Watch these videos to learn optimal sensor placement
Using sensors with holders
TrollByte Plus Sensor Positioning Guide
For especially sensitive patients, there are foam cushions specifically made for use with sensors. Many of these work very well with sensitive patients and make placement much more comfortable.
Use the paralleling technique using the holders.
Make sure the exposure settings are correct on the X-ray source (60-65 KVP suggested). You will need to adjust exposure times (pulses), depending on the X-ray source and the physical size of the patient. Remember that maxillary molar images need the most exposure time and mandibular anterior images need the least amount of time.
Place the sensor parallel to the teeth, but not necessarily up against the teeth.
For maxillary shots, place the sensor at the midline of the palate.
For mandibular shots, place the sensor more towards the tongue if necessary.
If patient has trouble closing their mouth, have them stabilize the arm of the holder with their finger.
Make sure the cone of the X-ray source is parallel to the arm of the holder and directed at the center of the aiming ring.
Tips for Handling the Gag Reflex
Have the patient breathe through their nose.
Breathe. Breathe. Breathe.