 Moreover, another deformation found with FCMS includes the failure of opercularization caused by the underdevelopment of the anterior part of the opercula found in the fetal brain in the 32nd week.The anatomic basis for the automatic voluntary dissociation is characterized by the following.Neurons that lie adjacently in the operculum project supranuclear fibers to the cranial nuclei for the voluntary movement of facial, phanryngeal, lingual, and masticatory muscles.