Medicine in evolution








- Abstract -

A common strategy for correcting Class II malocclusion without extraction is to distalize the molars.
The Distal Jet, described by Carano & Testa (1996), is the most widely used distalizer device in Orthodontics as it provides good distalization with minimum side effects compared to others (Chiu et al., 2005).
The Distal Jet consists of a bilateral piston and tube arrangement, with the tube embedded in an acrylic Nance button in the palate, supported by attachments on the first or second premolars. A bayonet wire is inserted into the lingual sheath of each first molar band and the free end is inserted into the tubes, much like a piston. A nickeltitanium open-coil spring and an activation collar are placed around each tube. Compressing the coil spring generates a distally directed force. The activation collar is retracted and the mesial setscrew in each collar is locked onto the tube to maintain the force. The active components have to be placed palatally. Ideally, they result in lines of force running close to the center of resistance of the molars. As opposed to the cervical headgear with which molar distalization can be achieved only as a combination of dental crown tipping with subsequent root uprighting, the biomechanics of the appliance should, in theory, allow translatory molar distalization.

Key words: distal jet, class II malocclusion, molar distalization.




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