Positioning of the film on

the palate and path of the X-rays. B. Schematic repre- sentation of the use of the film holder (adapted from Rinn Corporation). C. The mandible is slightly pro- truded to maintain the film holder in the correct po- sition. D. Correctly perfor- med radiograph. ���� C B A Upper incisors

The film must be positioned deeply enough in the palate, so that the apices are included in the radio- graph.

The midline of the radiograph must coincide with the midline of the dental arch. The plane of the film must be parallel to the long axis of the teeth. For this rea- son, the patient must bite the plastic support, holding the mandible in a slightly protruded position (Fig. 5.49) to avoid improper positioning (Fig. 5.50).

When the palate is particularly low, it is necessary to interpose a cotton roll between the plastic support and the incisal border of the upper incisors to maintain the parallelism between the radiograph and the tooth. In the case of the lateral incisor, the tooth of interest must be centered in the radiograph, without superim- position of the adjacent teeth (Fig. 5.51).

96 Endodontics 5 - Endodontic Radiography 97

A B

Fig. 5.50. A. The mandible is not protruded, the corner of the plastic support is outside the mouth, and the X-rays are perpendicular to the radiograph but not to the long axis of the tooth. B. A shortened image results.

Fig. 5.51. Preoperative radiograph of the upper la- teral incisor. A. Positioning of the film on the pala- te and path of the X-rays. B. The mandible is once again slightly protruded. C. Radiograph correctly performed: the lateral incisor must be in the cen- ter of the radiograph.

����

D

A B

C A

D ����

B

Fig. 5.52. Preoperative radiograph of the upper canine. A. Positioning of the film on the palate and path of the X-rays. B. The man- dible, still slightly protruded, keeps the film holder in position. C. Radiograph correctly performed.

98 Endodontics 5 - Endodontic Radiography 99

Upper premolars

The radiograph must be positioned in the palate far enough from the teeth being examined to allow the parallelism rule to be observed. The long axis of the film must be parallel to the occlusal plane. Because of the presence of the palate and the dental “arch”, the

two premolars are centered with much difficulty in the radiograph, while it will almost always be mesial- ly displaced.

In addition to the premolars, part of the canine, the first molar, and the mesial portion of the second molar will be visible in the same radiograph (Fig. 5.53).

C A

D ����

B

Fig. 5.53. Preoperative radiograph of the upper premolars. A. The film must be positioned with its long side parallel to the occlusal plane. B. Schematic re- presentation of the use of the film holder (Rinn Corporation, modified). C. Correct positioning of the film holder in the mouth. D. Correctly performed radio- graph.

If the patient claims to have an easily stimulated gag reflex, one must take certain precautions.

The patient must be upright and not recumbent in the seat, and must cooperate by breathing deeply through

Right then, every second counts.

Taking these precautions, one can obtain all the requi- red radiographs, even in a patient with the most sen- sitive reflex. C A D ���� B

Fig. 5.54. Preoperative radiograph of the upper molars. A. The long side of the radiograph is aligned along the median line of the palate. B. Schematic repre- sentation of the use of the film holder (Rinn Corporation, modified). C. Correct positioning of the film holder in the mouth. D. Correctly performed radio- graph.

100 Endodontics 5 - Endodontic Radiography 101

Lower incisors

The film must be oriented vertically and rather poste- riorly, but not too much, so as not to interfere with the lingual frenulum. The patient must then close the teeth, biting the plastic support.

Obviously, the law of parallelism must always be re- spected.

The lower incisor of interest must be centered in the film, since this guarantees the least distortion (Fig. 5.55). C A D ���� B

Fig. 5.55. Preoperative radiograph of the lower incisors. A. The radiograph is positioned vertically. B. Schematic representation of the use of the film holder (Rinn Corporation, modified). C. Correct positioning of the film holder in the mouth. D. Correctly perfor- med radiograph.

C A

D ����

B

Fig. 5.56. Preoperative radiograph of the lower canine. A. The radiograph is positioned vertically. B. Correct positioning of the film holder in the mouth. C. Correctly performed radiograph.

102 Endodontics 5 - Endodontic Radiography 103

Lower premolars

The radiograph must be positioned with its long side perpendicular to the long axis of the tooth. Its upper margin must be parallel to the occlusal plane.

Since the premolars are midway along the dental arch, they are difficult to center in the radiograph, which

will reveal the distal aspect of the canine, the two premolars, the first molar, and the mesial portion of the second molar.

The radiograph must not be placed too close to the teeth, or else the patient will feel pain in the floor of the oral cavity (Fig. 5.57).

C A

D ����

B

Fig. 5.57. Preoperative radiograph of the lower premolars. A. The long side of the radiograph is parallel to the occlusal plane. B. Schematic representation of the use of the film holder (Rinn Corporation, modified). C. Correct positioning of the film holder in the mouth. D. Correctly performed radiograph.

should be seated and asked to breathe deeply through the nose when the radiograph is introduced. Alternatively, the patient may be asked not to breathe for a moment.

any pain in the floor of the mouth.

The distal portion of the second premolar and the three molars will be visible in the radiograph (Fig. 5.58). C A D ���� B

Fig. 5.58. Preoperative radiograph of the lower molars. A. The radiograph is positioned horizontally. B. Schematic representation of the use of the film holder (Rinn Corporation, modified). C. Correct positioning of the film holder in the mouth. D. Correctly performed radiograph.

104 Endodontics 5 - Endodontic Radiography 105