The trigeminal motor nucleus contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid, and anterior belly of the digastric. This nucleus is located in the mid-pons (i.e. in the center of the pons going inferior to superior).
The trigeminal motor nucleus is primarily involved in the jaw jerk reflex. As the fibers involved in this reflex do not decussate, a lesion involving the trigeminal motor nucleus would cause ipsilateral motor deficits.