Intercenter comparison of different maxillary expansion modalities in patients with complete cleft lip and palate

Abstract

There is a lack of scientific literature comparing the effects of slow and rapid maxillary expansion in patients with complete cleft lip and palate. Purpose: The null hypothesis is that the orthopedic expander and the quad-helix produce similar changes in the maxillary arch widths, palate volume and posterior maxillary tooth tipping in patients with unilateral complete cleft lip and palate. Methodology: The study sample will be composed by 60 patients with unilateral complete cleft lip and palate and maxillary dental arch constriction treated with rapid maxillary expansion (group I, n=30) and slow expansion (group II, n=30). Maxillary expansion will be performed in the mixed dentition before bone graft procedure. Conventional dental casts will be collected before expansion and 6 months after the expansion, when the appliance is removed. After digitalization of the maxillary dental casts using the 3Shape R700 3D scanner (3Shape A/S, Copenhagen, Denmark), maxillary dental arch transverse dimensions, buccolingual inclination of posterior teeth, dental arch perimeter and palate volume will be measured. Dependent "t" tests will be used for evaluating the changes between phases, and independent "t" tests will be used for intergroup comparisons. (AU)