Methods : Under general anesthesia, root canal therapy was performed on the mandibular canines on one side of 16 adult cats. Tipping movement of the canines was induced with an orthodontic spring ( 100 to 120 g ). 16只成年家猫的一侧下颌尖牙在全麻下被开髓、拔髓、行一次性根管充填治疗术,随后在正畸弹簧的作用力(100~120g)下向远中发生倾斜移动。