ABSTRACT:
Recent years have seen an increase in aligner use by orthodontists and an increase in corresponding research. Potential deficiencies in aligner and auxiliary material properties and design, and wear protocols have been suggested as contributory factors in sub-optimal clear aligner therapy (CAT) outcomes. The aim of the present narrative review was to summarise the evidence regarding five specific factors to be considered in the choice of a clear aligner system. The findings indicated that the use of aligners with variable moduli of elasticity may offer the potential for improved treatment outcomes, with simple alignment using softer materials and more complex movements with higher modulus materials. CAT using straight extended trimlines provide better, larger areas of contact with tooth surfaces. This potentially improves force delivery to achieve more ideal tooth movement. The findings of the present review indicated that optimised attachments do not confer significant clinical advantages over conventional attachments. Aligner wear protocols should be determined by the case-specific features of biology and the type of tooth movement to be performed. Bite ramps and torque ridges are not efficacious in managing deep overbite and lingual root torque.