The current systematic review appraises the effectiveness of the types of tooth movements performed with Invisalign ® clear aligner on the maxillary incisors. An electronic literature search of published trials was performed through PubMed, LILACS, Scopus, Cochrane Library, and Web of Science databases, and selected journals, from 2009 to 2020. Out of 291 references, five relevant publications were identified for analysis: four studies were performed retrospectively and one prospectively, all non-randomized. Despite the limited set of selected articles, the sample size is significant, with 148 subjects included in the reviewed studies involving the orthodontic treatment of upper incisors. We concluded that movements with the Invisalign ® clear aligner on the upper incisors present distinct accuracy, possibly related with movement complexity; intrusion of the incisors has low accuracy (in some cases, 0% of accuracy was reported when the tooth extruded), while incisor extrusion exhibit some of the highest accuracy values reported in the included studies (45%-142%, when the achieved movement was greater than the predicted). Besides, axial (i.e., torque and tip) and horizontal (i.e., translation and rotation) movements are usually effective, with accuracy values between 39%-156% and 42%-79%, respectively. Overall, we determined that the efficiency of aligner to reach the desired movements in the upper incisors was low, as often refinements were required in the included studies. The use of aligner features must be more often considered to improve movement accuracy.

Introduction. There is a growing demand for more aesthetic, comfortable, and faster orthodontic treatments, and clear aligners emerged as a solution to fulfill this need. However, the effectiveness of clear aligners to treat complex malocclusions is yet contentious. The use of acceleration methods could improve the efficacy of clear aligners by stimulating cells' mechanobiology through numerous pathways, but this hypothesis is still poorly explored. Objective. We aimed to monitor the release profile of an inflammatory marker-the interleukin-1β-and to evaluate its relationship with self-reported pain scores with and without the use of acceleration techniques during an orthodontic treatment requiring difficult tooth movements with clear aligners. Case Report. Here, we report a case of a 46-year-old female patient who presented functional and aesthetic complaints. Intraoral examination revealed a diminished overjet and overbite, rotation of teeth 45 and 24, absence of teeth 25, 35, and 36, buccolingual dislocation of tooth 21, a tendency to a Class III malocclusion, and a 2 mm left deviation of the lower midline. This study is divided into three stimulation phases: no stimulation, mechanical vibration stimulation, and photobiomodulation. Interleukin-1β levels in gingival crevicular fluid samples from the pressure side of six selected teeth were evaluated at four time points after the orthodontic treatment onset. Pain monitoring in those teeth was performed using a visual analogue scale at the same time points. Results. Interleukin-1β protein production peaked 24 h after treatment onset. Complex movements were associated with increased self-reported pain. Conclusion. Clear aligners show limitations in solving complex tooth movements, even when combined with acceleration. The development of customized and programmable stimulation microdevices integrated into “smart aligners,” which could be designed to specifically stimulate the direction of movement and stimulation parameters and could constitute a solution to optimize the orthodontic tooth movement with clear aligners.