Abstract:
Deep overbite is a challenging malocclusion facing orthodontists and numerous treatment options were proposed. The intrusion of lower incisors is particularly practical in patients with adequate upper incisor display.
Aim of the study: The purpose of this study is to compare deep overbite correction using auxiliary cantilever springs to relative intrusion during initial stages of orthodontic treatment.
Materials and methods: Thirty patients exhibiting deep overbite malocclusion were divided into test and control groups. Test group received auxiliary cantilever springs on top of leveling arches to intrude lower incisors. Control group received sequential leveling arch wires. Treatment effect was evaluated after six months by using lateral cephalometric radiographs to assess incisors, molars and premolars changes. Comparison between T0 (preoperative) and T1 (6 months postoperative) within each group was done using paired samples T-test, while comparison of mean difference of different parameters between both groups was done using Mann-Whitney U test. Results: A mean overbite reduction of 3.2 mm was found in the experimental group. Incisor intrusion was found to be significant in the test group with a mean of -1.33 and -1.57 when measured from center of resistance and apex. Distal tipping of lower 1st molars was significant in the experimental group (P<0.001) while premolar extrusion was more significant in the control one.
Conclusion: Deep bite correction can be achieved during the leveling and alignment phase using cantilever springs with lower incisors intrusion without significant difference in labial tipping other than that created by relative intrusion with continuous sequential archwires.