Introduction: Virtual study models made their first appearance on the orthodontic market in 1999. The early systems offered two-dimensional images; reliable 3D images of study models were obtained only with the introduction of laser technology. Virtual study models have reduced the number of limitations and obstacles associated with the use of conventional plaster models and resulted in the creation of the "paperless orthodontic office". To understand their drawbacks, advantages and affordability, the different systems available for virtual dental casts were compared.
Discussion: The systems envisaging the use of 3D virtual study models are: Orthocad, e-models, Orthoproof, SureSmile, Invisalign and Libra. All of these systems offer model "manipulation" options, whereas only Orthocad, e-models and SureSmile offer advanced levels of software complexity, so as to ensure: virtual set-up, computer-aided bracket placement, planning and construction of orthodontic appliances. The use of hand-held scanners calls for highly specific skills. Basic requirements to use digital models include: a personal computer, internet access, management software.
Conclusion: The digital elaboration of orthodontic study models is developing beyond the collection of morphologic and diagnostic data, towards the planning and production of orthodontic devices, through the use of morphing simulating the several phases of the treatment. Digital 3D models can be used at a basic and at a more advanced level, depending on the clinician's level of experience.