Tooth pulp changes following Le Fort I maxillary osteotomy in a primate model.

Le Fort I maxillary 'down-fracture' osteotomy with 8 mm advancement was performed in 15 adult rhesus monkeys. Forty-five tooth pulps were examined histologically at intervals from 0 to 24 weeks after surgery. Cell degeneration occurred in 31% of pulps examined, necrosis in 16% of pulps and osteo-dentine was found in 7% of pulps. Almost half of the teeth examined (47%) showed marked cellular changes, more frequently found in posterior teeth. Other features noted were inflammation (13%) and reactive dentine in pulps (24%). Axons degenerated initially but recovered by 24 weeks. It is concluded that Le Fort I maxillary osteotomy caused pulpal disturbances in an animal model and the extent to which this occurs in patients needs to be carefully monitored.