Objective To study the mechanism and applicability of Bite-bumper combined with fixed appliance in treatment of lingual tipping deep bite. Methods 14 children aged 12-16 years old with lingual tipping deep bite participated in the experiment. Bite-bumper combined with fixed appliance was used to correct the deep bite. Clinic effect was observed. Lateral cephalograms were taken before treatment and after bite opening. The related hard tissues were estimated through the cephalograms. Results 1）The average duration for bite-opening with Bite-bumper and fixed appliance of 14 patients was 28 days. 2）After bite-opening, the changes in length direction of jaw（SNA, SNB, ANB） had no statistical variances. Anterior and posterior facial height（S-Go, ANS-Me） were increased. No significant changes were observed in the ratio of posterior facial height to anterior facial height（S-Go/N-Me）, angle of mandibular plane（SN-MP） and Y axis. Labial incline in upper and lower incisors（U1-SN, L1-MP） and interincisa angle（U1-L1） were decreased. The posterior teeth（U6-PP, L6-MP） were extruded and the upper incisors（U1-PP） were intruded. The overbite was decreased. Conclusion Bite-bumper combined with fixed appliance can be used effectively for deep bite correction and improve the short face of patients with lingual tripping deep overbite.
