A novel method for volumetric assessment of tooth wear using three-dimensional reverse-engineering technology: a...

To describe a newly developed three-dimensional (3D) digital superimposition method for quantitative evaluation of tooth wear that occurs during orthodontic treatment.

The sample consisted of dental casts obtained from 56 patients (23 male patients and 33 female patients; mean ± standard deviation age  =  21.8 ± 5.1 years) who received orthodontic treatment with extraction of four premolars. The maxillary and mandibular dental casts taken before (T1) and after (T2) orthodontic treatments were scanned, and 3D images of the canines were constructed. The canines at T1 were superimposed with those at T2 with the best-fit method using the middle third of the labial and lingual surface as the reference area. To measure the volume of the canines, four boundary planes were constructed, and the differences in volume before and after orthodontic treatment were calculated.

The mean volume of tooth wear of the 224 canines was 2.0 mm(3) after 35.5 months of orthodontic treatment. The volume of canine tooth wear was 2.3 ± 1.5 mm(3) in male subjects and 1.9 ± 1.2 mm(3) in female subjects. The mean wear of the upper right canines (2.4 ± 2.0 mm(3)) was significantly greater than that of the lower right canines (1.9 ± 2.6 mm(3)).

Regional registration of teeth in 3D digital models is useful for quantitative evaluation of tooth wear in orthodontic patients. This method may also be used to assess treatment results in restorative dentistry.