The standard method to study crack front deformation is based on the perturbation approach proposed by Rice , in which the crack front is represented as a line. However, recent studies have shown the importance of the fracture process zone for dynamic heterogeneous fracture. We simulate the deformation of a dynamic crack front propagating along an heterogeneous interface using a boundary integral method coupled with a cohesive zone model, which allows for a fine discretization of the process zone. We study extensively the dynamic deformation process and the final deformed front shape.