颈支抗治疗Ⅱ类一分类错(牙合)的X-线头影测量研究

Cephalometric study of Class n malocclusion treatment with cervical headgear

目的:研究颈支抗限制上颌骨发育治疗Ⅱ类一分类错(牙合)的临床效果。方法:采用治疗前后的X-线头影测量进行对比研究。结果:治疗的主要变化发生在上颌骨和上颌磨牙,上颌骨平均后退1.03mm;SNA平均减小0.6°,上颌磨牙平均远中移动2.33mm。治疗前后的(牙合)平面有所减小,下颌平面虽有增加但无显著性意义。治疗前后的面下1/3的高度无明显的增加。结论:一般认为颈支抗存在着明显的副作用,即促使磨牙伸长、增加面下1/3高度和促使下颌骨向下后旋转。本研究结果治疗前后的面下1/3的高度无明显的增加,认为适应证的选择,牵引力线的控制是颈支抗治疗安氏Ⅱ类畸形的关键。同时在治疗中下颌骨的生长有着明显的增加,一方面是其本身正常的生长能力,另一方面也可能是矫治器对其有一定的刺激作用。

Objective: To study using cervical headgear to restrict maxillary development for treating Class II malcoolu-sion. Methods: With the pre -cephalometric and post -cephalometric to compare the results of the treatment. Results: This study indicate maxillary and upper molar have been moved back 1.03mm and 2. 33mm respectively. SNA and OP decrease and MP has no obvious changes. Low facial height didn' t increase distinctly. Conclusions: If choose right cases and have good control of the force line, you can control the side -effect of the cervical headgear. For mandible growth, there are may two ways to affect it, one is the mandible itself, and one is stimulation of the appliances.