Trigeminal Nerve Reconstruction: Update 2022
Abstract
Trigeminal nerve injuries occur commonly following third molar surgery, orthognathic surgery, maxillofacial trauma, implant placement, and ablative mandibular resection for pathologic disease, and result in significant patient morbidity. Nerve injuries are diagnosed and classified based upon the likelihood of an injured nerve to recover spontaneously. Patient evaluation includes a standard set of objective and subjective neurosensory tests. Both non-surgical and microsurgical treatment options are available. In an effort to increase awareness and access to care, new technology, microsurgical techniques, and materials availability (processed nerve allograft) have improved our ability to manage these injuries most appropriately and have also expanded the applications of trigeminal nerve microneurosurgery, resulting in excellent success rates and decreased patient morbidity.
Learning Objectives
- Identify, diagnose, and manage trigeminal nerve injuries.
- Describe the current advances and applications in the field of microneurosurgery.
- Define the application of long-span nerve allografts in maxillofacial resections.
Ramiro De Paz Carranza
Tema muy importante
ASHLEY CUSACK
Vickas Agarwal
1. How do you test thermal sensation? Would a pressure algometer suffice for testing NST Level C?
ANSWER: There are several methods that could be used to test thermal discrimination. These include Minnesota thermal disks, and other temperature devices available commercially. For simplicity, and to test supra-threshold responses to thermal testing, ethyl chloride (endo-ice) can be sprayed on a cotton tip applicator and used on the tongue or lower lip. The other component of Level C testing is pain nocioception, and this can be performed with a 30 gauge needle or a pressure algometer as you have indicated. My preference is to perform BOTH pain and temperature testing, but an algometer reading may satisfy Level C testing.
2. Many of your cases were able to make it to your office and to surgery quickly. For those of us who are just beginning our careers and may not be as well known in our communities, how do you recommend we build a practice in nerve repair? How would you handle patients with symptomatic hypoesthesia that present to the office >6 months after injury?
ANSWER: As you have indicated it takes many years to develop a reputation as an “expert” in a certain area, but there are several steps that you can take to get started. Consider sending a letter to local/regional dentists and oral surgeons and other dental specialists (endodontists, periodontists) informing them that you are interested in evaluating patients who sustain IAN and lingual nerve injuries. If you are affiliated with a dental school, then consider sending an email to the dental school/hospital listserv. You can also use social media to promote yourself as a nerve expert. Consider lecturing at dental practice study clubs, and dental schools to students and post-graduate residents of all dental specialties. Finally, AxoGen has a “Find-A-Nerve-Surgeon” feature on their website that can be helpful if doctors or patients are trying to locate a nerve expert.
3. What size graft do you pefer for IO nerve reconstruction?
ANSWER: For infraorbital nerve reconstruction, I use the same 3-4mm diameter graft that I use for the IAN and LN since it matches very closely with the diameter of V2 and V3 nerves.
ASHLEY CUSACK
Godfrey Funari
To what extent does medical insurance cover nerve repair procedures? If insurance does not cover the procedure, what can the patient expect in out of pocket costs for a repair?
ANSWER: In general, medical insurance covers the nerve repair surgery using the appropriate CPT nerve repair codes, and it is rare that a patient would have to pay out of pocket for the surgery, but the rough cost of a nerve repair with an allograft is $10-15K.
ASHLEY CUSACK
David Fischer
What is your preferred method of controlling hemorrhage from the IAN vessel if needed during repair? With that, do you expect a reduction in NSR if any intervention is necessary?
ANSWER: Typically, the IAA/IAV will stop bleeding spontaneously with vasospasm and platelet plugging, but in the event that the bleeding is persistent, I prefer to use a bipolar cautery to isolate the vessel(s) from the nerve. Anecdotally, I do not think that this affects nerve recovery.
ASHLEY CUSACK
Tamzid Mafiz
Can Red Light Therapy be used for nerve regeneration?
ANSWER: Low level laser therapy has been used to augment spontaneous neurosensory recovery, but in my publication on LLL for IAN and LN injuries, there was not significant difference between LLL and placebo (see Miloro M, Criddle T-R. Does Low-Level Laser Therapy Affect Recovery of Lingual and Inferior Alveolar Nerve Injuries? J Oral Maxillofac Surg 76: 2669-2675, 2018).
ASHLEY CUSACK
Steven M. Rubin, D.M.D.
Could I get the specifics on the issues of the Journal of OMFS so I could review the articles cited in the presentation?
ANSWER: Each of the articles in the presentation has the publication reference on the individual slides. Please let me know if there are any specific articles mentioned that do not have a reference listed on the slide.