Influence of anatomical characteristics and tooth movement-related variables on root length changes in maxillary first molars undergoing orthodontic intrusion
Year: 2026
Type: article
Study design: Observational Study
Abstract: Objectives To identify the influence of anatomical characteristics and tooth movement–related variables on root length change in maxillary first molars undergoing orthodontic intrusion for anterior open-bite correction. Materials and Methods A total of 216 roots from 36 patients (mean age, 21.8 ± 2.7 years) with anterior open bite treated with either temporary anchorage device–supported fixed appliances (n = 17) or clear aligners (n = 19) was analyzed retrospectively. Cone-beam computed tomography images of the maxillary first molars were obtained at baseline (T0) to quantify initial root length, tooth inclination, and root-sinus proximity distance, and at 6 months of treatment (T1) to quantify vertical displacement, inclination change, and root length change. Multilevel linear mixed-effects regression analyses were performed to account for clustering of multiple roots within individuals (α = 0.05). Results Prior to model adjustment, clear aligners demonstrated significantly less root length change than fixed appliances ( P < .05). Multilevel regression analysis demonstrated that initial root-sinus proximity distance and initial root length were independently associated with root length change ( P < .001 and P < .01, respectively), whereas appliance type and tooth movement-related variables were not ( P > .05). Conclusions Root length changes during maxillary molar intrusion were influenced by anatomical factors rather than appliance type or tooth movement-related variables.
Source: The Angle Orthodontist
DOI: 10.2319/041726-357.1
Institution: Prince of Songkla University
Language: English
Subfield: Orthodontics
Field: Dentistry
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7222957933