Effects of Two Different Functional Appliances on Root Development of Posterior Teeth: Activator vs. Bite-jumping Appliance

Abstract

As a result of treatment with removable functional appliances, we observed locally different trends in root length increase in the posterior region in late-mixed and young adult dentitions, hence at a stage when root development had not concluded. The roots became longer during treatment with both the activator and bite-jumping appliance, but the maxillary first premolars' root development varied widely. This may be because the bite-jumping appliance's anchorage is right on the dentition, and the forces thus exert an immediate effect on the anchorage unit, particularly in the immediate vicinity of the protrusive bars in the maxilla. This led to certain groups of teeth to fail to achieve their entire potential length.

Effects of Conventional Anchorage on Premolar Root Development during Treatment with a Pendulum Appliance

“…Die Höhe der klinischen Krone wurde als konstant vorausgesetzt. Bei einem Betrag mit positivem Vorzeichen lag eine Längenzunahme, bei einem Betrag mit negativem Vorzeichen eine Längenab-nahme vor (Methode siehe [29,30]). …”

“…We assumed the height of the clinical crown to be constant. A positive value indicated an increase in length, a negative value a decrease in length (for methodology see [29,30]). The statistical analysis was performed using the MedCalc program (Version 9.3.0.0; Med Calc, Mariakerke, Belgium).…”