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.

Immediate Inferior Alveolar Nerve Reconstruction With Ablative Mandibular Resection Results in Functional Sensory Recovery.

BACKGROUND: Ablative mandibular resection with sacrifice of the inferior alveolar nerve (IAN) results in loss of sensation and decreased quality of life. PURPOSE: The purpose of this study is to evaluate functional sensory recovery (FSR) of immediate IAN allograft reconstruction performed during ablative mandibular resection at 1 year following surgery. STUDY DESIGN, SETTING, SAMPLE: This is a single-center retrospective cohort study that included consecutive subjects who underwent mandibular resection with IAN discontinuity and used a nerve allograft of ≥40 mm. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictor variable is the use of an immediate nerve allograft in mandibular reconstruction. MAIN OUTCOME VARIABLE(S): The main outcome variable is FSR at 1 year using the Medical Research Council Scale. COVARIATES: Covariates include subject age, sex, specific pathology, nerve gap length, and development of neuropathic pain. ANALYSES: Statistical analysis of comparison of neurosensory outcomes was measured by bivariate statistics, weighted values, repeated measures, analysis of variance, and McNemar test. RESULTS: The study sample was composed of 164 subjects, of whom 55 (33.5%) underwent nerve allograft reconstruction and 30 (18.3%) did not have nerve reconstruction. Seventy-nine subjects (48.2%) did not meet the inclusion criteria. In the entire nerve allograft group of 55 subjects, FSR was achieved in 80% at 1 year; however, in benign disease alone, 31 of 33 (94%) achieved FSR at 1 year. In the nonallograft group (all benign disease), only 2 of 30 (7%) achieved FSR at 1 year. The significant covariates were age and pathology. Benign pathologic resections were 5.2 times more likely to achieve FSR than malignancies, and all subjects ≤ 18 years of age achieved FSR. After adjusting for age, sex, pathology, nerve gap length, nerve allograft was significantly associated with achieving FSR at 1 year (adjusted odds ratio = 5.52, 95% confidence interval = (1.03, 29.51), P value = .045 < .05). CONCLUSION AND RELEVANCE: Immediate long-span IAN allograft reconstruction is effective in restoration of sensation with an overall 80% of subjects achieving FSR at 1 year, while benign disease resulted in 94% FSR at 1 year. Immediate IAN reconstruction should be considered with mandibular resection involving the IAN, especially for children and benign disease.

Complicación en la colocación de implante dental con compromiso de nervio dentario inferior reporte de caso clínico, seguimiento de 3 años / Complication in the placement of dental implants with compromise of the inferior dental nerve clinical case report, 3-year follow-up

Introducción: Los accidentes o complicaciones durante la colocación de implantes dentales a pesar de la planeación quirúrgica deben ser manejados de manera inmediata y oportuna. Objetivo: Recomendar el mejor protocolo para manejar la lesión del nervio dentario inferior consecuencia de la colocación de implante dentario. Caso Clínico: Paciente asiste a clínica privada pararecibir atención odontológica de especialidad, edad 67 años, sexo femenino, presenta hipertensión arterial, resistencia a la insulina, premedicada con Hidronorol T y Metformina. Paciente informa deexodoncia de cuatro molares, colocaron inmediata de cuatro implantes dentales, sintió un adormecimiento del mentón con la perdida de efecto del anestèsico; 72 horas posterior se procedió a realizar tomografía Cone Bean, observándose implante contactando el nervio dentario inferior, planificándose de forma inmediata el retiro del implante dental. Resultados: Control a 3, 6, 9 meses, 1 , 2 y 3 años posterior a retiro de implante, aplicación de terapia farmacológica a base de corticoides, aines y vitamina B , con resultados favorables en el tratamiento de la parestesia. Conclusiones: La extracción del implante dental antes de las 72 horas y la terapia farmacológica adecuada resulto exitosa en el tratamiento de la lesión del nervio dentario inferior. (AU)

Introduction: Accidents or complications during the placement of dental implants despite surgical planning should be handled immediately and in a timely manner. Objective: To recommend the best protocol to manage the injury of the inferior dental nerve resulting from the placement of dental implant. Clinical Case: Patient attends private clinic to receive specialty dental care, age 67 years, female, presents arterial hypertension, insulin resistance, premedicated with Hydronorol T and Metformin. Pacientereports exodontics of four molars, immediate placement of four dental implants, felt a numbness of the chin with the loss of effct of the anesthetic; 72 hours later proceeded to perform Tomography Cone Bean, observing implant contacting the inferior dental nerve, immediately planning the removal of the dental implant. Results: Control at 3, 6, 9 months, 1, 2 and 3 years after implant removal, application of pharmacological therapy based on corticosteroids, NSAIDs and vitamin B, with favorable results in the treatment of paresthesia. Conclusions: The extraction of the dental implant before 72 hours and the appropriate pharmacological therapy was successful in the treatment of the lesion of the inferior dental nerve. (AU)

What Do I Do if There is No Distal Nerve Stump for Inferior Alveolar Nerve Reconstruction?

This technical note describes an innovation that addresses a clinical problem in inferior alveolar nerve (IAN) reconstruction. In some cases of mandibular resection, there is a need to resect a significant amount of the IAN along with the pathologic lesion and this may result in a lack of a distal nerve stump for completion of the neural anastomosis. This technical note offers the option to perform the distal neurorrhaphy into the residual soft tissues with the expectation that axonal sprouting will occur and result in lower lip and chin sensory reinnervation. There are no inherent risks or additional costs. The significance of this technique is that it permits IAN reconstruction in cases where the actual nerve stump is not available and improves patient care. There should be no challenges or delays to implementing this innovation for surgeons who reconstruct the IAN during ablative mandibular resection.

Posterior ostectomy of a mandibular distal segment for nerve bundle traction to tensionless anastomosis of an inferior alveolar nerve.

Tensionless adaptation of nerve ends is a challenging task in the repair of damaged inferior alveolar nerve (IAN). A new technique is introduced with posterior ostectomy of a mandibular distal segment after sagittal splitting for nerve bundle traction to tensionless anastomosis of nerve ends. We were able to create tensionless anastomosis of an IAN defect without autogenous or alloplastic graft using this method. This method is suitable for neurorrhaphy after neuroma removal in cases of IAN damage during dental procedures.

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.

Clinical Outcomes of Minimally Invasive Corneal Neurotization After Cerebellopontine Angle Neurosurgical Procedures.

PURPOSE: To report 12 patients with neurotrophic keratopathy due to the trigeminal nerve injury after intracranial tumor surgeries underwent minimally invasive corneal neurotization and evaluate the outcomes of corneal reinnervation. METHODS: Twelve patients (12 eyes) with neurotrophic keratopathy caused by the trigeminal nerve injury after intracranial surgeries received minimally invasive corneal neurotization. All the preoperative central corneal sensation was under 5 mm, and minimally invasive corneal neurotization was performed over 6 months after the intracranial surgery. Follow-up was conducted 1 week and 1 month after the surgery and then every 3 months. Twelve healthy age-matched participants were enrolled as controls. The indicators included corneal sensation, best-corrected visual acuity, corneal nerve fiber length and branch density, diameter of nerve trunk, corneal ulcer lesion ratio, and sensation of the contralateral forehead. RESULTS: Mean follow-up was 24.7 ± 7.1 months. Mean central corneal sensation rose from 0.4 ± 1.4 to 31.7 ± 21.8 mm. Corneal nerve fiber length improved from 9.56 ± 5.00 to 14.96 ± 4.65 mm/mm2 and corneal nerve branch density and diameter of nerve trunk both increased (p < .01 and p < .05, respectively). Corneal lesion ratio decreased from 0.17 ± 0.12 to 0.10 ± 0.10 (p < .01). CONCLUSIONS: Minimally invasive corneal neurotization promotes corneal reinnervation for patients with neurotrophic keratopathy induced by the trigeminal nerve injury after intracranial surgeries. The process of corneal reinnervation after minimally invasive corneal neurotization often lasts over 12 months, and it takes about 18 months to return to a higher level. Corneal sensation and corneal nerve fiber length are related to clinical outcomes such as corneal ulcer lesion and best-corrected visual acuity. The effect on the sensation of the contralateral side forehead is temporary, and most patients can restore normal forehead sensation of the contralateral side.

Does the Lag Time Between Injury and Treatment Play a Role in Recovery of Inferior Alveolar Nerve Neurosensory Disturbances Following Mandibular Body Fracture?

BACKGROUND: The lag time between injury and treatment (LTIT) plays an important role in reduction of complications in mandibular fractures. The aim of this study was to measure the effect of LTIT on recovery of the inferior alveolar nerve (IAN) neurosensory disturbances (NSDs) following surgical management of mandibular body fractures. METHODS: This was a prospective cohort study. Patients who had a unilateral mandibular body fracture with paresthesia were studied. Paresthesia was evaluated by 2-point discrimination (TPD) test, brush stroke test and self-reporting before and 6 months after the surgical procedure. RESULTS: Forty-five patients were studied. There was a correlation between LTIT and TPD test result and self-reported paresthesia at 6 months, postoperatively (P = 0.001). Fifteen patients (33.3%) had complete improvement in NSD 6 months after treatments (group 1) and 30 patients (group 2) had hyposthesia (N = 17, 37.77%) and paresthesia (N = 13, 28.88%). There was a significant difference in LTIT between groups 1 and 2 at 6 months postoperatively (P = 0.001). Cox regression model demonstrated the hazard ratio increased significantly for self-reported NSD when treatment was done 10 days after trauma (P = 0.001, confidence level = 95%). CONCLUSION: It seems that conduction of open reduction with internal rigid fixation shortly after mandibular fracture may shorten the recovery time of NSDs of the IAN following mandibular body fractures.

Magnetic resonance imaging-a diagnostic tool for postoperative evaluation of dental implants: a case report.

OBJECTIVE: Compared with cone beam computed tomography (CBCT), magnetic resonance imaging (MRI) might be superior for the diagnosis of nerve lesions associated with implant placement. STUDY DESIGN: A patient presented with unilateral pain associated with dysesthesia in the region of the right lower lip and chin after implant placement. Conventional orthopantomography could not identify an association between the position of the inferior alveolar nerve and the implant. For 3-dimensional display of the implant in relation to the surrounding anatomy, CBCT was compared with MRI. RESULTS: MRI enabled the precise depiction of the implant position and its spatial relation to the inferior alveolar nerve, whereas the nerve position and its exact course within the mandible could not be directly displayed in CBCT. CONCLUSION: MRI may be a valuable, radiation-free diagnostic tool for the visualization of intraoral hard and soft tissues, offering an objective assessment of nerve injuries by a direct visualization of the inferior alveolar neurovascular bundle.

Resection of the Posterior, Middle, and Anterior Superior Alveolar Nerves and Infraorbital Nerve Neurolysis for Refractory Maxillary Pain.

Trigeminal injury can cause intractable facial pain. However, surgical approaches to the superior alveolar nerves have not been widely described. We report resection of the anterior superior alveolar nerve (ASAN), middle superior alveolar nerve (MSAN), and posterior superior alveolar nerve (PSAN) in a patient with refractory facial pain and outline an algorithmic approach to the treatment of trigeminal nerve injury. A 56-year-old woman presented with a 3-year history of refractory facial pain in the distribution of the right superior alveolar nerves after dental trauma. As a comorbidity, central sensitization developed in the patient, manifesting in the uninjured oral areas being painful. After several temporary nerve blocks and medical management, the patient underwent resection of the ASAN, MSAN, and PSAN, as well as neurolysis of the infraorbital nerve, through a Caldwell-Luc approach. One week postoperatively, she reported substantial improvement in pain symptoms, including burning and temperature sensitivity, in the right maxilla. These findings were maintained at 7 months, without any maxillary sinus complications. Central sensitization caused continued intraoral symptoms. The ASAN, MSAN, and PSAN can be surgically resected within the maxillary sinus to treat refractory neuropathic pain. An etiology-based approach can guide successful treatment of trigeminal neuropathy. Central sensitization as a comorbidity must be addressed medically.

Surgical treatment of painful inferior alveolar nerve injuries following endodontic treatment: a consecutive case series of seven patients.

PURPOSE: Injuries of the inferior alveolar nerve (IAN) related to endodontic treatment are being increasingly reported. However, consensus on the preferred intervention and the timing of and indications for surgical treatment is lacking. Here, we describe our experience with painful IAN injuries arising from endodontic treatment and requiring prompt microsurgical treatment. METHODS: Seven consecutive patients with painful IAN injuries were referred to the Maxillofacial Surgery Unit of San Paolo Hospital in Milan. All patients had undergone root canals endodontic treatment in the mandibular molar or premolar between 2007 and 2014. The time elapsed between injury and referral for surgical treatment ranged from 10 days to 20 months. Each patient was treated by one of several different microsurgical procedures, described herein. RESULTS: Overall, neurosensory status and IAN-related pain improved in all seven patients. The best results were obtained by IAN replacement with a sural nerve graft. However, complete sensory recovery was not achieved in any of the patients. CONCLUSIONS: Although our sample includes only seven patients, early surgical treatment with an interpositional sural nerve graft seems to allow neurosensory recovery. Less satisfactory results are achieved in patients with IAN injuries of > 12 months duration.

Secondary surgical decompression of the inferior alveolar nerve after overfilling of endodontic sealer into the mandibular canal: Case report and literature review.

The authors report the case of a 43-year-old woman who underwent endodontic treatment of the right second mandibular molar with substantial extrusion of endodontic material into the mandibular canal. The patient presented at the Department of Oral and Maxillofacial Surgery with a persistent total anaesthesia of the lower lip and chin after two months. 2D panoramic view and 3D CT-scan examination highlighted the overfilling into the mandibular canal with a more than 50% stenosis of the canal and a consequently significant compression of the dental pedicle. A surgical decompression of the inferior alveolar nerve was performed through an inferior vestibular approach, using PiezoSurgery®. The tooth was conserved. After a period of 8days, paraesthesia of the lower lip and chin appeared. Thermoalgic sensitivity was recovered at 1month. At 3months postoperatively, the patient had recovered protopathic and epicritic sensitivity. Dental prosthetic rehabilitation was finally achieved one year postoperatively. The authors discuss the physiopathology of nervous injuries during dental procedures, and further strategies in the case of persistent neurologic disorders.

Microsurgical Decompression of Inferior Alveolar Nerve After Endodontic Treatment Complications.

Iatrogenic injury in oral surgery is the most frequent cause of sensory disturbance in the distribution of the inferior alveolar nerve (IAN) and mental nerve.Inferior alveolar nerve damage can occur during third molar extraction, implant location, orthognathic surgery, preprosthetic surgery, salivary gland surgery, local anesthetic injections or during the resection of benign or malignant tumors.Injuries to the IAN can be caused also by endodontic treatment of mandibular molars and premolars when filling material is forced into the tooth and mandibular canal.The sensory disturbances that could follow a damage of the IAN could be hypoesthesia, dysesthesia, hyperesthesia, anesthesia, and sometimes a painful anesthesia that strike ipsilateral lower lip, chin, and teeth. These can undermine life quality by affecting speech, chewing, and social interaction.Treatment of these complications is sometimes difficult and could consist in observation or in surgical decompression of the involved nerve to relieve the patient's symptoms and improve sensory recovery. The most debated points are the timing of intervention and the effective role of decompression in clinical outcome-improvement.The purpose of this article is to show authors' experience with 2 patients treated with microsurgical nerve decompression to remove endodontic material from the mandibular canal and providing also a comprehensive review of the literature.

Efficacy of Acellular Nerve Allografts in Trigeminal Nerve Reconstruction.

PURPOSE: During trigeminal nerve repair, a gap is sometimes encountered that prevents the tension-free apposition of nerve endings. The use of a processed acellular nerve allograft is a novel technique that shows promise in overcoming this problem. The goal of the present study was to support the slowly evolving body of evidence that acellular processed nerve allografts (Avance; Axogen, Alachua, FL) are a viable alternative to autogenous nerve grafting and the use of conduits for reconstructing defects of the trigeminal nerve. PATIENTS AND METHODS: The study design consisted of a retrospective review of the medical records of patients referred to Rutgers School of Dental Medicine for management of trigeminal nerve injuries from July 2008 to August 2014. Sixteen patients met the inclusion criteria for the present study. All patients underwent nerve grafting using a processed nerve allograft. All operations were performed by the same surgeon (V.Z.). Serial neurosensory testing was performed by 1 clinician (V.Z.) in a standardized fashion. The primary outcome variable was the interval to functional sensory recovery as defined by the Medical Research Council Scale. RESULTS: The participants ranged in age from 16 to 62 years (mean 32). Of the 16 patients, 12 were female (75%) and 4 were male (25%), and 3 were smokers (18.75%) and 13 were nonsmokers (81.25%). One half of the patients (n = 8; 50%) underwent surgery on the inferior alveolar nerve, and 8 (50%) underwent surgery on the lingual nerve. The most common mechanism of injury was impacted third molar removal (n = 9; 56.25%) Of the 16 patients, 15 (93.75%) achieved functional sensory recovery during the study period. CONCLUSIONS: The results of the present study support the hypothesis that processed nerve allografts are effective in reconstructing small (<2-cm) trigeminal nerve defects.

Anterior loop of the mental nerve, mental foramen and incisive nerve emergency: tridimensional assessment and surgical applications.

PURPOSE: The aim of this study was to investigate the prevalence and length of the anterior loop (AL), the distance from this landmark to the alveolar crest and its relation with the shape of the foramen and emergency pattern in the Spanish population on helical computed tomography scan (helical CT scan) through tridimensional reconstructions. METHODS: Helical CT scan images of 41 patients aged 65 or older were analyzed. A total of 82 human hemi-mandibles were examined in this study. A tridimensional reconstruction of each mandible and Inferior Alveolar Nerve canal was created in AMIRA® software (AMIRA, Mercury Computer Systems, Berlin, Germany). Prevalence, length and distance between the AL, mental foramen and alveolar ridge were measured. This retrospective observational study was performed according to the STROBE guidelines. RESULTS: Prevalence of the AL was 53.7 % (n = 44) and the mean length was 1.3 ± 0.64 mm. The mean distance from the highest point of the loop to the alveolar ridge was 13.4 ± 2.8 mm. The mean diameter of the mental foramen was 3.5 ± 0.65 mm and the proportion of the oval-shaped was 62.2 % (n = 51) and round-shaped was 37.8 % (n = 31). The study found that patients with type 1 pattern emergency pattern had a higher prevalence of the AL (p = 0.03). CONCLUSIONS: Prevalence, location and length of the anterior loop can be overlooked if only two-dimensional pre-surgical studies are performed. Therefore, three-dimensional imaging and modeling of anatomic structures should be used for the pre-operative examination of the interforaminal area. Given the wide variability of the emergency pattern of the mental nerve and the prevalence and location of the anterior loop, it should be studied in every patient individually.

Enophthalmos and Hemifacial Skeletal Atrophy After Trigeminal Nerve Injury.

A 60-year-old woman presented with several years increasing right upper eyelid ptosis. She had undergone surgical decompression of the right trigeminal nerve in the posterior cranial fossa 15 years earlier for trigeminal neuralgia. This left her with permanent numbness in the second and third divisions of the trigeminal nerve. In addition to the ptosis, she was found to have right enophthalmos and a smaller right face. CT scans showed a smaller midfacial skeleton on the right and a depressed orbital floor. The changes were different to those seen in silent sinus syndrome. Photographs taken over many years showed the facial changes were acquired and came on gradually many years after the trigeminal nerve injury. It is possible that trigeminal nerve injury may lead to trophic changes in the facial skeleton, but these have not been previously reported.

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

PURPOSE: Contemporary management of ablative jaw defects includes not only hard and soft tissue reconstruction, but also restoration of neurosensory function. The goal of this study was to determine the outcomes of immediate reconstruction of long-span defects (≥50 mm) of the inferior alveolar nerve (IAN) after ablative mandibular resection using allogeneic nerve grafts. MATERIALS AND METHODS: A retrospective cohort study of patients who underwent immediate reconstruction of IAN gaps of at least 50 mm with allogeneic nerve graft (AxoGen Avance, Alachua, FL) at a single academic medical center by a single surgeon (M.M.) from September 2013 to March 2015 was completed. Demographic and clinical data were collected for each patient and analyzed using clinical neurosensory testing and were reported using the Medical Research Council Scale (MRCS) for functional sensory recovery. In addition, patient subjective perception of neurosensory recovery was recorded using a visual analog scale (VAS). Subjective (VAS) and objective (MRCS) measurements of functional sensory recovery were recorded and compared across the study population. In addition, examined demographic and clinical data included patient age, gender, pathology, length of nerve allograft, and follow-up period. RESULTS: Of 12 with nerve repairs, 7 patients met the inclusion criteria. The average age was 34.7 years (range, 18 to 61 yr) and 71.4% were men. All IAN defects resulted from resection of mandibular pathology (6 benign lesions, 1 malignant lesion). Six of the 7 IAN defects were reconstructed with a 70-mm nerve allograft, and 1 nerve defect was reconstructed with a 50-mm graft. Mean follow-up time was 17.7 months (range, 10 to 27.5 months). Mean VAS score reported was 3.7 (range, 0 to 7). In addition, 85.7% of patients displayed return of some superficial pain and tactile sensation without over-response (S3), with 14.3% displaying good stimulation localization (S3+). The patient who displayed S3+ recovery underwent reconstruction with the 50-mm graft. Only 1 of the 7 patients had no neurosensory recovery (S0). CONCLUSIONS: 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.

Management of endodontic injuries to the inferior alveolar nerve.

OBJECTIVE: Functional sensory recovery from microsurgical intervention for inferior alveolar nerve (IAN) injuries resulting from endodontic treatment were evaluated using a retrospective chart review. Other variables assessed included time from injury to surgery as well as other factors which improved functional neurosensory recovery (FSR). METHOD AND MATERIALS: This case series of seven patients evaluated the outcome of IAN microsurgery following endodontic-related nerve injuries. All patients were referred, evaluated, and operated on by the primary investigator (VBZ). Surgical intervention consisted of external and/or internal neurolysis with irrigation of the mandibular canal and decompression of the affected IAN as well as allogeneic nerve graft in one patient. Preoperative and postoperative sensory levels were recorded and FSR was assessed using the Medical Research Council scale. RESULTS: Seven subjects with a mean age of 35.57 years (range 22 to 55 years old) opted to undergo trigeminal nerve microsurgery for management of their IAN injury resulting from endodontic treatment of mandibular molar teeth. Six women and one man were included in this population. The majority of subjects presented with an initial chief complaint of dysesthesia and hypoesthesia. The mean interval between nerve injury and surgical treatment was 15 weeks (range 1 to 40 weeks). All patients had preoperative sensory level of S0, S1, or S2+, and achieved FSR following surgery. Two patients had postoperative sensory level of S3, four patients had a postoperative sensory level of S3+, and one had a postoperative sensory level of S4 (complete recovery). CONCLUSIONS: The results of this study suggest that trigeminal nerve microsurgery for the surgical treatment of endodontic injuries to the IAN can improve neurosensory function. Surgical intervention in this study was beneficial to alleviate neurosensory deficits and symptoms for those injuries to the IAN caused by endodontic treatment.