Which muscle fibers are responsible for mandibular RETRUSION (pulling the jaw backward)?

The posterior fibers of the temporalis muscle run in a nearly horizontal direction and are responsible for mandibular retrusion (pulling the condyle backward into centric relation). The anterior fibers of the temporalis run vertically and are primarily involved in mandibular elevation. The posterior temporalis fibers are important in the understanding of mandibular movement and in the diagnosis of TMD.