[Clinical analysis of two-phase treatment of 35 cases with Angle Class II division 1 malocclusion]

To evaluate the clinical value of the two-phase treatment of Angle Class II division 1 malocclusion.

Thirty five cases with Class II division 1 malocclusion were treated with two-phase treatment(Twin-block functional appliance and fixed appliance).Lateral cephalograms were taken before and after treatment for each patient. The results were analyzed with paired t test using SPSS11.0 software package.

After treatment ,the bite relation of molars ,the overbite and overjet and soft tissue profile were improved. ANB angle,U1-SN,OB,OJ,UL-E,ULP were decreased respectively(P<0.01). SNB, C(o)-G(o),G(o)-G(n),C(o)-G(n) were increased respectively(P<0.01). L1-Mp and FH-MP were increased, too(P<0.05).

Twin-block functional appliance possesses the orthopedic effects on Angle Class II division 1 malocclusion.It limits the maxillary growth forward and promotes the mandibular growth by repositioning the mandible forward.These may contribute to a harmonious relationship of upper and lower jaws and a better profile.