Construction of an ideal set-up model for lingual orthodontic treatment

Bae, Gi Sun; Son, Woo Sung

Abstract

Making a precise and ideal set-up model is an essential part in the indirect bonding procedure for lingual orthodontic treatment. To evaluate the accuracy of the making a set-up model, 22 adult patients who received lingual orthodontic treatment with 4 bicuspid extractions were selected, and 3 sets of dental models (before, set-up, and after treatment) were measured using the set-up model gauge, an instrument for measuring the inclination and angulation of the clinical crowns on the dental model. Two sets of lateral cephalograms (before and after) from each patient were also evaluated. The mean difference between the before treatment model and the set-up model was -3.93 +/- 6.98 degrees for the inclination and 1.87 +/- 5.79 degrees for the angulation. And the mean difference between the set-up model and the after treatment model was -4.31 +/- 5.91 degrees labiolingually and -2.16 +/- 3.27 degrees mesiodistally. The after treatment model differed from the before treatment model about -8.24 +/- 5.39 degrees in inclination. There were no significant difference between the measured gauge that measured from the dental model using the set-up model gauge and the calculated gauge angle measured from the lateral cephalogram using constructed points and lines. Using the set-up model gauge, it is possible to evaluate the study model 3-dimensionally in relation with the patient's lateral cephalogram and establish whether the doctor's prescription or overcorrection is built in the set-up model precisely.