Prediction of orthodontic treatment results

• Published in: Journal of Osaka Dental University Vol. 49; no. 2; pp. 229 - 235
• Main Authors: Inami, Kaoru, Chen, Yih-Wen, Matsumoto, Naoyuki
• Format: Journal Article
• Language: English
• Published: Osaka Odontological Society 2015
• Subjects: Orthodontics; Prediction; Treatment results; Treatment time
• ISSN: 0475-2058; 2189-6488
• DOI: 10.18905/jodu.49.2_229

With the recent development of three-dimensional (3D) technologies and the advent of orthodontic anchor screws that do not require patient intervention, accurate predictions of treatment results have become highly achievable. We reviewed the history of setting treatment goals and estimating treatment based on lateral roentgenographic cephalograms and study models, and assessed the validity of this approach. The subjects of this study were 39 Caucasian male and female patients (mean age of approximately 14 years) who had maxillary protrusion with a mean ANB angle of 5.5° and who had received orthodontic treatment using the same procedure. We compared the following parameters : results of measurements based on cephalometric tracing before and after treatment ; treatment goals ; the planned treatment duration established at the initiation of treatment ; the actual treatment duration at each treatment stage ; and the validity of the treatment duration and outcome predictions. Comparison of the ANB angle before and after treatment showed that the value decreased. There were no significant differences in the treatment goals or results. The distances from U1 to NA showed no differences between the objective value before treatment and the actual value after treatment. Although comparison of preoperative and postoperative values for mandibular L1 to NB showed a decrease after surgery, there was no difference between the objective and post-operative value. Although the FMA tended to decrease slightly, no significant difference was found. Even though there was a margin of error at each of the treatment steps, there were no significant differences between the number of treatment months planned before treatment and the actual number required. The decreased ANB angle and lack of differences between the objectives and the results suggest that treatment goals close to the target had been achieved. Because no significant differences were found between the treatment duration planned before surgery and the actual duration, the findings suggest that the time of treatment could be estimated at the initiation of treatment. The use of the treatment procedure described in this study was valid for predicting the treatment period as well as the treatment goals pertaining to the ANB angle and the positions of the maxillary and mandibular anterior teeth. The slight decrease in the FMA and the dynamics of the maxillary anterior teeth after treatment suggest that the procedure described in this study was effective in the treatment of maxillary protrusion.