Principles for Proper Radiographic Examination

Clinicians agree that the foundation of an accurate diagnosis and treatment plan is based on a comprehensive medical and dental history, a thorough clinical examination, and diagnostic radiographs.¹ Of the three, obtaining diagnostic radiographs in the pediatric dental patient is probably the most difficult to accomplish, not only from a technical standpoint but also because of parental fears and misconceptions.

With the news media reporting daily on the environmental insults experienced by the human body, parents are preoccupied with the effects of diagnostic and treatment procedures on the child's health. Limiting children to the possible deleterious effects of preventive and restorative materials, sterilization protocols, and diagnostic techniques are a concern to parents and dentists.

Parents’ resistance to the use of radiographs may be reduced by apprising parents of the need for radiographs to derive an accurate diagnosis, as well as educating them of the newer concepts and techniques for acquiring radiographs. At the time the parent schedules the first appointment, information should be offered explaining that for the dentist to perform a thorough dental examination and derive a correct assessment of a child's dental health, there may be a need for radiographs. Also, when parents and the dentist look at the teeth in a child's mouth, all that is seen is literally the tip of the iceberg. Visual examination reveals only three of the five surfaces of the teeth. In the absence normal physiological spacing, the interproximal surfaces cannot be visualized. The roots of the teeth anchored into the bone cannot be seen, nor the inside of the teeth, or the permanent teeth developing in the jawbone.

Parents should be informed radiographs enable the dentist to detect the start of visually undetectable cavities between teeth, infections of the teeth, gums and bones, the shape of unerupted permanent teeth, missing permanent teeth, future orthodontic problems, cysts, tumors, and a host of other pathological conditions.¹

Parents should be made aware that although excessive radiation exposure can result in cancer, birth defects, and genetic defects, the amount of radiation emitted by the newer x-ray units and the increased sensitivity of the x-ray film used by dentist has significantly reduced the amount of radiation to which patients are exposed. The newest technique for x-ray exposure, digital radiography, reduces the amount of exposure to a bare minimum.

Along with the above explanation and use of the proper equipment, the dentist should follow guidelines as recommended by a panel comprised of representatives from the Academy of General Dentistry, American Academy of Dental Radiology, American Academy of Oral Medicine, American Academy of Pediatric Dentistry, American Academy of Periodontology, and the American Dental Association.^2,3

• X-rays should not be taken routinely. A dentist or hygienist should first examine children’s teeth before deciding on the number and types of radiographs. The number and types of radiographs necessary is dependent on the age of the child, the presence of decay that can/cannot be detected visually, the child's and family's history of dental treatment, and spaces between teeth.

• If possible, obtain any prior radiographs (from another office, if available).

• Use only those views needed to complete the diagnostic task.

• The patient should be protected with a lead apron and thyroid collar to reduce body exposure to radiation.

• Follow recommendations to reduce radiation as low as reasonably achievable (ALARA).

• Use the fastest image receptor available.

  • Intraoral: changing from D to F speed film or to digital image receptors reduces dose by factors of at least 2.

  • Extraoral: high speed (400 or greater) rare earth screen film systems or digital imaging systems or equivalent.

• Rectangular collimation: reduces radiation dose by factor or 4 to 5 without adverse influence on image quality.

• Beam receptor alignment devices (e.g., XCP) for routine periapical radiography (only marginally effective for bitewing radiographs).

• Use 70 kvp or higher intraoral radiograph techniques.

• Use leaded apron with thyroid collar whenever possible.

• For conventional radiographs:

  • The highest speed and largest size film the child can tolerate should be used to reduce the number of x-rays needed to obtain the necessary information.

  • Use the proper time and temperature for processing as recommended by manufacturers.

  • Review in an environment free from distraction.

  • Reduce room illumination to level of displayed images.

  • Eliminate glare.

  • Use magnification.

  • Use opaque mount.

  • View with variable illumination.

• For digital radiographs:

  • Use software that permits adjustments of contrast, brightness and negative-positive viewing.

Parents may have the right to insist the dentist refrain from taking x-rays. However, if the dentist is of the opinion not taking the x-ray compromises the patient's treatment, he has the right to refuse to treat the child. Parents cannot offer to release the dentist from liability from subsequent damages that a radiograph might have prevented.