Correct management of periodontal patients in veterinary practice demands a thorough understanding of veterinary dental radiographic
anatomy, periodontal probing and many times open evaluation and direct visualization of diseased areas. Stage III periodontal
disease in particular requires advanced skills and familiarization with periodontal pathophysiology to make decisions to attempt
to grow new supportive tissue adjacent to compromised teeth or extract them.
Periodontal Disease Classification
The degree of severity of periodontal disease relates to a single tooth; a patient may have teeth that have different stages
of periodontal disease.
• Normal (PD 0): Clinically normal - no gingival inflammation or periodontitis clinically evident.
• Stage 1 (PD 1): Gingivitis only without attachment loss. The height and architecture of the alveolar margin are normal.
• Stage 2 (PD 2): Early periodontitis - less than 25% of attachment loss or at most, there is a stage 1 furcation involvement in multirooted
teeth. There are early radiologic signs of periodontitis. The loss of periodontal attachment is less than 25% as measured
either by probing of the clinical attachment level, or radiographic determination of the distance of the alveolar margin from
the cemento-enamel junction relative to the length of the root.
• Stage 3 (PD 3): Moderate periodontitis - 25-50% of attachment loss as measured either by probing of the clinical attachment level,
radiographic determination of the distance of the alveolar margin from the cemento-enamel junction relative to the length
of the root, or there is a stage 2 furcation involvement in multirooted teeth.
• Stage 4 (PD 4): Advanced periodontitis - more than 50% of attachment loss as measured either by probing of the clinical attachment
level, or radiographic determination of the distance of the alveolar margin from the cemento-enamel junction relative to the
length of the root, or there is a stage 3 furcation involvement in multi-rooted teeth.
Stage III periodontal disease as described represents a 25 50% loss of the tissue supporting the root. Three tissue types
become clinically relevant; bone, cementum and periodontal ligament. Depending upon the character of the bone loss, with proper
surgical and postoperative management new tissue can be grown to replace or partially replace that which has been lost. The
character of the bone loss is primarily determined radiographically.
Vertical or infrabony bone loss is represented radiographically by a defect adjacent to the tooth root whereby a periodontal
probe when passed into the defect resides apical to the level of the adjacent marginal bone. The radiographic void is grossly
filled with granulation tissue. Cementum and periodontal ligament are no longer present. Dentin is exposed often with open
tubules creating access or microbes to this passage-way to the pulp. Horizontal bone loss is recognized when the bone loss
pattern is more uniform whereby a periodontal probe passed into the defect resides on top of the marginal bone level rather
than apical to it. These defects commonly are associated with gingival recession exposing tooth roots. These roots are generally
void of cementum leaving open dentinal tubules that are exposed to periodontal pathogens as described with vertical defects.
This in an important point in both cases in that endodontic status should always be assessed when contemplating periodontal
surgery in stage III defects. Periapical lucencies or comparatively large pulp cavities are indications of non-vitality. If
these teeth are to be saved endodontic therapy is also required and usually caries a guarded prognosis.
Horizontal defects are not readily amenable to periodontal regenerative therapy. If recession is not present then apically
positioned mucoperiosteal flaps following debridement, treatment of exposed roots and bone contouring may be possible. This
requires exposure of the affected area through mucoperiosteal flap creation. The defect is debrided to the level of the marginal
bone. Proper bone contouring is followed by apical positioning of the flap at the new bone level. Roots are treated with bonding
agents to seal the dentinal tubules to eliminate microbe extravasation and sensitivity.