Lingual nerve impairment/injury after retrieval of the displaced mandibular third molar into the floor of the mouth.

Retrieval of the displaced mandibular third molar in the floor of the mouth is challenging as the lingual nerve is always at risk of injury. However, there are no available data to show the incidence of the injury caused by the retrieval. The goal of this review article is to provide the incidence of the iatrogenic lingual nerve impairment/injury caused by the retrieval based on the review of the existing literature. The retrieval cases were collected with the search words below using PubMed, Google Scholar, and CENTRAL Cochrane Library database on October 6, 2021. A total of 38 cases of lingual nerve impairment/injury in 25 studies were eligible and reviewed. Temporary lingual nerve impairment/injury due to retrieval was found in six cases (15.8%) and all recovered between three to six months after retrieval. General anaesthesia and local anaesthesia were used for retrieval in three cases each. The tooth was retrieved using a lingual mucoperiosteal flap in all six cases. The permanent iatrogenic lingual nerve impairment/injury due to retrieval of the displaced mandibular third molar is considered extremely rare as long as the appropriate surgical approach is chosen based on surgeons' clinical experience and anatomical knowledge.

Surgical anatomy of the lingual nerve for palate surgery: where is located and how to avoid it.

PURPOSE: To describe the anatomic relationship of the lingual nerve with the lateral oropharyngeal structures. METHODS: An anatomic dissection of the lateral oropharyngeal wall was conducted in eight sides from four fresh-frozen cadaveric heads. Small titanium clips were placed along the lingual nerve and the most anterior and medial border of the medial pterygoid muscle. Radiological reconstructions were employed for optimal visualization; the coronal view was preferred to resemble the surgical position. The distance between the lingual nerve and the medial pterygoid muscle at its upper and lower portion was measured radiologically. The trajectory angle of the lingual nerve with respect to the pterygomandibular raphe was obtained from the intersection between the vector generated between the clips connecting the upper and lower portion of the medial pterygoid muscle with the vector generated from the lingual nerve clips. RESULTS: The mean distance from the upper portion of the medial pterygoid muscle and superior lingual nerve clips was 10.16 ± 2.18 mm (mean ± standard deviation), and the lower area of the medial pterygoid muscle to the lingual nerve was separated 5.05 ± 1.49 mm. The trajectory angle of the lingual nerve concerning to the vector that describes the upper portion of the most anterior and medial border of the medial pterygoid muscle with its lower part was 43.73º ± 11.29. CONCLUSIONS: The lingual nerve runs lateral to the lateral oropharyngeal wall, from superiorly-inferiorly and laterally-medially, and it is closer to it at its lower third.

Management of inferior alveolar nerve and lingual nerve injuries in the UK - a cross-sectional study.

Post operative nerve injury following mandibular third molar (M3M) potentially impacts a significant number of patients. A lack of consensus for the management of trigeminal nerve injuries exists. It is important to know how clinicians manage these injuries, and how confidently. A 16-question online survey using SurveyMonkey was developed and sent to all current UK members of three oral srelated societies (ABAOMS, BAOS and BAOMS) from January 2021 to March 2021. The survey consisted of open free text, binomial and variable scale responses related to the management of inferior alveolar nerve and lingual nerve injuries. A total of 158 clinicians responded to the survey. The average number of M3M removed monthly over the last three years by a clinician was 25. The average number of nerve injuries seen in a clinician's practice, within the last three years, was three. Over two-thirds of respondents were only somewhat confident, not so confident, or not at all confident in the management of patients with inferior alveolar nerve (IAN) and lingual nerve (LN) injury. In occurrence of an injury, only 45% stated they would make an onward referral and a minority of clinicians had access to surgical repair within their own unit. Free text responses highlighted themes of a lack of UK awareness of management interventions and pathways for these patients. Clear national guidance on managing trigeminal nerve injuries was a commonly desired theme from responding clinicians. Joint speciality partnerships and a national nerve repair registry is now required.

Anatomical Relationship Between the Lingual Nerve and Submandibular Duct.

ABSTRACT: The purpose of this study was to investigate the anatomical relationship between the lingual nerve and submandibular duct. This study included 1403 patients with submandibular or sublingual gland diseases who underwent intraoral removal of submandibular gland sialoliths, submandibular glands, or sublingual glands. Of all patients, 33 patients underwent bilateral surgeries. All surgeries were performed a single surgeon, and the anatomical relationship between the lingual nerve and submandibular duct was always identified intraoperatively and recorded in the operation recorded. The anatomical relationship was investigated based on the intraoperative findings. The lingual nerve which crosses above the submandibular duct was detected in 8 of 1436 sides (0.6%). There were 4 in the right sides and 4 in the left sides. The lingual nerve below the submandibular gland was seen in 99.4%. Although the lingual nerve crosses above the submandibular duct with a rarer incidence, surgeons should beware of injuring the lingual nerve during intraoral salivary gland surgery.

An Atypical Path of the Lingual Nerve in the Retromolar Region: Incidence in Oral Surgery.

The Lingual nerve is frequently anesthetized during oral, maxillofacial, or otorhinolaryngology surgery. It originates below the oval hole in the infratemporal region, follows its path down and forward, and moves away from the medial surface of the ramus. From there, it goes just above the mylohyoid line. It approaches the lateral margin of the tongue and crosses the Wharton's canal, and divides into numerous branches. Some cases of temporomandibular joint syndrome or myofascial pain syndrome could be a result of its anatomical variations. Also, the jurisprudence has always condemned the practitioner if for not demonstrating that the path of the injured nerve presents an anomaly which makes his involvement inevitable. The purpose is to present one of the multiple atypical paths of the lingual nerve not described in the retromandibular trigone, demonstrating that its damage constitutes a risk that cannot be controlled.

Reconstrucción microquirúrgica del nervio lingual / Microsurgical lingual nerve repair

Resumen Introducción: El daño del nervio lingual posterior a un evento traumático es frecuente durante algunos procedimientos en cirugía maxilofacial. Siendo la desinclusión de terceros molares la causa más frecuente. La reconstrucción microquirúrgica del nervio es una técnica eficaz con éxito sobre el 80% de los casos. Objetivo: El objetivo de este artículo es presentar dos casos de reconstrucción microquirúrgica del nervio lingual. Casos Clínicos: Pacientes de sexo femenino tratadas por el equipo de Cirugía Maxilofacial del Hospital Dr. Abraham Godoy Peña. Donde se les realiza la reconstrucción microquirúrgica del nervio lingual, ambas presentan resultados positivos al año y medio, con una recuperación funcional sensorial (FSR +) y sensorial positiva S3 y S4+ respectivamente para cada paciente. Discusión: El momento de la reconstrucción microquirúrgica del nervio lingual no está bien definido. Sin embargo, la mayoría de los autores sugieren un tratamiento quirúrgico temprano, antes de los 6 meses. El daño del nervio lingual a menudo afecta la calidad de vida del paciente. La reconstrucción microquirúrgica del nervio lingual debe ser incorporada dentro del algoritmo de tratamiento del daño del nervio lingual.

Introduction: Lingual nerve injury after a traumatic event is frequent during some maxillofacial procedures, being the third molar extraction the most frequent cause. Lingual nerve injury may be performed in different grades of damage and it is often invalidating. Microsurgical reconstruction is an efficacy technique with a rate of success over 80%. Aim: To present two cases of lingual nerve microsurgical reconstruction after lingual nerve injury. Clinical Cases: Two female patients suffered lingual nerve injury after third molar extraction, both were submitted to lingual nerve reconstruction. It was performed the microsurgery reconstruction of the lingual nerve, both present favorable outcomes follow up to 1.5 years, including positive Functional sensory recovery (FSR +) and sensorial test S3 and S4+ respectively for each patient. Discussion: The timing of lingual nerve microsurgery is not well defined; however, most authors suggest an early surgical treatment before 6 months. The lingual nerve injury often affect the quality of life of the patient. Microsurgery reconstruction should be incorporated into the treatment algorithm of lingual nerve injury.

Clinical outcomes of lingual nerve repair.

Lingual nerve injury, a well-described complication of third molar removal, may result in permanent lingual sensory deficit leading to symptoms including lost or altered sensation, inadvertent tongue biting, and the development of unpleasant neuropathic pain, with consequent impaired quality of life. We analysed outcomes of a prospective case series to determine whether direct anastomosis of the lingual nerve results in improved sensory recovery and reduced neuropathic pain, and whether delayed surgery is worthwhile. In 114 patients who underwent nerve repair at our nerve injury clinic following damage sustained during mandibular third molar removal, sensory deficit was assessed before and after surgery using a questionnaire and visual analogue scales (VAS) to assess pain, tingling, and discomfort. Neurosensory tests were utilised to evaluate light touch, pin-prick, and two-point discrimination thresholds. Subjectively, 94% patients felt their sensation had improved following nerve repair, with significant reductions in the incidence of tongue biting (p<0.0001), impaired speech (p<0.0001), and neuropathic pain (p=0.0017). Quantitative neurosensory data showed highly significant improvements in light touch, pin-prick, and two-point discrimination (all p<0.0001), and VAS scores for pain (p=0.0145), tingling (p<0.0025), and discomfort (p<0.0001) were significantly reduced. Patients with high levels of pain preoperatively (VAS>40) showed highly significant reductions in pain (p<0.0001). No correlation was found between surgical outcome and patient's age or delay until surgery. Lingual nerve repair results in good sensory outcomes and significant improvements in the incidence and degree of neuropathic pain, even when delayed.

Outcomes of Direct Lingual Nerve Repair After an Injury: A Systematic Review.

PURPOSE: The purpose of this study was to conduct a systematic review with meta-analysis to investigate the outcomes of direct lingual nerve repair after injury. MATERIALS AND METHODS: The studies in this review were compiled by using PubMed/Medline and ScienceDirect, which were searched by a single reviewer (M.K.) from their inception until March 10, 2020. Two independent reviewers (M.K. and V.B.Z.) who were blinded to each other's assessments reviewed full-text articles to assess for study inclusion. Outcomes were dichotomized as either functional sensory recovery (FSR) or no FSR. Clinical testing must have been assessed at a minimum of 6 months postoperatively. FSR was defined as grade S3, S3+, or S4 on the British Medical Research Council scale of neurosensory function. Studies were only eligible if they provided the number of patients treated with conduits or time from injury to repair and the associated rates of FSR with each intervention. RESULTS: The initial search using the key terms yielded 4,921 results, which was then eventually filtered down to 6 articles after multiple levels of appraisal. Five articles were retrospective cohort studies and 1 was a randomized controlled study. Four of the 6 studies reported an FSR of grade S3 or higher in 85% or more of the patients. Conduit use was not associated with a significantly greater likelihood of achieving FSR (pooled risk ratio = 1.10; 95% confidence interval, 0.96 to 1.27; P = .17). Repair within 6 months was associated with significantly improved likelihood of achieving FSR (pooled risk ratio = 0.84; 95% confidence interval, 0.71 to 0.99; P = .04). CONCLUSIONS: The use of conduits during repair was not associated with clinically significant increased FSR. Early repair was associated with a beneficial effect on FSR; however, heterogeneity was an issue with the studies. There is a lack of strong evidence owing to the nature of studies analyzed and the need for further research is required.

Schwannoma arising from the sublingual glandular branch of the lingual nerve radiologically masquerading as sublingual gland tumor.

We report a rare case of schwannoma arising from the sublingual glandular branch of the lingual nerve radiologically masquerading as sublingual gland tumor. A 42-year-old female was referred to our department with a painless swelling in the left submandibular region. Contrast-enhanced computed tomography showed a well-circumscribed, heterogeneous low-density tumor with cystic change in the left sublingual region. Magnetic resonance imaging showed a well-circumscribed, heterogeneous sublingual tumor with low-signal intensity on T1-weighted image and high-signal intensity in T2-weighted image. The lesion was diagnosed radiologically as benign sublingual gland tumor. The patient underwent resection of sublingual gland tumor under general anesthesia. There was no definitive continuity between the tumor and the sublingual gland, and the tumor originated from sublingual glandular branch of the lingual nerve. Pathological examination of the specimen showed schwannoma with highly cellular areas (Antoni A) and hypocellular areas (Antoni B). The postoperative course was uneventful without lingual nerve palsy, and there was no recurrence 4 years after surgery.

Does early repair of trigeminal nerve injuries influence neurosensory recovery? A systematic review and meta-analysis.

This systematic review and exploratory meta-analysis of the available evidence was performed to examine whether early nerve repair of lingual nerve (LN) and inferior alveolar nerve (IAN) injuries has an effect on neurosensory recovery. A literature search was conducted to identify relevant studies meeting the inclusion criteria. Two reviewers independently evaluated the methodological quality of the included studies and the risk of bias using the ROBINS-I quality assessment tool. For the quantitative analysis, data were pooled using the Mantel-Haenszel random-effects method due to the clinical heterogeneity across the studies. Sensitivity and subgroup analyses were performed based upon the group definition of timing from injury to nerve repair, with breakpoints of 2, 3, and 6 months. A total 1236 citations were identified, with a final 13 studies included in the systematic review. A clear definition of 'early' versus 'late' repair was not reported in six studies, allowing only seven to be included in the meta-analysis. The effect of early repair on functional sensory recovery was found not to be significant in nine studies, while four studies found a significant effect of early intervention. The meta-analysis showed a combined success rate of 93.0% for the early group and 78.5% for the late group. The odds of improvement were 5.49 (95% confidence interval 1.40-21.45) in the 3-month breakpoint studies and 2.28 (95% confidence interval 1.05-4.98) in the 6-month studies. A trend towards early repair achieving better functional sensory recovery outcomes was observed, but the specific time period is unknown.

Solitary neurofibroma of the floor of the mouth: rare localization at lingual nerve with intraoral excision.

BACKGROUND: Neurofibromas (NF) are benign tumors of the peripheral nerves that are composed of Schwann cells, perineural-like cells and fibroblasts. The differential diagnosis for a solitary intraneural variant of neurofibroma arising in the floor of the mouth is broad and includes a submandibular gland neoplasm and adenopathy, among others. The intraoral approach is the best choice for a medium-sized lesion. CASE PRESENTATION: We report a rare case of a solitary neurofibroma of the floor of the mouth in a 31-year-old male. The patient consulted the dental emergency department for acute pain of the left mandible. Systematic clinical examination revealed the presence of a mass in the left mouth floor. The panoramic x-ray was not conclusive and the magnetic resonance imaging (MRI) revealed a well-defined soft tissue lesion with homogenous isosignal intensity on the T1-weighted image, high intensity signal on the T2-weighted image and heterogeneous enhancement following contrast-enhancement on the T1-weighted Fast Sat image. The surgical excision of the soft-tissue neoplasm was accomplished by an intraoral approach. The specimen was sent for histopathologic analysis and Immunohistochemical studies which confirmed the diagnosis of a myxoid predominant intraneural solitary neurofibroma. CONCLUSION: The diagnosis of neurofibroma was confirmed by histopathological evaluation and immunohistochemical studies which also excluded other entities in the histopathologic differential diagnosis including schwannoma and a malignant peripheral nerve sheath tumor among other. Localized (solitary) neurofibromas most often occur as sporadic lesions, however; diagnosis of a solitary neurofibroma prompts clinical evaluation to exclude the remote possibility of neurofibromatosis. The purpose of this case report is to raise awareness of the uncommon presentation of neurofibroma and to document the successful management of such a lesion using an intraoral approach.

Ultrasound-Guided Inferior Alveolar Nerve Block in the Horse: Assessment of the Extraoral Approach in Cadavers.

Blinded techniques to desensitize the inferior alveolar nerve (IAN) include intraoral, angled, and vertical extraoral approaches with reported success rates of 100%, 73%, and 59%, respectively. It has not been determined whether an ultrasound-guided extraoral approach is feasible. Further, the fascicular nature of the inferior alveolar and lingual nerves of the horse has not been described. The objectives of this study were to describe a low-volume ultrasound-guided vertical extraoral inferior alveolar nerve block technique and to describe the fascicular nature of these nerves. An ultrasound-guided approach to the IAN was conducted with a microconvex transducer and an 18-G, 15-cm spinal needle using a solution containing iodinated-contrast and methylene blue dye. Accuracy was assessed by contrast visualized at the mandibular foramen on computed tomography (CT) and methylene blue dye staining of the nerves on gross dissection. Sections of inferior alveolar and lingual nerves were submitted for histological analysis. Assessment by CT and dissection determined success rates of 81.3% and 68.8%, respectively; 68.8% of injections had inadvertent methylene blue dye staining of the lingual nerve. Nerve histology revealed both the inferior alveolar and lingual nerves to be multifascicular in nature. Mean fascicle counts for the inferior alveolar and lingual nerves were 29 and 30.8, respectively. The technique is challenging and no more accurate than previously published blinded techniques. Any extraoral approach to the IAN is likely to also desensitize the lingual nerve.

Objective Assessment of Lingual Nerve Microsurgical Reconstruction.

Lingual nerve (LN) injury is one of the most serious consequences of oral surgery. Prompt microsurgical reconstruction of the nerve can alleviate most of those symptoms leading to satisfactory functional recovery.Thirty-five patients with partial to complete LN injury underwent surgery in the period between January 2006 and May 2015. All patients underwent a preoperative clinical and neurological evaluation with the assessment of lingual tactile and pain sensory thresholds and masseteric inhibitory reflex.All patients underwent explorative surgery and direct microneurorrhaphy of distal and proximal stumps in case of complete lesion, while the removal of traumatic neuroma and the following microneurorrhaphy of distal and proximal stumps of the injured nerve was performed in case of incomplete lesion. Nerve grafting has always been avoided because of distal stump mobilization obtained by severing the submandibular branch of the LN.All patients but 1 exhibited good recovery of tongue sensation, never complete, both clinically and electrophysiologically: recovery of the excitability of masseteric inhibitory reflex suppression components SP1 and SP2 was observed, often with increased latencies but consistent with a functional recovery.All patients feeling pain preoperatively experienced complete relief of algic symptoms.The early microsurgical approach is the most suitable choice for the treatment of LN injuries.

The clinical view for dissection of the lingual nerve with application to minimizing iatrogenic injury.

The importance of the position of the lingual nerve in the oral cavity cannot be understated for dentists and oral surgeons. Therefore, the location of the lingual nerve with various positions of the tongue is important. However, most dental and medical students are taught oral cadaveric anatomy where tissues are fixed. Therefore, the focus of this article is to demonstrate how the lingual nerve moves based on tongue movement in fresh tissues and how this is important for dentists and oral surgeons. Clin. Anat. 30:467-469, 2017. © 2017 Wiley Periodicals, Inc.

Neuropathic Pain Due to Iatrogenic Lingual Nerve Lesion: Nerve Grafting to Reduce Otherwise Untreatable Pain.

Iatrogenic lingual nerve lesion is a well-known and unfortunate complication after mandibular third molar removal. Occasionally, the nerve injury can cause severe neuropathic pain.Here, the authors present the history of 2 patients with lingual nerve injury due to mandibular third molar removal, and with severe neuropathic pain in the craniomandibular region. Pharmacotherapy and physiotherapy did not reduce the pain, and ultimately, the lingual nerve was surgically explored. Scar tissue and a lingual nerve neuroma were observed and resected in both patients.In the first patient, the gap between the nerve stumps was bridged with an autologous sural nerve graft. In the second patient, some continuity of the lingual nerve was preserved and the resected part was substituted with an autologous sural nerve graft. Significant pain reduction was achieved in both patients and no further medical treatment was necessary at the end of follow-up.These reports show that lingual nerve reconstruction can be a successful therapy in patients experiencing severe neuropathic pain after iatrogenic lingual nerve injury. Different treatment options for neuropathic pain due to lingual nerve injury are discussed.

Nerve Sharing Between the Lingual and Mental Nerve to Restore Lower Lip Sensation After Segmental Resection of the Mandible.

This report demonstrates a successful new procedure for reconstructing the inferior alveolar nerve by transplanting the great auricular nerve (GAN) between the mental nerve and the remaining submandibular ganglion to achieve nerve sharing of the lingual nerve. A 59-year-old woman with discomfort in the left mandibular retromolar region and ipsilateral neck was referred to our hospital by a local dentist. Physical examination showed mild swelling and redness at the left mandibular retromolar region. The histologic diagnosis showed central mucoepidermoid carcinoma of the jaw. With the patient under general anesthesia, segmental resection of the mandible followed by level 1 selective neck dissection was performed. The resected mandible was reconstructed with a titanium plate. The submandibular incision was extended to the lower edge of the tragus for harvesting of the GAN. The GAN was grafted, and an epineural neurorrhaphy was carried out with the mental nerve, as well as the submandibular ganglion, under a microscope. After the operation, submental sensation was evaluated with a Semmes-Weinstein pressure esthesiometer. The Semmes-Weinstein pressure esthesiometer test showed a loss of perception at the third week after surgery. Within 12 months, nerve sensation was substantially improved and the patient was free from discomfort.

Impact of Sensory and Motor Defects on Oral Function in an Animal Model.

OBJECTIVE: To evaluate the combined functional impact on swallowing of tongue sensory and motor loss using a rat model. STUDY DESIGN: Rats underwent selective neurectomies with transection of the motor (hypoglossal) nerve or motor and sensory (lingual) nerves. Postoperative functional parameters were followed for 2 weeks. SETTING: Translational research. SUBJECTS AND METHODS: Thirty-six adolescent male Wistar rats were divided into 4 groups: anesthetic (n = 6), sham surgery (n = 8), hypoglossal transection (n = 10), and hypoglossal and lingual transection (n = 12). Each morning on postoperative days 1 to 14, the water and food intake were quantified and the animal weighed. Two-way analyses of variance (SigmaPlot; SYSTAT, San Jose, California) were performed with factors of "group" and "postoperative day" (POD) to analyze whether a significant difference existed between water intake, pellet consumption, and weight change. RESULTS: The hypoglossal and lingual group consumed significantly less water during PODs 1 to 2 and significantly less food during PODs 1 to 3 than any other group. This established a significant difference in body weight between the hypoglossal and lingual group and all other groups for the duration of the study. Measured parameters in the hypoglossal group better approximated those of the control anesthetic and sham groups. CONCLUSIONS: The addition of a sensory loss to a motor deficit involving the oral tongue results in a measurably significant difference in weight gain, a marker of function, compared with rats with only a motor deficit. Additional studies are needed to determine if there would be similar findings in a model of sensate vs asensate oral tongue reconstruction.

Longitudinal Treatment Outcomes of Microsurgical Treatment of Neurosensory Deficit after Lower Third Molar Surgery: A Prospective Case Series.

OBJECTIVE: To prospectively evaluate the longitudinal subjective and objective outcomes of the microsurgical treatment of lingual nerve (LN) and inferior alveolar nerve (IAN) injury after third molar surgery. MATERIALS AND METHODS: A 1-year longitudinal observational study was conducted on patients who received LN or IAN repair after third molar surgery-induced nerve injury. Subjective assessments ("numbness", "hyperaesthesia", "pain", "taste disturbance", "speech" and "social life impact") and objective assessments (light touch threshold, two-point discrimination, pain threshold, and taste discrimination) were recorded. RESULTS: 12 patients (10 females) with 10 LN and 2 IAN repairs were recruited. The subjective outcomes at post-operative 12 months for LN and IAN repair were improved. "Pain" and "hyperaesthesia" were most drastically improved. Light touch threshold improved from 44.7 g to 1.2 g for LN repair and 2 g to 0.5 g for IAN repair. CONCLUSION: Microsurgical treatment of moderate to severe LN injury after lower third molar surgery offered significant subjective and objective sensory improvements. 100% FSR was achieved at post-operative 6 months.

Minimally Invasive Approach to the Lingual and Hypoglossal Nerves in the Adult Rat.

Surgical manipulation of the sensory and motor nerves of the rat tongue is often employed in studies evaluating the oral cavity functions of mastication and deglutition. A noninvasive, atraumatic approach that will then facilitate sufficient manipulation of these structures is required. In this study, we detail an approach that consistently allows identification of the hypoglossal (motor) and lingual (sensory) nerves of the rat. Six Wistar rats (250-500 g) were anesthetized and dissected either as fresh tissue (N = 3) or following transcardial perfusion with 4% paraformaldehyde (N = 3). Both fixed and non-fixed specimens of the rat head and neck were incised in the right submandibular region. The first animal in each group was used to gain a basic understanding of the regional muscular anatomy with reference to the hypoglossal and lingual nerves. Subsequent animals were used for the development of an efficient and minimally invasive approach to these nerves. The resultant approach begins as an incision through skin and platysma, followed by medial reflection of the digastric muscle. This allows visualization of the hypoglossal nerve in the region of the bifurcation of the common trunk into medial and lateral subdivisions. Next, the lingual nerve dissection is approached by reflection rostrally of the transversus mandibularis muscle and a caudal reflection of the mylohyoid muscle. This dissection reveals the geniohyoid muscle which when separated bluntly using forceps, exposes the lingual nerve. The anatomical approach described and illustrated herein will aid investigators in consistent identification of these two nerves as fundamental methods of their projects.