title: Presurgical orthodontic decompensation alters alveolar bone condition around mandibular incisors in adults with skeletal Class III malocclusion.
abstract: This study is to use cone beam computed tomography (CBCT) to acquire accurate radiographic images for alveolar bone in lower incisors and the change after presurgical orthodontic treatment. Seventeen patients with skeletal Class III malocclusion, ten normal occlusion subjects, and fifteen patients treated with orthodontic treatment and orthognathic surgery were included. CBCT images were obtained. The labial and lingual inclinations of mandibular incisors, the thickness of alveolar bone, the vertical alveolar height and root length were measured. Alveolar bone thickness at the apex in patients with skeletal Class III malocclusion was thinner than normal subjects. The vertical alveolar bone heights at labial and lingual sides in patients with skeletal Class III malocclusion were both reduced compared with normal subjects, especially at the labial side. There were statistically significant correlations between lower incisor inclination and alveolar bone morphology. After orthodontics, the incisors root apex was closer to the lingual side of alveolar bone. The alveolar bone thickness at apex was not statistically changed. The vertical alveolar bone heights at the labial and lingual sides were both significantly reduced especially the lingual side after presurgical orthodontic treatment. The root length was not significantly changed. In conclusion, the alveolar bone thickness at apex is thinner and the vertical alveolar height is reduced at the labial side. Forward movement of lower incisors during presurgical orthodontic treatment can render the lower incisors root apex closer to the lingual side and the vertical alveolar height is reduced.
authors.affiliation: Department of Stomatology, Tangshan Branch of Jinling Hospital, School of Medicine, Nanjing University Nanjing 211131, P. R. China ; Department of Orthodontics, School of Stomatology, The Forth Military University Xi'an710032, P. R. China.
authors.forename: Boyang
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing 210001, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Stomatology, Tangshan Branch of Jinling Hospital, School of Medicine, Nanjing University Nanjing 211131, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Xiao
authors.affiliation: Department of Orthodontics, School of Stomatology, The Forth Military University Xi'an710032, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ding
keywords: Cone beam computed tomography; alveolar bone; lower incisors; orthodontic decompensation; skeletal Class III malocclusion