The hybrid hyrax. (A) Sketch of the modified hybrid hyrax device with rigid sectional wire for maxillary protraction in situ. (B) Hybrid Hyrax device in situ; because of the retarded dentition, the molar bands were fitted to the second deciduous molars. (C) Situation after rapid maxillary expansion (duration, 8 days). (D) Maxillary protraction with facemask and elastics; anterior-caudally angulated force direction of 20° to 30° with respect to occlusal plane.