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OACSTPCD

Objective:To compare the differences in the effect of FR-Ⅲ appliance treatment carried out in the differ-ent growth and development period on the patients'craniofacial structure by analyzing the measurements of lateral cephalo-grams 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).Ceph-alometric analysis of the patient's craniofacial structures was performed with Dolphin Imaging software(version,11.8).Re-sults: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 pro-file,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 in-duces clockwise rotation of the mandible.