Trigeminal Nerve Microreconstructive Surgery Using the Great Auricular Nerve Transfer Technique

Lingual nerve deficit following mandibular third molar removal: review of the literature and medicolegal considerations

The removal of mandibular third molars is probably the most frequently performed procedure in oral and maxillofacial surgery, and it is the most common surgical procedure associated with lingual nerve deficit. Lingual sensory impairment remains a clinical problem in oral and maxillofacial surgery and has serious medical and legal implications. In fact, damage to the lingual nerve is a common cause of litigation in dentistry. The purpose of this article was to review the literature about lingual nerve deficit following mandibular third molar removal and discuss the associated medicolegal aspects.

A bioabsorbable collagen nerve cuff (NeuraGen) for repair of lingual and inferior alveolar nerve injuries: a case series

PURPOSE

This study describes the results of using NeuraGen (Integra LifeSciences, Plainsboro, NJ) as a nerve cuff for repair of lingual and inferior alveolar nerve injuries following third molar surgery.

PATIENTS AND METHODS

Eight female patients received a total of 9 NeuraGen cuffs for repair of lingual (6) or inferior alveolar (3) nerves. All injuries were treated within 3 to 7 months following injury. All patients were evaluated by mechanoceptive and nociceptive testing via brush directional discrimination, pin-prick pressure and thermal sensation. Lateral trap-door osteotomy of the mandible was utilized to access the inferior alveolar nerve. The lingual nerve was approached via a lingual gingival sulcus incision. Following external neurolysis and primary neurorrhaphy, NeuraGen was split longitudinally, and encased the nerve with at least a 1.5 cm margin. One or 2 6-0 prolene horizontal mattress sutures were used to reapproximate the NeuraGen edges and Healon (hyaluronic acid; Advanced Medical Optics, Santa Ana, CA) was applied to the perineural tissues.

RESULTS

Five injuries resulted in objective anesthesia preoperatively with the other 4 having varying degrees of hypoesthesia. Six of the nerve injuries also resulted in dysesthesia. Four patients were followed for at least 1 year and the other 4 patients for about 2.5 years. The most recent data was used for this study. Postsurgical outcome was assessed utilizing some of the criteria proposed by Pogrel to classify patients as having good improvement, some improvement, no improvement, or worsening of symptoms. Four cases were found to have good improvement, 4 with some improvement and 1 had no improvement. None of the cases had worsening of symptoms.

CONCLUSION

While reports of the use of other alloplastic materials for nerve repair were found to be variable, NeuraGen seems to have good preliminary results. Bioresorption is complete which decreases the likelihood of interneural scarring. Also, NeuraGen is not associated with episodes of compression neuropathy reported with other rigid non biodegradable materials. Its use in hand surgery literature and in experimental animal studies showed no statistical significance in outcome when compared to end-to-end anastomosis or nerve grafts. The reported advantage of NeuraGen was the elimination of problems associated with graft harvesting. In this small series, 8 out of 9 nerve repairs showed sensory improvement which suggests a favorable role of NeuraGen as a nerve cuff and protective barrier around the nerve injury site. While primary end-to-end anastomosis has comparable results, a nerve cuff has the advantage of preventing axonal escape at suture lines, it minimizes scar ingrowth and nerve entrapment, and it concentrates growth factors at the injury site.

The use of autogenous vein grafts for inferior alveolar and lingual nerve reconstruction

PURPOSE

This study evaluated whether an autogenous vein graft forms a satisfactory conduit for nerve regeneration.

PATIENTS AND METHODS

Fifteen patients received a total of 16 autogenous vein grafts to repair continuity defects of the inferior alveolar (6) and lingual nerves (10) nerves. All were treated between 4 and 10 months after injury. At surgery, the postresection defects ranged from 2 to 14 mm. All lingual nerves were repaired with saphenous vein grafts from an intraoral approach and all inferior alveolar nerves were repaired with facial vein grafts inserted from an extraoral approach.

RESULTS

Lingual nerve repair in 3 cases where the gap between the nerve ends was 5 mm or less resulted in some return of sensation. In 7 cases where the gap was between 5 and 14 mm, there was no return of sensation. In the 6 inferior alveolar nerve repairs there was some return of sensation in all cases and there was good return of sensation in 3 cases. One patient redeveloped dysesthesia in the inferior alveolar nerve and subsequently had a neurectomy. Histologic material was available from this case.

CONCLUSIONS

It appears that a vein graft can form a physiologic conduit for nerve regeneration. The results are more successful with shorter gaps, which indicates that, in some respects, the vein acts like a barrier membrane. The increased success rate in the inferior alveolar nerve repair may be because the vein remains straight and patent in the inferior alveolar canal. The lack of success with a long lingual nerve gap repair may be because the vein is collapsed or kinked by movement of the tongue, which may inhibit neural regeneration. Therefore, vein grafts should not be used for long lingual nerve continuity defects.

Gore-Tex tubing as a conduit for repair of lingual and inferior alveolar nerve continuity defects: a preliminary report

PURPOSE

This report describes the results of using a Gore-Tex (Gore Company, Flagstaff, AZ) tube as a conduit for repair of continuity defects in the inferior alveolar or lingual nerves.

PATIENTS AND METHODS

Seven nerve repairs were performed in five patients (M:F = 1:4) with an age range of 16 to 56 years. The duration from injury to repair ranged from 4 to 30 months. Two inferior alveolar and five lingual nerves were repaired.

RESULTS

All seven patients had anesthesia by objective testing preoperatively and had a continuity defect at the time of operation. The size of the defects ranged from 2 to 15 mm. Two of the seven patients had some return of sensation, occurring in defects of 3 mm or smaller.

CONCLUSION

The results of this pilot study indicate that Gore-Tex tubing may not be effective in the repair of continuity defects except in those defects 3 mm or smaller, in which it may act as a protective barrier membrane rather than as a conduit.

Microanatomic analysis of the medial antebrachial nerve as a potential donor nerve in maxillofacial grafting

PURPOSE

To histologically compare the anterior branch of the medial antebrachial cutaneous nerve (MACN) with the sural nerve using biometric techniques.

PATIENTS AND METHODS

Twenty-centimeter segments of the right and left (MACN) and sural nerves from three cadavers were analyzed. The number of fascicles within the nerves were counted and the neural to connective tissue ratio was estimated.

RESULTS

Sural nerves consistently showed greater amounts of connective tissue between the fascicles than the MACN. Fascicle diameter varied less throughout the length of the MACN. Fascicle diameter varied less throughout the length of the MACN and it showed fewer and larger fascicles, more closely approximating the anatomy of the inferior alveolar nerve.

CONCLUSION

These preliminary data suggest that the MACN, on anatomic grounds, is theoretically more suited for grafting to the alveolar and lingual nerves than the sural nerve.