K G Smith1, P P Robinson. 1. Department of Oral and Maxillofacial Surgery, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, England.
Abstract
PURPOSE: This study compares three methods of lingual nerve defect repair. MATERIALS AND METHODS: The recovery of the mechanosensitive and thermosensitive afferent fibers in the lingual branch of the trigeminal nerve in cats was studied using electrophysiological techniques 24 weeks after the removal of a segment of lingual nerve and repair of the defect by one of three methods. The nerve gap was closed by either stretching the nerve ends together and repairing under tension, insertion of a sural nerve graft, or use of a freeze-thawed muscle graft. The characteristics of the regenerated fibers were investigated and the data were compared with that from normal control animals. RESULTS: After nerve repair, integrated whole-nerve activity evoked by thermal (cold) stimulation of the tongue was smaller than in the controls, but there were no differences between the repaired groups. However, recordings made from single axons in filaments dissected from the nerve revealed differences between the groups; the units were less sensitive after either method of grafting than after stretch repair. CONCLUSIONS: It is concluded that repair of a short gap in the lingual nerve by stretch repair with an end-to-end anastomosis, even with some degree of tension, is followed by better recovery than by grafting. However, where a graft is necessary, a similar level of recovery will result from use of a frozen muscle graft or a sural nerve graft.
PURPOSE: This study compares three methods of lingual nerve defect repair. MATERIALS AND METHODS: The recovery of the mechanosensitive and thermosensitive afferent fibers in the lingual branch of the trigeminal nerve in cats was studied using electrophysiological techniques 24 weeks after the removal of a segment of lingual nerve and repair of the defect by one of three methods. The nerve gap was closed by either stretching the nerve ends together and repairing under tension, insertion of a sural nerve graft, or use of a freeze-thawed muscle graft. The characteristics of the regenerated fibers were investigated and the data were compared with that from normal control animals. RESULTS: After nerve repair, integrated whole-nerve activity evoked by thermal (cold) stimulation of the tongue was smaller than in the controls, but there were no differences between the repaired groups. However, recordings made from single axons in filaments dissected from the nerve revealed differences between the groups; the units were less sensitive after either method of grafting than after stretch repair. CONCLUSIONS: It is concluded that repair of a short gap in the lingual nerve by stretch repair with an end-to-end anastomosis, even with some degree of tension, is followed by better recovery than by grafting. However, where a graft is necessary, a similar level of recovery will result from use of a frozen muscle graft or a sural nerve graft.