American Board of Orthodontics (ABO) Practice Exam

Clear aligners are often praised for their ability to move teeth predictably and minimize the visibility of the treatment; however, one significant limitation is their efficacy in controlling the rotation of teeth, especially those with a rounder shape, such as incisors.

The clear aligner system relies on the fit and engagement of the aligners with the surfaces of the teeth to apply forces for tooth movement. Round teeth, in particular, have less surface area for the aligner to engage with effectively compared to other tooth types, which leads to challenges in achieving the desired rotational movement. This results in minimal control over the rotation of such teeth, making it difficult to achieve precise alignment, particularly in cases where significant rotational torque is needed.

Other options imply higher control or effectiveness in areas where aligners may not perform optimally, but the inherent limitations in rotational control when dealing with various tooth shapes—including those that are round—underscore the challenges faced when utilizing clear aligners as a treatment modality in orthodontics.