Blog Post

Fabricating an Expansion Appliance with the RES
Apr 01th, 2012
by dentronixadmin

The Ratcheting Expansion Screw (RES) was designed to eliminate patient deactivation of the appliance when removing the expansion key. The screw will lock into the advanced position eliminating the possibility of backing up. The screw also “clicks” when activated to give the parent and patient an audible signal the screw has been properly activated. The RES has been on the market for 7 years and continues to grow in popularity. There have been several screws manufactured since the RES to try to mimic the ratcheting mechanism. The RES is the only screw on the market that actually locks in place when activated. Laboratories have had issues with standard screw tolerances being varied and not holding activations. This adds costs to the doctor and laboratory. It also causes great frustration with the parents and patients in dealing with the appliance remake. The RES screw eliminates that scenario due to its locking mechanism. Because the design has a positive locking mechanism, the screw does not have to rely on tight tolerances to prevent it from backing up. This enables the RES screw to have lower tolerances which give it some flex when seating the appliance. It is important to use the specially designed safety key when activating the RES screw. The key is designated with a hole in the blue handle to differentiate it from standard safety keys. Other activation keys will damage the holding clip. The screw can be used in the upper and lower arches for expansion. Due to the screw’s design it is comfortable in each arch. The screw will feel more like a TPA than an expansion screw to most patients. The screw’s small design does not affect the speech and swallow patterns like most expansion screws. The RES has an activation dot so positioning is easily identified. The screw has 11millimeters of expansion capability with 44 activations. Key steps when placing the RES screw in the upper and lower arches. [caption id="attachment_23" align="alignright" width="240"]RES Safety Key 10-pack #D10050 RES Safety Key 10-pack #D10050[/caption] Fig. 1 Models are prepared for indirect band seating. Fig. 2 Bands are placed on first permanent molars with archwire tubes. Fig. 3 Extension arms are placed on the upper bicuspids. Fig. 4 RES screw is placed proximal of first molars and second bicuspids on upper. Fig. 5 Upper RES screw is soldered and finished ready for delivery Fig. 6 Lower Arch has RES screw adapted to the teeth to act as lingual extensions Fig. 7 .032 wire rests are adapted to the lower first bicuspids. Fig. 8 Lower expander is soldered and finished and ready for delivery.
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Fig. 1 Fig. 2 Fig. 3 Fig. 4
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Fig. 5 Fig. 6 Fig. 7 Fig. 8

Category: Dentronix Quarterly

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