Abstract: Objective: This case reports the orthodontic treatment of hyperdivergent Angle classⅢ open-bite malocclusion. Diagnosis and Treatment: The patient received orthodontic treatment using straight wire fixed appliance after a clear diagnosis and the patient’s informed consent. Upper second premolars and lower first premolars were extracted. Impacted upper third molars were used to instead extracted upper second molars. Upper and lower teeth were aligned and leveled. Extraction spaces were used to retract anterior teeth. Open bite was closed. And the molar relationship was adjusted. Then vertical traction was applied to upper third molars. Results: After orthodontic treatment, the patient’s profile was optimized. The open bite was closed. The relationship of molars turned to be neutral. The crowding of anterior teeth was relieved. The long-term observation showed that the overbite and overjet were well maintained. Conclusions: Extracting premolars and using upper third molars to instead upper second molars can effectively help close the wide-range open bite and keep overbite and overjet stable. However, long-period retaining was still needed.

Key words: open bite, high angle, extraction treatment, stability, retaining