Practical Procedures in Implant Dentistry. Группа авторов
Procedures
3.2.1 Template Design
3.2.1.1 Traditional Templates
Various methods have been used in imaging, including the use of gutta percha markers, radiopaque teeth, or barium sulfate in acrylic resin. The use of radiopaque gutta percha markers have been used to simulate the alignment of the implants, providing information about the intended placement on the cross‐sectional imaging. These gutta percha markers are then removed, and the radiographic templates further modified to become a surgical template. These templates indicate teeth position but are not precisely defined because the surgeon may have to manually correct the placement of implants upon assessing the imaging.
3.2.1.2 Digital Templates
More recently, digital scanning has allowed us to ‘digitally’ wax up the tooth in the gap, design a template, and then either mill or 3D print this in acrylic. The design of the digital template should ensure that there is adequate support from hard tissues such as teeth adjacent to the gap, and the missing tooth is included in the template, so the doctor may drill through it to prepare space for the radiographic markers. Some doctors prefer to have ‘windows’ cut out of the acrylic to visually ensure seating of the template.
Although the digital workflow is constantly evolving, historically it began with this approach:
1 Intra‐oral scanning (or conventional impressions)
2 Construction of digital radiographic guides with radiopaque marker
3 CBCT (small FOV)
4 Conversion of radiographic guide to surgical guide based on the findings of the CBCT.
Modern digital workflows involve a streamlined approach which allows creation of the surgical guide being designed and milled from an initial intra‐oral scan and CBCT:
1 Intra‐oral scanning (or conventional impressions)
2 CBCT (small FOV)
3 Merging the intra‐oral scan with the CBCT, design and construction of a surgical guide.
3.2.2 Photography
The following sets of photographs are a minimum standard:
Full face (frontal): This image is shot at the same level as the patient and should cover their whole head. This vertical angle is important for majority of the images taken in dental photography. The interpupillary line and long axis of teeth is used to align the camera (Figure 3.4).
Full smile – frontal, right, and left lateral view: This view shows the lips as well as the teeth visible for this angle. The upper lateral incisor is centred on the slide. The contralateral central incisor should be visible and possibly the lateral incisor and canine (Figures 3.5–3.7).
Retracted anterior view: This is an intra‐oral photograph using retractors held by the patient, with the teeth together or slightly apart (Figures 3.8 and 3.9).
Upper and lower right and left lateral retracted view: The image is centred on the lateral incisor so that it is in the centre of the picture. The retractor is pulled to side that the picture is being taken of, while the contralateral retractor is loosely held which allows the photograph to extend further posteriorly to capture the posterior teeth (Figures 3.10 and 3.11).
Upper and lower occlusal retracted view (use mirror): This is a reflected view from a high‐quality mirror, with as many teeth as possible included. Keep the mirror clear of fogging by warming it or using an air–water syringe. The mouth should be opened as wide as possible to allow the best mirror position. In the lower jaw is exactly the same as with the upper teeth but the patient needs to be asked to keep their tongue back so that is does not obscure the teeth (Figures 3.12 and 3.13).
Figure 3.4 Full face frontal. This image is shot at the same height as the patient, including their whole head, and can be taken with lips at rest and also in broad smile.
Figure 3.5 Right lateral smile.
Figure 3.6 Frontal smile.
Figure 3.7 Left lateral smile.
Figure 3.8 Retracted frontal shot with teeth apart.
Figure 3.9 Retracted frontal shot with teeth in maximum intercuspation.
Figure 3.10 Retracted left photograph displaying left side of teeth. The left lateral incisor should be in the centre of the photograph.
Figure 3.11 Retracted right photograph displaying right side of teeth. The right lateral incisor should be in the centre of the photograph.
Figure 3.12 Occlusal photograph of mandibular teeth using a photographic mirror.