Biomechanical Analysis of Maxillary Expansion in CLP Patients

Abstract Objective: To carry out a comparative biomechanical analysis of maxillary low force expansion using the quadhelix appliance in cleft and noncleft patients. We also intended to determine whether a sufficient transverse skeletal effect could be achieved among cleft patients using the quadhelix appliance. Materials and Methods: Three finite element models of the viscerocranium and neurocranium were established in which a transverse expansion of the maxilla using a quadhelix (transverse force of 2 N) was simulated. Results: The skeletal effects at the anatomic structures of the midface and the cranial base were far more marked in the simulation models with clefts compared to the morphologically normal state. The highest expansions were measured for bilateral cleft palates. Thus, the expansion measured at the supraorbital margin was 4.7 μstrain with a bilateral cleft, 2.1 μstrain with a unilateral cleft, and only 0.2 μstrain with the morphologically normal state. For bilateral and also for unilateral ...