Effect of Quad Helix appliance on maxillary constriction (holdway measurements)

Objective: to evaluate expansion changes by removable Quad helix appliance on soft tissues profile in growing patients. Materials and Method: the present prospective clinical study consisted of fifteen subjects (8 girls and 7 boys) with cross bite due to constricted maxillary arch. Cases were selected to be treated for 8 months. Results: No significant difference Soft tissue facial angle, H angle, SK profile convexity, Soft tissues chin thickness, Superior sulcus depth, Nose prominence and significant difference of Basic upper lip thickness and Upper lip thickness. Conclusion: the effect of expansion by Quad helix appliance on soft tissue facial angle, H angle and profile convexity showed insignificant changes after the expansion period and significant change of upper lip thickness and Basic upper lip thickness.