Intrusion Effects on Maxillary Anteriors using Mini Implant Anchorage and K-Sir Loop in Subjects with Deep Overbite- A Cohort Study

Abstract

Introduction: Various options to treat deep bites nonsurgically involve extrusion of posterior teeth or intrusion of anterior teeth. Intrusion of anterior teeth is required in patients with excessive incisal display and to correct deep bite in adult patients when extrusion of posterior teeth is not desirable. Aim: To compare the rate of intrusion and dento-alveolar effects on maxillary anterior teeth by Kalra-Simultaneous Intrusion and Retraction loop (K-SIR loop) and Mini implant anchorage in subjects with deep overbite. Materials and Methods: This prospective cohort study included 12 patients with Class I or Class II Div 1 malocclusion having an overbite and overjet of >4 mm treated with therapeutic extractions of upper first premolars. Group A included six subjects treated using orthodontic Mini implants, while Group B had six subjects treated with K-SIR loop. Lateral cephalograms were taken before intrusion and retraction (T1) and at the end of six months (T2) into intrusion and retraction. Independent t-test and paired t-test was done for intergroup and intragroup comparison respectively. Results: The rate of intrusion was 0.38 mm/month and 0.31 mm/month for Group A and Group B, respectively. The amount of intrusion was significantly more in Temporary Anchorage Devices (TAD) group (p-value <0.01). Conclusion: In the TAD group, rate and amount of intrusion was significantly higher. There is no difference in vertical control between the two modalities statistically significant amount of molar extrusion was seen with the K-SIR loop group.