The Reverse Quad-helix Appliance - Differential Anterior Maxillary Expansion

Background: Cleft affected patients are characterized by a normal/almost normal posterior maxillary width and a severe anterior constriction of the maxilla in the mixed dentition period. We examined the differential expansion achieved in the premaxillary area of unilateral cleft lip and palate affected patients using a traditional and a reverse quad-helix expander. Objective: Assess the efficiency of the reverse quad-helix appliance for differential maxillary expansion of the cleft area prior to bone grafting compared to expansion achieved by the traditional appliance. Material and methods: The files of 40 patients (20 treated by means of a traditional quad helix and 20 with the reverse quad helix expander) were randomly selected. The upper arch width was assessed by means of plaster study models in the anterior and posterior maxillary regions. Results: Anterior occlusal expansion achieved by the reverse quad helix was statistically significantly larger than that achieved by the traditional appliance and than the expansion achieved in the posterior region (p=0.008 and p<0.0001, respectively) of the palatal cleft. Conclusion: The reverse quad helix is an efficient appliance for differential anterior maxillary expansion during the mixed dentition period.