In recent years, there has been a continual increase in the use of modern technologies in dental procedures. The most important of these include innovative facial and dental scanning technology, digital computer tomography, digital portrait photography as well as the development of software for computer aided smile design and simulation.
The computer process for designing and simulating a smile begins with the acquisition of a digital model of the patient’s dental area. To do this, it is possible to use a traditional scan of a mold made in a dental surgery or with an intraoral scanner (Photo. 1).
Photo. 1. Scanning the patient’s dental structure with an intraoral scanner
Intraoral scanning technology allows a digital dental model to be generated almost immediately. This can then be used directly in the dental surgery to create a new concept of the patient’s smile using specialized software (e.g. exocad Smile Creator). During one appointment in the dental surgery, the patient together with the dentist can decide on the proposed treatment method or the concept of a new smile. The decision taken becomes the starting point for suitable prosthetic work. A complement to the dental model are digital images of the facial skeleton created using computer tomography and registered in the DICOM format (Photo. 2).
Photo. 2. Visualization of the tomography area between the upper and lower jaws
Digital tomography is of particular use in the following areas: prosthetic implants, complicated prosthetic reconstruction requiring control over the bone condition as well as orthodontic work.
The basic element of the design and simulation process for a smile are photographic portraits of the patient. The photographs are a basic carrier of information for the exocad Smile Creator software and simultaneously represent part of the patient’s complex documentation. This also includes clinical photographs, in other words, photographs taken before and after treatment, as well as close-ups of the patient’s dental area (macro photographs). The state-of-the-art smile design software, for example exocad Smile Creator program, requires two basic photographs of the patient’s face. The first one is a view of the patient looking straight at the lens, simulating the natural smile in such a way as to reveal the maximum possible tooth area (Photo. 3).
Photo. 3. Photograph of the patient’s face with a smile
The second one is a view of the patient with the retractors applied looking straight at the lens (Photo. 4).
Photo. 4 Photograph of the patient’s face with applied retractors
Thanks to modern facial scanning software, dentists can transfer a 3-D image of the patient’s face to CAD software (Photo. 5).
Photo. 5. Facial scanning
Obtaining a realistic scan of the face takes only a few seconds and can be carried out using a standard mobile device equipped with a scanner (e.g. an iPhone X or iPad Pro) as well as the Bellus3D Dental Pro application. The 3-D image (Photos. 6) of the patient’s face allows the natural dental structure to be designed without actually meeting the patient. Thanks to the function that combines the facial scan with the new dental design, the software can be used during consultation with patients before treatment begins.
Photo. 6. Use of facial scan, tomography and virtual articulator
A digital smile project (Photo 7), thanks to the use of data from many sources, is more than just an image of the patient’s future appearance. The use of the patient’s photographs together with the dental and facial scans and tomography data, as well as articulation data, allows the treatment procedure to start even during the design stage. Preparing suitable entry data, especially photographs showing the actual perspective, allows the dental scan to be matched to the photographs, which represents the basis for projecting the new smile on the patient’s existing teeth.
Photo. 7. Digital smile design
The designed smile, reflecting the actual dental situation, occlusions and articulation, may be used to create a virtual wax-up, and later in prosthetic work (Photos. 8-9).
Photo. 8. Simulation of the digital metamorphosis conducted in the exocad Smile Creator software
In order to transfer the digital project to the patient’s teeth, it is necessary to create suitable tools. By using digital technologies, especially 3D printing, we can create a virtual wax-up, which can then be used to create a mock-up (Photo 9).
Photo. 9. Fitting of the mock-up
This is the basis for preparing composite prosthetics which can visualize the new dental shape inside the patient’s oral area.