The fusion of orthodontic treatment and periodontal tissue–regeneration therapy has attracted attention. However, regenerated bone has a higher density than physiologic bone, which may cause problems including root resorption or stagnation of orthodontic movement. Therefore, the optimized periaodontal regeneration for orthodontic movement (O-PRO) approach was developed with the aim of regenerating periodontal tissues with sparse bone quality. Unlike conventional methods, this concept is specifically suited for orthodontic movement. A new classification for the preoperative evaluation of periodontal tissues was also devised, and results are reported from cases where orthodontic treatment was implemented using each type of O-PRO method.
