title: Quantitative evaluation of cortical bone thickness and root proximity at maxillary interradicular sites for orthodontic mini-implant placement.
abstract: Few studies have evaluated interradicular anatomy for cortical bone thickness and root proximity when placing a mini-implant for orthodontic anchorage. The purpose of this study was to provide a clinical guideline to indicate the best location, according to different insertion angles, for placement of a mini-implant with respect to the thickness of cortical bone and root proximity. CT images from 14 men and 14 women (mean age, 27 years; range, 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness and root proximity from and mesial to the central incisor to the second molar. A measure of cortical bone thickness was performed at four different angles. Generally, thin cortical bone thickness was found in the central/central incisors and central/lateral incisors interradicular sites. Cortical bone thickness increased significantly as the insertion angle increased except for interradicular sites at the 2 mm level from the alveolar crest. The volume of cortical bone engagement increased significantly at the 4 and 6 mm levels from the alveolar crest with an insertion angle of 30 degrees and 45 degrees in most interradicular sites. The lateral incisor/canine and second premolar/first molar interradicular sites showed greater space between roots compared with other sites, although this was not statistically significant. Based on the findings of this study, we recommend that mini-implants be placed at the 4 and 6 mm levels from the alveolar crest with 30 degrees and 45 degrees angles for the majority of interradicular sites to ensure better cortical bone to mini-implant contact without root damage.
authors.affiliation: Department of Clinical Orthodontics, School of Clinical Dentistry, Ewha Womans University, Seoul, Korea.
authors.forename: Ju-Eun
authors.initials: JE
authors.lastname: Lim
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Lim
authors.forename: Yoon Sic
authors.initials: YS
authors.lastname: Chun
mesh_terms: D000328:Adult; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011859:Radiography; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
chemical_list: D015921:Dental Implants