Methods: Post-treatment digital models of 23 patients consecutively treated with SureSmile were digitally superimposed on their corresponding virtual treatment plan models utilizing best-fit surface-based registration. Individual tooth discrepancies between virtual treatment plan and actual outcome were computed and expressed in terms of a six-degrees-of-freedom rectangular coordinate system. Discrepancy less than 0.5mm in mesial-distal, facial-lingual and vertical dimensions, and discrepancy less than 2° for crown torque, tip and rotation were considered clinically satisfactory. One-sided test of equivalence was performed on each discrepancy measurement with P-values of less than 0.05 considered statistically significant.
Results: Mesial-distal tooth position was clinically satisfactory for all teeth with the exception of maxillary lateral incisors and second molars. Facial-lingual tooth position was clinically satisfactory for all teeth with the exception of maxillary central incisors, premolars and molars, and mandibular incisors and second molars. Vertical tooth position was clinically satisfactory for all teeth with the exception of mandibular second molars. For crown torque, tip and rotation, discrepancy exceeded the limits considered clinically satisfactory for all teeth except for crown torque on mandibular second premolars and crown tip on mandibular second premolars and first molars.
Conclusions: The effectiveness of orthodontic treatment using SureSmile technology to achieve predicted tooth position varies with tooth type and dimension of movement. Knowledge of dimensions in which final tooth position is less consistent with the predicted position enables clinicians to build necessary compensations into the virtual treatment plan.
Keywords: CAD/CAM, Effectiveness, Malocclusion, Orthodontics and Technology