Equipment

Panoramic x-ray machines are composed of an exposure control panel, a C-arm, and a patient positioning device.

Control panel and exposure switch. The control panel typically contains the program selector, exposure controls (milliamperage control, kilovoltage control), head positioning lights, temple bar operation, anteroposterior (AP) operation and other features. Control panels will vary among manufacturers as well as direct digital and plate-based machines. The complexity of the control panel increases with the incorporation of features such as multiple program options and automatic exposure control (AEC) features.

Figures 15A and 15B. Digital Panoramic Unit Control Panels.

Number Legend:

1 - Kilovoltage Display

2 - Milliamperage Display

3 - Program

4 - Patient Size → Set Exposure Factors

5 - Up and Down

6 - Temple Bars

7 - Anteroposterior Lights and Positioning

8 - Jaw Shape - Adjustable

C-arm (x-ray tubehead/receptor assembly) - The relationship of the x-ray tubehead is fixed spatially to the receptor assembly by a fixed C-arm support. (Figure 16) The panoramic x-ray tubehead is similar to an intraoral x-ray tubehead. However, unlike the intraoral tubehead, both pre- and post-patient linear collimation occurs to provide a slit beam.

Figure 16. C-arm Assembly

Source: 2009 Proline Panoramic XC, Planmeca

Patient Positioning Device - The radiographer must be familiar with the operation of the patient positioning device as it is this apparatus that is used to position the patient’s head into the focal trough of the machine. This device comprises a head holder and a chin rest/bite block. (Figures 17A-C) The chin rest/bite block is used to stabilize the patient’s dentition in the anteroposterior direction whereas the head holder is used to stabilize the orientation of the patient’s head in both the vertical and horizontal planes.

Figures 17A-C. Patient Positioning Devices.

0/41Next