Biomechanical response of the maxillofacial skeleton to transpalatal orthopedic force in a unilateral palatal cleft.

OBJECTIVES

To assess the skeletal and dental effects of rapid maxillary expansion in a patient with unilateral cleft deformity of secondary palate and alveolus using the finite element method.

MATERIALS AND METHODS

A patient-specific composite skull model was developed from a patient computed tomographic scan and a surface scan of the patient's maxillary cast using MIMICS imaging analysis software. For volumetric meshing and the finite element analysis, Abaqus (6.7) was used.

RESULTS

The typical wedge-shaped opening that occurs after RME, seen in non-cleft patients, is not seen in cleft patients. A clockwise rotation of the maxilla as a result of maxillary expansion was evident. The areas of maximum stress were the intact primary palate region, inferior orbital foramen of the non-cleft and the cleft sides, and the zygomatic buttress of the cleft side. During expansion, the intact primary palate showed high stress and acted as a region of major resistance, followed by the zygomatic buttress on the cleft side.

CONCLUSIONS

Clinicians should consider a need for customization of expansion therapy for cleft patients depending on the patient's age, the type of cleft present (primary or secondary palate), and the desired area of expansion (anterior or posterior).