Abstract
In this study, neurosensory dysfunction of the inferior alveolar nerve was evaluated histopathologically after implant placement posterior to the mental foramen and nerve repositioning in dogs.
Titanium endosseous implants were placed in the cortical bone of the mandibular base after extraction of the 4th premolar tooth and inferior alveolar nerve repositioning.
The animals were sacrificed at 1 week and 2, 3, and 6 months after surgery, and the mandibles were removed and fixed in 10% neutral buffered formalin. The samples were embedded in paraffin or Technovit® 7200 for light microscopic observation.
One week postoperatively, histological findings showed that there were marked endoneural edema and degenerative changes of the myelin sheath and axon on the implants. In these cases, some of the degenerative changes were found on the distal side of the nerve fibers but most of them were intact.
Two and three months postoperatively, regenerative findings showed that there was the degeneration of myelin sheath and axon on the implants but on the proximal and distal sides of the nerve fibers,most of them were intact.
Six months postoperatively, regenerative changes could not be distinguished from normal findings of nerve fibers on the implants.
Based on these findings, it was thought that the neurosensory dysfunction of the inferior alveolar nerve after implant placement and nerve repositioning was largely due to segmental demyelination of the nerve on the implants, many of which could be recovered.
