Cross-tongue: a clinical answer to long-standing lingual anaesthesia

Lingual nerve (LN) lesions may occur during several oral and maxillo-facial procedures. Prompt surgical nerve repair is mandatory in case of certain LN damage, since the sooner the repair procedure, the better the functional recovery. Furthermore, there is no literature consensus for surgical repairs taking place after 18 months or more, due to extremely variable results. Since employing a motor nerve source other than the proximal stump has proven effective for nerve regeneration in other clinical situations, the Authors proposed using the contralateral healthy LN to add a strong axonal sprouting source to treat 3 patients affected by long standing LN lesion. 30% of the contralateral LN fibres were co-opted by surgical side-to-end neurorrhaphy. Axonal regeneration was achieved on the pathological side of the tongue by a reverse sural nerve graft (cross-tongue procedure). Distal end-to-end neurorrhaphy was accomplished in the free half of the distal stump of the pathological LN.During the postoperative period the sensitivity of the hemi-tongue on the repaired side increased progressively, almost equating normal side levels, as evidenced by sensory and pain-potential registration results. Sensitivity restoration was demonstrated by sensory threshold testing, while improved taste, temperature and static/dynamic two-point discrimination also emphasized good recovery.