Reverse quad helix appliance: differential anterior maxillary expansion of the cleft area before bone grafting

Cleft-affected cases present a variable degree of transversal constriction of the maxilla. Our aim is to present a new method for differential expansion of the premaxillary area in unilateral cleft lip and palate-affected patients. The reverse quad helix appliance is made of a 0.036-in stainless-steel wire soldered to 2 bands placed on maxillary deciduous canines or first primary molars (or first permanent premolars). It incorporates 4 helical loops forming an inverse W-arch design. The spring is positioned posterior to the banded teeth; thus, the expansion effect is focused in the anterior maxillary region. A reverse quad helix appliance was activated and cemented in 20 patients for premaxillary expansion. Upper arch width was assessed by means of plaster study models in the anterior and posterior maxillary regions. The mean anterior occlusal expansion achieved by the reverse quad helix (9.60 [±5.24] mm) is statistically significantly larger than that achieved in the posterior region (5.50 [±3.07] mm) (P < 0.0001). The reverse quad helix is an efficient appliance for differential expansion of the anterior maxillary region as a preparatory stage for secondary bone graft procedures in unilateral cleft lip and palate-affected patients.