Pendulum is an orthodontic appliance, developed by James J. Hilgers in 1992,[1] that use forces to distalize the upper 1st molars to create space for eruption of impacted teeth or allowing correction of Class 2 malocclusion.
Then once the appliance is in the mouth, the springs are inserted into the lingual sheaths of the molar bands to allow the force distally and medially.
In order to avoid this side-effect, the adjustment loops are opened to counteract this medial movement of 1st molars.
In addition, the reported increase of Lower Anterior Facial Height for patient's who had pre-existing vertical growth.
Pendex is an appliance, similar to Pendulum, which is known to correct the transverse deficiency of maxillary teeth in addition to distalizing the upper molars.