1. Positioning difficulties in periapical radiography
I. Mandibular third molar
II. Gagging
III. Endodontics
IV. Edentulous alveolar ridges
V. Children
VI. Patients with disabilities

2. Possible solutions Using specially designed holders
Taking two radiographs of the third molar
using two different horizontal tubehead
angulations

3. Fig.8.28

4. Problems with gagging and possible solutions
The patient sucks a local anaesthetic lozenge before positioning of the film packet
The patient is asked to concentrate on breading deeply while the film packet is in the mouth
Placing the film packet flat in the mouth and using bisected angle technique

6. Problems encountered during endodontics
Film packet placement and stabilization when endodontic instruments, rubber dam and rubber dam clamps are in position
Identification and separation of root canals
Assessing root canal lengths from foreshortened or elongated radiographs

7. Possible solutions
Using a Rinn Eezee-Grip
Using Rinn endo instrument

8. Identification and separation of root canals

9. Assessing root canal length
Using paralleling technique
Calculating mathematically the actual length from a radiograph taken by bisected angle technique

11. Problems encountered with children