European Journal of Orthodontics 35 (2013) 236–243 doi:10.1093/ejo/cjr126 Advance Access publication 2 November 2011 © The Author 2011. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com Introduction Since the introduction of the Straight Wire Appliance™ in the 1970s (Andrews, 1979), there have been many suggested modications to the tip and torque values used in pre- adjusted edgewise appliances. Many of these changes involve alterations of a few degrees, even though it is known that torque expression in particular is affected by the amount of play between the archwire and the slot (Archambault et al., 2010), differences in the tolerance size of manufactured brackets and archwires (Cash et al., 2004), the method of ligation (Gioka and Eliades, 2004; Badawi et al., 2008), the initial inclination of the teeth (Archambault et al., 2010), additional widening and notching of the bracket slot when placing the larger archwires (Archambault et al., 2010), and even variations in the shape of the labial surface of teeth (Smith et al., 2007). The MBT prescription was introduced in 1997 and quickly established itself as one of the most popular bracket prescriptions on the market. The main differences with other bracket prescriptions are 1. Increased palatal root torque in the upper central incisor brackets (Andrews: 7 degrees, Roth: 12 degrees, and MBT: 17 degrees) 2. Increased palatal root torque in the upper lateral incisor brackets (Andrews: 3 degrees, Roth: 8 degrees, and MBT: 10 degrees) Roth versus MBT: does bracket prescription have an effect on the subjective outcome of pre-adjusted edgewise treatment? Bopelo Moesi*, Fiona Dyer** and Philip E. Benson* *Academic Unit of Oral Health and Development, School of Clinical Dentistry, University of Sheffield and **Department of Orthodontics, Charles Clifford Dental Hospital, Sheffield, UK Correspondence to: Philip Benson, Reader in Orthodontics, Academic Unit of Oral Health and Development, School of Clinical Dentistry, Sheffield S10 2TA, UK. E-mail: p.benson@sheffield.ac.uk SUMMARY The aim was to determine if bracket prescription has any effect on the subjective outcome of pre-adjusted edgewise treatment as judged by professionals. This retrospective observational assessment study was undertaken in the Orthodontic Department of the Charles Clifford Dental Hospital, Sheffield, UK. Forty sets of post-treatment study models from patients treated using a pre-adjusted edgewise appliance (20 Roth and 20 MBT) were selected. The models were masked and shown in a random order to nine experienced orthodontic clinicians, who were asked to assess the quality of the outcome, using a pre-piloted questionnaire. The principal outcome measure was the Incisor and Canine Aesthetic Torque and Tip (ICATT) score for each of the 40 post-treatment models carried out by the nine judges. A two-way analysis of variance was undertaken with the dependent variable, total ICATT score and independent variables, Bracket prescription (Roth or MBT) and Assessor. There were statistically significant differences between the subjective assessments of the nine judges ( P<0.001), but there was no statistically significant difference between the two bracket prescriptions ( P = 0.900). The best agreement between a clinician’s judgment of prescription used and the actual prescription was fair (kappa statistic 0.25; CI -0.05 to 0.55). The ability to determine which bracket prescription was used was no better than chance for the majority of clinicians. Bracket prescription had no effect on the subjective aesthetic judgments of post-treatment study models made by nine experienced orthodontists. 3. Increased lingual crown torque in the lower incisor brackets (Andrews: −1 degrees, Roth: −1 degrees, and MBT: −6 degrees) 4. Decreased tip in the upper canine brackets (Andrews: 11 degrees, Roth: 13 degrees, and MBT: 8 degrees). The developers of the appliance claim that the increased palatal root torque in the upper incisors improves the under- torqued appearance produced by other prescriptions and the increased labial root torque in the lower incisor counteracts the forward tipping during levelling (McLaughlin et al., 2001). To date, there have been no scientic studies to support these claims. Several studies have shown the variations in torque values of teeth achieved following treatment with pre-adjusted edgewise appliances (Dellinger, 1978; Vardimon and Lambertz, 1986; Ugur and Yukay, 1997). Kattner and Schneider (1993) found no differences in the ideal tooth relationship index when they compared the study models of patients treated using a Roth prescription pre-adjusted edgewise appliance with those treated using a standard edgewise appliances. Ugur and Yukay (1997) found no differences in the objectively measured torque values between cases treated using standard edgewise and a pre- adjusted Roth prescription appliance. The aim of this study was to investigate the bracket manufacturers’ claims that when a patient is treated to a Downloaded from https://academic.oup.com/ejo/article/35/2/236/489796 by guest on 08 March 2022