AVDS Newsletter March 2012

A 6-year-old miniature poodle presented with a 3 month history of jaw chattering.   No gross findings are detectable in this view.

Response to antibiotics prescribed by the referring vet was minimal. No other significant history exists.

Evaluate the mandibular radiographs shown below to see if you can determine the potential source of jaw chattering.

What can you do now to confirm the potential source of jaw chattering.

  1. Evaluate for views of the contralateral side
  2. Take multiple views of any suspicious area.

Both views of the rostral mandible and the contralateral caudal mandible appear normal.  Note the missing right second mandibular premolar (406).

The left caudal mandibular view demonstrate the absence of a periodontal ligament space surrounding the apex of the mesial root of the left mandibular first molar (tooth 309).  With the absence of any gross findings on this tooth and no history to support non-vitality additional views were requested.

The lucency is reproducible in the two additional views.  The cortical bone comprising the ventral border of the mandibular canal appears to expand ventrally adjacent to the lesion.  An increased radiopacity superimposed over the dorsal mandibular canal may also be seen on the distal aspect of the mesial root in the final view, suggestive of condensing osteitis or osteosclerosis.

.How would you treat this case?

Based upon the severity of the clinical signs extraction and gentle canal lavage with sterile saline was chosen.  Ampicillin was administered intraoperatively and clavulanic acid and multimodal analgesics were prescribed for 7 days (opiate, NSAID, gabapentin). The decision to extract was based upon the severity of signs and the potential for inflammatory pain and/or mass impinging on the inferior alveolar nerve.

Extraction of the mesial crown-root segment was straightforward.  Apical blunting and a distinct linear opening of the apex were evident. No apical alveolar bone was present ventral to the alveolus. The inferior alveolar nerve was visualized through the extraction site. The distal crown-root segment was removed and the site was closed.

This patient responded very well, achieving complete resolution of the jaw chattering post-extraction. Neuropathic pain associated with the non-vital tooth was one possible explanation for the jaw-opening reflex seen in this case, which is supported by the patient’s response to treatment.

Now look back at the original radiograph of 309. Do you see any other lesions?

There is a lucency on the mesial cusp. Closer inspection of the tooth on the lingual aspect may have uncovered this defect.