Clinical Application of Three-Dimensional Reverse Engineering Technology in Orthodontic Diagnosis (2011)

We have taken a comparison study using 30 dental study models (Cha et al., 2007).Orthodontic linear measurements were recorded between landmarks, directly on the study models and indirectly on the 3D digital models by using the INUS dental scanning solution ® (composed of Breuckmann's opto TOP scanner ® , INUS Rapidform 2002 ® , Autoscan system ® ).The resolution of the Topometric & Photogrametric 3D scanner ® after calibration is 8 m and the reliability is 15 m.This exceeds the accuracy required for orthodontic measurements such as the mesiodistal tooth width, arch length, and arch width.There were no significant differences between the measurements at the 1% level.The similar study (Keating et al., 2008) using another laser scanning device (Minolta VIVID ® 900, non-contact 3D surface laser scanner, Konica Minolta Inc., Tokyo, Japan) also shows that the difference between measurements on the study and 3D digital models was 0.14 mm, and was not statistically significant.In conclusion, measurements carried out on 3D digital models are a valid and reliable alternative to those currently used in study models in orthodontic practice with the advantage of significantly reducing measurement time. Some examples of research and clinical applications using 3D digital modelTooth size, crowding or spacing, overjet, overbite, and Bolton analysis are typically measured by hand on study models.3D digital model is valuable alternative to conventional study models and can be used to determine routine diagnostic value, such as the Bolton analysis, arch length discrepancy, sagittal or transverse symmetry (Cha et al., 2007;Santoro et al., 2003) (Fig. 1).Automatic identification system (the automatic recognition of tooth morphology) will be a suite of technologies, that enable and facilitate the accurate capture and rapid transmission of machine readable data, e.g.cusp tip or pit and fissure of certain teeth, to automated information systems, thereby enhancing the readiness of capabilities in support of their respective mission.Furthermore it also held information, which could previously be gathered only by complicated laboratory procedure, as sawing or wax up etc.There are numerous clinical examples to illustrate how such information could be applied in the diagnostic or treatment evaluation in orthodontics (Fig. 2).In counterpoint to the two-dimensional analysis, it is possible with 3D digital model to determine further parameters, such as palatal volume before and after maxillary expansion (Fig. 3) or volume or surface square measure of the deep structure of the palate (Fig. 4).3D digital model offers many advantages, including elimination of model breakage and storage problems, instant retrieval of models, ease of communication with patients and colleagues.A single set of 3D digital models typically requires 8 MByte of disc space.It means that the data of 5,000 patients can be stored on a 40 GByte drive.It enables the orthodontist to e-mail images if desired and is a convenient presentation tool (Cha et al., 2007).Disadvantages include lack of tactile input for the orthodontist and time needed to learn how to use the system (Santoro et al., 2003).3D digital models present several unique challenges compared with conventional study models.Because the 3D computer image is www.intechopen.