caa a22 4500 445347597 CHVBK 20180317142833.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00056-011-0049-9 doi (NATIONALLICENCE)springer-10.1007/s00056-011-0049-9 Comparison of estimated and actual changes in gap widths of expansion screws in plate appliances with 7- and 14-day activation [Elektronische Daten] [T.C. Schott, L. Engelhard, D. Gómez-Serrano, H. Meyer-Gutknecht] Vergleich errechneter und tatsächlicher Spaltbreitenänderungen von Dehnschrauben in Plattenapparaturen bei 7- und 14-tägiger Aktivierung Objective: To determine how gap opening is affected by the activation intervals of expansion screws in removable orthodontic appliances and which gap widths are achievable during therapy. Materials and methods: In this retrospective study, the increases in gap widths for transverse and distalizing screws activated at 7- and 14-day intervals were calculated. These estimates were based on measurements taken with a caliper of the gap widths of 242 screws integrated in the plates of 137 patients examined during 4-5 follow-up visits over a 6- to 7-month therapy period. Results: A comparison of the theoretical gap widths that we had estimated with those actually measured revealed for the first time that differences in activation intervals have a statistically significant effect on gap width. The 7- and 14-day activation intervals can lead to a linear or nonlinear increase in gap width that greatly depends on the type of expansion screw. Within the therapy period, transverse screws achieved gap widths as much as twice as wide as those achieved with the distalizing screw. Conclusion: The gap widths are illustrated in graphs and summarized in tables. These values offer practical orientation for clinicians planning and controlling the therapy course, and they can help to prevent "overactivation” with removable expansion plates. Urban &amp; Vogel, Muenchen, 2011 Expansion plates nationallicence Transverse expansion screw nationallicence Distalizing screw nationallicence Gap opening nationallicence Activation intervals nationallicence Dehnplatten nationallicence Transversaldehnschraube nationallicence Distalisierungsschraube nationallicence Spaltverbreiterung nationallicence Aktivierungsintervalle nationallicence Schott T.C. Department of Orthodontics, Zentrum für Zahn-, Mund- und Kieferheilkunde (ZZMK), Universitätsklinikum Tübingen, Osianderstr. 2-8, 72076, Tübingen, Germany aut Engelhard L. Department of Orthodontics, Zentrum für Zahn-, Mund- und Kieferheilkunde (ZZMK), Universitätsklinikum Tübingen, Osianderstr. 2-8, 72076, Tübingen, Germany aut Gómez-Serrano D. Private Orthodontic Practice, Reutlingen, Germany aut Meyer-Gutknecht H. Private Orthodontic Practice, Leverkusen-Opladen, Germany aut Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie Springer-Verlag 72/6(2011-11-01), 446-456 1434-5293 72:6<446 2011 72 56 https://doi.org/10.1007/s00056-011-0049-9 text/html Onlinezugriff via DOI 1 article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00056-011-0049-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schott T.C. Department of Orthodontics, Zentrum für Zahn-, Mund- und Kieferheilkunde (ZZMK), Universitätsklinikum Tübingen, Osianderstr. 2-8, 72076, Tübingen, Germany aut NATIONALLICENCE 700 1- Engelhard L. Department of Orthodontics, Zentrum für Zahn-, Mund- und Kieferheilkunde (ZZMK), Universitätsklinikum Tübingen, Osianderstr. 2-8, 72076, Tübingen, Germany aut NATIONALLICENCE 700 1- Gómez-Serrano D. Private Orthodontic Practice, Reutlingen, Germany aut NATIONALLICENCE 700 1- Meyer-Gutknecht H. Private Orthodontic Practice, Leverkusen-Opladen, Germany aut NATIONALLICENCE 773 0- Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie Springer-Verlag 72/6(2011-11-01), 446-456 1434-5293 72:6<446 2011 72 56 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer