Outcomes of Immediate Allograft Reconstruction of Long-Span Defects of the Inferior Alveolar Nerve

Abstract

Immediate reconstruction of the IAN with allogeneic nerve grafting of long-span defects (≥5 cm) is a viable and predictable option to achieve useful functional sensory recovery.

Virtual Surgical Planning for Inferior Alveolar Nerve Reconstruction

“…8 In addition, the most appropriate time to consider nerve grafting is at the time of resection and reconstruction because a delayed approach would allow time for wallerian degeneration of the resected nerve stumps, possible trigeminal ganglion cell body death, 9 and the MILORO AND MARKIEWICZ possibility of central cortical changes that would affect the success of microneurosurgical repair. Our preliminary data have been published, 5 and the results of neurosensory recovery using VSP appear to be consistent with those results; however, additional investigation is required to determine whether an improved outcome in sensation can be observed with VSP.…”

“…This question is especially important when the current data indicate that success rates for neurosensory recovery in these cases are excellent. 4,5 In fact, these nerve ''injuries'' must be considered different from the usual third molar-related injuries to the lingual nerve or IAN, in which there is generally an avulsive injury with fascicular scarring and a time delay during which time both wallerian degeneration and central cortical changes may occur that may result in a less than ideal neurosensory recovery, although the results continue to be reported at higher levels than in the past. 6,7 These resection and immediate repair injuries are clean, controlled, sharp transection nerve injuries without prior injury, scarring, or abnormal sensations, and they are repaired with immediate microneurosurgical techniques under operating magnification.…”

“…The restoration of neurosensory function of the lower lip and chin is of paramount importance in the overall reconstructive effort, yet this area of reconstruction has been largely ignored by most reconstructive surgeons, despite recent evidence that neurosensory recovery after immediate nerve grafting to ablative inferior alveolar nerve (IAN) defects is excellent. 4,5 Perhaps prior prejudice against nerve reconstruction focused around the following areas: a global perception that nerve repair outcomes were poor, a lack of microneurosurgical experience to perform this specific procedure, the additional donor site for nerve graft harvest and associated morbidity, and/or the additional operative time required for nerve reconstruction during an already extended operative surgical procedure.…”

Restoration of Neurological Function Following Peripheral Nerve Trauma

“…When anastomosis is performed within 14 days of nerve trauma, functional recovery is good in about 80% of patients [37]. However, with increasing time between nerve trauma and anastomosis, the extent of recovery decreases [38][39][40]. The types of changes that occur over time that lead to this decrease in recovery are discussed below.…”

Nerve stepping stone has minimal impact in aiding regeneration across long acellular nerve allografts

“…4,5 However, although adequate for short gaps (<3 cm), ANAs have limited clinical data to support their use to reconstruct longer nerve gaps (>3-5 cm) to provide functional recovery, especially motor, comparable with the autograft standard. [6][7][8][9][10] In addition, multiple animal studies have demonstrated that acellular nerve scaffolds, such as ANAs, do not facilitate comparable axon regeneration to isografts 4,5 and fail to consistently facilitate axon regeneration across longer gaps (>3 cm) or promote motor recovery. 11,12 Overall, these issues present concerns regarding the use of ANAs to treat long gap clinical nerve injuries.…”