The Invisalign technique (synonym: invisible teeth straightening) is an orthodontic procedure to eliminate misaligned teeth using a series of removable transparent plastic trays called aligners. Each aligner has a wearing period of 14 days. With each aligner, the strength and direction of the forces acting on the teeth change minimally, so that progress towards the treatment goal is made in many small individual steps. Depending on the severity of the malocclusion to be treated, 10 to 50 aligners are required. The splints must be worn for at least 22 hours a day, except for meals and intensive oral hygiene and special occasions. The treatment period stretches over 9 to 18 months.
Indications (areas of application)
The major advantages of therapy with aligners are unrestricted oral hygiene and the fact that they are almost invisible. Phonetics (sound formation) is also comparatively unproblematic; thus, the Invisalign technique represents an enrichment for the orthodontic treatment spectrum with regard to professional groups that have special aesthetic and phonetic requirements. Moreover, studies show that the initial wearing is less uncomfortable for the patient compared to fixed appliances. A disadvantage is that, in principle, splints do not have the same possibilities as fixed orthodontic techniques with regard to the force applied to the tooth. Therefore, where necessary, additional attachments (fasteners), such as buttons adhesively attached to the tooth with composite technology, must be used to move a tooth spatially, i.e., not just to tilt it two-dimensionally. Finally, the combination with fixed appliances is also possible, which means that the range of indications can be expanded almost indefinitely. The range of possible applications varies from simple (10 to 20 aligners) to pronounced (20-50 aligners) tooth position corrections. The latter may be necessary, for example, after tooth extractions (tooth removals). The main area of application is for the following correction needs, assuming stable neutral intercuspidation (multipoint contact between upper and lower teeth):
- Moderate crowding of the anterior teeth.
- Medium degree gap of the anterior teeth
- Protrusion of the anterior teeth (tooth crowns are tilted towards the lip).
- Retrusion of the anterior teeth (tooth crowns are tilted towards the oral cavity).
- Low-grade intrusion (teeth are recessed into the jaw).
- Low-grade extrusion (teeth are elongated): in this case, the above-mentioned attachments are also used
Only conditional use option is available for the following correction requirements, unless further orthodontic appliances are to be used:
- Cancellation of torsion (rotation around the longitudinal axis) of the canines or premolars (anterior molars);
- Gap closure, for example, after systematic symmetrical extraction of the first premolars (removal of the first anterior molars);
- Tooth retentions (teeth remaining in the bone beyond their natural eruption time).
The procedure
- Preparation of the report on the present malocclusion and planning of the treatment by the orthodontist.
- Impressions of the upper and lower jaw with an addition-curing silicone (shrinkage-free impression material).
- Bite taking to transfer the positional relationship between the upper and lower jaw.
- Scanning of the impressions
- Computer-aided 3D simulation of the planned tooth position corrections.
- Production of the splint series by the company Invisalign Technology on the basis of the planning documents sent by the orthodontist.
- Insertion of the first aligner on the patient, instructions for wearing behavior.
- Regular progress checks
INVISALIGN is a registered trademark of Align Technology, Inc.
