The aim of the present study was to evaluate the quality and readability of content contained within clear aligner therapy (CAT) informed consent forms.

CAT informed consent forms were identified via an online search. The presence of details related to CAT-related processes, risks, benefits and alternatives in each form was recorded. A 4-point Likert type scale was used to determine the quality of content (QOC). The readability of content was evaluated with the Simple Measure of Gobbledegook (SMOG) and Flesch Reading Ease Score (FRES).

A total of 42 forms satisfied selection criteria. Nineteen (45.2%) were authored by companies who provided aligners to patients via clinicians. The QOC regarding CAT-related treatment processes [median 2.0; IQR 0, 2] and benefits [median 2.0; IQR 1, 2] was adequate. The QOC scores regarding treatment alternatives, consequences of no treatment and relapse were poor. There was no difference (P=0.59) in the median (IQR) QOC of the informed consent forms provided by direct-to-consumer (DTC) aligner providers [10 (8.25, 16.25)] and non-DTC aligner providers [12 (10, 14)]. The median (IQR) SMOG score was 12.1 (10.9, 12.7) and FRES was 39.0 (36.0, 44.25).

The QOC of the evaluated forms was incomplete and poor. The content was difficult to read and failed to reach recommended readability standards. Consent is unlikely to be valid if it is based solely on the content of the forms. Clinicians need to be aware of the limitations of informed consent forms for CAT particularly in relation to alternatives, prognosis, risks, and the need for long-term maintenance of results.