A case approach to canine dental radiograph interpretation (Proceedings)

Radiographic evaluation has fast become a common facet of veterinary dentistry and only practices that utilize dental radiography can practice quality dentistry. Interpretation of radiographic changes that occur in the tooth and surrounding bone take many forms. Identification of oral pathology in most cases can only be determined by proper radiographic technique and correct interpretation of radiographic findings. A basic understanding of canine and feline oral disease can only be appreciated by matching gross clinical findings with radiographic changes. This lecture provides an interactive case approach to radiographic interpretation. Some of the more commonly encountered entities and their corresponding radiographic findings are listed below.

Normal Anatomy

Normal structures that are readily recognizable radiographically include mandibular symphysis, palatine fissures, middle and caudal mental foramina

Periodontal Disease

     • Mild - Marginal bone density is noticeably decreased in density. Interdental marginal bone cupping

     • Moderate – Infrabony or suprabony defects

     • Severe – greater than 50% marginal bone loss

     • Furcation bone loss is graded based upon clinical severity but is readily recognizable by decrease in the density of bone at the marginal level between tooth roots

     • Watch for concurrent endodontic changes.

Endodontic Disease

Lucencies present at the tooth apex. Increase in pulp cavity diameter compared to the same tooth in the opposite arcade. Chronic pulpitis may be associated with an increase in density adjacent to the root apex as well. Widened periodontal ligament space surrounding the apex and coursing coronally is also a sign of the loss of pulp vitality

Cysts

Well defined dense lucency with regular borders in bone. Generally associated with unerupted first premolars in brachycephalic dogs, however it can be other teeth in any breed. Rare in cats.

Neoplasia

Any or all of the following may be present with aggressive rapidly progressive disease like squamous cell carcinoma: Periosteal reaction, tooth resorption, bone destruction, bone proliferation, bone destruction and proliferation, teeth location not disrupted.

Less aggressive disease like acathomatous ameloblastomas tend to move teeth and display diffuse mild to moderate bone loss adjacent to the soft tissue component of the mass.

Tooth Maturation

The radiographic appearance of teeth in different stages of normal and abnormal maturation from deciduous to mature adult will be shown.

Tooth Resorption

Dog

External resorption consists of crater like lucenies within the tooth at the tooth bone interface. Internal resorption consists of irregular lucent areas expanding from the pulp cavity. Diffuse resorption also occurs and is appreciated most often in old dogs.

Cat

Tooth resorption can appear as lucencies within the crown or the root and can be diffuse or distinct. External and internal resorption as seen in the dog are generally not appreciated in this species.