Dentofacial Changes at the three different stages on the malocclusion with severe overbite and overjet treated by Tip-Edge Plus technique

Objective To investigate the skeletal and soft tissue changes at the three different stages on the malocclusion with severe overbite and overjet treated by Tip-Edge Plus technique.Methods The sample comprised 23 malocclusion with severe overbite and overjet patients in adolescence (age 13.6± 1.8 years).First premolars were extracted in maxilla in all patients.Lower second premolars of 14 patients and lower first premolars of 9 patients were extracted.All patients were treated by Tip-Edge Plus technique,4 lateral cephalometric radiographs were taken before treatment,after stage Ⅰ of opening overbite,after stage Ⅱ of closing space and after treatment.Computerized cephalometric analysis was carried out.ANOVA and q test were performed using software package SAS 8.0.Results After treatment,highly significant changes were noted in overbite,overjet and soft profile.Overbite decreased from 5.35 mm to 0.52 mm at stage Ⅰ (P＜0.05).U1/SN decreased 20.21° at stage Ⅰ,decreased 7.56° at stage Ⅱ and increased 10.16° at stage Ⅲ (P＜0.05).U1-AP decreased 6.41 mm at stage Ⅰ,decreased 2.79 mm at stage Ⅱ and increased 2.19 mm at stage Ⅲ (P＜0.05).Conclusions Malocclusion with severe deep overbite and overjet could be treated successfully by Tip-Edge Plus technique in adolescence.Overbite opening happened at stage Ⅰ.Both torque and tip of teeth could be corrected at stage Ⅲ. Key words: Tip-Edge Plus appliance; deep overbite; deep overjet.