WALRUS
Primary periodontal disease is virtually unknown in walrus.
Walrus in captivity invariably suffer damage to their tusks because of the environment they are housed in. Their normal behaviour employs their tusks in digging at the bottom of their pool and hauling themselves out of the water. The wear to the tusks can be rapid at any age.
The tusk anatomy is that of an elodont tooth, with a permanently dilated apical foramen. The pulp cavity can become infected even if no exposure takes place as bacteria will bypass the porous, loosely attached reparative secondary dentine inside the pulp cavity. Because of these reasons endodontic therapy is not possible on these teeth.
Marine parks should improve the environment these animals are housed in as a matter of priority to prevent tusk wear.
Worn and infected tusk with no pulp exposure.
Radiograph of an extracted tusk demonstrates the thick layer of porous, reparative dentine layer that is invariably present ventral to the infected canal. Note the permanently dilated apical foramen.
Sinus tract on the face of a walrus due to pulpal infection.
Dorsal view of large periapical abscesses. Tusk infections become a serious threat to life and numerous deaths have been reported relating to infected walrus tusks. (Postmortem)
Experience has shown that a flap technique offers the most rapid and predictable surgical option to extract walrus tusks. These extractions are complicated operations on substantial structures and their extraction requires careful planning and teamwork.
Although crowning the tusks appears an attractive option to prevent wear and pulp necrosis, experience has shown that this approach will fail rapidly in the great majority of cases through various reasons.