Prediction of orthodontic treatment results

Abstract

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 re$ults have become highly achievable. We reviewed the history of setting treatment goals and estimating treatment based on lateral roentgenographic cephalograms and study models, and asse$sed 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 ot 5.5" and vvho had received orthodontic treatment using the same procedure. We compared the following parameters : results of measurements based on cephatometrlc tracing betore 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 ot the treatment duration and outcome predictions. Comparison of the ANB angle before and after treatment showed that the value decreased. There were no signiticant difierences in the treatment goals or results. The distances from Ul to NA showed no diiferences between the objective value before treatment and the actual value after treatment. Atthough comparison of preoperative and postoperative values for mandibular Ll 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 ot 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 ot differences between the objectives and the results suggest that treatment goal$ close to the target had been achieved. Because no significant differences were found between the treatment duration planned betore surgery and the actual duration, the findings suggest that the time ot treatment could be estimated at the initiation ot treatment. The use of the treatment procedure described in this study was valid for predicting the treatment period as wel1 as the treatment goals pertaining to the ANB angle and the positions of the maxiilary and mandibular anterior teeth. The slight decrease in the FMA and the dynamics ef the maxi11ary anterior teeth after treatment suggest that the procedure described in this study was effective in the treatment of maxilLary protrusion. (J Osaka Dent Univ 2015 ; 49 : 229-235}