改良Nance弓矫治后牙锁伴前牙深覆的临床效果

Clinical Effects of Modified Nance Arch on Curing Molars Right Locked Occclusion Coupled by Anterior Teeth Deep Overbite

目的 探讨改良Nance弓矫治上颌第二磨牙正锁[牙合]伴前牙深覆[牙合]病例的临床效果。方法 应用改良Nance弓矫治40例上颌第二磨牙正锁[牙合]伴前牙深覆[牙合]患者，对矫治前后X线头影进行测量分析和测量临床牙冠高度，并设空白对照组24例作对照。结果 治疗组经过3—4个月的矫治，上颌第二磨牙正锁[牙合]解除，前面高平均增加（2．63±0．57）mm，后面高平均增加（1．66±0．26）mm，覆[牙合]平均减少（2．59±1．28）mm，上下前磨牙临床牙冠高度均有显著增加，下颌多于上颌。下磨牙临床牙冠高度亦明显增加，上磨牙不明显。结论 改良Nance弓是一种简单有效的矫治上颌第二磨牙正锁[牙合]的口内装置，并能快速打开咬合，尤其适用于深覆[牙合]低角型患者。

Objective To investigate the effects of curing the second maxillary molar with right locked occlusion coupled by deep overbite of anterior teeth by use of Modified Nanee Arch. Methods 40 cases （20 male cases, 20 female cases, ranging from 14 to 20 years old with the average age 17 years old） were treated with Modified Nace Arch, and 24 cases （12 male cases, 12 female cases） were as controls, Cephalometric analysis was carried out and clinical crown heights of maxillary and mandibular premolrs were measured before and after treatmnt. Results After 3 to 4 months＇ remedy, the right locked occlusion was reheeed. AFH and PHF were significantly increased by （2.63 ± 0.57） mm and （ 1.66±0.26） mm, respectively. Overbite decreased by （2.59 ± 1.28） ram. The clinical crown heights of maxillary and mandibular premolars grew significantly with that of the maxillary was more than that of the mandibular. The lower molars grew obviously while the upper molars not. Conclusion Modified Nanee Arch is a simple and effective inter-oral equipment in curing this monstrosity,and it can soon open the occlusion. Especially, it applies to curing deep overbite with short-feature and low-angle.