Panoramic Radiographs: Technique & Anatomy Review
Course Number: 533
Course Contents
Equipment Preparation
As with any dental procedure, it is important to properly prepare the equipment beforehand. Equipment preparation includes items such as the receptor, bite block, exposure settings, and patient selection (Table 2). If the panoramic image is being taken with a direct digital system, which transfers the image directly to the computer, it is important that the proper patient is selected in the electronic health record prior to the exposure. Otherwise, the image will be stored in the wrong location.
Setting the proper exposure time prior to beginning the procedure will help improve efficiency and reduce the possibility of over-exposing the patient to unnecessary radiation. The results of one survey of general dentists found that clinicians did not always change the exposure time related to the patient’s need. In fact 74% of respondents used the same exposure time for all patients.7 In order to properly protect patients, the exposure setting must be tailored for each individual patient. Most machines have settings that can be adjusted according to the stature of the patient. For example, when imaging a pediatric patient, the child exposure setting should be selected. Exposure settings should be adjusted accordingly as height and mass increases. There are usually two or three settings available for adult patients and one for children (Figure 4), which makes it possible to tailor the amount of radiation being produced.
Figure 4. Sample screen for selecting exposure settings for a child, slender adult, average adult, and large adult (circled in red). It is currently set for a slender adult with a curved arch.
Figure 4. Sample screen for selecting exposure settings for a child, slender adult, average adult, and large adult (circled in red). It is currently set for a slender adult with a curved arch.
Image source: Dr. Specht.
Table 2. Equipment Preparation.1
| Receptor | Analog/PSP plate placed in cassette according to guidelines. |
| Select patient | Direct digital sensor – have the correct patient assigned in computer before setting up. |
| Bite-block | Cover with disposable plastic covering (Fig. 5) or use a sterilized bite block made of impervious material between patients. |
| Exposure Settings | Set according to the manufacturer’s recommendations, which are pre-programmed according to the size of the patient. Most machines have a single setting for pediatric patients and two options for adult patients (according to their size (Fig. 4). Newer machines do not require that the clinician selects specific exposure times and doses for each patient. |
| Height | Adjust entire machine to the correct height for the patient and any other moveable parts as necessary (Fig. 6). |
Figure 5. Bite block covered with disposable plastic covering.
Image source: Dr. Specht
Figure 6. Control panel for pano machine. Area for setting height of machine and activating lights for patient positioning is circled in red.
Figure 6. Control panel for pano machine. Area for setting height of machine and activating lights for patient positioning is circled in red.
Image source: Dr. Specht