fa Retracted: Selective use of hand and forearm muscles during mini-implant insertion: a natural torquimeter ارتودنسی Orthodontics پژوهشي Research <p> <strong>Objective:</strong> </p><p> To compare maximum torque produced by different muscular groups and its influence on mini-implant insertion torque and fracture prevention. Design: A prospective study involving in vivo and in vitro laboratory experiments. </p><p> <strong>Materials and methods:</strong> </p><p> Eighty-seven professionals were evaluated for maximum torque produced using a screwdriver with combined action between thumb and index fingers [maximum digital torque (MDT)] and by forearm supination movement [maximum brachial torque (MBT)]. Ninety mini-implants distributed over nine different diameters and twenty commercially available mini-implants of two different diameters and trademarks were fractured to determine the fracture torque (FT). The fracture resistance index (FRI) was obtained from: FRI_MDT = FT/MDT and FRI_MBT = FT/MBT. The analysis of variance (ANOVA) and t tests were used to compare the groups. </p><p> <strong>Results</strong>:</p><p>  MDT was smaller than MBT and both were smaller in females. FT increased for each 0·1 mm of diameter increment. FRI_MDT was greater than FRI_MBT for all diameters. FRI_MDT>1 was found when the diameter was greater than or equal to 1·5 mm. FRI_MBT>1 occurred with diameters equal or greater than 1·7 mm for females and 1·8 mm for males. The 1.5 mm and 1.6 mm diameter of commercially available and mini-implants presented FRI_MBT<1 and FRI_MDT>1. </p><p> <strong>Conclusions:</strong></p><p>  Digital torque was 42% smaller than brachial torque, and it was mechanically safer and biologically more compatible, allowing fracture prevention of 1·5 mm or thicker mini-implant diameter due to insertion torque limitation at 15 N/cm. </p><hr><p></p><p> <strong>Source: </strong>Journal of Orthodontics </p><p> <a href="http://jorthod.maneyjournals.org/content/39/4/270.abstract" target="_blank"><font color="#0000ff">Full Text</font></a></p> Muscle strength, mini-implant, fracture ,accident prevention 0 0 http://idai.ir/browse.php?a_code=A-10-32-1863&slc_lang=fa&sid=1 Sérgio Estelita sergioestelita@yahoo.com.br 10031947532846008785 10031947532846008785 Yes Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil Guilherme Janson 10031947532846008786 10031947532846008786 No Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil Kelly Chiqueto 10031947532846008787 10031947532846008787 No Porto Alegre, Rio Grande do Sul, Brazil Eduardo Ferreira 10031947532846008788 10031947532846008788 No Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil Marcos Marcos 10031947532846008789 10031947532846008789 No Bauru, São Paulo, Brazil