Neural innervation of the tusk pulp of the African elephant (Loxodonta africana)

Treatment and Outcomes of Tusk Fractures in Managed African Savanna and Asian Elephants (Loxodonta africana and Elephas maximus) across Five Continents

Elephant tusk fractures are a clinical challenge that can impact the overall health of the animal, particularly when they result in pulp exposure. An international survey was sent to veterinarians to understand individual fracture characteristics and management strategies as they relate to outcomes, with the goal of better informing treatment procedures. The data set consisted of 79 fractures from 64 elephants (including Asian and African males and females), 44.3% of which were Class III fractures with pulpal involvement. Of this subset, pulp canal exposures of >0.5 cm were 23.8-fold more likely to develop pulpitis than fractures with <0.5 cm exposed, though canal size did not impact healing versus extraction outcome. Odds ratios showed that treatments including endodontics were 12.0-fold more likely to heal than tusks treated exclusively with medical management, though no association was observed in reducing the risk of pulpitis. Further, pulpitis was 7.58-fold more likely to develop when tap water was used to rinse exposed pulpal tissue; a finding that merits further investigation. The use of endodontic treatment versus medical management alone was significantly associated with improved recovery outcomes (i.e., reduced risk of extraction) in tusk fractures with pulpal involvement.

Structure and innervation of the tusk pulp in the African elephant (Loxodonta africana)

African elephants (Loxodonta africana) use their tusks for digging, carrying and behavioural display. Their healing ability following traumatic injury is enormous. Pain experience caused by dentin or pulp damage of tusks seems to be negligible in elephants. In this study we examined the pulp tissue and the nerve distribution using histology, electron microscopy and immunhistochemistry. The results demonstrate that the pulp comprises two differently structured regions. Randomly orientated collagen fibres characterize a cone-like part lying rostral to the foramen apicis dentis. Numerous nerve fibres and Ruffini endings are found within this cone. Rostral to the cone, delicate collagen fibres and large vessels are orientated longitudinally. The rostral two-thirds of the pulp are highly vascularized, whereas nerve fibres are sparse. Vessel and nerve fibre distribution and the structure of connective tissue possibly play important roles in healing and in the obviously limited pain experience after tusk injuries and pulp alteration. The presence of Ruffini endings is most likely related to the use of tusks as tools.