Dental Tribune United Kingdom Edition

June 6-12, 201122 United Kingdom EditionClinical page 21DTß Various volumes The first-generation devices featured very large volumes that required time-consuming reworking of the immense data record for problems be- yond large and reconstructive surgery in order to be able to evaluate the relevant data and/ or regions in a target-orient- ed manner. Today, numerous manufacturers offer devices with small and medium sized volumes. Three types of devic- es are available: • small volume (4 x 5 cm) for oral surgery and dental proce- dures • medium-sized volume (8 x 10 cm and higher) for oral surgery and reconstructive surgery • large volume (18 x 20 cm and higher) for oral surgery and re- constructive surgery Problems with small and medium-sized volume de- vices Small- and medium-sized vol- ume devices are generally used for preimplantological diag- nostics, oral surgery, and or- thodontic and endodontic pro- cedures. The limited volume size requires careful device setting and patient positioning so that the relevant structure is accurately captured. For new users and those who only take volume tomo- grams once in a while, this cor- rect setting can pose difficul- ties, which was our motivation for developing a DVT phantom that can be used for training purposes and for direct prepa- ration of an image with a pa- tient. The DVT phantom and its application The DVT phantom is an X-ray phantom that depicts a me- dium-sized mandibular and maxillary dental arch with the teeth positioned in ideal den- ticulation. The phantom, which con- sists of a mandible and maxilla, is mounted on the individual bite or positioning support of the respective device. Barium sulphate is added to the plastic teeth so that they are visible in the X-ray image. These teeth are made by the manufacturer especially for X- ray applications. The DVT plat- form is then mounted on the device with the original bite support instead of a patient. The device setting can be done in two different ways: aThe desired volume is pre-set using the device pro- gramme and then manually fine-tuned. bThe device is manually set directly upon the region to be captured with the aid of the light visors. Thereafter, the set position- Fig 1a Fig 1b Fig 2 Fig 3 Fig 5 Fig 4 page 24DTà ‘The limited volume size requires careful device setting and patient position- ing so that the relevant structure is accurately captured’