Distraction osteogenesis for cleft palate closure: A fi nite element analysis

Abstract

Background: Current methods of closure of the cleft palate result in the formation of scars and

impairment of growth. Distraction osteogenesis (DO) might be an effective means to repair or at

least reduce the size of wide clefts. This study investigates the biomechanical aspects of this process.

Materials and Methods: DO simulation was applied to reduce the size of a unilateral hard

palate cleft on a three-dimensional (3D) model of the maxilla. For the position of osteotomy lines,

two different models were assumed, with the osteotomy line on the affected side in model A and

on the intact side in model B. In each model, DO screws were placed on two different positions,

anteriorly (models A1 and B1) and posteriorly (models A2 and B2). Displacement pattern of the

bony island in each of the four models, reaction forces at DO locations, and von Mises stress were

estimated. Mesh generation and data processing were carried out in the 3D fi nite element analysis

package (ABAQUS V6.7-1; Simulia Corp., Providence, RI, USA).

Results: In model B2, the island moved almost evenly, assuring a more complete closure of the

cleft. The most uniform stress distribution was found in model B1.

Conclusion: The results suggest that the best positions for the DO screw and the osteotomy line

for closure of the cleft palate are posteriorly and on the intact side, respectively.

Key Words: Cleft palate, distraction osteogenesis, fi nite element analysis