Ryo Hamanaka1, Daniele Cantarella2, Luca Lombardo3, Lorena Karanxha4, Massimo Del Fabbro4,5, Giuseppe Siciliani3, Noriaki Yoshida1. 1. Department of Orthodontics and Dentofacial Orthopedics, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852-8588, Japan. 2. Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Commenda 10, Milan, Italy. danielecant@hotmail.com. 3. Postgraduate School of Orthodontics, Ferrara University, Via Luigi Borsari 46, Ferrara, Italy. 4. Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Commenda 10, Milan, Italy. 5. Dental Clinic, IRCCS Orthopedic Institute Galeazzi, Via Riccardo Galeazzi 4, Milan, Italy.
Abstract
BACKGROUND: The aim of this study is to compare the biomechanical effects of the conventional 0.019 × 0.025-in stainless steel archwire with the dual-section archwire when en-masse retraction is performed with sliding mechanics and skeletal anchorage. METHODS: Models of maxillary dentition equipped with the 0.019 × 0.025-in archwire and the dual-section archwire, whose anterior portion is 0.021 × 0.025-in and posterior portion is 0.018 × 0.025-in were constructed. Then, long-term tooth movement during en-masse retraction was simulated using the finite element method. Power arms of 8, 10, 12 and 14 mm length were employed to control anterior torque, and retraction forces of 2 N were applied with a direct skeletal anchorage. RESULTS: For achieving bodily movement of the incisors, power arms longer than 14 mm were required for the 0.019 × 0.025-in archwire, while between 8 and 10 mm for the dual-section archwire. The longer the power arms, the greater the counter-clockwise rotation of the occlusal plane was produced. Frictional resistance generated between the archwire and brackets and tubes on the posterior teeth was smaller than 5% of the retraction force of 2 N. CONCLUSIONS: The use of dual-section archwire might bring some biomechanical advantages as it allows to apply retraction force at a considerable lower height, and with a reduced occlusal plane rotation, compared to the conventional archwire. Clinical studies are needed to confirm the present results.
BACKGROUND: The aim of this study is to compare the biomechanical effects of the conventional 0.019 × 0.025-in stainless steel archwire with the dual-section archwire when en-masse retraction is performed with sliding mechanics and skeletal anchorage. METHODS: Models of maxillary dentition equipped with the 0.019 × 0.025-in archwire and the dual-section archwire, whose anterior portion is 0.021 × 0.025-in and posterior portion is 0.018 × 0.025-in were constructed. Then, long-term tooth movement during en-masse retraction was simulated using the finite element method. Power arms of 8, 10, 12 and 14 mm length were employed to control anterior torque, and retraction forces of 2 N were applied with a direct skeletal anchorage. RESULTS: For achieving bodily movement of the incisors, power arms longer than 14 mm were required for the 0.019 × 0.025-in archwire, while between 8 and 10 mm for the dual-section archwire. The longer the power arms, the greater the counter-clockwise rotation of the occlusal plane was produced. Frictional resistance generated between the archwire and brackets and tubes on the posterior teeth was smaller than 5% of the retraction force of 2 N. CONCLUSIONS: The use of dual-section archwire might bring some biomechanical advantages as it allows to apply retraction force at a considerable lower height, and with a reduced occlusal plane rotation, compared to the conventional archwire. Clinical studies are needed to confirm the present results.
Entities:
Keywords:
Archwire; Digital simulation; FEM; Finite element method; Skeletal anchorage; Tooth movement
Authors: Luca Lombardo; Angela Arreghini; Elena Bratti; Francesco Mollica; Giorgio Spedicato; Mattia Merlin; Annalisa Fortini; Giuseppe Siciliani Journal: Angle Orthod Date: 2014-11-18 Impact factor: 2.079
Authors: Julie E Olson; Ying Liu; Jeffrey C Nickel; Mary P Walker; Laura R Iwasaki Journal: Am J Orthod Dentofacial Orthop Date: 2012-09 Impact factor: 2.650