Why To Add Clear Braces In Your Practice?

Since the form fitted plastic used in clear aligner is not as rigid as the metal used in the traditional braces, sometimes the flexibility in the materials needs to be compensated in areas that require movements. Sometimes modifications and attachments are done to facilitate tooth movement, which can make the aligner less esthetically pleasing.

Patient compliance

Since the clear aligner is removable, patient motivation is necessary for achieving the desired result for the appliance to be effective. Patient must wear it according to the clinician’s advice.

• Each aligner is intended to be worn for an optimal time of the 20-22 hours a day.
• Average treatment period varies form 12-14 months, although the treatment time varies based on the complexity of the planned teeth movements.
• Aligners are only removed for brushing, flossing and eating.
• While undergoing treatment, hot liquid should be avoided to protect the shape of the aligners and from becoming stained.
• Once the treatment period is over, the patient is advised to continue wearing a retainer at night for a foreseeable future.

Extraction cases

Patient having premolars extracted may not be the ideal case for using clear aligners, because this appliance cannot keep teeth upright during space closure. It is found that only 29% of those with 1 or more premolar extracted were able to achieve space closure with initial aligners, none completed the overall treatment. Since clear aligners provide movement of 0.25-0.3 mm, it is not sufficient in extraction cases.

Teeth movement

As it is removable appliance, the clear aligners have limited control over precise tooth movement. Inconsistently successful corrections have been:

• root paralleling during space closure after extraction
• tooth up righting
• significant tooth rotations
• tooth extrusion

Efficiency of Clear Aligner therapy

Many studies were conducted to assess the efficacy of clear aligner therapy. Within certain limitations (e.g. small sample size, bias, lack of binding etc.), it was concluded that clear aligner therapy was effective in

• aligning and levelling dental arches and
• anterior intrusion with molar bodily movement (distalization of 1.5 mm).

However, this therapy was not effective in

• anterior extrusion movement or
• for controlling rotated teeth.

To improve tooth movement, auxiliaries such as attachments, interdental elastics and interproximal reduction (IPR) should be used along with the clear aligner therapy. Another systemic review was conducted which showed that a clear aligner is able to alter intercanine, interpremolar and intermolar width in the presence of crowding. Moreover, incisors tend to procline and protrude when crowding is >6mm. Vertical movements and de-rotations are difficult movements to accomplish with aligner, and interproximal reduction is recommended especially in canines.

Indications and contraindications

• Invisalign® appliance is most successful for treating mildly misaligned malocclusion (1 to 5 mm of crowding and spacing) and deep overbite problems.
• Clear aligner therapy is indicated to be used in adults/adolescents with fully erupted permanent teeth.

Conditions that can be difficult to treat with an Invisalign® appliance or contraindicated include:

• Crowding or spacing over 5mm.
• Centric relation and centric occlusion discrepancies.
• Severely rotated teeth.
• Open bite (anterior or posterior) that need to be closed.
• Extrusion of teeth.
• Severely tipped teeth.
• Teeth with short clinical crown.
• Arches with multiple missing teeth.

Conclusion

Clear aligner therapy has improved over the last 18 years and is still being improved. In developed countries like USA, Invisalign® is widely acceptable but in developing countries such as India sometimes cost of aligner could be a major concern in large number of populations. If patients, especially adults, seek therapy, the clinician should offer clear aligner therapy and be clear about its advantages and disadvantages.

Clear or aesthetic braces should be selected after diagnosis and comparison with other suitable orthodontic treatment options.