Effect of different surgical repair modalities on regeneration of the rabbit mandibular nerve.

A study was designed to evaluate the ability of the rabbit mandibular nerve to regenerate when exposed to crush and resection injuries, as well as to determine how differently sized resection injuries healed when repaired with either autogenous grafts or laminin-lined collagen tubulization. The nerve demonstrated a regenerative capacity over a 1-cm defect, with morphology and function that approximated normals, but could not span a 2-cm gap defect unaided. Crush injuries produced findings that were inferior to both those in normal nerves and in those with resections. In 1-cm defects, both grafting and tubular repairs produced similar results, with substantial recovery of neural function after 16 weeks. In 2-cm defects, autogenous grafting was superior to tubulization by both morphologic and functional assessment. Replacement of the lateral cortex of the mandible after nerve repair was shown to be unnecessary. The implications of these findings as they relate to nerve injury and repair in humans is discussed.