Evaluation of crown inclination and angulation after orthodontic treatment using digital models : Comparison to the prescription of the brackets used.

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.