4-7. POSITIONING THE PATIENT
Standard radiographic procedures include precise positioning of the patient's
head as one step in placing film. The tissues to be radiographed and the x-ray beam
must be in proper relationship to produce an accurate radiographic image. This is
particularly important when using the bisecting angle technique. In adjusting the
backrest and headrest, it is important to make the patient as comfortable as possible to
minimize movement during exposure. As in photography, movement during exposure
will result in a blurred image. Blurring may be greatly reduced through the use of ultra-
a. Head Positioning in Radiography of the Maxilla Using the Bisecting
of the maxilla, the head should
so that the
occlusal surfaces of the maxillary teeth are in a horizontal plane (see figure 4-2). This is
done by adjusting the headrest so that the median plane (sagittal plane) is vertical and a
line from the ala of the nose to the tragus of the ear is horizontal.
Figure 4-2. Head position for making maxillary periapical radiographs.
b. Head Positioning in Radiography of the Mandible Using the Bisecting
In periapical radiography
of the mandible, the head should
so that the occlusal surfaces of the mandibular teeth will be horizontal when the mouth
is opened to the position in which the radiographs are to be made (see figure 4-3). This
is done by adjusting the headrest so the median plane is vertical and a line from the
corner of the mouth to the tragus of the ear is horizontal.