Biomechanical limitations of clear aligners – posterior teeth

Vol. 16 – Number 62 – 2023 Case report Page 31-37 Biomechanical limitations of clear aligners – posterior teeth Weber José da Silva Ursi¹ Murilo Matias² Abstract In recent years, an increasing number of adult patients are seeking orthodontic treatment and have expressed a desire for esthetic and comfortable alternatives to conventional fixed appliances. The possibility of using orthodontic clear aligners was introduced by Kesling, in 1946, with the concept of a thermoplastic positioners to progressively move misaligned teeth into correct positions. However, the biomechanical limitations of clear aligners led to the development of auxiliary tools, such as optimized attachments, skeletal anchorage and hybrid treatments combined with fixed appliances with continuous or segmented arches, which can be incorporated before, during, or after the use of the clear aligners. To illustrate, we present a clinical case of maxillary second molars positioned in crossbite, crown lingual torque and mesial rotation, corrected with segmented mechanics, using rectangular TMA archwires with “T” loops to obtain a better three-dimensional control of the movement. Descriptors: Orthodontics, clear aligners, biomechanics. ¹ Master. and Doctor. in Orthodontics – FOB/USP, Full Professor – ICT/UNESP. ² Master. and Doctor. in Orthodontics – FOB/USP, Professor of the Professional Master’s Program in Orthodontics – UNG. DOI: 10.24077/2023;1662-060123e7