Okano KS, et al. - In this three-dimensional (3D) study, researchers evaluated retrospectively the middle cranial fossa and central skull base of patients treated with the Herbst appliance (HA). Clinically significant changes were not produced by HA therapy in the middle cranial fossa and central skull base. Along the observational period, point-to-point linear measurements and skeletal rotation (pitch, roll, and yaw) changes were very small and were not significantly different between Herbst appliance (HAG) and control group (CG).