3 steps to the best interpretation of dental radiographs

Full-mouth dental radiographs are still the golden standard of imaging in veterinary dentistry, especially if the animal is presented for the first time, or if the clinical condition has changed significantly since the previous visit. Without obtaining dental radiographs, there is a great chance to miss clinically important findings and poorly treat the patient.

1 Use only good quality dental radiographs

Obtained full-mouth dental radiographs need first to be examined for their technical quality – check, if:

  • the area of interest is on the image,
  • there is any elongation/foreshortening of the teeth radiographed,
  • the quality of exposure is appropriate,
  • there are any processing errors.

2 Orient dental radiographs appropriately

Radiographs should then be properly oriented using “labial mounting”:

  • if using conventional dental films assure that the embossed dot/orientation mark faces up for all radiographs, where intra-oral technique was used,
  • by knowing anatomical features, determine, what are maxillary and what mandibular views,
  • crowns of the maxillary teeth are to point down and crowns of the mandibular teeth up,
  • occlusal views are in the center, with first incisor teeth at the midline,
  • last molar teeth are on the periphery.

This orientation results in the radiographs of the teeth from the patient’s left side to be on the right side and vice-versa (note positioning of the extra-oral views with the dot facing down if using conventional dental films or flip the dental radiograph if using digital system). Hence, there is no need for “L” and “R” marks on the dental films.

3 Systematically review each dental radiograph

Systematic examination of diagnostic-quality dental radiographs is ideally performed on a tooth-by-tooth basis and findings directly compared to those found on the detailed dental examination (dental charting).

Interpretation of dental radiographs requires knowledge of normal dental/oral radiographic anatomy. Closely examine the crown, root (and apex), dentin, enamel (rarely seen on dental radiographs), pulp cavity, alveolar margin, periodontal ligament space (lamina lucida), alveolar bone (with the cortical bone of the alveolus – lamina dura, and trabecular bone of the alveolus) and bone forming the jaw.

Be consistent in the evaluation of dental radiographs and review:

  • Anatomical/developmental findings (e.g., missing teeth, supernumerary teeth, unerupted teeth, odontogenic cysts, …),
  • Periodontal findings (e.g., rounding of the alveolar margin, widening of the periodontal ligament space, loss of integrity of the lamina dura, horizontal bone loss, vertical bone loss, any “perio-endo” type lesions, …),
  • Endodontal findings (e.g., integrity of the crown, pulp cavity width and shape, width of the periodontal ligament space (especially apically), integrity of the periapical bone (presence of periapical lesion) and of the apex (inflammatory root resorption)),
  • Other findings (e.g., tooth resorption, jaw fracture, osteolysis …)

It is important to remember, that bone loss is only radiographically evident once 30-50% of mineralized component is lost; hence bone loss will be underestimated on the radiographs. Also, radiographs will only give a 2-dimensional view of a 3-dimensional structure, therefore sometimes several views may help to better visualize a specific structure.

Limitations of dental radiography must especially be considered when dealing with e.g., palatal defects, maxillofacial trauma, TMJ disease or oral neoplasia, when advanced 3-dimensional imaging techniques (usually computed tomography (CT) or cone-beam computed tomography (CBCT)) are recommended.

Having some trouble interpreting dental radiographs? Contact me for telemedicine support!