Evaluation of crown inclination and angulation after orthodontic treatment using digital models : Comparison to the prescription of the brackets used.
Author(s): Castro IO, Frazão Gribel B, Alencar AHG, Valladares-Neto J, Estrela CR
Key words: Cephalometry; Cone beam computed tomography; Orthodontics; Roth prescription; Torque
Purpose To compare crown inclination and angulation results obtained after orthodontic treatment to the Roth prescription. Methods The study design was based on files and documents obtained from a database of 26 patients who had undergone orthodontic treatment using the straight-wire technique and the Roth prescription. The crown inclination and angulation were measured using a three-dimensional (3D) cephalometric module (VistaDent, Dentsply, New York, NY, USA) by an orthodontist. A coordinate system (x, y, z) was developed for each tooth that used the Andrews plane as a para-axial reference. Descriptive statistical analysis provided the mean and standard deviation (SD) of crown inclination and angulation obtained after orthodontic treatment, which were compared to the Roth prescription.
Results Method reproducibility is an important test to investigate the margin of error and to verify the reliability of results. The results at time 1 (1.6°±1.1°) and time 2 (1.7°±1.2°) of the pilot study were not statistically different (p=0.99). Maxillary lateral and central incisors presented significant differences in crown angulation (p < 0.05) compared to the Roth prescription. The crown angulation of maxillary second premolars with regard to the occlusal plane presented a similar value to the Roth prescription.
Conclusion Crown inclination and angulation found at the end of orthodontic treatment did not match the prescription of the brackets for most teeth, as measured using digital models.
