Intrusion Of Maxillary Anterior Teeth: A Comparative Clinical Study Between Mini-Implants And Utility Arch

Background: Deep bite is a common orthodontic malocclusion caused by factors like incisor supra-occlusion, molar infra-occlusion, or incisor angulation. Nonsurgical correction of deep bite involves extrusion of posterior teeth, intrusion of incisors, or both. Extrusion of posterior teeth in growing patients provides stable results due to secondary remodelling. In patients with deep bite and excessive gingival display, intrusion of incisors is typically required which can be accomplished using intrusion arches or mini-implants. Materials and Methods: A total of 10 subjects with an anterior deep bite (overbite >4mm) with excessive incisal display at rest and at smile were taken. Participants were evenly allocated into two groups based on their gingival display. Group I included five participants with less than 4 mm of gingival display, who received treatment using Rickett’s intrusion utility arch. Group II consisted of five subjects with more than 4 mm of gingival display, who were treated with two anterior mini-implants. Lateral cephalograms were utilized to evaluate maxillary anterior intrusion at two specific time points: Pre-treatment (T1) and following a 6-month interval (T2). Results: The amount of bite opening in both groups was comparable, however the amount of incisor intrusion was greater with mini-implants than with the utility arch. The utility arch group showed significantly greater labial tipping (P<0.01) and increased overjet (P<0.05) compared to the mini-implant group. The distance between the maxillary first molar (U6) and palatal plane (PP) significantly increased with the utility arch but decreased with mini-implants. The mandibular plane angle (GoGn-Sn) increased with the utility arch and decreased with mini-implants; however, the difference was statistically non-significant. Conclusion: Deep bite correction with intrusion utility arch occurs through incisor intrusion, incisor flaring, and molar extrusion, whereas with mini-implants, bite opening mainly occurs through incisor intrusion, making it an efficient alternative in cases where dental side effects such as incisor flaring and molar extrusion are undesirable.