment, a thorough clinical examination, patient history, diagnosis, case presentation including alternative treatment plans, if appropriate, and informed consent should be completed before treatment begins. Treatment using Invisalign® involves a process of at least six steps (Figure 2). They include:
Step 1: Patient records, diagnosis, and treatment plan submission
Step 2: Records submission
Step 3: 3-D computer modeling
Step 4: Review of ClinCheck® by doctor
Step 5: Manufacturing of aligners, initiation of treatment, and aligner delivery
Step 6: Treatment, midcourse correction, refinements, and retention
Step 1: Diagnosis and Treatment Plan Written by Doctor When all necessary preliminary restorative treatment has been completed and the patient is free of active periodontal disease, the patient can be evaluated further to assess the orthodontic needs. As with any orthodontic treatment, a comprehensive evaluation of the patient is advised. Not all records from this evaluation need to be submitted to Align Technology, if treatment with Invisalign® is feasible. Eight photographs are required for submission: Extraoral: frontal smiling (1), frontal repose (2), lateral profile repose (3); Intraoral: anterior (4), right and left buccal (5,6), and maxillary and mandibular occlusal (7,8). The patient should also have fully erupted second molars, which limits the care of many adolescents. Good candidates for Invisalign® treatment include patients with:
Generalized mild to moderate crowding
Evidence of orthodontic relapse
A moderately deep bite
A need for combined restorative/orthodontic treatment
A need for posterior dental expansion of
1 to 2 mm per quadrant
Late-onset lower crowding (adults)
Step 2: Records Submission
The minimal needs for submission to Align Technology are original Polyvinyl Siloxane (PVS) upper and lower impressions, an original PVS bite registration, photographs, and a prescription form (Figure 3a). When the technique was first available, duplicate X-rays were also necessary but currently are not required. With the exception of the impressions and bite registration, the patient’s diagnostic data can be submitted online, along with the provider’s preferences as to how each case should be managed.
For example, in a case that exhibits crowding, the provider may want to use interproximal enamel reduction, dental expansion, or incisor proclination to alleviate the crowding. Doctors can register their general priorities and preferences for case treatment in their personal data record on the Align Technology Web site. This record will serve as a general guide to the Align technician for all of the doctors’ cases.
Before submitting records, practitioners should have a clear idea of their specific objectives for treatment. When cases are submitted, new disposable trays, submission forms and boxes are supplied by the company. Prepaid mailing boxes are provided by Align Technology. Different types of prescription forms can be submitted. The first is the more traditional FULL-Prescription and Diagnosis Form, which is used for aligners fabricated to treat the full arch and includes three refinements (additional aligners or slight modifications), if necessary, at no additional charge. Midcourse corrections are also available and will be described later in this article. The second is the Anterior Prescription and Diagnostic Form, which is used for aligners fabricated to treat only anterior teeth, canine to canine, with no extractions (this includes three refinements, if necessary, and midcourse corrections are also available). Finally, there is the Invisalign® Express Form, which is used for single- or dual-arch treatment for very minor cases of crowding and spacing that meet the Invisalign® Express criteria and require 10 aligners or less to complete the patient’s treatment. One refinement and one detailing set (fine, finishing movements) can be requested for an Invisalign® Express case, but no midcourse corrections can be ordered.
Invisalign® Express is an orthodontic treatment for patients with very minor malocclusions. Treatments must meet the Invisalign® Express criteria and be 10 or fewer stages. Invisalign® Express delivers similar esthetic benefits to patients, with limited orthodontic needs. The clinical criteria for Invisalign® Express include: spacing or crowding of less than 2 mm per arch, rotation of canines/bicuspids that are less than 10 degrees, rotation of incisors less than 15 degrees, less than 1.5 mm dental expansion per arch, less than 2 mm midline correction, no mesial or distal movement of the molars or premolars and less than 1 mm distal movement of any canine, and no extrusions.
Aside from determining the proper diagnosis and treatment plan, the most critical step in fabricating aligners is obtaining accurate PVS impressions. Attention to detail is of the utmost importance.
Step 3: 3-D Computer Modeling
Once records are submitted, Align Technology transforms the patient’s PVS impressions into 3-D images to prepare a three-dimensional computer graphic image of the patient’s teeth and associated tissues. Later, additional models are used to validate the orthodontist’s diagnosis and treatment plan. The PVS impressions are archived for model duplication or replacement.
ClinCheck® is a three-dimensional representation of the planned orthodontic tooth movement in increments or stages. The ClinCheck® software uses the practitioner’s treatment form and stated preferences to generate a computerized final status, which includes stages in between the start and finish. Planned movements of teeth are projected at two-week intervals with approximately 0.25 mm of movement anticipated for anterior tooth movement. After this computerized plan of treatment is projected, the doctor is notified that the case is ready for review of its ClinCheck®.
Step 4: The Doctor Reviews and Approves ClinCheck® There are five basic steps that Align Technology recommends for reviewing ClinCheck®. A “ClinCheck® Review Guide” is available on the Web site. Careful review of ClinCheck® is essential to achieve the best possible results. If tooth movement is not planned properly in ClinCheck® treatment, results may be disappointing.
When first viewing ClinCheck®, it is important to verify that the interocclusal relationship is correct. If it is not, the practitioner must communicate with the Align technician and have the occlusion reset in its proper position.
The areas to review are:
1. The final positions of the teeth as viewed from the anterior, overjet, occlusal, buccal, and lingual perspectives. Basically, the doctor must have his or her specific goals and objectives for the case represented in the CliniCheck® simulation.
2. Interproximal reduction (IPR): recommendations regarding the quantity, location, and timing of the enamel reduction. Interproximal reduction of enamel [also referred to as Air-Rotor Stripping (ARS)], reproximation, slenderizing, stripping, or interproximal recontouring are often necessary and integral parts of Invisalign® treatment. Any case requiring interproximal reduction will have an IPR form indicating when, where, and how much is required.9 IPR is performed where additional space needs to be established to alleviate crowding. IPR is usually done during treatment, but it can be done before the PVS impression, as long as the space is retained until aligners are delivered. If performed during treatment, properly adhering to the IPR instructions is important to achieve the predicted treatment outcome. If the IPR is inadequate, crowded teeth will not be able to align properly and treatment will not progress or come to a successful completion.
3. Staging is the process of determining the sequence, timing, and rate of tooth movement from the initial to the final occlusal position. Each stage represents one aligner. Aligners are fabricated to move teeth 0.25 mm per tooth per stage. However, the practitioner may choose to provide movement speeds different from those recommended in the proposed protocol in certain cases. More difficult and less predictable movements may be slowed and staged over a longer period to better express the movement.
4. Attachments and pontics. Align Technology defines attachments as three-dimensional shapes added to tooth geometry to enhance the interaction between an aligner and the teeth. These are represented by red shapes on the ClinCheck®. Attachments are tooth-colored composite forms that are bonded onto the teeth using a template and a restorative composite (Figure 6). Attachment can be used to anchor aligners for better retention, to modify force delivery, or to improve specific tooth movements. The most commonly used attachments are rectangular or elliptical shapes and may be oriented either horizontally or vertically, depending on their function. Pontics are spaces built into the aligner that narrow over the course of treatment as the spaces are closed. In the ClinCheck®, pontics are represented as half a tooth with a retention dimple.
5. Overcorrection is planning tooth movement beyond ideal to anticipate tooth relapse. However, trying to predict before treatment begins which teeth may need overcorrection is difficult and unreliable. It is recommended that overcorrection be done as part of refinement. If overcorrection of specific teeth has been requested as part of your treatment plan, try to be as precise as possible in prescribing the amount (in millimeters or degrees) and direction of movements.
Step 5: Aligners Manufactured and Shipped to Practitioner for Delivery to Patient.
After ClinCheck® approval of the treatment plan, Align Technology uses the sequence of graphical images combined with CAD/CAM to produce clear, lightweight aligners. Within 10 business days of the ClinCheck® approval, Align Technology ships the aligners to the doctor’s office. If attachments are part of the plan of treatment, an “attachment template” is sent with the aligners.
After any necessary attachments are placed, the aligners are delivered to the patient with a starter kit, and written and verbal instructions are provided as well. Patients are generally instructed to wear the aligners full time, except for eating and drinking. The patient wears each set of aligners for two-week intervals until treatment is complete. Monitoring the treatment occurs as the patient visits the doctor every six to eight weeks or as otherwise instructed.
The attachments referred to previously are composite forms bonded to a tooth surface or surfaces to aid in movement of the teeth. They serve as “handles” used to assist in the retention of the appliance or specific types of movements.
These composite attachments are bonded to teeth by the doctor at the beginning of treatment using a ready-made template. They are placed to assist in: (1) retention of the aligner, (2) intrusion, (3) rotations of teeth, (4) limited uprighting, and (5) space closure. The attachment
templates can be made in different shapes, as prescribed by the practitioner.
Step 6: Monitoring Treatment, Obtaining Desired Results, and Retention.
Careful treatment monitoring will help identify problems and issues before they become major issues that may limit the success of the planned treatment. When monitoring a patient’s treatment, it is important to make sure that the teeth are tracking (fitting intimately within the aligner), as planned in the appliance. Sometimes, one or more teeth do not track according to the plan mapped out in the ClinCheck®. This may occur for a variety of reasons, including a lack of patient compliance, inadequate IPR, excessively tight proximal contacts, or planned tooth movement that exceeds the capability of the aligner.
An important routine procedure in any Invisalign® treatment is to check the tightness of interproximal contacts with a thin piece of dental floss at each visit and to relieve tight contacts in areas of planned tooth movement.
At each patient visit, check the occlusion and verify that aligners are fitting and tracking properly, perform IPR as planned, and check the condition of the attachments. It is advisable to compare treatment progress to the ClinCheck® simulation at three-month intervals to evaluate that the treatment is proceeding appropriately and according to plan. If teeth do not seem to be tracking well in the aligners or treatment needs to be modified, some type of midcourse correction or “refinement” may be necessary. REFINEMENTS AND MIDCOURSE CORRECTIONS
During treatment, it may be necessary to revise the original plan or augment it with additional or slightly modified aligners. When additional aligners are needed to move teeth closer to the desired final position originally approved in the ClinCheck® setup, a refinement may be requested.
A midcourse correction is an option to order new aligners during treatment if clinical results have deviated to such an extent that the aligner(s) no longer fit(s). It is advisable to take new PVS impressions for such refinements and midcourse corrections.
Using other supplemental appliances along with Invisalign® is considered “auxiliary” treatment. Buttons, elastics or other techniques, including brackets and bands, before, after or in combination with aligners may be required to achieve certain tooth movements or occlusal seating. Auxiliary treatment may also include the use of more traditional fixed appliances in one arch or the use of traditional fixed appliances, as needed, for surgery patients.
When the case has been completed, the patient goes into retention. The final aligner should not serve as a long-term retainer as the material is not as durable as other available retainers. A retainer may be fabricated by Align Technology, but the practitioner may elect to design and fabricate the retainer elsewhere. Align Technology does not accept work models or additional impressions to make retainers. Retainers are only created from initial or case refinement ClinCheck® plans. In retention all of the more complex restorative procedures that could not be completed before or during treatment can now be accomplished.
An Overview of Invisalign® Treatment courtesy of Stuart D. Josell, DMD, MDent Sc, Chair of the Department of Orthodontics at the University of Maryland Dental School and Steven M. Siegel, DMD, Clinical assistant professor in the Department of Orthodontics in private practices in Glen Burnie, Reisterstown, and Owings Mills, Md.