“Shepherd’s hook”: sharp, slender tip used as tactile instrument to detect soft enamel (pre‐carious), open canals and enamel defects, especially feline resorptive lesions (Figure 2.2).

       Can be gently used subgingivally to detect calculus deposits.

       Initial assessment with probe in the early stages of dental therapy to identify specific areas of concern (“red flag check”) for better treatment planning and to inform owner of unexpected problems:Palatal pockets of maxillary canines.Pockets between mandibular canines and incisors.Pockets at mesial or distal surface of mandibular molars.Any chipped or broken teeth to assess pulp exposure.

       Complete probing and charting must be done after plaque and calculus is removed because some areas will be occluded with the debris.

       After cleaning (in lateral positioning) each “half‐mouth” examine and probe the buccal/facial surfaces of the “upside” and the lingual/palatal surfaces of the “downside.”

       Gently insert the probe into the gingival sulcus, advancing to the depth of the sulcus or pocket until touching the base (Figure 2.3). Note: with inflamed pockets, the probe can easily be pushed past the base attachment because the tissue is delicate – use great care!

       “6‐points” refers to gently placing the probe at the six line angles of the tooth (in human dentistry with interproximal contact points, the probe cannot be advanced circumferentially around the tooth). Alternatively, probe circumferentially around the tooth.

       Measure and record abnormalities encountered:The base of the sulcus or pocket is the level of attachment; any abnormality is an indication of attachment loss.Periodontal pocket (PP): pathologic depth greater than normal sulcus.Greater than 2–3 mm in the dog (more critical in smaller dogs).Greater than 0.5 mm in the cat (Figure 2.4).Figure 2.3 The tip of a periodontal probe is gently inserted into the gingival sulcus or pocket and advanced carefully to the base (without penetrating tissue further).Figure 2.4 Normal sulcus depth in a cat is usually less than 0.5 mm, so 3 mm the pocket on the distal/palatal aspect of the right maxillary canine (104) is significant for this cat.Mark “PP” and millimeter depth on chart: there may be several measurements recorded around an individual tooth.Gingival recession (GR) or root exposure (RE): area of exposed root now visible due to gingival and alveolar bone loss (Figure 2.5).Mark “GR” or “RE” and mm depth on chart.If additional pocket formation, mark that as well.Attachment loss (AL) (see Chapter 26).Any decrease or apical “movement” of the attachment level.Combination of RE and PP depths.Figure 2.5 Total attachment loss (AL) on the right maxillary canine (104) of this cat is the summation of root exposure (3 mm) and pocket depth (3 mm), a significant level of loss.Total AL is the measurement from original site of attachment at the neck of the tooth (cementoenamel junction, CEJ) to the depth of the pocket.Furcation exposure (FE): space between roots of multirooted teeth are exposed due to gingiva and bone loss.F1: stage 1 exists when a periodontal probe extends less than halfway under the crown in any direction of a multirooted tooth with AL.F2: stage 2 exists when a periodontal probe extends greater than halfway under the crown of a multirooted tooth with AL but not through and through.F3: stage 3 exists when a periodontal probe extends under the crown of a multirooted tooth, through and through from one side of the furcation out the other.

       Areas of note: while every tooth surface should be probed and examined, there are specific areas that demand special attention or can often be accompanied by minimal outward indications (see “red flag check” above).Palatal surface of maxillary canines (Figure 2.6): an inapparent deep infra‐bony pocket may be present and, if advanced, the bone loss can form a communication into the nasal cavity, which would then necessitate extraction of the canine and special closure of the oronasal fistula (ONF) (see Chapter 22). Early intervention before fistula formation is essential.Rostral/mesial surface of mandibular canines (Figure 2.7): a significant pocket beside the lower third incisor can significantly compromise the lower canine, and advanced procedures may be used to save the incisor or more thoroughly treat the lower canine and soft tissues once the incisor is extracted.Lower first molar, mesial and distal surfaces (Figure 2.8): deep pockets at either aspect