Effects of mandibular incisor intrusion obtained using a conventional utility arch vs bone anchorage

Abstract

To compare the dentofacial effects of mandibular incisor intrusion using mini-implants with those of a conventional incisor intrusion mechanic, the utility arch. Materials and Methods: Twenty-six deep-bite patients were enrolled to one of the two groups. In group 1 the mandibular incisors were intruded using a 0.16 3 0.22-inch stainless-steel segmental wire connected to two mini-implants. In group 2 the mandibular incisor intrusion was performed using a conventional utility arch. Conventional lateral cephalometric radiographs were taken at pretreatment and at the end of intrusion. Thirty landmarks were identified to measure 23 linear and 20 angular measurements. Intragroup comparisons were made using a paired t-test or a Wilcoxon test. Intergroup comparisons were made using a Student's t-test or a Mann-Whitney U-test.Results: The duration of intrusion was 5 months for group 1 and 4 months for group 2. In the implant group, the mean amount of change was 0.4 mm/mo for the incisor tip and 0.3 mm/mo for the center of resistance, and in the utility arch group, the mean amount of change was 0.25 mm/mo for the incisor tip and 0.2 mm/mo for the center of resistance. The mandibular incisors showed an average protrusion of 7u in the implant group and 8u in the utility arch group. Conclusions: Incisor intrusion that was achieved using an implant-supported segmented archwire was no different than the movement achieved with a conventional intrusion utility arch. The only difference between the two methods was in the molar movement. ( Recently, several researchers 3,4 have focused on the effect of aging on anterior tooth display and on how treatment mechanics change the perception of age. Sarver and Ackerman 3 and Zachrisson 4 drew attention to the importance of lower incisor intrusion in deep-bite patients with reduced upper incisor display to preserving a youthful appearance.Lower incisor intrusion can be accomplished using different arches, such as a reverse Spee arch, 5 a three-piece intrusion arch, 6 or a utility arch. 7 Even though intrusion can be achieved successfully with all of these appliances, incisor proclination during intrusion and unwanted distal tipping on posterior anchorage teeth are inevitable.The use of temporary anchorage devices for lower incisor intrusion have been described in a few case reports, 8,9 and the effects were limited to the mandibular anterior area. In this prospective study, the effects of mandibular incisor intrusion achieved using a segmented arch and two miniscrews were evaluated a Private Practice, Edirne, Turkey.

Effectiveness of miniscrew-supported maxillary incisor intrusion in deep-bite correction: A systematic review and meta-analysis

“…According to quantitative synthesis, miniscrews had a greater overall effect on reducing overbites than did the intrusion arches. Similarly, Aydogdu andÖzsoy 24 found that miniscrews resulted in a similar amount of deep-bite correction compared with conventional utility arches during intrusion of mandibular incisors. Howev- er, they had to place their miniscrews in a strictly narrower interradicular space between the mandibular incisors; thus, some difficulties might have been expressed in sustaining the miniscrews.…”

Dento-skeletal changes associated with treatment of deep overbite in class II malocclusion

“…Tip-back bends and base arches are some of the mechanics that have been suggested for the extrusion of posterior teeth [10][11][12][13] . In order to intrude the incisors, J-hook headgears, functional appliances, anterior bite-planes, segmented arch technique, Begg mechanics, edgewise mechanics, three piece base arch, utility intrusion arch, connecticut intrusion arch, and temporary anchorage device can be used [14][15][16][17][18][19][20][21][22] . The specific treatment objectives need to be determined before the mechanotherapy is initiated.…”

Fricción en Ortodoncia

“…Los brackets de autoligado activo, donde la plancha de cierre ejerce una presión sobre el arco que le obliga a tomar contacto con la base del slot, generan mayor fricción que con las que no aplican tal fuerza (1,22). Dicho de otra manera, a mayor asentamiento del arco en el surco, mayor fricción se genera por el contacto de la superficie plana del arco con la superficie plana de la base del slot (2).…”