Procuring posterior radiographs can be made more pleasant by associating it with a pleasurable taste….bubble gum. Before placing the radiograph in the patient's mouth apply bubble gum flavoured toothpaste to the film. The child will be more accepting of the radiograph.
Some patients, young and old, have an exaggerated gag reflex. The aetiology of an exaggerated gag reflex had been attributed to psychological and physical factors. There are numerous techniques to control the gag reflex during the radiograph procedure.
The easiest is through diversion and positive suggestion. The operator suggests to the patient the gag reflex can be reduced by concentrating on something other than the procedure. The patient can hum a song, raise a leg, or look at himself or herself in a mirror. However, this technique is not always successful so other techniques must be brought into play. The patient's palate can be sprayed with a topical anaesthetic to reduce the sensation of the radiograph on the palate and tongue. This technique is more successful with adults than children since a pleasant tasting topical anaesthetic has yet to be invented and children often object to the numb feeling.
An alternative is the use of nitrous oxide analgesia. One of the effects of nitrous oxide analgesia is it reduces the gag reflex, but unlike general anaesthesia it does not affect the cough reflex.
Another alternative is to place the radiograph in such a manner to not come in contact with the palate or tongue. This is accomplished by either extraoral placement of the film or placing the film between the cheek and the tooth and exposing the film from the opposite jaw. Figure 22 illustrates the typical placement of a radiographic film between the teeth and tongue.
In the reverse radiograph the film is placed on the buccal surface of the tooth between the tooth and the cheek. The film side of the packet (the solid colour side) is facing the buccal surface of the tooth.
The x-ray head is placed at the opposing side, and the cone is positioned under the angle of the ramus on the opposite side. The radiation is directed through the tongue, through the tooth structure, and onto the film. As the x-ray beam is traveling a longer distance to the film than in the typical positioning, it is necessary to double the exposure time.
The quality of the film, while not as detailed as the customary technique, can provide adequate information to develop an accurate diagnosis. It is imperative when you mount the radiographs you note the radiographs are reversed. In other words, what appears to be a radiograph of the right side is really a radiograph of the left side and vice versa. Incorrect mounting and labelling of the reverse radiograph can result in misdiagnosis and treatment of the wrong tooth.
Some of the newer digital panoramic radiographic units, i.e., Planmeca Promax, have programs that can take bitewing radiographs extraorally using less radiation than conventional radiographs yet providing diagnostic quality.