Abstract
Objective
The goal of the present work was to determine the influence of screw activation rates and electronically tracked wear times on transverse maxillary expansion with removable orthodontic appliances.
Methods
In all, 28 patients were included in an open prospective observational study covering approximately 6 months of maxillary transverse expansion. In each of these patients, the maxillary plate appliance used for treatment was fitted with a wear-time sensor to document wear time for the duration of the study. Patients were instructed to activate the transverse expansion screw in their plate appliance by 0.2 mm/week. The resultant gap-width increases were monitored with a caliper over three follow-up appointments scheduled at 2-month intervals.
Results
Largely linear increases in gap width due to screw activation were only noted within the first 4 months of treatment. The mean increases in gap width fell short of the values that were anticipated after calculations. Longer daily wear times were, on average, associated with larger gap widths.
Conclusion
Treatment can be objectively monitored by referring to wear-time tracking and by measuring increases in gap width, thus, ensuring that the appliance fits well. In this way, the process can be customized to serve individual needs and to better utilize the full potential of therapy.
Zusammenfassung
Fragestellung
Wie wirken sich Aktivierungsintervall und elektronisch gemessene Tragezeit auf die transversale Erweiterung des Oberkiefers mit herausnehmbaren KFO-Apparaturen aus?
Patienten und Methodik
In einer prospektiven offenen Beobachtungsstudie mit 28 Patienten wurde die Spaltverbreiterung der Transversaldehnschraube einer Oberkiefer-Plattenapparatur mit integriertem Tragezeitsensor gemessen und die Tragezeiten während des etwa 6-monatigen Therapieabschnitts dokumentiert. Der alle 7 Tage um 0,2 mm zu erweiternde Spalt der Schraube wurde an drei Kontrollterminen in Abständen von jeweils etwa 2 Monaten mit einer Schieblehre gemessen.
Ergebnisse
Die Aktivierung löste nur in den ersten 4 Therapiemonaten eine annähernd linear steigende Zunahme der Spaltbreite aus. Die mediane Spaltverbreiterung lag im Verlauf unter den errechneten Werten. Längere tägliche Tragezeiten führten im Mittel zu größeren Spaltbreiten.
Schlussfolgerung
Auf der Basis der Tragezeitdokumentation in Verbindung mit der gemessenen Zunahme der Spaltbreite und der Passung der Apparatur kann die Therapie objektiv nachvollzogen und den Gegebenheiten des Patienten individuell angepasst und so optimiert werden.
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Acknowledgment
We thank Drs. Schrey in Leverkusen-Opladen for their support in data collection.
Danksagung
Wir danken Dr. Sarah Schrey und Dr. Sigrid Schrey, Leverkusen-Opladen, für ihre Unterstützung bei der Datenerhebung.
Compliance with ethical guidelines
Conflict of interest. T.C. Schott, U. Fritz and H. Meyer-Gutknecht state that there are no conflicts of interest. All studies on humans described in the present manuscript were carried out with the approval of the responsible ethics committee and in accordance with national law and the Helsinki Declaration of 1975 (in its current, revised form). Informed consent was obtained from all patients included in studies.
Einhaltung ethischer Richtlinien
Interessenkonflikt. T.C. Schott, U. Fritz und H. Meyer-Gutknecht haben keine Angaben gemacht.
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Schott, T., Fritz, U. & Meyer-Gutknecht, H. Maxillary expansion therapy with plates featuring a transverse screw: implications of patient compliance with wear-time and screw activation requirements. J Orofac Orthop 75, 107–117 (2014). https://doi.org/10.1007/s00056-013-0197-1
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DOI: https://doi.org/10.1007/s00056-013-0197-1