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Background: Cone-beam computed tomography (CBCT) provides additional 3-dimensional information on the relationship between the mandibular third molar (M3M) and the inferior alveolar nerve (IAN). As such, CBCT is being increasingly utilized in preoperative M3M assessment., Purpose: The purpose of the study was to compare the radiographic findings on panoramic and CBCT and their association with postoperative IAN paresthesia., Study Design, Setting, Sample: We conducted a retrospective cohort study in a sample of patients referred to the Department of Oral and Maxillofacial Surgery at the Royal Dental Hospital of Melbourne, for management of impacted M3Ms. Patients were included in this study if they had 1 or more high-risk findings on orthopantomogram (OPG), had both OPG and CBCT imaging taken and if at least 1 M3M had been extracted. Subjects were excluded from this study if their M3Ms were not extracted or if a CBCT was not indicated., Independent Variable: The independent variable was radiographic features identified on OPG (Rood and Shehab's radiographic signs, root morphology, impaction type, Pell and Gregory classification) and CBCT (number and location of roots, severity of IAN compression and the presence of ankylosis)., Main Outcome Variable: The outcome variable was postoperative neurosensory function defined as any reported paresthesia at 2-week postprocedural review., Covariates: The covariates were patient demographic information (age, sex)., Analyses: Variables were initially assessed with univariate logistic regression analysis to determine factors related to developing postoperative paresthesia. Multivariate logistic regression analysis was then used to assess the association between positive univariate study variables and postoperative paresthesia, while adjusting for potential confounders. Covariates were assessed using an omnibus likelihood ratio test and included if they were statistically significant at the P < .05 level., Results: The study sample consisted of 257 subjects who underwent surgical removal of n = 386 M3Ms. The mean age was 25.9 (standard deviation = 7.05). The panoramic features of narrowing of canal, diversion of canal and dark and bifid roots were identified as statistically significant associations of postoperative paresthesia. No CBCT features were significantly associated of postoperative paresthesia., Conclusion and Relevance: Certain panoramic features, along with patient age, are significant predictors of IAN paresthesia. CBCT findings were not significant predictors upon multivariate analysis, thus additional CBCT imaging did not significantly improve ability to predict paresthesia., (Copyright © 2025 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The number of dental implants placed and restored every year is increasing across the world. However, there has been an increase in the number of reports with implant-related surgical complications in which the inferior alveolar nerve injury is the most serious one. This surgical problem can be avoided by using cone beam computed tomography (CBCT), three-dimensional (3D) implant planning software, and computer-aided design and computer-aided manufacturing (CAD-CAM) technology such as stereolithographic surgical guides. The objective of this report is to present the clinical and radiologic findings of a female patient with the injury of inferior alveolar nerve after implant insertion where CBCT has not been used prior to implant placement.

Background: Mandibular nerve injury is a common clinical condition that affects clinicians' management and patients' quality of life. In the literature, there are various effective treatments available. The primary purpose of this study was to determine and compare the effects of dexamethasone and concentrated growth factor (CGF) on regeneration in patients with nerve trauma that mimics clinical situations., Methods: In this study, 36 rats were divided into 3 groups: the control, dexamethasone and CGF groups. The inferior alveolar nerve was traumatized through the extraction socket after mandibular molar tooth extraction in each group., Results: The data showed a decrease in the control (4.5-4), dexamethasone (3-2), and CGF (4-3) groups according to the histological injury severity score (HISS) results. Compared with those in the other groups, the number of degenerative axons and edematous areas observed via histological examination were significantly lower in the CGF groups. Similarly, compared with those in the control group, the nNOS and Neurofilament-H positivity in the dexamethasone group on the 30th day (2,2 to 1,1 respectively) was significantly lower. The positivity of all the primary antibodies in the 3rd and 30th day CGF groups was significant compared than that in the dexamethasone 30th day group., Conclusion: According to the results of the analysis of the immunohistopathological and HISS data, the CGF groups exhibited greater regeneration than did the dexamethasone groups., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Introduction: Mandibular fractures are common in maxillofacial trauma, often requiring surgical intervention for optimal recovery. One critical concern during such procedures is the potential for nerve damage, specifically involving the mandibular canal. This study aims to investigate whether the presence of postoperative mandibular canal discontinuity is associated with an increased risk of nerve damage., Methodology: A retrospective analysis was conducted on a cohort of 72 postoperative mandibular fracture patients. In total, 58 patients had entire mandibular canal continuity, while 14 showed discontinuity. Clinical records and follow-up data were examined to assess the occurrence of nerve injury. Statistical analysis was performed to determine the significance of any correlation., Results: Of the 14 patients with mandibular canal discontinuity, 9 (64.28%) exhibited paresthesia. In patients where mandibular canal continuity was maintained, 5 (8.62%) patients reported paresthesia. These results suggest a higher incidence of paresthesia in patients with mandibular canal discontinuity, albeit with a small sample size. Notably, only 3 patients in the discontinuity group did not show any sign of improvement, while the remaining patients in both groups demonstrated complete recovery in 6 months of follow-up period., Discussion: The findings suggest a potential link between mandibular canal discontinuity and an increased risk of paresthesia in postoperative mandibular fracture patients. It is hypothesized that discontinuity may lead to nerve compression, irritation, or direct damage during healing. The observed complete recovery in most patients, including those with paresthesia, highlights the potential for the nervous system to repair itself over a period of time. However, further studies with larger sample sizes are warranted to establish a more definitive correlation., Conclusion: This study provides preliminary evidence that mandibular canal discontinuity may contribute to a higher incidence of paresthesia in postoperative mandibular fracture patients. Clinicians should be cautious when addressing mandibular fractures to minimize the risk of nerve damage, particularly in cases involving canal discontinuity. The encouraging trend of complete recovery among the majority of patients suggests a positive prognosis for nerve healing., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Objective: An altered sensation during endodontic treatment can occur due to the extrusion of endodontic materials. This study aims to discuss intentional replantation to address paresthesia resulting from an endodontic file penetrating the inferior alveolar nerve canal and provide a protocol for managing nerve injuries in such incidents., Case Presentation: A 12-year-old girl developed paresthesia when an endodontic file separated and was inadvertently pushed through the apical foramen into the inferior alveolar nerve canal during root canal treatment of the mandibular left first molar. A CBCT scan revealed the file penetrating the canal towards the inferior border of the mandible. After considering the treatment options, intentional replantation was deemed suitable. The tooth was atraumatically extracted and preserved in sterile saline. The surgeon then carefully cleaned and irrigated the socket. The radiographic assessment confirmed successful file removal from the socket. The root ends were resected, and retrograde preparation and obturation were conducted using ultrasonic tips and mineral trioxide aggregate. The tooth was then replanted into the socket. Successful replantation was confirmed by tooth stability and an audible click. The patient was prescribed antibiotics and steroids. After completion of the endodontic treatment, a stainless steel crown was cemented. The successful intentional replantation procedure resulted in rapid improvement in the patient's condition. The normal sensation had been restored, indicating nerve recovery. At the 15-month follow-up, periapical bone healing and the eruption of the adjacent second molar were observed, affirming the treatment protocol's overall success., Conclusion: Prompt intervention and immediate intentional replantation facilitated direct inspection of the separated file within the socket. Collaboration between an oral maxillofacial surgeon and an endodontist ensures expedited and targeted treatment, leading to favorable outcomes.

Background: Inferior alveolar nerve (IAN) injury is one of the complications of impacted lower mandibular third molar (LM3) extraction. Given the unknown prognosis of IAN injuries and limited treatment options, it is critical to understand the risk factors of IAN injury before LM3 extraction., Purpose: The purpose of the study was to identify risk factors associated with IAN injury after LM3 extraction., Study Design, Setting, Sample: This was a prospective cohort study including patients who underwent LM3 extraction from May to December 2021 at the authors' institution. Patients with systemic diseases, previous maxillofacial surgeries, or sensory abnormalities were excluded., Predictor Variable: The predictor variable is composed of several risk factors. The variables were grouped into four categories: demographic, radiographic, procedure-related, and surgeon experience., Main Outcome Variable(s): The outcome variable was postoperative neurosensory disturbance coded as present or absent and was measured at 1-month (transient) and 1-year (permanent)., Covariates: Not applicable., Analyses: The measurement data were represented by mean and standard deviation. The association of each variable with the presence of an IAN injury was tested by the χ 2 test. Statistical significance was accepted at P < .05., Results: The study sample consisted of 705 patients (37.0% male) with an average age of 28.51 ± 6.51 years. A total of 17/705 (2.4%) and 4/705 (0.57%) patients developed transient and permanent IAN injuries. The results demonstrated that the following factors were associated with higher rates of transient injury: use of chisels during surgeries (6.4%; 95% confidence interval (CI): 2.7 to 12.3; P = .02; relative risk (RR) = 11.4), LM3s located below the IAN canal (8.7%; 95% CI: 4.3 to 15.7; P < .01; RR = 7.3), compressed contact between LM3s and the IAN canal (36.4%; 95% CI: 12.3 to 78.2; P < .001; RR = 25.4), and not using corticosteroids after surgeries (3.8%; 95% CI: 1.9 to 6.5; P = .03; RR = 3.1). The only factor associated with permanent injury was compressed contact between LM3s and the IAN canal (18.2%; 95% CI: 2.2 to 62.3; P < .001; RR = 48.2)., Conclusion and Relevance: Close proximity between LM3s and IAN canal and the use of chisels increase the risk of transient IAN injury. Corticosteroid treatment may promote nerve recovery. Compressed contact between LM3s and IAN canal is the only risk factor for permanent injury., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Dental malpractice claims, which pertain to legal actions against dentists accused of clinical negligence that caused harm to patients, have increased in the past ten years in South Korea. The claims are caused by complications, particularly trigeminal nerve injuries, resulting from various dental procedures. Medicolegal issues related to trigeminal nerve injury have not been previously described in South Korea. Therefore, in this study, we aimed to identify the general, dental, and judicial characteristics of closed dental malpractice claims., Methods: This study was designed as a descriptive study. We collected the data of 51 closed claims related to trigeminal nerve injury resulting from dental procedures such as dental implant emplacement, tooth extraction, and local anesthesia. The claims were decided by courts in South Korea between 2016 and 2023. The general, dental, and judicial characteristics of the claims were analyzed retrospectively., Results: The average claim resolution period was 4.2 (range: 1.47-8.39) years post-adverse events that occurred more frequently in dental clinics (68.6 %) than in dental (25.5 %) or general hospitals (5.9 %). Inferior alveolar (66.7 %) and lingual (17.6 %) nerves were injured following dental procedures. The duty to inform was breached in 68.6 % of claims. The dental procedure performed (P < 0.001) and the injured nerve (P < 0.001) were associated with the violation of the duty to care., Conclusion: To improve the quality of dental care services, the analysis of the adverse events using various resources including judgments should be strongly addressed., Competing Interests: Declaration of competing interest The author declares no conflicts of interest., (Copyright © 2024 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

The following case report presents a 37-year old male patient who was referred for an emergency assessment due to suspected neurovascular damage of the inferior alveolar nerve following placement of two implants in the posterior left mandible. Immediate explantation for nerve decompression is essential combined with supportive analgesic and antiphlogistic medication. Furthermore, oral glucocorticoids were prescribed, starting with 20mg with a stepwise phasing out of the medication thereafter., (Copyright 2024 Sandra Fatori, Claude Anderoni, Heinz Theo Lübbers, Sonja Gröschel, Michael M. Bornstein. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

Purpose: To assess the impact of endoscope-assisted fractured roots or fragments extraction within the mandibular canal, along with quantitative sensory testing (QST) alterations in the inferior alveolar nerve (IAN)., Methods: Six patients with lower lip numbness following mandibular third molar extraction were selected. All patients had broken roots or fragments within the mandibular canal that were extracted under real-time endoscopic assistance. Follow-up assessments were conducted on postoperative days 1, 7, and 35, including a standardized QST of the lower lip skin., Results: The average surgical duration was 32.5 min, with the IAN exposed in all cases. Two of the patient exhibited complete recovery of lower lip numbness, three experienced symptom improvement, and one patient remained unaffected 35 days after the surgery. Preoperative QST results showed that the mechanical detection and pain thresholds on the affected side were significantly higher than those on the healthy side, but improved significantly by postoperative day 7 in five patients, and returned to baseline in two patients on day 35. There were no significant differences in the remaining QST parameters., Conclusions: All endoscopic surgical procedures were successfully completed without any additional postoperative complications. There were no cases of deterioration of IAN injury, and lower lip numbness recovered in the majority of cases. Endoscopy allowed direct visualization and examination of the affected nerve, facilitating a comprehensive analysis of the IAN., (© 2024. The Author(s).)

Inferior alveolar nerve (IAN) injury is a severe complication associated with mandibular third molar (MM3) extraction. Consequently, the likelihood of IAN injury must be assessed before performing such an extraction. However, existing deep learning methods for classifying the likelihood of IAN injury that rely on mask images often suffer from limited accuracy and lack of interpretability. In this paper, we propose an automated system based on panoramic radiographs, featuring a novel segmentation model SS-TransUnet and classification algorithm CD-IAN injury class. Our objective was to enhance the precision of segmentation of MM3 and mandibular canal (MC) and classification accuracy of the likelihood of IAN injury, ultimately reducing the occurrence of IAN injuries and providing a certain degree of interpretable foundation for diagnosis. The proposed segmentation model demonstrated a 0.9 % and 2.6 % enhancement in dice coefficient for MM3 and MC, accompanied by a reduction in 95 % Hausdorff distance, reaching 1.619 and 1.886, respectively. Additionally, our classification algorithm achieved an accuracy of 0.846, surpassing deep learning-based models by 3.8 %, confirming the effectiveness of our system., Competing Interests: Declaration of competing interest None Declared., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Neurosensory disturbance (NSD) is a common complication after sagittal split ramus osteotomy (SSRO) due to inferior alveolar nerve (IAN) injury. The impact of intraoperative nerve manipulation on NSD remains debated., Purpose: The purpose of this study was to evaluate the influence of IAN exposure and manipulation during SSRO on functional sensory recovery (FSR)., Study Design: This was a single-center, prospective cohort study of 40 patients undergoing SSRO at Mahidol University from December 2020 to December 2021. The inclusion criteria were patients aged 20-34, ASA Class I-II. The exclusion criteria were patients with systemic bone disease, history of head and neck or neurological pathology, previous SSRO, or incomplete data collection., Predictor Variable: Degree of intraoperative nerve manipulation was divided by the attending surgeon as follows; 1) Nerve fully encased in distal segment and not visible (NS); 2) Nerve encased in distal segment but partially visible (DS); and 3) Nerve partially encased in proximal segment and fully dissected free (PS)., Outcome Variables: The area of interest was divided into the lip and chin. The primary outcome was time to FSR. The secondary outcome was subjective patient report, using a visual analogue scale, compared to FSR., Covariates: The covariates were sex, age, skeletal diagnosis, degree of movement, and concomitant genioplasty/subapical procedure., Analyses: Kaplan-Meier survival analysis, Cox proportional hazards regression, and Mcnemar test were utilized. P-value < .05 was significant., Results: In the lip, the median times to FSR were NS, 2 days; DS, 45 days; PS, 102 days. (Interquartile range: 77,127, 114, respectively) In the chin, the median times to FSR were NS, 23 days; DS, 92 days; PS, 87 days. (Interquartile range: 77, 161, 101, respectively.) Nerve manipulation significantly affected FSR in the lip and chin (P = .001, <0.001, respectively. Cox hazard ratios for DS and PS were lower compared to NS. Patients consistently reported more NSD compared to FSR as per Mcnemar test., Conclusion and Relevance: After SSRO, FSR in the lip is prolonged when the IAN is partially encased in the proximal segment and released. This raises the question of the efficacy of surgically releasing a partially encased IAN., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

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; I 2 (inconsistency index) = 0%; P = .0001], postoperative pain (OR: 0.97; 95% CI: 0.33-2.86; I 2  = 81%; P = .01), and alveolitis (OR: 0.38; 95% CI: 0.13-1.09; I 2  = 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; I 2  = 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., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Surgical extraction of the lower third molar (LTM) may trigger neurosensory injury of the inferior alveolar nerve, making extraction a real challenge. This study set out to assess whether is it possible to predict neurosensory alterations from preoperative imaging., Material and Methods: A total of 99 patients underwent 124 impacted lower third molar (ILTM) surgeries. Prior to surgery, panoramic and CBCT images were evaluated in an attempt to predict a neurosensory disturbance. Preoperative data (ILTM position, panoramic radiograph signs, inferior alveolar nerve (IAN) location and its contact with the ILTM roots) and intra/postoperative findings (extraction difficulty and sensitivity alterations) were recorded. Descriptive and bivariate data analysis was performed. Statistical comparison applied the chi-square test, Fisher test, and one-way ANOVA test. Statistical significance was established with a confidence interval (CI) of 95%., Results: In 4.03% of cases, patients experienced neurosensory alterations. Of 124 ILTM positions in panoramic radiographs, 76 cases were considered to exhibit a potential neurosensory risk as they presented two or more types of superimposed relationships between ILTM and mandibular canal. Of these, alterations were reported in only three cases (3.95%). Of the 48 remaining ILTM images presenting only one sign, neurosensory alterations were observed in two cases (4.17%). No permanent alterations were recorded in any of the five cases observed., Conclusions: Within the limitations of the present study, prediction of neurosensory alterations prior to ILTM extraction by means of preoperative imaging did not show a significant statistical correlation with post-surgical incidence. Nevertheless, interruption of the canal´s white line (ICWL) or a diversion of the canal (DC) may predict an increased risk of IAN injury.

Introduction: We hypothesize that the removal of mandibular third molars (M3) 6 months prior to a bilateral sagittal split osteotomy (BSSO) could allow the displacement of the inferior alveolar nerve (IAN) in a favorable lingual position. This study aimed to radiographically compare the position of IAN before and after M3 removal in patients with Class II malocclusion., Materials and Method: The CBCT images of 30 randomly selected patients (mean age 15.5 years, 19 females and 11 males) were segmented regarding the mandibular bone and the IAN canal. Mandibles were then superimposed and compared using 3D slicer (www.slicer.org). An orthonormal system was constructed, and the coordinates of IAN were assessed in the x- (horizontal axis), y- (depth axis), and z- (vertical axis) directions., Results: The mean changes in x- and z-values were 0.37 %, -0.09 % for the right IAN, 0.07 %, and -0.10 % for the left IAN, respectively. Y-axis was the dimension the most impacted by the M3 removal with a mean variation of -11.96 % for the right IAN, and 0.45 % for the left nerve (p 1 =0.74 and p 2 =0.04, respectively). Three patients presented a change in the IAN position superior to 1 mm on at least one coordinate axis. We observed a more important change in x-values of the right IAN in male than in female (p = 0.04), and no significant modifications regarding the other dimensions. Finally, there was no correlation between the age of the patients and the changes in IAN position., Conclusion: This study confirms the absence of influence of mandibular third molar removal on the inferior alveolar nerve route prior to BSSO., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Objective: To compare a three-dimensional (3D) artificial intelligence (AI)- driven model with panoramic radiography (PANO) and cone-beam computed tomography (CBCT) in assessing the risk of inferior alveolar nerve (IAN) injury after mandibular wisdom tooth (M3M) removal through a within-patient controlled trial., Methods: From a database of 6,010 patients undergoing M3M surgery, 25 patients met the inclusion criteria of bilateral M3M removal with postoperative unilateral IAN injury. In this within-patient controlled trial, preoperative PANO and CBCT images were available, while 3D-AI models of the mandibular canal and teeth were generated from the CBCT images using the Virtual Patient Creator AI platform (Relu BV, Leuven, Belgium). Five examiners, who were blinded to surgical outcomes, assessed the imaging modalities and assigned scores indicating the risk level of IAN injury (high, medium, or low risk). Sensitivity, specificity, and area under receiver operating curve (AUC) for IAN risk assessment were calculated for each imaging modality., Results: For IAN injury risk assessment after M3M removal, sensitivity was 0.87 for 3D-AI, 0.89 for CBCT versus 0.73 for PANO. Furthermore, the AUC and specificity values were 0.63 and 0.39 for 3D-AI, 0.58 and 0.28 for CBCT, and 0.57 and 0.41 for PANO, respectively. There was no statistically significant difference (p>0.05) among the imaging modalities for any diagnostic parameters., Conclusion: This within-patient controlled trial study revealed that risk assessment for IAN injury after M3M removal was rather similar for 3D-AI, PANO, and CBCT, with a sensitivity for injury prediction reaching up to 0.87 for 3D-AI and 0.89 for CBCT., Clinical Significance: This within-patient trial is pioneering in exploring the application of 3D AI-driven models for assessing IAN injury risk after M3M removal. The present results indicate that AI-powered 3D models based on CBCT might facilitate IAN risk assessment of M3M removal., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Background: The injury of the inferior alveolar nerve (IAN) is one of the most serious complications of impacted mandibular third molars (IMTMs) extraction. The influence of the root orientation of IMTMs on IAN injury is still controversial. A deeper understanding of the risk factors of IAN injury conduces to better prevention of IAN injury. This study aims to explore whether root orientation is an independent risk factor of IAN injury during IMTMs extraction using the statistical strategy of propensity score matching (PSM)., Methods: This retrospective cohort study included 379 patients with 539 cases of high-risk IMTMs screened by panoramic radiography and cone beam computed tomography. The IAN injury incidence after extraction of different groups of IMTMs was analyzed using the chi-square test or Fisher's exact test. The correlation between third molar root orientation and impaction depth/contact degree with IAN was evaluated by the Lambda coefficient. Based on PSM for balancing confounding factors including age, sex, impaction depth, and contact degree, the effect of root orientation on the incidence of IAN injury was further analyzed using Fisher's exact test., Results: There were significant group differences in IAN injury incidence in impaction depth, root orientation, and contact degree of root-IAC before PSM. Root orientation was correlated with impaction depth and contact degree of root-IAC. After PSM, there were 9 cases with IAN injury and 257 cases without IAN injury. There were significant group differences between the buccal and non-buccal groups after PSM, and the risk of IAN injury was higher when the root was located on the buccal side of IAC (OR = 8.448, RR = 8)., Conclusions: Root orientation is an independent risk factor of IAN injury, and the risk is higher when the root is located on the buccal side of IAC. These findings could help better evaluate the risk of inferior alveolar nerve injury before the extraction of IMTMs., (© 2023. The Author(s).)

Injuries to the mental nerve are not an uncommon complication in maxillofacial surgeries. Manipulation close to the mental nerve poses a great risk of nerve injury from drills, bone cutting and trimming burs, and oscillating/reciprocating saws. Nerve injuries can be painful and affect the patient's quality of life. The accompanying complication of the nerve injury depends on the severity of the damage inflicted and can range from transient hypoesthesia to neuropathic pain or trigeminal neuralgia. It is considered that direct injury to the nerve may lead to permanent damage and more severe postoperative clinical symptoms than indirect injuries caused by nerve stretching or during endosteal implant fixation. This technical note describes a technique for shielding the mental nerve and protecting it from rotary drill injury during mandibular inferior border recontouring, orthognathic surgeries, and mandibular body fracture fixation., (Copyright © 2023 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Coronectomy is an operation to manage impacted third molars (M3s) considered at high risk for mandibular nerve injury but long-term outcomes are still lacking. The purpose of this study was to estimate the risk of late complications occurring within 10 years following lower M3 coronectomy., Methods: The investigators designed a prospective cohort study and enrolled a sample of 94 patients treated with coronectomy of third mandibular molars at the Unit of Oral and Maxillofacial Surgery of the University of Bologna, from 2009 to 2012. This follow-up study included all of the patients from the original study who completed 10 years of follow-up. The primary outcome variables is postoperative late complication occurring between 5 and 10 years after coronectomy coded as present or absent. Late complications were defined as root exposure, nerve injury, pulpitis, periapical infection, and reoperation. The secondary outcome variable was probing pocket depth. Covariates examined were age, smoking and type of M3 impaction. Descriptive statistical analyses were performed., Results: The inception cohort was composed of 94 subjects who had 116 coronectomies (k) completed. The study cohort was composed of subjects with 10 years of follow-up and included 48 subjects (k = 60) with a mean age of 28.99 ± 8.9 years. Between years 5 and 10 of follow-up, 2 subjects (4%) have complications; all root exposures diagnosed at years 8 or 9 after surgery. In another case root removal was required for orthodontics reason. No case of nerve injury to the inferior alveolar nerve occurred, and no periapical infection was observed around the residual roots. The mean 10-year probing pocket depth was 3.31 ± 0.92 mm (1,66-5,66 mm). There were too few complications to identify risk factors for late complications., Conclusions: Within all the limitations of this study, the results of this prospective study imply that coronectomy is a useful surgical technique for the treatment of M3s at high neurological risk, to avoid nerve injury to the inferior alveolar nerve. In addition, after coronectomy, retained roots did not develop late infection or periapical infection in the long term. However, in a few cases, removal of retained roots was required at 10 years, due to root migration in the oral cavity. The risk for late complications is uncommon, but persistent., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To assess whether differences exist in signs observed in 2D radiographs of mandibular third molars between a case group of patients with and a control group without permanent sensory disturbance of the inferior alveolar nerve (IAN) after removal., Study Design: Three observers blinded to patient status assessed radiographs from the case group (n=162) and the control group (n=172). Two new signs, craniocaudal relation of the roots and the mandibular canal and position of the canal over the roots; and 4 "classic" signs, interruption of the white borders of the canal, darkening of the roots, narrowing of the canal lumen, and diversion of the canal over the roots were registered. Chi-square tests assessed differences in distribution of radiographic signs between the groups. Odds ratios expressed the association between radiographic signs and permanent sensory disturbance. Inter- and intraobserver reliability values were calculated., Results: We found significantly more teeth with roots positioned inferiorly to the canal borders (P<0.001; OR 4.1-5.3) and with the canal superimposed over the upper or middle third of the roots (P<0.001; OR 2.6-3.9) in the case group than in the control group. Inter- and intraobserver reproducibility was excellent for roots inferior to the canal borders and fair to good for canal superimposition., Conclusions: Two radiographic signs are valid predictors of permanent sensory disturbance of the IAN in 2D radiographs., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objectives: Extraction of impacted mandibular third molars (IMTMs) is the most common surgery performed in the Department of Oral and Maxillofacial Surgery. Inferior alveolar nerve (IAN) injury is a rare but severe complication, and the risk is significantly higher in cases of IMTM near the inferior alveolar canal (IAC). The existing surgical method to extract such IMTMs is either not safe enough or is time-consuming. A better surgical design is needed., Materials and Methods: From August 2019 to June 2022, 23 patients underwent IMTM extraction by Dr. Zhao at Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, and were found to have IMTMs in close proximity to the IAC. Due to high IAN injury risk, these patients underwent coronectomy-miniscrew traction to extract their IMTMs., Results: The time between coronectomy-miniscrew insertion and complete removal of the IMTM was 32.65 ± 2.110 days, which was significantly shorter than that of traditional orthodontic traction. Two-point discrimination testing revealed no IAN injury, and no injury was reported by patients during follow-up. Other complications, such as severe swelling, severe bleeding, dry socket, and limited mouth opening, were not observed. Postoperative pain levels were not significantly higher in the coronectomy-miniscrew traction group than in the traditional IMTM extraction group., Clinical Relevance: For IMTMs that are in close proximity to the IAC and must be extracted, coronectomy-miniscrew traction is a novel approach to minimize the risk of IAN injury in a less time-consuming way with a lower possibility of complications., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Purpose: This prospective cohort study aimed to assess early root migration after a coronectomy of the mandibular third molar at 2 and 6 months after surgery., Methods: We included all patients treated with a coronectomy of an impacted mandibular third molar. The primary outcome measure was the extent of postoperative root migration after 2 and 6 months. Migration was measured as the distance between the root complex and a fixed point on the inferior alveolar canal. The secondary aim was to identify factors (age, impaction pattern, and patient sex) that affected the extent of root migration., Results: One hundred and sixty-five coronectomies were performed in 141 patients (96 females and 45 males; mean age 33.1 years, SD 16.0). The 2-month checkup was completed by 121 patients that received 141 coronectomies. The 6-month check-up was completed by 73 patients that received 80 coronectomies. The mean root migrations were 3.30 mm (SD 2.53 mm) at 2 months and 5.27 mm (SD 3.14 mm) at 6 months. In the 2-6-month interval, the mean root migration was 2.58 mm (SD 2.07 mm). The extents of migration were similar during the 0-2-month interval and the 2-6-month interval (p = 0.529). Younger age was associated with greater root migration, and females experienced significantly greater migrations than males (p = 0.002)., Conclusion: Roots migrated more rapidly in the first two postoperative months, compared to the 2-6-month interval. Age was negatively correlated with the extent of root migration, and females showed significantly greater migrations than males., (© 2022. The Author(s).)

Purpose: To analyse and quantify ocular surface parameters in patients with unilateral neurotrophic keratitis (NK) induced by trigeminal nerve injury post-neurosurgery., Methods: The study included 26 unilateral NK patients who had undergone neurosurgery, and 20 matched normal controls. Demographic and clinical characteristics of all participants were collected and analysed. Slit-lamp examination, Cochet-Bonnet aesthesiometry, Keratograph 5 M, and LipiView interferometer were performed on both eyes of 17 mild NK patients. For nine moderate/severe NK patients, sub-basal nerve density was measured by in vivo confocal microscopy., Results: Of the 26 patients, nine had acoustic neuroma, nine had trigeminal neuralgia, and eight had neoplasms. Facial nerve paralysis was observed in one of the 17 mild NK eyes (5.9%) and seven of the nine moderate/severe NK eyes (77.8%). Compared to contralateral and normal control eyes, 26 NK eyes showed significantly reduced sensitivity in five corneal regions (P < 0.05). Corneal sensitivity in moderate/severe NK eyes was significantly lower than in mild NK eyes (P < 0.05). Moderate/severe NK eyes had poor visual acuity, and their sub-basal nerve density was lower than that of the controls. The onset of the moderate/severe NK was from 0.5 to 24 months (median [Q1, Q3], 1 [0.5, 2.5] months) after neurosurgery. For the mild NK eyes, the number of total blinks, the first non-invasive tear breakup time (NITBUT) and average NITBUT were significantly lower than contralateral and normal control eyes (P < 0.05), and the number of partial blinks and partial blinking rate were significantly higher than the other two control groups (P < 0.05)., Conclusions: Patients with NK induced by trigeminal nerve injury following neurosurgery had decreased corneal sensitivity to various degrees accompanied by increased partial blinks and shortened NITBUT. The severity of NK is related to the severity of the corneal sensory impairment. Facial nerve paralysis can worsen the clinical progression of NK. Trial registration Chinese Clinical Trial Registry (ChiCTR2100044068, Date of Registration: March 9, 2021)., (© 2022. The Author(s).)

Purpose: A recently proposed modification of the sagittal split osteotomy (SSO) of the mandible places the horizontal medial cut 'low and short' of the lingula. The purpose of the study was to answer the following clinical question: Among patients undergoing mandibular setback procedures (≤ 8 mm) via SSO, does the placement of the medial horizontal osteotomy below the lingula (infralingular), when compared to placement above the lingula (supralingular), results in different neurosensory, bite force, and range of motion outcomes?, Materials and Methods: This was a single-center, double-blind, parallel-group study among patients undergoing mandibular setback by SSO (≤ 8 mm), between January 2021 and September 2022. Patients were randomly allocated in a ratio of 1:1 to the supralingular (control) and the infralingular (study) group. Primary outcome variables included neurosensory disturbance of the inferior alveolar nerve based on clinical neurosensory testing and severity graded using Zuniga and Essick's protocol, bite force, and maximum mouth opening evaluated postoperatively during the first week (T1), first month (T2), and third month (T3) of follow-up. Secondary outcome measures included the incidence of a bad split and distal segment interferences intraoperatively. Association between the variables was assessed using Pearson chi-squared test or Fisher's exact test based on the expected observations. A P value of ≤.05 was considered statistically significant., Results: A total of 29 patients (58 osteotomies) were included in the study. Group 1 consisted of 15 patients (9 females and 6 males) with a mean age of 26.4 years. Group 2 consisted of 14 patients (8 females and 6 males) with a mean age of 25.9 years. Patients with severe neurosensory disturbance of the inferior alveolar nerve were more common in group 2 (n = 15, 53.6%) than group 1 (n = 4, 13.3%) at T1 (P value = .0001) and insignificant between the two groups at T2 (P value = .63) and T3 (P value = .99). Comparison of maximum mouth opening between the two groups at T1 (P value = .535), T2 (P value = .934), and T3 (P value = .703) and bite force at T1 (P = .324), T2 (P = .113), and T3 (P = .811) was not significant., Conclusion: Both SSO techniques have similar clinical outcomes among patients having mandibular setbacks (≤ 8 mm) for the variables studied., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The Purpose: Of the study is to reduce the risk of postoperative neuropathy of the inferior alveolar nerve by improving diagnostic methods, assessment of individual topographic and anatomical features and extraction technique of impacted teeth adjacent to the mandibular canal., Materials and Methods: According to the CBCT examination, orthopantomography and macroscopic examination of removed third molars roots ( n =140) the relative position of the mandibular canal and the roots of the third molars were studied., Results: Three variants of close mandibular canal and third molars position have been identified. In the lateral and apical nerve position, the root surface depressions were detected. With inter-radicular position fit, the mandibular canal and the nerve bundle form a «bed» in between impacted tooth roots., Conclusion: The injury of neurovascular bundle prognosis during extraction with an interadicular mandibular position depends on roots anatomy and their convergence degree. If the interradicular distance is less than the diameter of the mandibular canal, nerve injury during tooth extraction is inevitable, in such cases coronectomy is indicated.

Purpose: Neurosensory disturbance is the most common consequence of sagittal split osteotomy (SSO). The purpose of this study is to quantitatively assess neurosensory deficiency and recovery to the preoperative status when the inferior alveolar nerve (IAN) was exposed versus unexposed during SSO., Methods: This is a single-center, prospective, cohort study of all patients undergoing bilateral SSO between August 2018 and July 2019. Patients were included in the study sample if they underwent bilateral SSO with an intact intraoperative IAN and were received follow-up assessment for at least a year. The predictor variable was the intraoperative IAN status (exposed vs unexposed). The outcomes of interest were the rate and timing of recovery to the preoperative status. The covariates were age, sex, and the magnitude and direction of surgical movements. Neurosensory function was quantitatively evaluated using the Semmes-Weinstein monofilament test at follow-up intervals of 1, 3, 6, and 12 months. Descriptive statistics, bivariate statistics, Cox proportional hazards regression, and Kaplan-Meier analyses were performed. P value <.05 was considered statistically significant., Results: Of 90 patients, 86 patients who underwent 172 SSOs were included in this study. The mean age was 22.95 ± 3.34 years (range, 17 to 30), 65 were women, and the range of surgical movements was 3 to 8.3 mm of advancement and 2 to 12 mm of setback. Eighty-five nerves (49.4%) were allocated to the unexposed group, and 87 (50.6%) to the exposed group, with statistically significant differences in the rate and timing of recovery (hazard ratio = 2.368; 95% confidence interval, 1.662 to 3.376; P < .001). Among those with recovered nerves, the median time to recovery was 90 days in the unexposed group and 364 days in the exposed group (P < .0001)., Conclusions: IAN exposure during SSO is associated with an increased risk of neurosensory deficiency and an increased time of sensory recovery to the baseline threshold in patients aged 17 to 30 years. When the IAN remained fully enclosed in the canal of the distal segment, only 11% of patients had a measurable sensory deficit 1 year after surgery. In those patients with any degree of IAN exposure, 36% had a residual sensory deficit 1 year after surgery., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The removal of impacted teeth is a common office-based oral and maxillofacial surgical procedure. Complications associated with the procedure are uncommon; however, in the mandible, close proximity of the third molars to the inferior alveolar nerve can potentially lead to temporary or permanent sensory disturbances. The intentional partial odontectomy (coronectomy) procedure is a surgical option aimed at mitigating and reducing the incidence of this potential risk and complication.

The aim of this study was to assess the occurrence of neurosensory disturbance of the inferior alveolar nerve (IAN) following modified mandibular bilateral sagittal split osteotomy (BSSO) that preserves the mandibular inferior border. All patients undergoing BSSO, associated or not with a Le Fort I osteotomy (performed by the same senior operator) between January 2018 and December 2019, were eligible. The modified BSSO consists of a modification of the technique described by Epker: the bony section of the buccal cortex stops 3-4 mm above the basal mandibular edge. While respecting the basilar border, sectioning is then performed up to the gonial angle where bicortical section is finally performed. Sensibility of the labial and chin area was evaluated immediately postoperatively, and at six months and two years of follow up. A total of 140 eligible patients underwent the modified BSSO between January 2018 and December 2019, and 72 were included. Hypoaesthesia was found in 81.9% of the patients (59/72 patients) at initial evaluation. It decreased to 45.8% (33/72 patients) at the six-month examination and to 12.5% (9/72 patients) at the last examination. Four bad splits were recorded. The modified BSSO preserves the inferior border of the mandible and maintains the IAN in the lingual fragment. There is no need to release the IAN, hence its manipulation is reduced and the incidence of IAN postoperative hypoaesthesia is also reduced., (Copyright © 2022 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Introduction: Maxillofacial trauma can be limited to superficial lacerations, abrasions, and facial bone fractures. The objective of this study was to determine the etiology, pattern, and predictors of soft tissue and bony injuries., Materials and Methods: This study was conducted in the department of maxillofacial surgery Lady Reading hospital Pakistan from Jan 2019 to June 2021. The nonprobability consecutive sampling technique was used for the selection of patients. All patients were assessed clinically and radiologically. The neurosensory examination was done for any altered sensation, anesthesia, or paresthesia. Motor nerve function was also assessed clinically. Data were analyzed using SPSS version 26. The etiology and pattern of maxillofacial trauma were stratified among age and genders using the chi-square test to see effect modifiers. Tests for regression analysis were also applied. P≤0.05 was considered significant., Results: A total of 253 patients meeting inclusion criteria were included in this study. The majority of these patients were males, 223 (88.1%), while only 30 (11.9%) were females. The mean age for the group was 25.4 ± 12.6 years. RTAs were the most common causes of trauma (63.6%) followed by assault (15.0%), falls (11.5%), FAIs (5.9%), and sports (0.4%). The most vulnerable skeletal part was the mandible (22.9%) followed by Zygoma (7.1%), significantly predicted by RTAs. Soft tissue laceration analysis showed a high frequency of multiple lacerations (38%) significantly predicted by FAIs. The frequency of trigeminal nerve injury was 5.5% (14 patients) and that of the facial nerve was 1.6% (4 patients). The strongest association of nerve injury was with firearm injury (47%), followed by road traffic accidents and sports injuries., Conclusion: Road traffic accident was the most common etiological factor and mandible fracture was commonly predicted by RTA. Trigeminal nerve injuries were common, frequency of nerve injuries was highly associated with mandible fracture and was predicted by FAI., Competing Interests: The authors have declared that no competing interests exist.

Objectives: Investigation in Saudi Arabia or the Arab Gulf States to assess the unfavorable impacts of the bilateral sagittal split osteotomy (BSSO) is non-existent, so questions have been raised about the success rate of this operation and the frequency of unwilling outcome. To address these worries, we directed a case series study to evaluate the hypoesthesia, a type of neurosensory deficit (NSD) of the inferior alveolar nerve (IAN) after BSSO, and if the hypoesthesia outcome will improve if the surgeries performed by a single surgeon., Patients and Methods: This was a prospective case series study for the patient who underwent BSSO in a medical complex that is considered one of the largest in Saudi Arabia (Riyadh). The inclusion criteria include patient aged 18-40 years, any gender, and American Society of Anesthesiologists (ASA) class I. They will undergo BSSO for either mandibular, retrognathia, prognathic, or to follow the maxilla. The outcome will be measured after evaluating the neurosensory by four means light touch (LT), pinprick (PP), 2-point discrimination (2PD), and thermal sensations (TT) in four repeated measurements (preoperatively, 1 week, 1 month, 3 months postoperatively) as the primary outcome. Other confounding factors were the secondary outcome (age, gender, visualization of the I.A.N, the type of mandibular movement, split favorability, mandibular canal location, and patient reports about paresthesia or dysesthesia on any given side); these data analyses were carried out using SPSS ver. 25 data processing software., Results: The nerve was visible in 93% of cases. During the operation, none of the nerves was transected. Hypoesthesia on the first follow-up was 94% of cases for LT, 92% for PP, 82% for TT, and 100% for the 2PD. On the last follow-up, the patients still had hypoesthesia for the LT 51%, PP 35%, TT41%, and 2PD 55%; age and sex did not significantly affect hypoesthesia outcomes. Nerve visibility and inferior alveolar nerve canal (IAC) distance did not influence the results. The level of confidence for all tests was set at p < 0.05., Conclusions: The 2PD sensation was the most affected sense on the last visit, and the right side of the chin and lower lip was affected most both on early and long-term follow-up due to several reasons. A 3-month period was enough as a recovery time to restore 100% of neurological sensation for 45% of the sample, which is similar to several studies in the literature. A single surgeon did not show superior result compared to two surgeons' literature papers. Advancement movement was associated with a high percentage of hypoesthesia., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., (Copyright © 2022 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

The present aim was to estimate direct health care costs of patients suffering from post-traumatic trigeminal neuropathy (PTTN) and to compare the use of health care services, medications, and costs between temporary and persistent (>3 months) PTTN cohorts. A pre-existing clinical dataset of PTTN patients visiting a tertiary orofacial pain clinic in Belgium was utilized, including symptoms and quality of life measurements. Cost and resource utilization data were obtained by Belgium's largest health insurance provider for a period of 5 years after onset. Data from 158 patients was analyzed. The average cost per patient in the first year after injury was €2353 (IQR 1426-4499) with an out-of-pocket expense of 25% of the total cost. Hospitalization and technical interventions were the main drivers of cumulative costs, followed by consultation costs. For each cost category, expenditure was significantly higher in patients with persistent PTTN than in those with temporary PTTN (median 5-year total costs in persistent PTTN patients yielded €8866 (IQR 4368-18191) versus €4432 (IQR 2156-9032) in temporary PTTN, p <0.001) PTTN patients received repeated and frequent head and neck imaging (mean number of imaging investigations per patient was 10 ± 12). Medication consumption was high, with an unwarranted higher use of opioids and antibiotics in persistent PTTN patients. Within the limitations of this study, it seems there is a need for informing patients in detail on the inherent risks of nerve damage during dental and oromaxillofacial procedures. Every surgery should be preceded by a risk-benefit assessment in order to avoid unnecessary nerve damage., Competing Interests: Declaration of competing interest None to declare., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: The objective of this study was to identify the incidence of inferior alveolar nerve (IAN) injury after extraction of mandibular third molars with confirmed "high-risk" features on cone beam computed topography scans and establish any risk factors that significantly increase the chances of sustaining an IAN injury., Study Design: This study is a retrospective analysis of outcomes after surgical extraction of 500 mandibular third molars over a 5-year period. All teeth showed signs of contact with or compression of the IAN on cone beam computed topography scans., Results: The overall incidence of IAN injury was 6.6%, with permanent neuropathies accounting for 1.8% within this high-risk cohort. Statistically significant factors shown to increase the risk of nerve injury included increasing age (P = .002), compression of the nerve evident on cone beam computed topography scan (P = .005), and buccal or interradicular position of the nerve (P = .042)., Conclusions: Results indicate a low incidence of IAN injury, particularly given the high-risk nature of all teeth that were extracted. It highlights the benefits of cone beam computed topography scans in surgical planning. These data are an important contribution to the existing literature and valuable in the consent procedure for patients undergoing surgical removal of mandibular third molars in contact with the IAN., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Neurosensory disturbance (NSD) occurring in the lower lips and chin is a major postoperative complication related to bilateral sagittal split osteotomy (SSO). The purpose of this study is to identify preoperative radiographic findings following SSO procedure associated with persistent NSD., Methods: This retrospective cohort study analyzed data for consecutive patients who underwent SSO. Primary predictor variables, including ramus width, mandibular body height, mandibular angle length, gonial angle, distance from mental foramen to distal aspect of mandibular second molar (MFD), and measurement of bone marrow space (BMS), were examined in a series of radiographic images. The primary outcome variable was NSD. Patients with NSD were divided into 2 groups based on findings obtained 1 year postoperatively: persistent, for those with NSD remaining after 1 year, and transient, when NSD occurred for less than 1 year. Covariates included sex and age. Comparisons were analyzed by use of Mann-Whitney U test or χ 2 test. Multivariate analysis was performed using step-wise logistic regression to determine significant factors related to persistent NSD. A P value .005 or less was considered statistically significant., Results: Of the 349 sides investigated, the persistent NSD group consisted of 59 sides (16.9%), while the transient NSD group consisted of 290 sides (83.1%). The occurrence of persistent NSD was correlated with age (P < .05), MFD (P < .001), mandibular body height (P < .05), and BMS (P < .001). Multivariate logistic analysis also showed a significant association of MFD (P < .001) and BMS (P < .001)., Conclusions: Preoperative MFD and BMS are radiographic findings that are associated with an increased risk for persistent NSD following SSO procedure., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Inferior alveolar neurosensory disturbance (IAND) is the most common complication of bilateral sagittal split osteotomy (BSSO). The aim of the present study was to evaluate IAND with subjective tests postoperatively and assess the relationship between three-dimensional measurements of the mandibular canal (MC) and IAND., Methods: Eighteen patients (Mean age: 24.05 ± 5.85 years) treated with BSSO were retrieved from the archive. Subjective tests (light touch, tactile sensitivity, 2-point discrimination, brush-stroke directional discrimination, sharp/blunt discrimination, dental vitality, questionnaire) and three-dimensional measurements related to MC and fixation screws were done postoperatively (on average 20.43 ± 8.76 months after surgery). Statistical significance was set at P  < 0.05., Results: Subjective test results were found compatible with each other except brush-stroke directional discrimination test. According to the questionnaire, IAND was apparent in all patients immediately after surgery, and recovery after 1 to 2 years was statistically significant ( P  < 0.05). Preoperative ramus width, medial and lateral cancellous bone lengths, the decrease in MC length, and the presence of screw in MC were not related to IAND ( P  < 0.05)., Conclusions: There is a high incidence of IAND following BSSO, and the subjective tests are efficient to evaluate the disturbance. Spontaneous recovery of the nerve occurs during the follow-up periods. Instead of preoperative measurements of bone thickness, MC length, and the position of fixation screws, the surgical procedure seems to be more important in IAND occurrence., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Preoperative assessment is essential to prevent inferior alveolar nerve (IAN) injury during surgical extraction of the lower third molar (LM3). Here, we aimed to establish an assessment system to predict IAN injury during surgical extraction of the LM3. We conducted a retrospective cohort study on 115 patients diagnosed as 'high-risk' based on our previous risk assessment method involving three anatomical features of the inferior alveolar canal using computed tomographic (CT) images. We evaluated the occurrence of neurosensory impairment in these high-risk patients, and its association with novel anatomic features based on CT images. Neurosensory impairments were observed in 19 patients (16.5%). The inferior alveolar canal major diameter (p < 0.0001) and lingual bone thickness (p = 0.0039) were significantly associated with the occurrence of neurosensory impairment during LM3 extraction. Receiver operating characteristic curves were used to determine cut-off values of these quantitative factors to specifically predict IAN injury. Preoperative risk assessment with quantitative factors based on anatomical features observed on CT images may facilitate more appropriate surgical planning for patients at a high risk of IAN injury., Competing Interests: Conflict of interest We have no conflicts of interest., (Copyright © 2021 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

This prospective study aimed to evaluate neurosensory disturbance and quality of life in patients who underwent mandibular resection for benign tumors and whose inferior alveolar nerve (IAN) was either preserved or sacrificed. Mandibular resection was indicated owing to the presence of osteoradionecrosis in 25 patients and ameloblastoma in 15 patients. Resection was unilateral in 24 patients and bilateral in 16 patients. The authors assessed the inferior alveolar nerve's sensory dysfunction by measuring the electroexcitability of skin receptors using an electro-odontometer. Study participants' quality of life was estimated with the oral health impact profile (OHIP)-14 and short-form (SF)-36 questionnaire. All the patients in whom the inferior alveolar nerve was sacrificed experienced persistent numbness in the area of innervation with mental nerve on the affected side. The average pain threshold reached preoperative levels (point 1-22.7 ± 2.5, p-value = .025; point 2-25.8 ± 2.7, p-value = .023) 6 months after the operation in patients in whom the IAN was preserved (point 1-23.7 ± 2.3, p-value = .022; point 2-25.4 ± 2.8, p-value = .025). The results of the OHIP-14 and SF-36 showed that patients with preserved IANs had a significantly better quality of life than the patients in whom the IAN was sacrificed. The results of OHIP-14 twelve months after the operation in unilateral resection: control group - 16.0 ± 1.6, p-value = .029; study group - 8.0 ± 0.8, p-value = .029, and in bilateral resection: control group - 26.0 ± 3.2, p-value = .044; study group - 9.0 ± 0.7, p-value = .027. The possibility of sparing the inferior alveolar nerve should not be ignored when planning mandibular resection and reconstruction., (Copyright © 2022 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Abstract: During root canal treatments, calcium hydroxide can extrude through the apex causing chemical, mechanical, and/or thermal injuries to the inferior alveolar nerve, which can lead to neurological disorders. unfortunately, dental practitioner negligence can produce this potentially life-changing injury that can compromise the patient's life. The aim of this study is present a case of dental negligence by calcium hydroxide extrusion causing inferior alveolar nerve damage, discuss the methods of prevention, and characterize the medico-legal aspects of complication., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Introduction: This study aimed to construct a predictive scoring system for inferior alveolar nerve injury (IANI) following lower third molar (LM3) surgery based on cone-beam computed tomography (CBCT) images., Material and Methods: Of the 1573 patients who underwent LM3 removal following the CBCT, 39 with IANI and 457 randomly selected patients without IANI were enrolled. We collected information regarding the demographic characteristics of the patients, surgical situations, and inferior alveolar canal (IAC)-related CBCT factors. The association with IANI-risk was evaluated with a backward stepwise logistic regression model as per the Akaike information criterion. Scoring models' abilities of discrimination (area under the curve) and calibration (Hosmer-Lemeshow test and calibration plots) were assessed, followed by evaluation of the clinical usefulness using decision curve analysis., Results: As per the multivariate analysis, the coronal positioned IAC on the enlarged root (odds ratio [OR], 3.78; P = 0.001), the length of perforated IAC (>3.4 mm) (OR, 3.05; P = 0.012), lingual/inter-radicular position of the IAC (OR, 3.96; P = 0.001), multiple roots closed to the perforated IAC (OR, 2.78; P = 0.025), and age >30 y (OR, 2.31; P = 0.076) were identified in the extended scoring model ranging from 0 to 12. This model was compared with our previously constructed baseline model that involved the latter three variables mentioned above, resulting in superior performance than that of the baseline model., Conclusion: The extended model would be a useful tool for reliable determination of the preoperative probability of IANI., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Aims and Objectives: The aim of the current cross-sectional study was to conduct a survey among the oral and maxillofacial surgeons of South India regarding their experiences of incidence of inferior alveolar nerve (IAN) neurosensory deficit after bilateral sagittal split osteotomy (BSSO) for correction of mandibular retrognathism and to assess the intra-operative nerve encounters and its effect on the inferior alveolar neurosensory deficit (NSD), 6 months post-operatively., Materials and Methods: A self-administered questionnaire (SAQ) was prepared using Google Forms (Google Inc.) and sent to the prospective participants through various social media outlets such as Facebook, WhatsApp groups etc., of the maxillofacial surgery specialty for a period of 3 months. SAQ from surgeons with more than 5 years of experience in orthognathic surgery were included., Results: The incidence of NSD post-BSSO advancement surgery from 859 cases after 6 months was 15.1% (130). After splitting the mandible, the IAN was seen in the proximal fragment in 472 sites and needed dissection. The nerve was transected and neurorrhaphy was carried out in 26 sites. A Chi-square test was used to analyse the qualitative variables. The IAN was not visible post-osteotomy in 140 sites and in the distal fragment in 1080 sites. These groups had decreased incidence of NSD. The NSD was significantly higher in cases where the nerve was transected and sutured, P value <0.001 as compared with the other nerve status, followed by the nerve in the proximal fragment needing dissection., Conclusion: The IAN status intra-operatively can be assumed to have a significant role in persisting NSD., Competing Interests: None

Objective: To evaluate the risk factors of inferior alveolar nerve injury (IANI) after surgical removal of the mandibular third molars (M3) and present a new risk scoring system to predict the probability of IANI. Methods: Patients who underwent extraction of M3 in the Stomatology Hospital, Zhejiang University School of Medicine from April 2017 to December 2019 were involved. The investigators enrolled a sample composed of 949 mandibular third molars. Prediction model was used for univariate and multivariate analysis of gender, age, M3, inferior alveolar canal (IAC), and the contact between M3 and IAC, to assess the risk factors of IANI. Combined with the risk factors determined by the outcomes of prediction model, the risk scoring system was constructed. The diagnostic performance of each cut-off score was examined to conduct a risk stratification of IANI risk scores. The predictive ability and reliability of the model were evaluated. Results: In prediction model, twenty nine cases (4.4%, 29/664) experienced postoperative IANI. Number of root ( P <0.01), depth of impaction ( P <0.05), contact between M3 and IAC ( P <0.01) and their contact position ( P <0.05) were statistically significant as contributing risk factors of IANI. Specifically, the incidence of temporary IANI was higher in those who aged under 25 years ( P <0.001), while female suffer more permanent injury ( P <0.05). Based on the IANI risk scoring system, patients were stratified into low-risk, middle-risk and high-risk groups at cutoff scores of 3 and 4. The area under the receiver operator characteristic curve of the risk scoring system were 0.81 [95% CI (0.70-0.90), P =0.002] and 0.80 [95% CI (0.68-0.92), P =0.007] towards good discrimination. Conclusions: Age, gender, number of root, depth of impaction, and contact between M3 and IAC were risk factors of IANI. IANI risk scoring system might help in preoperative assessment, recognition of high-risk cases and decision-making to reduce IANI.

An over-representation of women in dental implant-related inferior alveolar nerve injuries (IANIs) is recognized in the literature but has not been investigated. Therefore, a nationwide retrospective register study was conducted to analyse how IANIs compare with other implant-related complications (infection, implant malposition, lack of bone at implant site, mechanical damage, or failed osseointegration) separately in women and men. Financially compensated malpractice claims related to dental implant surgery were collected from the Finnish Patient Insurance Centre for the years 1997-2013, while the total number of nationally placed implants was ascertained from the implant register held by the Finnish Institute for Health and Welfare. In the 242 complications, the following were analysed: age of subject, absolute risk for complication, and aetiological factor of IANI. Statistical tests applied include Mann-Whitney U-test, Chi-squared test, and Fisher's exact test. Women sustaining IANI were more likely older than those having infection, mechanical damage, or failed osseointegration (P<0.05), while no significant differences emerged in men. Women were more likely at risk for IANI (P<0.01) or implant malposition (P<0.05) than men. The results support earlier propositions that women are more vulnerable than men to iatrogenic IANI., (Copyright © 2021 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: The present study aimed to assess whether anatomical variations of the mandibular canal are associated with neurosensory disturbances of the inferior alveolar nerve (IAN) following mandibular third molar removal., Methods: Two observers compared the detection of third molar root-nerve relations and bifurcations of the mandibular canal on panoramic radiographs and CBCT images of 201 patients undergoing removal of 357 mandibular third molars. Potential neurosensory disturbances of the IAN were surveyed ten days after surgery. Fisher's Exact was performed to correlate presence of canal variations to postoperative neurosensory disturbances. Positive and negative predictive values (PPV, NPV) and likelihood ratios (LR + , LR-) were calculated., Results: Thirteen patients reported postoperative altered sensation of the lower lip, with 2 of them having mandibular canal bifurcations on the ipsilateral side of the injury. Fisher's Exact showed that the studied mandibular canal variations were not related to postoperative neurosensory disturbances. CBCT was superior in visualization of anatomical variations of the mandibular canal. Prevalence of bifurcations was 14% on CBCT and 7% on panoramic radiographs. In both imaging modalities and for all parameters, PPVs were low (0.04 - 0.06) and NPVs were high (0.92 - 0.98), with LR ranging around 1., Conclusion: In the present study, the assessed mandibular canal variations had limited predictive value for IAN neurosensory disturbances following third molar removal., Clinical Relevance: While a close relation between the third molar and the mandibular canal remains a high risk factor, mandibular canal variations did not pose an increased risk of postoperative IAN injury after third molar removal., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The present study aimed to evaluate which factors were statistically associated with a greater probability of inferior alveolar nerve (IAN) damage during lower third molar surgery., Methods: A prospective observational study was performed at the Oral Surgery Unit of the Umberto I Hospital on 92 patients who underwent surgical extraction of a lower third molar that was radiographically overlapped with the mandibular canal. All surgeries were performed by the same expert surgeon. A principal component analysis and the exact 2-tailed Fisher exact test were used., Results: Temporary IAN damage occurred in 10 cases (10.9%). Symptoms lasted from 18 to 180 days (73 ± 49.15). IAN damage was more frequent in difficult and long-lasting surgeries, in the presence of many risk factors and in patients with a reduced maximum mouth opening., Conclusion: Such factors should be accurately evaluated before surgery to assess and discuss the overall surgical risk of IAN damage with the patient especially when they are over the maximum limit of their significant variability range found in the present study, that is, >12 for difficulty index, >2 for number of orthopantomography risk markers and <3.7 cm for maximum mouth opening., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The aim of this retrospective study was to describe the etiology and characteristics of trigeminal nerve injuries referred to a specialized center in Buenos Aires, Argentina. A retrospective analysis was performed of patients referred from February 2016 to January 2020. Age, sex, intervention performed, nerve affected, time elapsed from injury, diagnosis, location, and whether patient had signed informed consent were recorded. A descriptive analysis of the data was made, and 95% confidence intervals were calculated for prevalence. The study sample consisted of 30 subjects (31 nerve injuries), 19 female and 11 male, average age (±SD) 40 ± 17 years. The inferior alveolar nerve was the most frequently injured nerve (74%,) while the lingual nerve accounted for 26%. The most common etiologies were inferior molar extractions (47%), dental implants (20%), and local anesthesia (13%). Other etiologies were autologous mandibular bone grafts for dental implants, removal of cysts associated with the inferior third molar, and endodontic treatment. Dental Institutions at which treatment was provided were found to be significantly associated with patients being warned and asked to sign informed consent (p<0.05), while dentists working at private offices requested fewer consents. The most frequent symptom was paresthesia, and 5 patients suffered spontaneous or evoked pain. Only 2 patients intended to file legal claims. Dentists should be aware of the debilitating effects resulting from trigeminal injuries, the complexity of their resolution and the importance of carefully planning dental procedures to prevent them., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article, (Sociedad Argentina de Investigación Odontológica.)

Purpose: To assess the long-term recovery of sensation in the lower lip after mandibular resection without reconstruction of the inferior alveolar nerve., Material and Methods: Thirty patients who had mandibular resection carried out without reconstruction of the inferior alveolar nerve were examined after an interval ranging from 6 to 33 years., Results: Only 1 patient, seen 10 years after resection, was totally numb over the distribution of the inferior alveolar nerve. The other 29 patients had some return of sensation and many had a significant return, though it may take several years to reach the final result. Utilizing the MRC scale 70% of patients achieved S3 (return of superficial cutaneous pain and tactile sensibility without over response) CONCLUSION: This study can serve as a baseline for comparison with patients who have had mandibular resection with reconstruction of the inferior alveolar nerve to assess if this procedure improves the outcomes., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Intentional coronectomy has become a commonplace procedure as an alternative to full third molar removal in order to decrease the occurrence of inferior alveolar nerve (IAN) injury. It is well known that one of the sequelae of this procedure is superior root migration. This is usually not a significant problem as the migrated roots may erupt to a position where they are more readily removed. This report presents a case in which a curvature at the apex of the root displaced the IAN causing neurologic symptoms., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: An uncommon, but serious complication of endodontic treatment is inferior alveolar nerve (IAN) injury warranting operative intervention for exploration, debridement, and repair. The purpose of the study was to evaluate outcomes of microneurosurgical intervention for endotontic-related IAN injuries in terms of achievement of functional sensory recovery (FSR) and pain relief and to identify factors affecting outcomes., Methods: A retrospective cohort study of patients who had microsurgical exploration and repair of IAN injuries sustained during endodontic therapy was performed. The primary predictor variable is time to surgery and the primary outcome variables were time to FSR, whether or not the patient regained FSR, and postoperative pain level at 12 months (1-10 on a visual analog scale). Secondary variables include intraoperative findings, surgical treatment rendered, sensory recovery, and preoperative pain level. Analyses include Kaplan-Meier estimation, Fisher exact test, 1-way and mixed-design analysis of variance, and paired t-test., Results: The sample included 23 patients with a mean age of 48.6 years with a female:male ratio of 20:3. Painful sensation was present in 17 (73.9%) of 23 patients at initial consultation. Mean time to surgery was 10.9 months (median 4.8 months, standard deviation = ±16.9). FSR was achieved in 10 of 21 patients at 1 year. Pain level at 1 year following surgical intervention improved from 4.86 to 2.76 (P = .001) with no effect from other variables., Conclusions: Surgical exploration and repair of endodontic-related IAN injuries is shown to improve neuropathic pain levels, while only delivering a modest recovery of sensory function. These injuries can be severe and debilitating and present with a variety of diagnoses and surgical findings. While this study fails to identify any particular factors affecting outcome, the data presented can help with clinician recommendations for treatment in patient-centered care., (Copyright © 2021 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Extraction of mandibular third molars (M3M) close to the inferior alveolar nerve (IAN) has a higher risk of neurological disturbance. This review aims to evaluate the evidence supporting the use of the coronectomy technique compared to complete extraction for such M3Ms. Case studies by a specialist oral and maxillofacial surgeon are included to illustrate clinical practice., Methods: Three databases (Cochrane Library, Embase, PubMed) were searched (November 2020). Additional articles were sought by hand searching the reference list of included articles. All studies published in English comparing outcomes of coronectomy with complete extraction with at least 50 subjects and 6 months follow-up were included., Results: Of the six included studies, five reported a lower rate of IAN disturbance after coronectomy compared with complete extraction. There were no reported cases of lingual nerve disturbance. Other outcomes of coronectomy such as pain, infection, alveolar osteitis were either similar or lower compared to complete extraction. There were high rates of root migration but low rates of exposure and reoperation. Follow-up protocols varied considerably., Conclusions: There is medium quality evidence to support the option of coronectomy for high risk M3M cases. Further studies to develop follow-up protocols to assist general dental practice is warranted., (© 2021 Australian Dental Association.)