乳牙反矫治后硬组织及牙弓长度的改变

Changes of Skeletal Tissue and Length of Dental Arch after Treatment of Deciduous Anterior Crossbite

目的探讨乳牙期牙性、功能性反早期Ⅲ类牵引矫治后硬组织及牙弓长度的改变。方法采用固定矫治器对30例乳牙期前牙反患儿进行早期Ⅲ类牵引矫治,配对t检验比较头颅侧位定位片的21项测量值及上、下颌牙弓长度矫治前后之差异。结果与矫治前相比,上中切牙角显著增大,下中切牙角显著减小(P<0.01);上牙弓长度增加,而下牙弓长度减小(P<0.01)。结论早期Ⅲ类牵引矫治乳前牙反的过程中,上切牙唇倾和(或)下切牙舌倾,且上下切牙发生唇舌向的移位,但下颌位置未发生显著改变。

Objective To study changes of skeletal tissues and length of dental arch after treatment of dental and functional deciduous anterior crossbite with early class Ⅲ elastic, Methods Paried t test was used to compare the difference of 21 cephalometric indexes and dental arch length before and after treatment of 30 decidous anterior crosshite patients with fixed appliance and early Ⅲ elastic. Results Upper central incisor angle and upper dental arch length increased, while lower central incisor angle and lower dental arch length decreased significantly. Conclusion During the treatment of deciduous anterior crossbite with fixed appliance and early Ⅲ elastic, lip inclination and lip-tongue direction of upper and lower incisors changed, while the position of mandible had no significant change.