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Background: The aim of this study was to investigate the effectiveness of topical application with dexamethasone during BSSO due to its anti-inflammatory effect and decreasing of postoperative nerve oedema in minimising clinical symptoms of NSD associated with inferior alveolar nerve (IAN) injury in postoperative period, based on the results of sensory diagnostic tests, such as light touch test and its modifications., Methods: Through randomisation, 2 groups were selected from 22 patients: the experimental- where topical application with solution of dexamethasone phosphate 0.4% (4 mg/1 ml ampules) during sagittal split osteotomy of the mandible was used, and the control- where the classical technique of BSSO was held., Results: Authors performed diagnostics of NSD using Light Touch test on 1st day, 1st week, 1st month, 3rd month and 6th month postoperatively. The experimental group showed improvements in sensory recovery compared to the control group, particularly from 1 week to 3 months post-surgery. By 6 months, both groups achieved similar levels of sensitivity restoration., Conclusions: This confirms the effectiveness of proposed method and opens up further prospects for the updated function of the IAN following the BSSO., Clinical Trial Number: Not applicable., Competing Interests: Declarations. Ethics approval: All procedures performed in the study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. A study was approved by the Ethics Committee of Central Laboratory Diagnosis of the Head, Kyiv, approval number 501. The authors informed the participants about the anonymous and voluntary participation, and the participants provided their consent. Consent for publication: Written informed consent was provided by all participants allowing the publication of any identifying images or clinical information related to them in this study. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

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.)

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., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

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.)

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.)

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.

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.

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.)

Backround: This study was designed to analyse the value of preoperative Cone Beam CTs (CBCT) prior to the surgical removal of complex lower third molars. Furthermore, the aim was to assess injuries to the inferior alveolar nerve (IAN) bundle and postoperative neurological disorders depending on the position of the lower third molar and the inferior alveolar nerve bundle., Methods: In this retrospective examination preoperative Cone Beam CTs and Orthopantomographs (OPT) of 324 patients were analysed concerning the location of the lower third molars in relation to the mandible and the inferior alveolar nerve bundle. Surgery protocols of all patients who underwent the surgical removal of at least one complex lower third molar were analysed concerning patient data, length of surgery, intraoperative haemorrhage, intraoperative exposure of the inferior alveolar nerve bundle, postoperative swelling and postoperative neurological disorders. The data was then compared to data from international studies., Results: In all 324 patients a permanent neurological damage was not found. Temporary neurological damage was recorded in 13 cases (2.6%). A caudal nerve position with no measurable distance to the root of the lower third molar was associated with the highest risk of a temporal neurological damage. A vestibular touching nerve route also correlated with postoperative sensitivity impairment. If a mesioangulation (Winter) or a Pell and Gregory Type IIIC appears in the OPT, risk of neurological damage is at its highest., Conclusions: Three-dimensional radiographic imaging, in our patient group, does not significantly affect the risk for complications during the surgical removal of complex lower third molars. Therefore, it should only be utilized for risk assessment, especially in cases of symptom-free lower third molars. A preoperative orthopantomogram still can be accepted as standard for radiographic imaging. An intraoperative exposure of the IAN bundle does not necessarily predict simultaneous neurological damage. Exposure of the IAN bundle is no indication for a discontinuation of the surgery., (© 2021. The Author(s).)

An orthodontic extraction technique with a ramus mini-screw was used to remove a deeply impacted mandibular third molar contacting the inferior alveolar nerve, avoiding damage to the inferior alveolar nerve and relieving postsurgery inflammation. Case presentation: A 24-year-old man was required to extract impacted third molars for orthodontic treatment. Panoramic radiographs and CBCT images showed that his mandibular left third molar penetrated into the inferior alveolar nerve canal and a distomolar was inverted and impacted distally to the third molar. The distomolar was directly removed and the impacted third molar was extruded with the aid of a ramus mini-screw. After 4 months of traction, the mandibular left third molar was successfully moved away from the inferior alveolar nerve canal. No nerve injury occurred after the surgical extraction and the patient was very satisfied with the treatment outcome. Conclusion: Orthodontic extraction, with the aid of ramus mini-screws, is a safe, effective, and efficient technique for the removal of high-risk impacted molars contacting the inferior alveolar nerve. (Quintessence Int 2021;52:538-546; doi: 10.3290/j.qi.b1244345).

Purpose: In bilateral sagittal split osteotomy (BSSO), the risk of lesion of the inferior alveolar nerve (IAN) is important. The aim of this study was to investigate the situation of the IAN in the area of the BSSO in preoperative 158 CBCT., Methods: The situation of the mandibular canal (MC) has been studied in six coronal sections (one section each 4 mm) from the proximal root of the second mandibular molar. The height of the MC related to the height of the mandible, and the horizontal distance between the MC and the lateral cortical plate related to the mandibular width have been determined in each section. The cancellous bone width has been measured allowing to determine a cancellous bone ratio., Results: The variability of the MC was high, depending mainly on the cancellous bone ratio which was higher when the IAN was deep. When a third molar was present, the MC was lower in the area of the third molar., Conclusions: To decrease the risk of injuring the IAN in BSSO, the evaluation of the cancellous bone ratio by a preoperative CBCT may be proposed to adapt the surgical technique to the anatomy.

In recent years, coronectomy of impacted lower third molar teeth has become an increasingly popular alternative to removal. Traditionally, orthopantomograms of mandibular third molars have been used to indicate features that show that the tooth is in close proximity to, or in an intimate relation with, the inferior dental nerve. Some authors advocate coronectomy as opposed to surgical removal to reduce the risk of damage to the nerve. In our Trust during the last two years, there has been a noticeable increase in the prescription of coronectomy for the management of pericoronitis associated with mandibular third molars. The purpose of this study therefore was to examine the differences among clinicians in their assessment of the need for coronectomy using plain-view radiographs. An online survey was completed by 25 clinicians with different levels of experience from six units across the UK and Republic of Ireland. We found a wide variation in the number of coronectomies prescribed (intraclass correlation 2.67), and when prescribed, a lack of agreement about the radiographic feature that had influenced the decision. These judgments are not straightforward. They are, to some extent, subjective, and in certain cases may benefit from a team-led approach., (Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.)

Purpose: The sensory trigeminal nerve in the trigeminal cave of Meckel-which is an individualized lodge-is classically segmented into two parts: the trigeminal ganglion (TG) and the triangular plexus (TP). The TP has been defined as the portion of the trigeminal nerve from the posterior margin of the TG to the path over the upper ridge of the petrous bone. Due to its relatively unrecognized status, its morphological and functional anatomy has been reviewed by the authors through a PRISMA systematic review of the literature., Methods: The authors have carried out a systematic review of the TP according to the PRISMA model with various bibliographical bases. Before 1947: Medic @ Library (BIU Santé Paris, 2017); Index-Catalog of the Library of the Surgeon-General's Office (US National Library of Medicine, 2017); Gallica (French National Library, 2017). After 1947: PUBMED, PubMed Central and MEDLINE., Results: 56 articles were retained for full-text examination, of which 23 were chosen and included. The TP was described as having a triangular shape (30.2%), a plexual organization (97.4%) with sensory-, motor- and sympathetic-anastomoses (96.7%) that, however, respect the somatotopic trigeminal distribution (93.3%). The direct electrical stimulation of the root at the level of the TP (during radiofrequency-thermorhizotomy procedures) confirmed a clear-cut somatotopy., Conclusion: An understanding of both the morphological and the functional anatomy of the triangular plexus can contribute to accuracy and safety on the surgeries performed for trigeminal neuralgia and tumor removal inside the trigeminal cave.

Introduction: Mandibular osteotomies aim to displace the dental arch to the necessary position, ideally without limitation, while preserving inferior alveolar nerve (IAN) function. Supraforaminal osteotomies offer nerve safety but limit the extent of advancement, whereas Epker and Obwegeser-Dal Pont osteotomies enable unchallenged mandibular advancement but are associated with an inferior border notch. Here, we describe a new technique to avoid such disadvantages., Technical Note: The beginning of the procedure was similar to Epker's technique, with sectioning of the lingual cortex up to the level of the lingula. Sectioning of the buccal cortex was stopped 3 to 4 mm above the inferior border and then performed horizontally up to the gonial angle in total thickness. The inferior border periosteum and muscles attachments were conserved and hence, appropriately vascularized., Discussion: This technique offers 4 advantages: absence of the inferior border notch, lower risk of damage to the IAN than with Epker's technique, sufficiently large bony surface to obtain bone healing as in Epker's technique, and no limitation to setback movement in contrast to Obwegeser-Dal Pont's or the supraforaminal osteotomy techniques.

During surgical third molar removal and coronectomy procedures, tooth sectioning is an important and, in some cases, an inferior alveolar nerve-endangering step. This article introduces a drilling sleeve that was printed according to the individual tooth-sectioning situation preoperatively, using diagnostic cone-beam computed tomography data. Not only did the sleeve function in our case as a mark on the drill; it was also a reliable physical limiter, serving as a determinant of the required depth during tooth sectioning. This fast and cost-effectively produced drilling sleeve may help younger colleagues when the depth of tooth sections should be precisely controlled., (Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Coronectomy has become an increasingly prescribed surgical treatment for mandibular third molars that are deemed to pose a risk to the inferior dental nerve. Retention of the roots poses a risk of need for root retrieval in the future if symptoms are present. Long-term outcomes and the symptoms that lead to root retrieval via coronectomy have not been well documented or studied, and this has understandably led to hesitation in some clinicians in offering the procedure. The current series assesses patients who have undergone root retrieval, their reported indications for removal, and the histopathologic status of the removed roots., Study Design: A total of 92 cases of root retrievals via coronectomy carried out at Guy's Dental Hospital are included in this analysis. Data were collected retrospectively from patient records regarding patient symptoms, clinical and radiographic findings, function of the inferior dental nerve, and histologic results., Results: The mean age of patients in the study group was 31.6 years (range 19-70 years), with a female-to-male ratio of 62:18 (77.5% female). Mean time to the second surgery for root retrieval was 17 months. In "successfully" performed coronectomies, 75.3% (61 of 81) of root pulps appeared vital histopathologically. Mucosal tenderness (39 of 81 [48.1%]) was the most common symptom leading to root retrieval., Conclusions: Root retrieval after coronectomy should be based on findings from sound clinical and radiographic examinations. In the presence of obvious indications, such as an unhealed socket resulting from retained enamel or soft tissue infection after eruption of roots, then retrieval should be performed with confidence that resolution would occur. However, if the coronectomy root appears an unlikely culprit, then the clinician should consider and investigate alternative diagnoses, such as overerupted upper third molars causing trauma, temporomandibular dysfunction, and the dental status of the adjacent tooth as potential causes of symptoms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Mandibular angle osteotomy (MAO) and mandibular angle splitting osteotomy (MASO) are the two main surgical approaches used to correct a square mandible for a desirable aesthetic appearance. However, there are concerns about the safety and accuracy of both procedures as they may lead to unsatisfactory results such as injury to the nerve. To achieve symmetry and security we designed and evaluated a 3-dimensional printed surgical template, which indicates the outer cortex splitting line of the MASO, and the curved cutting line of the MAO. We operated on 11 patients who had been diagnosed with broad mandibles using the assisted template. The mean duration of osteotomy, degree of numbness of the inferior alveolar nerve, and reduction in the width of the mandible (Go-Go) were recorded. The mandibular curve before and after operation was fitted to evaluate its accuracy. The results showed that mean duration of osteotomy and numbness of the nerve were reduced, and there was no significant difference between simulation and postoperatively. The mean (SD) reduction in the mandibular width was 15.2 (1.6)mm. The template facilitated accuracy and safety in both procedures., (Copyright © 2018. Published by Elsevier Ltd.)

The sagittal split osteotomy (SSO) is an indispensable tool in the correction of dentofacial abnormalities. In elective orthognathic surgery, it is important that surgeons inform patients about the risk of complications related to inferior alveolar nerve damage and unfavorable split. The purpose of this article is to describe a novel, hybrid technique to SSO by combining a reciprocating saw and piezoelectric devices with several advantages over traditional "pure" methods (osteotomies performed by reciprocating saw or piezoelectric devices only) in terms of precision, rapidity, easier splitting, and decreased complications related to inferior alveolar nerve damage and bad split with reduced overall morbidity. The level of evidence was Level IV, therapeutic study., Competing Interests: None of the authors has a financial interest in any of the products, devices, or drugs mentioned in this manuscript., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Background: The introduction of CAD/CAM technology allowed clinicians to carry out complex procedures with a high level of precision and reproducibility and minimize the risk of injury during the procedure., Purpose: The aim of the present study is to evaluate the efficacy of the CAD/CAM surgical guide during chin harvesting procedures in reducing the risk of neurosensory damage and patient morbidity compared with the standard technique., Materials and Methods: About 20 cases of autogenous block chin harvest were randomly into two groups. The first group received computer-guided chin block harvest while the second group received autogenous block chin harvest using the standard approach., Results: In the guided group, out of the 10 subjects, 2 subjects presented with wound dehiscence which resolved within 1 month. No teeth showed any negative pulp sensitivity results. The pointed-Blunt test and 2 point discrimination tests showed a single case of neurodeficits at 1 week follow-up appointment which resolved within 1 month. In the nonguided group, out of the 10 subjects, 1 case presented with wound dehiscence that resolved completely within 1 month. Pulp vitality test showed negative results in 29.4% of the involved teeth at 1 week which decreased to 9.8% and 3.9% at 1 and 6 months follow-up, respectively. The pointed blunt test revealed 3 subjects with neurodeficits at 1 week, out of which 2 subjects showed persisting symptoms at 6 months follow-up. The 2 point discrimination test showed 3 subjects with neurodeficits, out of which two subjects showed persistent symptoms with no resolution at the 6 months follow-up., Conclusion: Within the limits of this study, computer-guided chin harvest shows promising results in the reduction of neurosensory complications following harvesting procedures and presents as a safe alternative to the standard technique., (© 2018 Wiley Periodicals, Inc.)

The aim of this study was to determine the accuracy of the pre-surgical assessment of the mandible using cone beam computed tomography (CBCT) images. For surgical procedures in the mandible, it is important to determine the position of the mandibular canal in order to avoid damage to the inferior alveolar nerve (IAN). The best method to investigate this nerve is with the help of panoramic reconstructed images combined with cross-sectional reconstructed images. To protect the IAN during treatment, this research indicates that a minimal safety zone of 1.13 mm is advisable. When distances were being measured, a larger exaggeration of reality was observed with small distances. It appears that (semi)automatic tracing methods of the mandibular canal still cannot be used in clinical practice. When a CBCT scan reveals a lingual position of the mandibular canal in combination with a narrowing of the mandibular canal at the contact point with the root of a third molar the risk of damaging the IAN increases. CBCT imaging should only be applied in specific cases.

Introduction: This study was designed to quantify the important anatomical landmarks and the path of the inferior alveolar nerve (IAN) within the human mandibular body and ramus, in particular with reference to the bilateral sagittal split osteotomy (BSSO)., Materials and Methods: Four hundred and eleven CT scans were studied, 299 of these were involved in determining the position of lingula; and 230 were involved in determining the course of IAN in the mandibular molar region, namely from the mesial of the mandibular first molar to the distal of the mandibular second molar; 118 were involved with both measurements., Results: On average, the lingula was located 17.0 ± 2.2 mm from the external oblique ridge; 11.6 ± 2.0 mm from the internal oblique ridge; 17.2 ± 2.7 mm from the sigmoid notch; and 15.6 ± 1.9 mm from the posterior border of the mandible. The course of the IAN in the mandibular molar region was found to descend vertically from the distal of the mandibular second molar (7) to reach its lowest point between the first and second molars (6 and 7), and then ascend towards the mesial of the first molar (6). Horizontally, the IAN was found to traverse medially between the distal of the 7 and the middle of the 7, and then changes its path laterally towards the mesial of the 6., Conclusion: Precise knowledge of the individual's position of the IAN will help surgical planning.

Placement of dental implants in the posterior mandibular alveolar ridges may become a challenging procedure because of limited bone height between the crest of the ridge and the inferior alveolar canal. The aim of this study was to introduce an innovative, less invasive, highly accurate, and easy surgical technique of inferior alveolar nerve lateralization in the posterior deficient mandible using a special customized 3-dimensional-printed surgical guide to enhance the bone height for implant placement. This case series study included 7 patients with unilateral edentulous mandibular alveolar ridges. Customized surgical guides were manufactured using fused deposition modeling technology to accurately place a rectangular window to uncover the canal and also for immediate placement of dental implants in all cases. The results of this limited study provided information on an innovative technique that decreased intraoperative time and demonstrated decreased risks for (1) inferior alveolar nerve injury and (2) postoperative nerve dysfunction.

Background: The purpose of this study was to assess the efficacy of intraoperative nerve integrity monitoring (NIM) to prevent marginal mandibular nerve injuries during neck dissection., Methods: This prospective study compared 36 patients undergoing NIM-assisted neck dissection from July 2014 to March 2015 to a cohort of 35 patients subjected to neck dissection over an identical period of time before the technique was introduced. We also assessed possible correlations between marginal mandibular nerve injuries and other factors, such as anthropometric measurements, presence of clinical neck metastases, type of neck dissection, and site of primary tumor., Results: The incidence of marginal mandibular nerve paralyses was significantly lower among the group of patients undergoing NIM-assisted neck dissection (P = .021). There was no significant difference in the duration of the procedure, and the technique resulted in a limited increase of cost. No other factor seemed to influence the onset of marginal mandibular nerve palsy., Conclusion: In our opinion, NIM is a valuable aid for preventing marginal mandibular nerve injuries during neck dissection., (© 2018 Wiley Periodicals, Inc.)

Purpose: This study aimed to investigate the prevalence of juxta-apical radiolucency (JAR), assessing its association with third molar status and describing its radiologic features through panoramic radiography., Materials and Methods: We evaluated 1,050 radiographs (1,830 third molars) for the presence of JAR. The JAR and control groups were classified according to the third molar's angulation, impaction, and root development. The presence of radiographic signs of proximity between the mandibular canal and third molar and the imaging features of JAR also were recorded., Results: JAR was identified in 116 patients (11%) and 130 third molars (7.1%), being significantly associated with female patients and with the second and third decades of life. There also was an association with teeth with a vertical angulation and complete root formation. Radiographic signs of proximity to the mandibular canal were absent in 66.2% of JAR cases. In most cases, there was lamina dura in the juxta-apical area that appeared to overlap the mandibular canal and to have a cortical outline., Conclusions: JAR is not a rare imaging finding. Given its possible relationship with nerve injuries and its differential diagnostic possibilities, knowing the characteristics of JAR is important to assist professionals in treatment planning and making the correct diagnosis., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The removal of mandibular third molar teeth is one of the most common oral surgical procedures. In a significant number of patients, it carries a degree of associated morbidity, including damage to the inferior alveolar nerve (IAN). For this reason, practitioners desire the most up-to-date guidance on the most appropriate technique, informed by the best available evidence that will produce the lowest incidence of iatrogenic complications. The aim of this study was to perform a systematic review comparing the effect of coronectomy vs complete surgical extraction of mandibular third molar teeth on the risk of IAN injury and other complications in adults. Studies were identified through Embase (1980-2016) and Ovid MEDLINE (1946-2016) database searches. Search terms included coronectomy, partial root removal, deliberate vital root retention, odontectomy, surgical removal, surgical extraction, complete tooth extraction and extract. Limits of the study included humans, English language and randomised controlled trials (RCTs). Only RCTs comparing IAN damage associated with surgical extraction of mandibular third molars vs coronectomy were included. From our database searches, we identified two unique RCTs matching the inclusion criteria. Both evaluated patients who had specific radiographic signs of intimate relationships with the IAN. Upon detailed analysis, the studies were noted to exhibit a high risk of bias in many categories, thereby rendering their results inconclusive. Although evidence from two RCTs suggests that coronectomy can reduce the risk of IAN injury compared to surgical removal of high-risk mandibular third molars, the quality of evidence is insufficient to provide definitive conclusions regarding the preferred technique., (© 2017 John Wiley & Sons Ltd.)

Purpose: We propose a 2-stage orthodontic lower third molar extraction procedure to reduce iatrogenic inferior alveolar nerve injury. We tested our hypothesis that there are factors that can predict both dislodgement of the root portion and limited traction distances., Patients and Methods: Fifteen patients (mean age, 25.7 years; age range, 17 to 65 years) with 20 lower third molars were enrolled. Panoramic films and cone beam computed tomography were analyzed. Dislodgement of the root portion, traction distance, duration of the orthodontic phase, and postoperative complications were documented. The predictive factors were analyzed and discussed., Results: Three teeth had dislodgements of the root portion. The mean traction duration was 59.2 days (range, 33 to 77 days), and the mean traction distance was 2.60 mm (range, 0.27 to 5.20 mm). Root apex cortical bone indentation and root curvature were significantly associated with traction distance. Pulpitis symptoms were documented in 1 tooth, and no postoperative nerve disturbances occurred., Conclusions: Our proposed 2-stage orthodontic lower third molar extraction procedure reduced iatrogenic inferior alveolar nerve injury. Cortical bone indentation and root curvature predicted dislodgement of the root portion and limited traction distances., (Copyright © 2017. Published by Elsevier Inc.)

Purpose: The aim of this study was to investigate the protection of the inferior alveolar neurovascular bundle in alveolar bone operation in conditions such as chronic osteomyelitis and cementoma., Patients and Methods: The study enrolled 7 cases, 4 with chronic osteomyelitis and 3 with cementoma with pain. Computed tomography scan and 3-dimensional reconstruction were performed for the diseases. Data were processed by ProPlan CMF 1.3 software. The edge of lesion was defined and the inferior alveolar nerve was marked. Template was designed to guide the osteotomy line. Piezosurgery was used for osteotomy, with the avoidance of nerve canal. Current perception threshold (CPT) was performed to evaluate the nerve function after operation., Results: The CPT difference of the affected side before and after operation showed no statistically significant differences compared with that of the unaffected side (P = 0.0556)., Conclusions: Digital template protects the inferior alveolar neurovascular bundle with the aid of piezosurgery during alveolar bone resection, which obtained satisfying clinical results. As powerful assistive tools of functional surgery, digital template and piezosurgery achieve both the purposes of treatment and function.

Background: The supratrochlear nerve (STN) is relatively superficial and therefore vulnerable to iatrogenic injury., Objective: To elucidate the course of STN with reference to the lacrimal caruncle, with the aim of preventing nerve injury during surgery in the forehead region., Materials and Methods: Thirty-four hemifaces from 18 Korean cadavers were dissected. The vertical line through the apex of lacrimal caruncle and the horizontal line through the supraorbital margin were used as horizontal and vertical reference lines, respectively. The course of STN in the frontal view and the point at which it pierced the overlaying musculature were examined., Results: After exiting the corrugator muscle cushion, the STN enters the subcutaneous plane by piercing the frontalis muscle. These piercing points occurred at mean horizontal and vertical distances relative to the medial branch of the STN of 9.2 and 9.6 mm, respectively; the corresponding distances for the lateral branch of the STN were 1.1 and 15.3 mm, respectively., Conclusion: When performing surgery in the medial forehead region, the surgeon must ensure that the dissection plane of forehead tissue is more superficial: superiorly within 1.5 cm from the supraorbital margin and medially within 1.0 cm from the vertical line through the apex of lacrimal caruncle.

Purpose: This retrospective study evaluated the localization, incidence, and dimensions of the mandibular lingual canal and the anterior loop in the Taiwanese population using the simulation and visual interpretation of cone-beam computed tomography to minimize complications during symphysis block surgical procedures., Materials and Methods: The sample population consisted of 215 patients (105 men and 110 women; mean age, 57 yr). The median lingual canal, symphysis bone thickness, and anterior loop length were defined and calculated using cone-beam computed tomography and 3-dimensional reconstructed images. The correlation of all data for men and women was assessed and analyzed statistically using unpaired t tests., Results: All patients exhibited at least 1 median lingual canal in the symphysis, and the diameter of the main branch ranged from 0.21 to 1.48 mm (mean, 0.85 mm), with relevant differences between genders (longer in men than in women). A harvesting depth of 4 mm for the distance from the buccal bone to the terminal end of the median lingual canal resulted in a risk of neurovascular injury (13.0%); this risk was notably higher in women (19.1%) than in men (6.7%). The right and left anterior loop lengths ranged from 0 to 5.46 mm (mean, 2.60 mm) and from 0 to 5.57 mm (mean, 2.61 mm), respectively, with no relevant differences between genders or sides., Conclusions: The results suggest that routine cone-beam computed tomographic examinations before surgical interventions in the symphysis region are necessary because of the numerous complicated anatomic variations., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study was to compare orthopantomography (OPG) and computed tomography (CT) accuracy in predicting inferior alveolar nerve (IAN) injury after lower wisdom teeth extraction., Methods: Twenty-three patients with completely impacted lower third molars were enrolled in this study and OPG and CT exams were obtained before surgical intervention. Finally, a total of 26 lower third molars were extracted and cases of paresthesia following a IAN lesion have been registered. Then, OPG and CT images of the same patients have been randomly submitted to four experienced oral surgeons (with a seniority of at least 5 years) who were required to predict the possibility of a IAN injury by only evaluating the radiological exams. The images were anonymous and have been submitted to the surgeons without an order avoiding to influencing the answers. The agreement between the predicted and the real outcomes was statistically evaluated using the positive predictive value (PPV), the negative predictive value (NPV), Sensitivity, Specificity and the Spearman's rank correlation coefficient., Results: A perfect agreement between OPG-based prevision and the real development of paresthesia due to IAN injury has been observed. This agreement was only moderate when considering CT images., Conclusions: OPG is a first-level diagnostic exam that provides enough information for predicting IAN lesions after impacted lower third molars surgery. CT is a second-level radiological exam that provides more information on roots morphology and on the amount of the contiguity between roots and mandibular canal resulting useful in performing a minimally invasive surgery.

Background: Implant surgery in the mandible can cause serious complications that can be life threatening. The incidence and cause of iatrogenic trigeminal nerve injury (TNI) related to dental implant surgery was investigated in a survey of the opinion and experience of the UK dentists and reported by the authors in part 1 of this series of articles. Part 2 reported on the risk assessment and management of implant-related inferior alveolar nerve (IAN), mental nerve (MN), and lingual nerve (LN) injuries. This article evaluates the significance of these findings and recommends an evidence-based protocol of risk management strategies to reduce the risk of TNI related to dental implant surgery., Methods: A survey was distributed among 405 dentists attending an Association of Dental Implantology (ADI) congress, of which 187 completed the survey., Results: In this study, the strategies to manage the risk of TNI included unilateral staging of implant placement (57%) and identification the MN when placing implants (43%). Twelve percent used drill stops when operating in the mandible. Nineteen dentists used steroids (eg, dexamethasone) routinely preoperatively and postoperatively. Twenty-six dentists used basic cone beam computed tomography minimally invasive techniques, and 70% encountered a large anterior loop of the IAN. Most dentists (76%) allowed a 2- to 4-mm safety zone radiologically above the IAN when placing implants, and over half of the responders (56%) used implants that were 10 mm in length., Conclusion: Given the elective nature of implant surgery, TNI should be fully avoidable. The evidence suggest that TNI can be minimized with meticulous attention to accurate assessment and surgical planning as well as carrying out the surgery with a high degree of precision. In part 3 of their series of articles, the authors presented an evidence-based protocol that comprises preoperative, intraoperative, and postoperative risk management strategies for dental implant surgical procedures in the mandible.

Background: Clinicians generally use panoramic radiographic (PR) images to assess the proximity of the mandibular third molar to the inferior alveolar nerve (IAN). However, in cases in which a patient needs to undergo a third-molar extraction, many clinicians also assess computed tomographic (CT) images to prevent nerve damage., Types of Studies Reviewed: Two of the authors independently searched MEDLINE (through PubMed), Cochrane Library, Scopus, and Ovid. The authors included randomized or nonrandomized longitudinal studies whose investigators had compared the number of IAN injuries after third-molar extraction in patients who had undergone preoperative CT with patients who had undergone only PR., Results: The authors analyzed the full text of 26 of the 745 articles they initially selected. They included 6 studies in the meta-analysis. Four of the studies had a high risk of bias, and the investigators of only 1 study had used blinding with the patients. The authors observed no statistically significant differences between groups related to the total number of nerve injuries (risk ratio, 0.96; 95% confidence interval, 0.50 to 1.85; P = .91). The prognosis of the injuries was similar for both groups., Conclusions and Practical Implications: Although having preoperative CT images might be useful for clinicians in terms of diagnosing and extracting mandibular third molars, having these CT images does not reduce patients' risk of experiencing IAN injuries nor does it affect their prognosis., (Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.)

The objectives of this study were to evaluate the efficacy of additional cone beam computed tomography (CBCT) imaging on decreasing the risk of inferior alveolar nerve (IAN) injury during third molar removal in patients at high risk and to assess the surgical outcomes. The study sample included patients considered at high risk for IAN injury based on panoramic radiography (PAN) evaluation. The primary predictor was the type of imaging method (PAN only or with additional CBCT). The other variables were demographic and anatomical/radiographic factors. The primary outcome variable was IAN injury. The secondary outcome variables were the preoperative surgical plan and surgical results including IAN exposure and duration of surgery. The sample comprised 122 patients (139 teeth) aged 18-48 years. Postoperative temporary IAN injury was present in three (4.2%) cases in the CBCT group and 11 (16.4%) in the PAN group at 7 days after surgery. However, none of the patients had a permanent IAN injury at the 6-month follow-up. Additional CBCT imaging was not superior to PAN in reducing IAN injury after third molar surgery during long-term follow-up. Nonetheless, CBCT may decrease the prevalence of temporary IAN injury and improve the surgical outcomes in high-risk patients., (Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: Dental implant-related iatrogenic injuries are proportionally increasing with dental implant surgery. This study assessed the experience of implant-related trigeminal nerve (TG) injuries among UK dentists. Risk management strategies and management of implant-related inferior alveolar nerve (IAN), mental nerve (MN), and lingual nerve injuries were investigated., Methods: A survey was distributed among 405 dentists attending an Association of Dental Implantology (ADI) congress, of which 187 completed the survey., Results: Most dentists (76% of 134 responses) allowed a 2 to 4 mm safety zone radiologically above the IAN when placing implants, and over half of the responders (56%) used implants that were 10 mm in length. The most frequent precautionary measure used by 73 (80%) responders was antibiotic coverage routinely to reduce the risk of infection when placing grafts in the posterior mandible. Other precautionary measures included unilateral staging of implant placement (57%), and 43% always identified the MN when placing implants. Nineteen dentists used steroids (eg, dexamethasone) routinely preoperatively and postoperatively. Twenty-six dentists used basic cone-beam CT (CBCT) minimally invasive techniques, and drill stops during implant placement were used by 14 responders. Although it is not highly recommended, steroids were used to manage the neuropathic pain and discomfort experienced by patients with IAN injuries in 40% of cases., Conclusion: Further training of dentists undertaking implant surgery is required so that they acquire up-to-date and evidence-based knowledge and skills in the prevention, diagnosis, and management of dental implant-related TG injuries. This training should also involve the justification and interpretation of CBCTs.

Many forms of dental treatment have the potential to cause injury to the oral branches of the trigeminal nerve, including local anesthetic injections, root canal therapy, implant insertion, bone grafting, and dentoalveolar surgery. Based on the records of a referral center with more than 30 years' experience in managing 3200 of these injuries, this article reviews etiology and prevention; suggests criteria for referral of patients; and discusses treatment for the various types of injury and the results of such treatment.

Background: Postoperative functional impairment of the inferior alveolar nerve (IAN) has been a common and well-recognized complication. Our study introduced a modified Obwegeser-Dal Pont bilateral sagittal split osteotomy (BSSO) technique and evaluated the subsequent incidence of postoperative neurosensory disturbance of IAN., Methods: In this prospective cohort study, 57 patients receiving our modified BSSO during orthognathic surgery were enrolled. The technique contained opening the 2 ramus cortices and inserting the osteotome bypassing the IAN to avoid nerve injury. A 5-point scale self-assessment questionnaire was used to evaluate IAN neurosensory disturbance one week, six months and 12 months postoperatively. Differences between groups were analyzed using χ test for categorical and Wilcoxon signed-rank test for pairwise categorical data., Results: Complete ramus splitting could be achieved in 109 (95.6%) sides. Lower lip or chin neurosensory disturbances presented in 72 (63.2%) sides 1 week postoperatively and gradually reduced to 9 (7.9%), and 4 (3.5%) at postoperative months 6 and 12, respectively., Conclusions: This BSSO technique could be safely performed with low rates of IAN exposure and injury and a low incidence of persistent neurosensory disturbance in 3.5% of patients 12 months postoperatively.

Background: The aim of this study is to evaluate if the statistical significant relations between the measures taken exists or not and to show how the 3D reconstruction could be help the oral surgeon in all those instances in which it may have a direct impact on the planning of the surgical steps., Methods: Thanks to use of NobelClinician™ Software it was possible to analyze 200 mandibular tomography computerized, random selected, and create a 3D reconstruction of mandibular bone, point out dental structure of wisdom tooth and the way of IAN. Statistical analysis was performed using the Statistical Package for Social Sciences. One way ANOVA test was used to measure the association between each independent variable and the outcome variable, followed by the post-hoc least significant difference (LSD) test for intergroup differences., Results: Two independent variables were significant predictors for risk to have the distance 0 mm from IAN to apex: "Ramus relationship/space available" and "depth"., Conclusions: The 3D reconstruction software provide surgeons with an additional planning tool, offering: immediate and neat visualization of the noble structures that have to be respected and their localization in the three spatial planes; the exact morphology of the relevant root apex; a 360° view of the relationship between the IAN and the third molar and the exact point in which the root is in relationship with the canal.

Objectives: The objective of the present study was to evaluate the anatomical relationship between mental foramen (MF), including the incidence of the anterior loop of the inferior alveolar nerve (AL), and roots of mandibular teeth in relation to risk of nerve injury with endodontic treatment., Materials and Methods: Cone-beam computed tomography (CBCT) images, which included teeth either side of the MF, were randomly selected. The anonymised CBCT images were reconstructed and examined in coronal, axial and sagittal planes, using three-dimensional viewing software, to determine the relationship and distance between MF and adjacent mandibular teeth. The actual distance between the root apex and MF was calculated mathematically using Pythagoras' theorem. If present, the incidence of an AL in the axial plane was also recorded., Results: The root apex of the mandibular second premolar (70 %), followed by the first premolar (18 %) and then the first molar (12 %), was the closest to the MF. Ninety-six percent of root apices evaluated were >3 mm from the MF. An AL was present in 88 % of the cases., Conclusions: With regards to endodontic treatment, the risk of nerve injury in the vicinity of the MF would appear to be low. However, the high incidence of the AL highlights the need for clinicians to be aware and careful of this important anatomical feature., Clinical Relevance: The risk of injury to the MN with endodontic treatment would appear to be low, but given the high incidence, it is important to be aware and be careful of the AL.

DesignMulticentre, randomised controlled clinical trial.InterventionPatients referred for third molar removal received a digital panoramic radiograph(PR). Adults with one or more lower third molars in a close relationship with the mandibular canal were eligible for the study. Patients randomised to the cone beam computed tomography (CBCT) group received a high resolution CBCT scan in addition to the PR. All lower third molar extractions were performed under local anaesthesia without sedation and without antibiotic prophylaxis. Information on variables such as experience of the surgeon, duration of surgery and technique for third molar removal were recorded.Outcome measureThe primary outcome measure was the number of patient-reported altered sensations one week after surgery. Secondary outcomes included the number of patients with an objective IAN injury; permanent IAN injury (>6 months); occurrence of other postoperative complications (wound infection, alveolar osteitis); Oral Health Related Quality of Life-14, questionnaire responses; pain (VAS score); duration of surgery; number of emergency visits; and number of missed days of work or study.ResultsThree hundred and forty-one patients with 477 lower third molars were randomised from three centres. Two hundred and sixty-eight patients with 320 mandibular third molars were analysed according to the intention-to-treat principle for the primary and secondary outcomes. The overall incidence of patient-reported altered sensations one week after surgery was 6.3%. At one week there was no difference in subjective IAN injury between the CBCT and PR group. No significant differences were noted between the two groups for any of the secondary outcomes recorded.ConclusionsAlthough CBCT is a valuable diagnostic adjunct for identification of an increased risk for IAN injury, the use of CBCT does not translate into a reduction of IAN injury and other postoperative complications, after removal of the complete mandibular third molar. In these selected cases with a high risk for IAN injury, an alternative strategy, such as monitoring or a coronectomy, might be more appropriate.

Objective: To evaluate the influence of the anatomic position and intraoperative exposure of the inferior alveolar nerve on neurosensory disturbance (NSD) in sagittal split ramus osteotomy., Study Design: The anatomic factors of the nerve were measured on preoperative three-dimensional computed tomography in 98 patients. The intraoperative nerve exposure was assessed. NSD was evaluated for 1 year after surgery. The correlations between NSD and the factors were analyzed., Results: The NSD decreased as the lateral marrow space from the nerve increased (P < .01). The complete nerve exposure increased NSD by 7.6 times (P = .01). The nerve exposure increased as the buccal plate thickness increased (P = .01) and decreased as the vertical marrow space from the nerve increased (P = .01)., Conclusions: The nerve exposure and the lateral marrow space from the nerve affected NSD. The buccal plate thickness and the vertical marrow space indirectly affected NSD through nerve exposure., (Copyright © 2016 Elsevier Inc. All rights reserved.)

A prospective study on 100 patients presented with a mesioangular impacted mandibular third molar in close proximity to the inferior alveolar nerve canal (IANC) was done to evaluate the efficacy of tooth sectioning in reducing the incidence of inferior alveolar nerve (IAN) injury during their surgical removal. The patients were divided into two groups: group A, where tooth sectioning was not performed, and group B, where tooth sectioning was performed. Patients were recalled 7 days, 15 days, 30 days, 3 months, and 6 months postoperatively for evaluation of nerve injury and its recovery. A total of 13 patients suffered from nerve damage out of which 10 patients (10/50 or 20 %) belonged to group A and 3 patients (3/50 or 6 %) belonged to group B. All patients showed complete recovery from nerve damage within 6 months except 1 patient. The result of the study showed that tooth sectioning significantly reduces the incidence of nerve damage by 14 %. Deviation of the IANC, increased depth of the impacted tooth, intraoperative hemorrhage within socket/nerve exposure, and increased duration of procedure were found to be the significant risk factors associated with nerve injury.

The aim of this study was to evaluate the outcomes of coronectomy as an alternative surgical procedure to complete removal of the impacted mandibular third molar in patients with a suspected close relationship between the tooth root(s) and the mandibular canal. A total of 151 patients underwent coronectomy and were followed up with clinical examinations and panoramic radiographs for a minimum of 6 months after surgery. None of the patients exhibited inferior alveolar nerve injury. Eruption of the retained root(s) was more frequent in younger patients (18-35 years). Thirty-six patients (23.8%) exhibited insufficient growth of new bone in the alveolar defect, and 11.3% required a second surgical procedure to remove the root remnant(s). Our results indicate that coronectomy can be a reliable alternative to complete removal of the impacted mandibular third molar in patients exhibiting an increased risk of damage to the inferior alveolar nerve on panoramic radiographs., (Copyright © 2016. Published by Elsevier Ltd.)

Purpose: To evaluate whether a low-dose subperiosteal anaesthesia is effective in minimising risks of inferior alveolar nerve damage at implant placement when compared to high-dose infiltration anaesthesia., Material and Methods: One hundred and twenty patients requiring the placement of a single implant in order to replace a missing first mandibular were randomly allocated to two groups: group A (awake hemilip) subperiosteal crestal injection equal to 0.9 ml of articaine with 0.5% epinephrine and group B (numb hemilip) infiltration equal to 7.2 ml of articaine with 0.5% epinephrine in the vestibular fundus. Intraoperative sensory control using sensory tests was carried out in all patients. Outcome measures were neurological complications, intraoperative and postoperative visual analogue scale (VAS) scores for pain and swelling, and a questionnaire evaluating patient satisfaction. Patients were followed for 1 week postoperatively., Results: There were no cases of nerve injury. Seven days after surgery the postoperative VAS score for pain and swelling was lower in group A in a statistically significant manner (difference = -3.41%; 95% CI: -5.57, -1.26; P = 0.002 and difference = -3.33%; 95% CI: -5.41, -1.25; P = 0.002, respectively)., Conclusions: No nerve damage occurred using either anaesthesia types, therefore the choice of type of anaesthesia is a subjective clinical decision, however it may be preferable to use a low dose (0.9 ml) of subperiosteal anaesthesia, since it is unnecessary to deliver 7.2 ml of articaine to anaesthetise a single mandibular molar implant site.

Extractions of mandibular third molars are a common procedure in dental practice. In cases where a close anatomical relationship of the root and the inferior alveolar nerve exists, the risk of transient or even permanent nerve injury increases. Nerve injury is difficult to manage and symptoms may cause severe patient discomfort, i.e. lifelong dysesthesia, i.e. painful sensation of the lower lip and chin area on the affected side. An alternative surgical procedure is coronectomy, which has first been described 25 year ago. Instead of complete tooth removal only the crown is extracted and the root is intentionally left in situ. A lower incidence of inferior alveolar nerve injury has been found with coronectomy in case of high-risk mandibular third molars, as was shown in randomized controlled trials. Coronectomy is presented in detail with indications as well as contraindications. A patient case is shown and recent literature is discussed.

Purpose: The aims of this study were to investigate the effectiveness of cone beam computed tomography (CBCT) compared to panoramic radiography (PR), prior to mandibular third molar removal, in reducing patient morbidity, and to identify risk factors associated with inferior alveolar nerve (IAN) injury., Material and Methods: This multicentre, randomised, controlled trial was performed at three centres in the Netherlands. Adults with an increased risk for IAN injury, as diagnosed from PR, were included in the study. In one arm of the study, patients underwent an additional CBCT prior to third molar surgery. In a second arm of the study, no additional radiographs were acquired. The primary outcome measure was the number of patient-reported altered sensations 1 week after surgery. As secondary outcome measures, the number of patients with objective IAN injury, with long-term (>6 months) IAN injury, the occurrence of other postoperative complications, the Oral Health Related Quality of Life-14 (OHIP-14) questionnaire responses, postoperative pain (visual analogue scale score), duration of surgery, number of emergency visits, and number of missed days of work or study were scored., Results: A total of 268 patients with 320 mandibular third molars were analysed according to the intention-to-treat principle. The overall incidence of IAN injury 1 week after surgery was 6.3%. No significant differences between CBCT and PR for temporary IAN injury (p = 0.64) and all other secondary outcomes were registered. A lingual position of the mandibular canal (MC) and narrowing, in which the diameter of the MC lumen was decreased at the contact area between the MC and the roots, were significant risk factors for temporary IAN injury., Conclusion: Although CBCT is a valuable diagnostic adjunct for identification of an increased risk for IAN injury, the use of CBCT does not translate into a reduction of IAN injury and other postoperative complications, after removal of the complete mandibular third molar. In these selected cases of a high risk for IAN injury, an alternative strategy, such as monitoring or a coronectomy, might be more appropriate. (http://clinicaltrials.gov, NCT02071030)., (Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The removal of mandibular third molars can be complicated by injury to the inferior alveolar nerve (IAN). Coronectomy retains the tooth root; this method has been found to be preferable to extraction in the context of mandibular third molars. A failed coronectomy may cause mobilization of these roots, thereby requiring a subsequent extraction. Having undergone a previous coronectomy, extraction is then safer as the roots usually migrate away from the IAN. Computed tomography is more accurate than radiography when imaging mandibular third molars pre-operatively owing to its three-dimensional nature. Longer studies need to be conducted to evaluate the long term benefits of coronectomy. CPD/CLINICAL RELEVANCE: The removal of mandibular third molars can be complicated by the presence of the close lying inferior alveolar nerve. Coronectomy can be useful in this setting and therefore it is important to be aware of the pros and cons of this technique.

Iatrogenic injury to the trigeminal nerve can remain a source of concern and litigation even for the most experienced oral and maxillofacial surgeons. This article provides the most up-to-date evidence-based recommendations for identification, prevention, and management of these injuries to help clinicians provide the highest level of patient care., (Copyright © 2015 Elsevier Inc. All rights reserved.)