Step 2: Anesthetized probing
Next, while the animal is under anesthesia, examine each tooth for mobility, probing depths and bleeding upon probing.
Slight tooth mobility is considered normal. Greater than 0.2 mm is abnormal and could be caused by trauma or, more commonly,
advanced periodontal disease. To check for tooth mobility, use a periodontal probe to push against the tooth crown. Record
mobility findings such as the following in the medical record:
• Stage 0 (M0): The physiologic mobility is up to 0.2 mm.
• Stage 1 (M1): Mobility is increased in any direction other than axial over a distance of more than 0.2 mm and up to 0.5 mm.
• Stage 2 (M2): Mobility is increased in any direction other than axial over a distance of more than 0.5 mm and up to 1 mm.
Photo 3: Stage 3 mobility in a maxillary canine.
• Stage 3 (M3): Mobility is increased in any direction other than axial over a distance exceeding 1 mm, or axial movement is present (Photo
Photo 4: Millimeter markings on a Williams before insertion.
Every professional oral hygiene procedure conducted under general anesthesia should include probing and charting. To determine
the probing depth, insert the periodontal probe into the gingival sulcus, and record the findings in millimeters (Photos 4
and 5). With gentle pressure, the probe will stop where the gingiva attaches to the tooth.
Photo 5: A 6-mm probing depth.
There are two methods of probing:
• Spot probing is the insertion and withdrawal of the probe at a single area per tooth. Because single areas don't represent the entire
tooth, an inaccurate assessment may be obtained.
• Circumferential probing is the insertion of the probe in the sulcus or pocket in at least four places (two buccal and two lingual or palatal) around
the tooth. This method compensates for inaccurate readings when subgingival calculus or isolated areas of vertical bone loss
Cats normally have probing depths less than 1 mm. In dogs, there's great variability of probing depth scores, depending on
a dog's size and tooth location. For a typical 25-lb dog, a 2- to 3-mm probing depth around the canines is considered normal.
Greater depths may indicate periodontal disease requiring further evaluation and treatment (Photo 6).
Photo 6: An 8-mm probing depth between the maxillary fourth premolar and first molar.
Finally, bleeding on probing doesn't occur in healthy tissue unless abnormally traumatized by the probe. Gingival bleeding
is an objective, easily assessed sign of inflammation associated with periodontal diseases.
Photo 7: Bleeding on probing on a maxillary first premolar in a dog.
Rare causes of gingival bleeding may include hemophilia, leukemia, thrombocytopenia and liver and kidney disease. More commonly,
bleeding is secondary to gingival inflammation due to inadequate plaque and tartar removal beneath the gum line. Gingival
bleeding on probing indicates an inflammatory lesion in the epithelium and connective tissue. If you encounter bleeding during
pocket-depth probing (Photos 7 and 8), stop immediately to document, diagnose and react (see "Periodontal probing: Stop when
you see red" in the June 2012 issue).
Photo 8: Bleeding on probing on a left mandibular canine in a cat.