title: The apple of Sir Isaac Newton.
authors.forename: Alexander
authors.initials: A
authors.lastname: Spassov
authors.forename: Dragan
authors.initials: D
authors.lastname: Pavlovic
mesh_terms: D001696:Biomechanical Phenomena; D017276:Friction; D006801:Humans; D008311:Malocclusion, Angle Class I / Q000628:therapy; D008312:Malocclusion, Angle Class II / Q000628:therapy; D052280:Orthodontic Anchorage Procedures / Q000379:methods*; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D019516:Orthodontic Space Closure / Q000295:instrumentation; D009969:Orthodontic Wires; D014087:Tooth Movement Techniques / Q000379:methods*