title: A novel method for volumetric assessment of tooth wear using three-dimensional reverse-engineering technology: a preliminary report.
abstract: OBJECTIVE
  To describe a newly developed three-dimensional (3D) digital superimposition method for quantitative evaluation of tooth wear that occurs during orthodontic treatment.
  
  
  METHODS
  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.
  
  
  RESULTS
  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)).
  
  
  CONCLUSIONS
  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.
authors: a  Private Practice, Department of Orthodontics, Ye Dental Clinic, Chuncheon, South Korea.
authors: Jina
authors: J
authors: Park
authors: Dong-Soon
authors: DS
authors: Choi
authors: Insan
authors: I
authors: Jang
authors: Hyun-Tae
authors: HT
authors: Yook
authors: Paul-Georg
authors: PG
authors: Jost-Brinkmann
authors: Bong-Kuen
authors: BK
authors: Cha
mesh_terms: D017076:Computer-Aided Design; D003481:Cuspid / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007834:Lasers; D008297:Male; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D003765:Models, Dental; D009971:Orthodontics, Corrective; D057085:Tooth Wear / Q000175:diagnosis* / Q000473:pathology; D014584:User-Computer Interface; D055815:Young Adult
keywords: Orthodontic treatment; Superimposition; Three-dimensional; Tooth wear; Volume