Micro-implant anchorage for directional force technique

Dr. Merrifield urged to use the directional force technology to get best facial harmony, harmonious occlusion, and good stability. But the sucess of treatment is largely dependent upon patient compliance, because of using extraoral force (HPJH wear) as orthodontic anchorage, and treatment time was fairly long. We used micro-implants as orthodontic anchorage instead of HPJH, and could get good result, which was accordance with Tweed-Merrifield philosophy. The treatment using micro-implant are independent upon patient compliance, make treatment time shorter, and can achieve good result. The Micro-implants could provide us absolute anchorage.