51 - Comparison between nance button and transpalatal arch for preventing anchorage loss in orthodontics. Systematic review

Abstract

Maintaining posterior anchorage during orthodontic treatments involving extractions remains a clinically relevant challenge, particularly in cases requiring en-masse retraction of the anterior segment. Anchorage refers to the resistance to unwanted tooth movement, and its loss can significantly compromise treatment outcomes. This systematic review, conducted according to PRISMA guidelines, aimed to compare the effectiveness of the Nance button and the transpalatal arch (TPA) as conventional intraoral anchorage devices to prevent anchorage loss in patients requiring maximum anchorage. A comprehensive literature search was performed using the Web of Science and Ovid platforms, accessing databases including PubMed/MEDLINE, Embase, Scopus, and SciELO. Search terms included “Nance button,” “transpalatal arch,” “anchorage,” “maximum anchorage,” “tooth migration,” and “orthodontic appliance,” with inclusion criteria limited to studies published between 2005 and 2025. From an initial pool of 22 articles, 10 studies were included in the qualitative synthesis. These comprised randomized and non-randomized clinical trials, retrospective studies, and systematic reviews with meta-analyses. Methodological quality and risk of bias were assessed using GRADE, ROBINS-I, RoB 2, and AMSTAR 2 tools. The results confirm that both devices are effective, but not equivalent. For sagittal anchorage purposes, the Nance button has proven to be more effective due to its greater rigidity and ability to limit mesial molar displacement. The TPA is more suitable when transverse and rotational control is required. The device should be selected based on the specific biomechanical requirements of the treatment rather than general criteria. Differentiated use of both appliances should align with the clinical needs of each case, highlighting the importance of individualized orthodontic planning. Further controlled clinical studies are recommended.