Comparison of Subjective and Objective Assessments of Neurosensory Function after Lingual Nerve Repair.

OBJECTIVE: Mandibular third molar extractions are important in oral maxillofacial surgery. Damage to the lingual nerves, although rare, is a possible complication. There are reports of postoperative recovery after lingual nerve repair, but few reports have compared subjective and objective assessments of neurosensory function. Therefore, this study aims to compare subjective and objective assessments of neurosensory function after lingual nerve repair. SUBJECTS AND METHODS: This retrospective cohort study comprised 52 patients with lingual nerve anesthesia after third molar extraction at the Department of Oral and Maxillofacial Surgery, Wakayama Medical University Hospital, Wakayama, Japan, between December 2008 and December 2015. We recorded pre- and postoperative (6 months and 12 months) neurosensory examinations. RESULTS: Patient's subjective assessments of neurosensory function suggested improvement between the preoperative period and 12 months postoperation, although this difference was not significant. Objective assessment based on examination and testing, on the other hand, showed a significant difference in improvement (p < 0.05). CONCLUSIONS: There was no evidence that improvement of subjective preoperative and postoperative assessments was significantly associated with improvement of objective neurosensory assessments after lingual nerve repair. Overall physical condition and background were thought to affect subjective evaluation. Subjective assessment is important in conjunction with objective evaluation because it may reveal dysesthesia that would otherwise be missed. In the future, we will examine those cases in whom subjective assessments showed no improvement although objective assessments showed improvement.

A case report of a long-term abandoned torn lingual nerve injury repaired by collagen nerve graft induced by lower third molar extraction.

BACKGROUND: The lingual nerve plays an important role in multiple functions, including gustatory sensation and contact sensitivity and thermosensitivity. Misdiagnosed conservative treatments for serious lingual nerve (LN) injuries can induce the patient to serious mental disability. After continuous observation and critical diagnosis of the injury, in cases involving significant disruption of lingual nerve function, microneurosurgical reconstruction of the nerve is recommended. Direct anastomosis of the torn nerve ends without tension is the recommended approach. However, in cases that present significant gaps between the injured nerve ends, nerve grafts or conduits (tubes of various materials) are employed. Recently, various reconstruction materials for peripheral nerves were commercially offered especially in the USA, but the best method and material is still unclear in the world. There currently exists no conventional protocol for managing LN neurosensory deficiency in regard to optimal methods and the timing for surgical repair. In Japan, the allograft collagen nerve for peripheral nerves reconstruction was permitted in 2017, and we tried to use this allograft nerve and got a recommendable result. CASE PRESENTATION: This report is a long-term abandoned torn LN reconstructed with allograft nerve induced by the lower third molar extraction. CONCLUSIONS: In early sick period, with the exact diagnosis, the LN disturbance should be managed. In a serious condition, the reconstruction with allograft nerve is one of the recommendable methods.