title: T-loop position and anchorage control.
abstract: The effect of off-center positioning on the force system produced by segmented 0.017 x 0.025-inch TMA T-loops was measured. A T-loop was designed to produce equal and opposite moments in the centered position. The spring was tested in seven positions, centered, 1, 2, and 3 mm toward the anterior attachment, and 1, 2, and 3 mm toward the posterior attachments. The horizontal force, vertical force, and alpha and beta moments were measured over 6 mm of spring activation. The results showed that the alpha/beta moment ratio was dependent only on the spring position, and independent of spring activation. Eccentric positioning of T-loop springs effectively produces a consistent moment differential through the range of spring activation.
authors.affiliation: Department of Orthodontics, University of Connecticut School of Dental Medicine 06030, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Kuhlberg
authors.forename: C J
authors.initials: CJ
authors.lastname: Burstone
mesh_terms: D003799:Dental Stress Analysis; D006801:Humans; D016014:Linear Models; D016382:Orthodontic Appliance Design; D019516:Orthodontic Space Closure / Q000295:instrumentation* / Q000379:methods*; D009969:Orthodontic Wires; D013314:Stress, Mechanical