Gallagher R W, Miranda F, Buschang P H
Department of Orthodontics, Baylor College of Dentistry, Dallas, Texas 75246, USA.
Am J Orthod Dentofacial Orthop. 1998 Jun;113(6):612-9. doi: 10.1016/s0889-5406(98)70220-3.
This study evaluated the treatment response and posttreatment follow-up of children with Class III malocclusions treated with palatal expansion and reverse-pull face mask to the maxilla. The sample included 22 white children, 9 boys and 13 girls. Treatment began at a mean age of 9.8 years (range 5.6 to 13.3 years) and lasted 0.7 years (range 0.3 to 1.3 years). With a protraction force of 600 to 800 gm, the patients were treated until a 2 mm positive overjet had been attained. Radiographs were taken before treatment (T1), immediately after face mask treatment (T2), and 1.4 years after treatment (T3). An age and sex matched sample of untreated white schoolchildren served as normal controls. The results showed that the anterior maxilla was protracted forward 1.6 mm per year more than normal. The posterior maxilla dropped inferiorly more than the anterior maxilla. The mandible was rotated downward and backward, while the lower incisors were uprighted. The effects on the mandible were attributed to a significant chincup effect exerted by the face mask. After treatment, the maxilla relapsed relatively backward in the anterior and upward in the posterior, negating some of the treatment results. The mandible resumed a normal growth direction, and the lower incisors flared more than normal.
本研究评估了采用腭扩展及上颌反向牵引面罩治疗的Ⅲ类错牙合儿童的治疗反应及治疗后随访情况。样本包括22名白人儿童，9名男孩和13名女孩。治疗开始时的平均年龄为9.8岁（范围5.6至13.3岁），持续时间为0.7年（范围0.3至1.3年）。采用600至800克的牵引力量对患者进行治疗，直至获得2毫米的正覆盖。在治疗前（T1）、面罩治疗后即刻（T2）以及治疗后1.4年（T3）拍摄X线片。选取年龄和性别匹配的未接受治疗的白人学童作为正常对照。结果显示，上颌前部每年向前牵引的距离比正常情况多1.6毫米。上颌后部向下移动的幅度大于前部。下颌向下和向后旋转，而下前牙直立。对面部的影响归因于面罩产生的显著颏兜效应。治疗后，上颌前部相对向后复发，后部向上复发，抵消了部分治疗效果。下颌恢复正常生长方向，下前牙比正常情况更加唇倾。
