FR-Ⅲ型矫治器对不同生长发育期Ⅲ类错牙合颅面结构的影响

The effect of FR-Ⅲ appliances on the craniofacial structure of Class Ⅲ malocclusion at different growth and development periods

目的:对不同生长发育期的安氏Ⅲ类错牙合畸形,根据颈椎骨龄分期分组,通过对正畸治疗前后头颅侧位片的测量分析,比较不同生长发育期开展FR-Ⅲ型矫治器治疗的颅面部效果差异。方法:选取34例使用FR-Ⅲ型矫治器治疗,处于生长发育期的安氏Ⅲ类患者,根据颈椎骨龄分期分组:生长发育高峰前期组(CVMⅠ~Ⅱ期)、生长发育高峰期组(CVMⅢ~Ⅳ期)。使用Dolphin 11.8软件对患者颅面结构进行X线头影测量分析。结果:治疗后SNA角、ANB角、U1-SN角、U1-APog距和覆盖、NA-PA角均显著增大(P<0.01);Z角亦增大(P<0.05);FH-N′Pog′角、N′-Sn-Pog′角和IMPA角显著减小(P<0.01)。比较生长发育高峰前期组和高峰期组FR-Ⅲ型矫治器矫治前后的差值,高峰期组SNB角、MP-SN差值绝对值显著大于高峰前期组(P<0.05)。结论:FR-Ⅲ型矫治器可促进上颌骨向前生长,改善软组织侧貌,但没有显著抑制下颌骨生长。在生长发育高峰前期矫治,促进上颌骨向前生长的可能性更大,在高峰期矫治会引起下颌骨顺时针旋转。

Objective:To compare the differences in the effect of FR-III appliance treatment carried out in the different growth and development period on the patients' craniofacial structure by analyzing the measurements of lateral cephalograms before and after the treatment of patients with Class Ⅲ malocclusion at different stages.Methods:Lateral cephalograms of 34 patients with Class Ⅲ malocclusion treated with FR-Ⅲ appliance were selected and divided into two groups according to cervical vertebral maturation method: prepubertal group(CVM Ⅰ to Ⅱ),and pubertal peak group(CVM Ⅲ to Ⅳ).Cephalometric analysis of the patient's craniofacial structures was performed with Dolphin Imaging software(version, 11.8).Results:SNA,ANB,U1-SN,U1-APog, Overjet and NA-PA were significantly increased after treatment(P<0.01),Z angle were also increased(P<0.05),FH-N′Pog′,N′-Sn-Pog′ and IMPA were significantly reduced(P<0.01).The absolute values of SNB and MP-SN difference in the pubertal peak group were significantly higher than those in the prepubertal group(P<0.05).Conclusion:The FR-Ⅲ appliance treatment promoted the forward growth of the maxilla and improved soft tissue profile, but did not significantly inhibit mandibular growth.The orthodontic treatment during the prepubertal growth period is more probable to promote forward growth of the maxilla.In addition, the FR-Ⅲ treatment during the pubertal growth period induces clockwise rotation of the mandible.