Quad Helix
A fixed palatal expansion appliance with four helical coils used to widen the upper dental arch in cases of posterior crossbite or arch constriction.
Full Definition
The quad helix is a fixed orthodontic appliance consisting of a palatal wire incorporating four helical loops, attached to bands on the upper first molars. The helical coils provide a continuous, gentle force to expand the upper arch transversely. It is commonly used in mixed and early permanent dentition to correct unilateral or bilateral posterior crossbite. Editors should note the term is written as two words without a hyphen, and 'quad' should not be capitalised unless at the start of a sentence.
Usage
Usage note: Two words, no hyphen. Do not capitalise 'quad'. Occasionally written as a single word 'quadhelix' in some publications, but the two-word form is preferred.
In Context
- "A quad helix was placed to correct the bilateral posterior crossbite prior to fixed appliance therapy." — Referral letter
- "The quad helix was activated by 3 mm at the six-week review." — Clinical note