Evaluating Lingual Nerve Repair Outcomes: A Systematic Review.

PURPOSE: The lingual nerve (LN) is susceptible to injury during oral and maxillofacial procedures, leading to neurosensory deficits. Advances in microsurgical techniques necessitate a comprehensive review of overall effectiveness and influencing factors. METHODS: A systematic review was performed via Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies. Inclusion criteria were full text availability, studies written in english, and studies published after 2000 reporting LN repair. The primary outcome was sensory improvement defined via functional sensory recovery (FSR) or neurosensory testing (NST). Sex, time from injury to repair, method of repair, and graft length were examined to see if each influenced outcomes. RESULTS: A sample of 786 subjects across 17 studies was examined. Most patients were female (73.3%) and suffered injuries from third molar extractions (72.8%). Of the studies, 10 defined improvement by FSR with a total of 88.8% (500/563) of nerves achieving such. Of those achieving FSR, 91% did so within a year. The remaining 7 studies defined sensory improvement by individually setting various NST thresholds, with the combined improvement rate being 88.6% (203/229). Positive outcomes were achieved with graft lengths up to 70 mm. Results on time to repair were mixed. The methods of repairs were not different based on statistical analysis short of performing an equivalence trial. CONCLUSION: Conclusions made from studies using FSR were similar to studies using NST, meaning the method of measuring outcomes does not seem to be a confounder. FSR is the superior scale due to being objective and standardized. LN repair produced high rates of sensory improvement, which is expected to occur within 1 year postoperative. Sex and graft length did not influence outcomes. More research is needed to determine the effect of time to repair on efficacy. Most methods of repair produced similar outcomes, suggesting multiple valid techniques exist.

Permanent lingual nerve injury after dental procedures: a retrospective study of 228 patients.

Lingual nerve injury (LNI) is a rare, serious complication and previous studies include limited numbers of cases. The aim of this retrospective study was to report the neurosensory outcomes for a large patient cohort with permanent LNI and correlate the mechanism of injury (surgical vs non-surgical) to neurosensory characteristics. Demographics, procedural parameters, mandibular third molar (M3) position, surgeon type, neurosensory test results, and symptoms were recorded for 228 patients and analysed. The majority were female (67.1%). Overall, 59.6% of LNIs were caused by M3 removal and 36.4% by local anaesthesia. Complete loss occurred more frequently in surgical LNIs (P = 0.013). The presence of pain did not differ significantly, however the burning type of pain was significantly more frequent in non-surgical LNIs (P = 0.008) along with altered gustation (P = 0.025). The most common M3 position related to LNI was distoangular (40.4%), class III (63.2%), level A (58.1%) (Winter/Pell and Gregory classifications). The majority of patients undergoing M3 removal were >24 years. A total of 71.7% showed no sign of recovery and 5.5% reported further impairment in their condition. Overall, nine patients underwent microsurgical repair. This study presents neurosensory characteristics potentially decisive for timely referral of operable LNIs.

Prevalence of lingual sensory impairment following bilateral sagittal split osteotomy: a systematic review and meta-analysis.

PURPOSE: Our study aims to estimate the prevalence of lingual nerve injury following bilateral sagittal split osteotomy (BSSO). METHODS: Two reviewers independently conducted a systematic literature search in the Medline and Scopus databases. The pooled prevalence with 95% confidence intervals (CI) was estimated, and quality assessment, outlier analysis, and influential analysis were performed. RESULTS: In total, eleven eligible studies comprising a total of 1,882 participants were included in this meta-analysis. One study was identified as critically influential. The overall prevalence of lingual sensory impairment was estimated to be as high as 0.1% (95% CI 0.0%-0.6%) with moderate heterogeneity observed between studies. CONCLUSION: It is important for healthcare professionals to be aware of this issue, despite the relatively low rate of lingual nerve deficit after BSSO. Additional research will provide a more comprehensive understanding of the underlying factors contributing to lingual nerve injury, leading to improved preventive measures and treatment strategies. Furthermore, insights gained from future studies will enable healthcare professionals to inform patients about the potential complications and manage their expectations before undergoing BSSO.

Clinical insights into traumatic injury of the inferior alveolar and lingual nerves: a comprehensive approach from diagnosis to therapeutic interventions.

OBJECTIVES: This scoping review explores the risk and management of traumatic injuries to the inferior alveolar and lingual nerves during mandibular dental procedures. Emphasizing the significance of diagnostic tools, the review amalgamates existing knowledge to offer a comprehensive overview. MATERIALS AND METHODS: A literature search across PubMed, Embase, and Cochrane Library informed the analysis. RESULTS: Traumatic injuries often lead to hypo-/anesthesia and neuropathic pain, impacting individuals psychologically and socially. Diagnosis involves thorough anamnesis, clinical-neurological evaluations, and radiographic imaging. Severity varies, allowing for conservative or surgical interventions. Immediate action is recommended for reversible causes, while surgical therapies like decompression, readaptation, or reconstruction yield favorable outcomes. Conservative management, utilizing topical anesthesia, capsaicin, and systemic medications (tricyclic antidepressants, antipsychotics, and serotonin-norepinephrine-reuptake-inhibitors), proves effective for neuropathic pain. CONCLUSIONS: Traumatic nerve injuries, though common in dental surgery, often go unrecorded. Despite lacking a definitive diagnostic gold standard, a meticulous examination of the injury and subsequent impairments is crucial. CLINICAL RELEVANCE: Tailoring treatment to each case's characteristics is essential, recognizing the absence of a universal solution. This approach aims to optimize outcomes, restore functionality, and improve the quality of life for affected individuals.

Assessing the Efficacy of Allogeneic Nerve Grafts in Trigeminal Nerve Repair: A Systematic Review.

PURPOSE: Our primary objective was to assess the efficacy of allogeneic nerve grafts in inferior alveolar nerve or lingual nerve repair. We hypothesized that using allogeneic nerve grafts would be effective, as evidenced by achieving high rates of functional sensory recovery (FSR). Additionally, we looked if sex, time from injury to repair, etiology of nerve damage, and graft length affected outcomes. METHODS: A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. PubMed and Scopus databases were searched using specific search strategies to generate eligible studies. Inclusion criteria encompassed studies reporting use of allogeneic grafts, assessing FSR using either Medical Research Council Scale or Neurosensory Testing, and published within the past 15 years. RESULTS: Across 10 studies conducted between 2011 and 2023, analysis was performed on 149 patients and 151 reconstructed nerves. Allogeneic nerve grafts showed an average FSR rate of 88.0%. Kaplan-Meier analysis of time to FSR postoperatively revealed that of those achieving FSR, 80% achieved it within 6 months and 98% achieved it by 1 year. The mean graft length was 29.92 mm ± 17.94 mm. The most common etiology for nerve damage was third molar extractions (23.3%). Sex distribution among patients revealed that 85 were female (57.0%) and 64 were male (43.0%). CONCLUSION: Our primary hypothesis was supported as nerve allografts achieved high rates of FSR. FSR was achieved in normative timeframes, which is 6 to 12 months postoperatively. Furthermore, allografts reduced the risk of posttraumatic trigeminal neuropathy. Time from injury to repair, graft length, etiology of nerve damage, and sex did not affect FSR. As the assessed variables in our study did not affect outcomes, there needs to be a more nuanced approach to understanding and addressing various factors influencing sensory recovery.

Benefits of Coronectomy in Lower Third Molar Surgery: A Systematic Review and Meta-analysis.

PURPOSE: The purpose of this study was to measure and compare coronectomy versus extraction in patients at increased risk for inferior alveolar nerve (IAN) injuries associated with third molar removal in terms of IAN injury and other complications. METHODS: The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist. We conducted a comprehensive literature search across six databases and the gray literature from July 15 to August 01, 2022. We employed Rayyan software to identify and remove duplicate articles to ensure data integrity. Our research followed the strategy patient (P), intervention (I), comparison (C), outcome (O), and study (S): (P) patients needing lower third molar surgery at higher risk of IAN injury; (I) surgery options, coronectomy or complete extraction; (C) comparisons included reduced risks of nerve injuries, postoperative complications (pain, infection, alveolitis), and increased risks of reoperation, root migration, and extraction; (O) desired outcomes were preventing nerve injuries and reducing other surgical complications; and (S) observational study designs (cohort, case-control). Excluded from consideration were studies involving teeth other than lower third molars, as well as reviews, letters, conference summaries, and personal opinions. To gauge the certainty of evidence, we employed the Grading of Recommendation, Assessment, Development, and Evaluation instrument, selecting the most current papers with the highest levels of evidence for inclusion. The primary outcome variable of our study centered on evaluating the incidence of IAN injury, and secondly, the lingual nerve (LN) injury, the postoperative pain, infection, localized alveolitis, the necessity for surgical reintervention, root migration, and extraction. These assessments were carried out with respect to their chosen operative technique for managing third molars, either coronectomy or extraction, as predictor variables. We also considered covariates such as age, gender, and the presence of systemic diseases in our analysis to account for potential confounding factors. The pooled data underwent rigorous analysis utilizing an inverse variance method with both random and fixed effect models by the "metabin" function in the R program's meta-package. Additionally, we assessed the risk of bias in the selected studies by utilizing the Joanna Briggs Institute's Critical Appraisal Checklist for Studies Reporting Prevalence Data and the Critical Appraisal Checklist for Case Reports. RESULTS: Of the 1,017 articles found, after applying the inclusion and exclusion criteria, 42 were included in this study (29 cohort and 13 case-control studies), including 3,095 patients from 18 countries. The meta-analysis showed that coronectomy reduced the risk of IAN injury [OR (Odds Ratio): 0.14; 95% CI (confidence intervals): 0.06-0.30; I2 (inconsistency index) = 0%; P = .0001], postoperative pain (OR: 0.97; 95% CI: 0.33-2.86; I2 = 81%; P = .01), and alveolitis (OR: 0.38; 95% CI: 0.13-1.09; I2 = 32.2%; P = .01) when compared to complete tooth extraction. However, it also highlighted a greater risk of reintervention (OR: 5.38; 95% CI: 1.14-25.28; I2 = 0.0%; P = .01). CONCLUSIONS: This study has demonstrated that coronectomy is associated with a decreased risk for IAN injury and decreased pain and localized alveolitis when compared to complete tooth extraction. However, it is essential to acknowledge the higher likelihood of requiring reintervention with coronectomy. Therefore, clinicians should carefully consider the advantages and potential drawbacks of both techniques and tailor their choices to the unique clinical circumstances of each patient.

The perception and practice of routine lingual flap retraction in lower third molar surgery among oral and maxillofacial surgeons in Nigeria.

Background: Lingual nerve injury is a known complication of mandibular third molar (M3M) surgery, and retraction of the lingual flap is reported to reduce the incidence of this complication. However, there is no global consensus on the routine retraction of lingual flap. Aim: The aim of the study was to assess the perception and practice of lingual flap retraction amongst oral and maxillofacial surgeons in Nigeria. Materials and Methods: This cross-sectional national survey was conducted amongst 122 oral and maxillofacial surgeons in Nigeria from January 2023 to March 2023 using a validated, structured, self-administered questionnaire. The questionnaire had three sections and 14-item questions. Section A consists of the sociodemographic questions, Section B comprises questions on perception towards lingual flap retraction, whereas Section C consists of questions on the practice of lingual flap retraction. These questionnaires were deployed as an online survey and as hard copies. Both qualitative and quantitative data were analysed. A critical probability level (P < 0.05) was used as the cut-off level for statistical significance. Results: Most of the participants (47.6%) belong to the age group of 31-40 years. The male-to-female ratio was 6:1. Only 12 (9.8%) participants had a positive perception towards routine lingual flap retractions following M3M surgery. Perception of lingual flap retraction was found not to be associated with the demographic variables of the participants (P > 0.05). A total of 95 participants (77.9%) did not raise nor retract the lingual flap during lower third molar surgery. The rate of practice of lingual flap retraction during third molar surgery was not influenced by any of the factors studied (P > 0.05). Conclusion: The majority of oral and maxillofacial surgeons in Nigeria do not agree that routine retraction of the lingual flap is necessary to reduce lingual nerve injury and majority, too, do not practice this in their management of impacted lower third molar.

Lingual Nerve Injury During Impacted Mandibular Third Molar Surgery.

OBJECTIVE: To determine the frequency of lingual nerve injury (LNI) during the surgical removal of mandibular third molar and the associated risk factors. STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Oral and Maxillofacial Surgery, Ayub Teaching Hospital, Abbottabad, from January to June 2021. METHODOLOGY: A total of 121 patients were included in this study who had undergone impacted third molar surgery. Data were collected on a proforma via interview. Patients were followed up after 1 week, 1 month, and 3 months of duration. Frequency of LNI and its association with various surgical procedure steps were determined. RESULTS: This study shows that out of 121 patients, frequency of LNI was found to be 3.3% (n=4). The type of impaction (p=0.047), lingual flap retraction (p<0.001), tooth splitting (p=0.029), and longer duration of surgery were found to be significantly associated with it. CONCLUSION: The frequency of LNI during mandibular impacted third molar surgery was 3.3% in this study, and significantly associated with horizontal impaction, lingual flap retraction, tooth splitting, and duration of surgery longer than 30 minutes. KEY WORDS: Lingual nerve injury, Tooth, Impaction, Third molar, Lingual flap retraction, Tooth splitting.

The complete anatomy of the lingual nerve: A meta-analysis with implications for oral and maxillofacial surgery.

Lingual nerve (LN) injury during surgical procedures in the third molar region warrants a detailed study of its common pathway and important variations. Therefore, the objective of this study was to analyze and compile the multiple anatomical variations of the LN for use in oral and maxillofacial surgery. It is anticipated that the results of the present meta-analysis may help to minimize the possible complications when performing procedures associated with this anatomical entity. Major online databases such as PubMed, Web of Science, Scopus, Embase were used to gather all relevant studies regarding the LN anatomy. The results were established based on a total of 1665 LNs. The pooled prevalence of the LN being located below the lingual/ alveolar crest was found to be 77.87% (95% CI: 0.00%-100.00%). The LN was located above the lingual/ alveolar crest in 8.21% (95% CI: 4.63%-12.89%) of examined nerves. The most common shape of the LN was established to be round with a prevalence of 40.96% (95% CI: 23.96%-59.06%), followed by oval at 37.98% (95% CI: 23.98%-53.02%) and flat at 25.16% (95% CI: 12.85%-39.77%). In conclusion, we believe that this is the most accurate and up-to-date study regarding the anatomy of the LN. The LN was found to be located below the lingual/alveolar crest in 77.87% of the cases. Furthermore, the LN was found to enter the tongue under the submandibular duct in 68.39% of the cases. Knowledge about the anatomy of the LN is crucial for numerous oral and maxillofacial procedures such as during the extraction of the third molar.

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.

Incidence of lingual nerve damage following surgical extraction of mandibular third molars with lingual flap retraction: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to examine more recent data to determine the extent of lingual nerve injury (LNI) following the surgical extraction of mandibular third molars (M3M). A systematic search of three databases [PubMed, Web of Science and OVID] was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The inclusion criteria encompassed studies on patients who underwent surgical M3M extraction using the buccal approach without lingual flap retraction (BA-), buccal approach with lingual flap retraction (BA+), and lingual split technique (LS). The outcome measures expressed in LNI count were converted to risk ratios (RR). Twenty-seven studies were included in the systematic review, nine were eligible for meta-analysis. Combined RR for LNI (BA+ versus BA-) was 4.80 [95% Confidence Interval:3.28-7.02; P<0.00001]. The prevalence of permanent LNI following BA-, BA+ and LS (mean%±SD%) was 0.18±0.38, 0.07±0.21, and 0.28±0.48 respectively. This study concluded that there was an increased risk of temporary LNI following M3M surgical extractions using BA+ and LS. There was insufficient evidence to determine whether there is a significant advantage of BA+ or LS in reducing permanent LNI risk. Operators should use lingual retraction with caution due to the increased temporary LNI risk.

Bilateral Lingual Nerve Injury Following Endotracheal Intubation: Risk Factors and Diagnostic Considerations.

BACKGROUND Endotracheal intubation is an essential procedure to protect the airway. However, immediate complications like voice hoarseness, cervical spine injury, and tooth trauma are common. One of the rarest complications is lingual nerve palsy. Risk factors include small airway instruments, non-supine position, nitrous oxide use, and difficult intubation. Only 15 cases of lingual nerve injury were identified worldwide, and only 2 of them were bilateral. This case report describes the third case of bilateral lingual nerve palsy after intubation. CASE REPORT We present a 52-year-old woman admitted for a total abdominal hysterectomy. Postoperatively, the patient noted voice hoarseness, left tongue numbness, and loss of taste on both sides of the tongue. MRI brain revealed no new masses or lesions, and a diagnosis of bilateral lingual nerve palsy was made. She was treated conservatively with symptom observation for 14 weeks. On follow-up, she remained with only a patch of numbness and dryness, and loss of taste on the top middle area of the tongue. CONCLUSIONS Lingual nerve palsy is a very rare but devastating adverse effect of airway manipulation. Symptoms can include dryness, loss of sensation, and loss of taste of the anterior two-thirds of the tongue on the ipsilateral side. Salivary function assessment is important to determine the location of peripheral nerve injury. All possible causes like stroke, hemorrhage, and nerve impingement should be evaluated. MRI is advised to exclude central etiologies. Steroids may be used to decrease tissue edema and inflammation.

Influence of the anesthetic modality on the development of neurological injury after lower third molar extraction: A systematic review of the literature.

The aim of this study was to determine if the risk of neurological injury to the inferior alveolar nerve (IAN) and the lingual nerve (LN) following the extraction of lower third molars is affected by the anesthetic modality (local anesthesia (LA) vs. general anesthesia (GA)). A systematic search was performed through the PubMed, Scopus, Cochrane Library, and Web of Science databases; furthermore, a manual search was performed by analyzing the references of full-text articles. From a total of 309 studies (collected after the removal of duplicates), 6 studies were selected. Of these, 4 reported a correlation between GA and nerve damage, while the other 2 did not show an obvious association. The level of bias in the studies was also calculated. Only 2 studies showed a medium risk of bias, while 4 studies showed a high risk of bias; no study showed a low risk of bias. Four of the 6 studies highlighted a higher incidence of IAN and LN injury following the extractions performed under GA. Although no scientific evidence is yet available, due to the scarcity and the limited quality of the studies in the literature, considering the risk­benefit ratio, LA should be the first choice in lower third molar surgery.

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.

Lingual bone thickness in the apical region of the horizontal mandibular third molar: A cross-sectional study in young Japanese.

BACKGROUND: Perforation of the lingual plate in the apical region of mandibular third molars will increase the risk of aberration and migration of the root tip and the risk of lingual nerve injury. The aim of this study was to analyze anatomical information, including relationships between the apical region of horizontally impacted mandibular third molars and lingual plates, in young Japanese. METHODS: Japanese patients, with horizontally impacted third molars, who underwent CT examination as a preoperative assessment for mandibular third molar extraction were included, and anatomical characteristics in the apical region of the right mandibular third molar were analyzed, in this study. RESULTS: A total of 121 patients were included based on the inclusion and exclusion criteria of this study. The mean and standard deviation of the bone thickness on the lingual side of the mandibular third molar in the apical region was 1.5 ± 1.6 mm, and the absence of lingual cortical bone in the apical region, namely, "perforation", was observed in 44 patients. The statistical analysis revealed the predictors of cases with perforation as follows: gender, age, and the available space evaluated by Pell and Gregory classification. CONCLUSIONS: This study clarified that "perforation" was sometimes observed in young Japanese, and that the predictors of those cases were as follows: gender, age, and the available space evaluated by Pell and Gregory classification.

Transient unilateral lingual nerve injury following the use of laryngeal mask airway Supreme: a case report.

Lingual nerve injury rarely occurs after using the laryngeal mask airway (LMA). A 40-year-old woman with no comorbidities visited the hospital for left breast-conserving surgery. Anesthesia was performed using LMA Supreme™. She complained of decreased sensation in the right front part of the tongue postoperatively. She received prednisolone and tongue sensation returned on postoperative day 28. The lingual nerve could be damaged by the LMA, particularly the lateral edge of the tongue base and inner part of the mandible around the third molar. When using the LMA, it is necessary to check the cuff pressure to prevent lingual nerve damage.

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.

Nociceptive receptors are expressed differently in trigeminal nociception after lingual nerve injury and unilateral external carotid artery occlusion in rats.

OBJECTIVES: To investigate the different changes in nociceptive activity between two animal models of trigeminal neuropathic pain: unilateral external carotid artery ischemic reperfusion and lingual nerve crush in rats. DESIGN: In this study, changes in nociceptive activity were investigated in unilateral external carotid artery ischemic reperfusion and lingual nerve crush models of trigeminal neuropathic pain in rats. Field excitatory postsynaptic potentials (fEPSPs) evoked by capsaicin application on the tongue of rats were recorded in the trigeminal nucleus caudalis. In addition, immunohistochemistry was performed in the trigeminal ganglia and trigeminal nucleus caudalis. RESULTS: The fEPSP in unilateral external carotid artery ischemic reperfusion and lingual nerve crush rats was irregular relative to that in sham rats. In particular, the fEPSP spike in lingual nerve crush rats had a higher amplitude and shorter duration than that in sham rats. Unilateral external carotid artery ischemic reperfusion and lingual nerve crush also increased c-fos expression in the trigeminal nucleus caudalis. Upregulation of transient receptor potential vanilloid 1 in trigeminal ganglion was observed in unilateral external carotid artery ischemic reperfusion and lingual nerve crush rats, whereas upregulation of purinergic receptor subtype 3 in trigeminal ganglion was observed only in lingual nerve crush rats. CONCLUSIONS: Although unilateral external carotid artery ischemic reperfusion and lingual nerve crush similarly increased nociceptive activity at the trigeminal nucleus caudalis, the fEPSPs and expression of nociceptive peripheral afferent neurons were different. Therefore, direct and indirect nerve injuries apparently induced the same nociceptive activity by different signaling responses dependent on nociceptive receptors.