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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.)

Objectives: The study represents a preliminary evaluation of the accuracy of the dynamic navigation system (DNS) in coronectomy of the mandibular third molar (M3M)., Methods: The study included participants with an impacted M3M near the inferior alveolar canal. The coronectomy planes were designed before the surgery using cone-beam computed tomography (CBCT) imaging data and then loaded into the DNS program. Intraoperatively, the navigation system was used to guide the complete removal of the target crown. Postoperative CBCT imaging was used to assess any three-dimensional deviations of the actual postoperative from the planned preoperative section planes for each patient., Results: A total of 12 patients (13 teeth) were included. The root mean square (RMS) deviation of the preoperatively designed plane from the actual postoperative surface was 0.69 ± 0.21 mm, with a maximum of 1.45 ± 0.83/-1.87 ± 0.63 mm deviation. The areas with distance deviations < 1 mm, 1-2 mm, and 2-3 mm were 71.97 ± 5.72 %, 22.96 ± 6.57 %, and 4.52 ± 2.28 %, respectively. Most patients showed extremely high convexity of the surface area located in the mesial region adjacent to the base of the extraction socket. There was no observable evidence of scratching of the buccolingual bone plate at the base of the extraction socket by the handpiece drill., Conclusions: These results provide preliminary support for the use of DNS-based techniques when extracting M3M using a buccal approach. This would improve the accuracy of coronectomy and reduce the potiential damage to the surrounding tissue., Clinical Significance: DNS is effective for guiding coronectomy., Competing Interests: Declaration of Competing Interest The authors declare there is no conflict of interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Inferior alveolar nerve (IAN) entrapment in third molar (M3) roots bears a significant risk for nerve injury. The aim of this study was to identify specific panoramic radiographic (PR) signs that can reliably identify IAN entrapment (IANE) root conformations. In a retrospective case-control study, 10 IANE and 218 non-IANE third molar risk cases were examined by PR and CBCT. The collected data included "classic" specific high-risk panoramic signs, number of M3 roots, extent of inferior alveolar canal (IAC)-root tip overlap, rotated position of M3 and impaction pattern. After bivariate analysis, sensitivity, specificity, positive and negative predictive values, positive likelihood ratios (LR+) and accuracy (AC) were calculated for the most significant predictive variables. Interruption of both cortical lines (LR + : 43.6; AC: 96.0%) and upward diversion of the IAC (LR + : 36.3; AC: 96.5%) were the most accurate single signs indicating IANE. Upward diversion combined with root darkening and interruption of the IAC (AC: 97.4%) and the combination of darkening with interruption and with a rotated M3 (LR + :130.8; AC: 97.8%) were the most accurate combinations predicting IANE. IANE may be correctly filtered with PR when focusing on the signs of upward diversion, darkening, interruption and rotated M3 position, especially in cases involving their multiple (≥3) presence. CBCT evaluation is highly recommended in these cases before partial and total tooth removals., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could influence the work in this paper. Kata Janovics: investigation, writing the original draft. Balázs Soós: investigation, writing the original draft. Ákos Tóth: statistical analysis, methodology. József Szalma: conceptualization, methodology, writing, review, and editing., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: This study aimed to assess the factors that can possibly affect the positioning of the inferior alveolar nerve (IAN) in the proximal or distal segment following sagittal split osteotomy (SSO)., Materials and Methods: This was a prospective cohort study. The patients were assigned according to the position of the IAN: the IAN was attached to the buccal plate in group 1 (27 SSOs), while it was in the distal segment in group 2 (83 SSOs)., Results: The mean of the buccolingual thickness of the proximal segment at the vertical cut of the osteotomy (BLTP) was 5.0 ± 0.62 mm in group 1 and 4.16 ± 0.72 mm in group 2. The mean of the distance between the IAN and the external cortical bone at the distal of the second molar before the osteotomy (IANB) was 0.5 ± 0.24 mm in group 1 and 1.24 ± 0.45 mm in group 2. There were significant differences for the mean BLTP and IANB between the two groups (P = 0.001)., Conclusion: It seems that the thickness of the buccal plate of the proximal segment, the distance from the IAN to the external cortical bone, the osteotomy technique, and the presence or absence of impacted third molars may be associated with the positioning of the IAN following SSO., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: To assess the reliability of radiographic signs of the relationship between impacted mandibular third molars (IMTMs) and the inferior alveolar canal (IAC), and the vertical relationship between IMTM and IAC on panoramic radiographs (PRs) as risk indicators for IAC exposure during extraction., Study Design: Seven radiographic signs regarding the appearance of roots and the IAC were assessed as present or absent on PRs. The vertical relationship between IMTM and the IAC was divided into 3 levels. The correlation between radiographic data and IAC exposure during extraction was analyzed by using χ 2 statistics and logistic regression analysis., Results: In total, 198 IMTMs were examined. In 46 cases (23.2%), the IAC was exposed during extraction. Four radiographic signs-darkening of the root, narrowing of the root, narrowing of the IAC, and diversion of the IAC-were associated with IAC exposure (P < .05). Concurrence of 2 or more of 7 radiographic signs increased the risk of IAC exposure (P < .001). The vertical relationship between IMTM and the IAC was found to be a risk indicator for IAC exposure (P < .001). No significant correlation was found between IAC exposure and inferior alveolar nerve damage (P = .148)., Conclusions: Panoramic radiography is useful for assessing the risk of IAC exposure during IMTM extraction., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to analyze cases of liability claims related to persistent altered sensation following endodontic treatments so as to characterize the medico-legal aspects of this complication., Study Design: A comprehensive search of an Israeli professional liability insurance database was conducted to retrospectively identify and analyze cases of persistent altered sensation following endodontic treatment., Results: Sixteen claims of persistent altered sensation following endodontic treatments were identified and analyzed. The typical profile of a claim was a female patient who underwent an endodontic treatment at a second mandibular molar, which was associated with overfilling. A significant correlation between the tooth location and the suggested cause of nerve injury was found. None of the claims were reported by the practitioners, and all cases were identified as a result of the patient's demand for financial compensation, either directly or by legal actions., Conclusions: When a nerve injury is diagnosed, the treating practitioner should be encouraged to seek medical and legal assistance so as to prevent permanent damage and to enable a better medico-legal response., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: In this study, we investigated the multivariate relationships among risk factors and hypoesthesia of the lower lip., Study Design: Various risk factors of hypoesthesia of the lower lip after mandibular third molar extraction were investigated by univariate and multivariate analyses., Results: Applying the logistic regression model and forward stepwise algorithms, canal observed, remarkable hemorrhage, loss of the white line of the root, diversion of the canal, and close relationship of the roots to the inferior alveolar nerve were identified as significant variables., Conclusions: Procedure-related factors during surgery, such as canal observed and remarkable hemorrhage, and radiographic signs, such as loss of the white line of the root, diversion of the canal, and close relationship of the roots to the inferior alveolar nerve, were high risk factors of hypoesthesia of lower lip after extraction., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: Surgical removal of impacted third molar is one of the most frequent procedures in oral surgery. Today 3-dimensional (3D) imaging is occasionally used. The aim of this study was to describe and estimate the frequencies of anatomic variations of lower third molars in patients with panoramic findings at high risk for inferior alveolar nerve (IAN) injury., Study Design: The investigators designed and implemented a retrospective cases series study with a study population composed of patients presenting with an impacted lower third molar with projection of the tooth over the full width of the IAN in panoramic radiograph and, therefore, 3D imaging before a planned surgical removal. Spatial relationship to the IAN, type of angulation, root configuration and maturation were primary study variables. Descriptive statistics were computed for all variables., Results: A total of 707 wisdom teeth in 472 patients (54% female, 46% male) were evaluated. A close relationship to the IAN was seen in 69.7%, and in 45.1% the diameter of the mandibular canal was reduced. In 52.8% the IAN was vestibular and in 37.3% lingual to the roots; there were 9.9% with an inter- or intraroot course. Most teeth had 1 or 2 roots (86.7%), but 13.3% had ≥3 roots. Mesial angulation was the main type (40.2%), followed by vertical (29%), horizontal (13.9%), distal (10.2%), and transverse (6.8%) positions., Conclusion: Based on the range of variations in the course of the nerve and the number of roots the authors recommend 3D imaging before surgical removal of a lower third molar that shows signs of a close relationship to the IAN., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: The authors used comprehensive national registry and clinical data to conduct a study of adverse drug reactions (ADRs), in particular neurosensory disturbance (NSD), associated with local anesthetics used in dentistry, Methods: The study included data sets of annual sales of local anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent, prilocaine 3 percent, and articaine 4 percent sold in cartridges., Results: The study results showed a highly significant overrepresentation of NSDs associated with articaine 4 percent, in particular with mandibular blocks., Conclusions: The distribution of NSDs was disproportionate to the market share of three of the four drugs in both national registry data and clinical data. These findings indicate that the main cause of injury was neurotoxicity resulting from administration of the local anesthetic rather than the needle penetration., Clinical Implications: Clinicians may consider avoiding use of high-concentration (4 percent) anesthetic formulations for block anesthesia in the trigeminal area in cases in which there are viable alternatives.

Introduction: This retrospective study comprises an exploratory analysis of 10 years of surgical treatment of symphysis (S) and parasymphysis/body (P/B). Correlations of complications, as well as dependencies of surgical concepts, are investigated., Materials and Methods: All surgically treated patients in the period of 1995 to 2005 with at least one mandibular fracture mesial to the mandibular angle were included in this study. A total of 63 patients (46 men, 17 women) with 63 symphysis fractures were included and 497 patients (369 men, 128 women) with 553 P/B were included; 99.27% (549) of these fractures were included in the study, 4 had to be dismissed because of inconclusive documentation., Results: Of patients with P/B, 96.04% were successfully treated with 1 open reduction, 3.76% had 2, and 0.20% had 3 surgeries. Of the surgically treated patients, 75.77% (416) were completely free of complications, whereas the other 24.23% of the P/B showed 1 or more complications. The main complication was mild nerve damage (24.8%). Osteosynthesis failure rate (OFR) was 2.4% (7 of 298) for 2 miniplates, 5.7% (3 of 53) for 1 tension screw, and 8.4% (9 of 107) for 1 miniplate. Regarding OFR, 2 miniplates showed to be superior in a Fisher exact test (P = .018, adjusted P = .132). Symphysis fractures were completely free of complications in 81.8% and showed 2 major complications, i.e., 1 severe nerve damage and 1 osteosynthesis failure., Discussion: This study has the limitations of a retrospective study., Conclusion: A high success rate of open reduction and osteosynthesis with 2 miniplates can be guaranteed., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Introduction: The main procedure specific complication of sagittal split osteotomy of the mandibular ramus (SSOMR) is inferior alveolar nerve (IAN) injury. This can be produced by poor intraoperative visibility of the IAN due to bone bleeding. In our centre, mandibular nerve blocks (MNBs) are usually performed for intra- and post-operative analgesia. We observed that MNB seems to decrease intraoperative bleeding and thus to improve IAN visibility. Our study was performed to evaluate the effect of MNB on intraoperative bleeding during SSOMR and, secondarily, on the duration of this procedure., Material and Methods: Patients scheduled for bilateral SSOMR under general anaesthesia were prospectively randomized into two groups. The Block group received bilateral MNB (5 mL ropivacaine 0.5% for each block) and the Control group sham MNBs (bilateral cutaneous puncture, without block). The operations were carried out under a standardised general anaesthetic. Post-operatively, the surgeon, blinded to group allocation, assessed intraoperative bone bleeding using a Numerical Rating Scale (NRS) (0: no bleeding, perfect visibility to 100: major bleeding, no visibility). Osteotomy duration, intraoperative anaesthetic requirements, and pain score in the recovery room were also recorded. Results are expressed as median [25-75th percentiles]., Results: Nineteen patients were included in each group. Osteotomy under MNB had a decreased intraoperative bone bleeding score compared with controls (20 [0-40] versus 55 [20-80], p=0.0002). They had a dry surgical field more frequently (29% versus 5%, p=0.01), and a shorter mean time for the osteotomy (15 [12.25-17.75] versus 17.5 [15-21]min, p=0.009). Block patients had reduced intraoperative opioid consumption (770 [678-1430] versus 2310 [1908-3058]mcg of remifentanil, p=0.0001), and lower pain scores in the recovery room (0 [0-2] versus 3 [1-5], p=0.12)., Conclusion: MNB decreases intraoperative bone bleeding during SSOMR under general anaesthesia. Three hypotheses to explain this result are discussed., (Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: This study investigated a new technique for the bilateral sagittal split osteotomy (BSSO) by adding a new osteotomy line at the inferior border of the mandible in the Obwegeser-Dal Pont operation., Material and Methods: For this purpose a test system was designed and 100 pig mandibles were split to assess the test's reliability, to compare the torque necessary to split the mandible in both techniques and to record the fracture lines. The splitting technique was standardized, avoiding any contact with the inferior alveolar nerve. All outcomes were statistically examined by paired t-tests., Results: By using the new technique, we demonstrated a decrease in the torque force required to split the mandible of 29.7% (t(69)=-12.68; p<0.05, paired t-test) compared to the Obwegeser-Dal Pont technique. The fracture lines were close to ideal., Conclusion: The additional osteotomy facilitates the BSSO technique and it reduces the likelihood of bad splits and damage to the inferior alveolar nerve in pig mandibles., (Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

This article presents a simple deroofing technique to retrieve a broken endodontic file lodged in the mandibular canal and causing dysesthesia with pain. Many unsuccessful attempts were made to retrieve the broken instrument. The deroofing technique described is simple, requiring local anesthesia and done on an outpatient basis with minimum morbidity. A brief review of the literature on dysesthesia of the inferior alveolar nerve caused by endodontic materials is also presented., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: The objective of this study was to compare postsurgical neurosensory alteration and recovery patterns among different nerve fiber types and orthognathic surgeries by measuring current perception thresholds (CPT)., Study Design: CPTs of 186 patients who underwent various orthognathic surgeries (Le Fort I or II, bilateral sagittal split [BSSRO] or intraoral vertico-sagittal [IVSRO] ramus osteotomy with or without genioplasty) were measured at 2000, 250, and 5 Hz, assessing 3 different nerve fiber types before surgery and at 3, 6, and 12 months after surgery., Results: CPTs were highest at 3 months postsurgery and gradually returned to presurgical levels until 12 months postsurgery in most cases. CPT at 2000 Hz showed the largest amount of increase. Le Fort I and IVSRO caused less neurosensory alteration compared with Le Fort II and BSSRO, respectively., Conclusion: Our data provide nerve recovery patterns following various orthognathic surgeries that may be applied to evaluating the patient's severity and recovery of nerve damage., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: The objective of this study was to evaluate the inferior alveolar nerve (IAN) morphologically in patients with symptomatic posttraumatic sensory disorders using magnetic resonance imaging (MRI) on a high-field system., Study Design: Sixteen patients who complained of persistent sensory disturbance attributed to unilateral IAN injury participated in the investigation. High-resolution 3-dimensional volume rendering magnetic resonance neurography was performed on a 3.0-T MRI system., Results: In 15 (94%) of 16 patients, high-resolution 3-dimensional volume rendering magnetic resonance neurography demonstrated morphologic abnormalities of the IAN as well as connective tissue overgrowth. These findings were confirmed intraoperatively (6 patients) and histopathologically (5 patients). The duration of sensory disturbance correlated significantly with the pattern of morphologic deformity and connective tissue overgrowth., Conclusions: The current study clearly demonstrated that appropriate application of clinical MRI techniques can significantly improve the diagnosis and potential treatment of patients with orofacial peripheral nerve disorders., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: Earlier reports, including a preliminary study within our unit, have shown that the surgeon's experience is one of the most influential factors in determining the likelihood of both permanent inferior alveolar nerve (IAN) and lingual nerve (LN) paresthesia, following third molar surgery. The effect of this and other factors influencing such prevalence are assessed in this study., Study Design: This prospective study involved 3236 patients who underwent surgical removal of impacted third molars. Patients' demographics and radiological parameters were recorded along with the grade of the treating surgeon. The prevalence of inferior alveolar and lingual nerves paresthesia at 1 month, 6 months, and 18 to 24 months postoperatively were also traced., Results: At 1 month postoperatively, the incidence of IAN paresthesia was 1.5% and the LN was 1.8%. These figures decreased over time and 18 to 24 months postoperatively, the incidence of permanent dysfunction of the IAN was 0.6% and LN was 1.1%. With regard to inferior alveolar nerve paresthesia, risk factors included the patient's age (26-30 years), horizontally impacted teeth, close radiographic proximity to the inferior alveolar canal (IAC), and treatment by trainee surgeons. With regard to the lingual nerve, risk factors included male patients, distoangular impactions, close radiographic proximity to the IAC, and treatment by trainee surgeons., Conclusion: One of the main risk factors of developing permanent sensory dysfunction in the distribution of these nerves is related to the surgical skills/experience of the operator. Other factors are associated with the type of impaction and the radiographic proximity of the tooth to the inferior alveolar nerve. Such long-term complications can affect the patient's quality of life; the impact on profession, education, and research is unknown., (Copyright 2010 Mosby, Inc. All rights reserved.)

Background: Paresthesia is a well-known complication of extraction of mandibular third molars (MTMs). The authors evaluated the relationship between paresthesia after MTM extraction and the cortical integrity of the inferior alveolar canal (IAC) by using computed tomography (CT)., Methods: The authors designed a retrospective cohort study involving participants considered, on the basis of panoramic imaging, to be at high risk of experiencing injury of the inferior alveolar nerve who subsequently underwent CT imaging and extraction of the MTMs. The primary predictor variable was the contact relationship between the IAC and the MTM as viewed on a CT image, classified into three groups: group 1, no contact; group 2, contact between the MTM and the intact IAC cortex; group 3, contact between the MTM and the interrupted IAC cortex. The secondary predictor variable was the number of CT image slices showing the cortical interruption around the MTM. The outcome variable was the presence or absence of postoperative paresthesia after MTM extraction., Results: The study sample comprised 179 participants who underwent MTM extraction (a total of 259 MTMs). Their mean age was 23.6 years, and 85 (47.5 percent) were male. The overall prevalence of paresthesia was 4.2 percent (11 of 259 teeth). The prevalence of paresthesia in group 3 (involving an interrupted IAC cortex) was 11.8 percent (10 of 85 cases), while for group 2 (involving an intact IAC cortex) and group 1 (involving no contact) it was 1.0 percent (1 of 98 cases) and 0.0 percent (no cases), respectively. The frequency of nerve damage increased with the number of CT image slices showing loss of cortical integrity (P=.043)., Conclusions: The results of this study indicate that loss of IAC cortical integrity is associated with an increased risk of experiencing paresthesia after MTM extraction.

Objective: The aim of the study was to estimate the accuracy of panoramic radiographic signs predicting inferior alveolar nerve (IAN) paresthesia after lower third molar removal., Study Design: In a case-control study the sample was composed of 41 cases with postoperative IAN paresthesia and 359 control cases without it. The collected data included "classic" specific signs indicating a close spatial relationship between third molar root and inferior alveolar canal (IAC), root curvatures, and the extent of IAC-root tip overlap. Bivariate and multivariate logistic regression analyses were completed to estimate the association between radiographic findings and IAN paresthesia., Results: The multivariate logistic analysis identified 3 signs significantly associated with IAN paresthesia (P < .001): interruption of the superior cortex of the canal wall, diversion of the canal, and darkening of the root. The sensitivities and specificities ranged from 14.6% to 68.3% and from 85.5% to 96.9%, respectively. The positive predictive values, calculated to factor a 1.1% prevalence of paresthesia, ranged from 3.6% to 10.9%, whereas the negative predictive values >99%., Conclusion: Panoramic radiography is an inadequate screening method for predicting IAN paresthesia after mandibular third molar removal., (Copyright (c) 2010 Mosby, Inc. All rights reserved.)

The inferior alveolar nerve is at risk during surgical removal of impacted mandibular teeth and excision of benign tumors of mandible. Manual and/or mechanical instruments used in the close proximity of delicate structures do not allow the control of the cutting depth and can damage these structures by accidental contact. Piezoelectric surgery is a new and innovative bone surgery technique using the microvibrations of special scalpels at ultrasonic frequency so therefore soft tissue will not be damaged even upon accidental contact with the cutting tip. This article presents an alternative technique that uses piezoelectricity to minimize trauma to the inferior alveolar nerve, vascular tissues, or surrounding dental tissues.

Introduction: The purpose of this analysis was to determine whether, over a 2-year period after bilateral sagittal split osteotomy, patients who received facial sensory-retraining exercises with standard opening exercises in the first 6 months after surgery were as likely to report an alteration in facial sensation as those who received standard opening exercises only., Methods: 186 subjects were enrolled in a multi-center, double-blind, stratified-block, randomized clinical trial with 2 parallel groups. Patient reports of altered sensations were obtained before surgery, and 1, 3, 6, 12, and 24 months after surgery. A marginal model was fit to examine the effect of sensory retraining while controlling for potential explanatory effects related to demographic, psychological, and clinical factors on the odds of postoperative altered sensations being reported., Results: Age (P <0.0001) and severity of presurgical psychological distress (P <0.0001) were significantly associated with the presence of altered sensations after controlling for the exercise training received. After controlling for age and psychological distress, patients who received opening exercises only were approximately 2.2 times more likely to report postoperative altered sensations than those who also received sensory-retraining exercises (P <0.03)., Conclusions: These results suggest that a simple noninvasive exercise program started shortly after orthognathic surgery can lessen the likelihood that a patient will report altered sensations in the long term after orthognathic surgery.

Objective: The objective of this study was to compare the surgical complications and neurosensory disturbances of coronectomy and total excision of lower wisdom teeth with roots in close proximity to the inferior dental nerve (IDN)., Study Design: A randomized controlled trial was conducted to compare the surgical complications and IDN deficit of coronectomy and total removal of wisdom teeth. Patients with specific radiographic signs of close proximity of wisdom teeth roots to the IDN were randomized., Results: A total of 231 patients underwent surgery for 349 lower wisdom teeth (171 coronectomies, 178 controls); 16 coronectomies failed and were removed in total. Nine patients in the control group presented with IDN deficit, compared with 1 in coronectomy group (P = .023). Pain and dry socket incidence was significantly lower in the coronectomy group, and there were no statistical differences in infection rate between the 2 groups. Reoperation of one coronectomy case was performed owing to persistent root exposure., Conclusion: There are fewer complications in terms of IDN deficit, pain, and dry socket after coronectomy, but the infection rate is similar to that of total excision.

Objective: The aim was to compare digital and conventional panoramic imaging techniques for identifying high-risk radiographic markers associated with mandibular nerve (MN) injury after mandibular third molar (M3) removal., Study Design: The study used a retrospective cohort model. The predictor variable was the presence or absence of radiographic signs associated with MN exposure during M3 removal. The outcome variable was MN exposure. Intraexaminer variability was estimated using a kappa statistic. Logistic regression modeling was used to measure the association between radiographic signs and MN exposure and determine if imaging technique modified that association. The level of statistical significance was set at P < .05., Results: The sample was composed of 571 patients having 1,017 mandibular M3s removed. The MN was visualized in 66 extraction sites (6.5%). In the adjusted logistic model, radiographic signs were statistically associated with MN exposure (P < .001) and imaging technique was a statistically insignificant effect modifying variable (P = .4)., Conclusion: The results of this study suggest that imaging technique does not modify the relationship between high-risk panoramic radiographic signs and MN exposure.

Objective: To evaluate postextractive neurological complications after third molar extraction under general anesthesia and to identify correlations between the surgical procedure, the third molar-related pathology, and neurological involvement., Study Design: The clinical records of 183 patients were analyzed for a total of 408 third molars extracted at the Dental Clinic of Trieste (Italy). Individual effects of clinical data on the presence of paresthesia were evaluated by a logistic regression model., Results: Neurological involvement was observed in 13 patients (6.1%). No permanent inferior alveolar nerve damage was found (0%) and only 1 patient presented a permanent lesion of the ipsilateral lingual nerve (0.3%). Pell and Gregory classification and surgical difficulty were not associated with the incidence or gravity of neurological lesions (P = NS). Among the pathologies associated with third molars, only the variable "abscess" presented a significant correlation with paresthesia (OR 6.86; 95% CI 1.21-38.8; P = .029)., Conclusion: The percentage of nerve injuries agrees with the literature data, inclusion class, and surgical technique seem not to influence paresthesia risk. Further studies are necessary to evaluate the role of infectious pathologies as a cofactor in the development of neurological lesions after oral surgery.

Objective: To examine the prognosis of the neurosensory disturbance (NSD) in the chin after bilateral sagittal split ramus osteotomy (BSSRO), using the heat flux technique., Study Design: Twenty-nine patients (total 58 sides) undergoing BSSRO were examined. The warm sensory threshold (WHF) and cold sensory threshold (CHF) in the chins of these patients were measured by the heat flux technique. Touch sensory threshold (TS) was measured by an Semmes-Weinstein esthesiometer. Touch sensory disturbance was subjectively evaluated by visual analog scale., Results: At all of the postoperative time points, there were no significant differences in the incidence rate among all tests (chi-squared test; P > .05). WHF, CHF, and TS were significantly correlated with the subjective evaluation. Recovery from NSD was delayed in cases that the postoperative variation of 2 weeks was >400 W/m(2) in WHF and CHF and the filament marking at 2 weeks after surgery was >3.5 in TS., Conclusion: The heat flux technique appears to be a useful method for the prediction of the recovery from NSD in the chin.

Objectives: The objective of this study was to analyze the etiological factors and neurosensory signatures of patients attending with a primary complaint of numb chin., Methods: Charts of 27 patients referred to Hadassah School of Dental Medicine, Jerusalem, Israel, with a complaint of unilateral numbness or paresthesias of the chin were reviewed. Demographic and etiologic data and special tests, including imaging, that were prescribed as necessary for the treatment protocol were evaluated. The neurosensory evaluation protocol included assessment of detection thresholds to electrical stimulation (assessing large myelinated nerve fibers) and heat (assessing thin unmyelinated nerve fibers) in the mental and infraorbital nerves regions bilaterally. Data from 8 healthy, age and sex-matched subjects who underwent similar sensory testing served as the control group., Results: Invasive dental procedures (eg, extractions, implants) were the etiologic factor in 63% of the cases. Inflammatory pathoses (15%) (eg, periapical periodontitis or infection), and malignant lesions (22%) were identified as causative in the remaining patients. Frank nerve injury due to advanced malignant processes was characterized by significantly elevated heat and electrical thresholds (hyposensitivity). Inflammatory process was accompanied by reduced electrical detection thresholds (hypersensitivity)., Conclusions: This study concurs with previous studies that sensory hyposensitivity accompanies nerve damage. Accordingly, quantitative sensory testing may contribute to the diagnostic process of patients with mental nerve neuropathy. In this sample of patients, the most common cause for mental nerve neuropathy was dental treatment followed by malignant metastasis.

Lip paresthesia during mandibular molar orthodontic distalization is rare. When it occurs, it is often related to excessive dimensions of the mandibular second molar roots. In this clinical report, we describe a patient who developed lip paresthesia during orthodontic treatment. The paresthesia was relieved by immediate interruption of the forces applied to the mandibular second molars and pharmacologic therapy. Before fixed orthodontic treatment proceeds in patients with large tooth roots, it is important to diagnose the relationship between the roots and the mandibular canal to prevent nerve numbness and damage.

Objective: The purpose of this study was to objectively evaluate the relationship between recovery of hypoesthesia of the lower lip after sagittal split ramus osteotomy (SSRO) with trigeminal somatosensory evoked potential (TSEP) and sagittal split area or plate screw position, using postoperative computerized tomography (CT)., Study Design: The subjects consisted of 58 patients (116 sides) with mandibular prognathism who underwent SSRO. The patients were divided into 2 groups. The Ob group, consisting of 62 sides, underwent the Obwegeser method. The OD group, consisting of 54 sides, underwent the Obwegeser-Dal Pont method. Trigeminal nerve hypoesthesia at the region of the lower lip was assessed bilaterally by the TSEP method. An electroencephalograph recording system (Neuropack Sigma; Nihon Koden, Tokyo, Japan) was used to analyze the potentials. Each patient was evaluated preoperatively and then postoperatively at 1 week, 2 weeks, 1 month, 3 months, 6 months and 1 year. Postoperative CT was performed in all cases to measure the sagittal split area (SSA) as well as the distance between the plate (the most medial point of screw) and the mental foramen (PM). Then comparisons between the 2 groups in recovery period of the lower lip, SSA, and PM were performed. Furthermore, the relationships between recovery period of hypoesthesia of the lower lip and SSA or PM were evaluated statistically., Results: The average measurable period and standard deviation of TSEP of the lower lip was 3.4 +/- 5.5 weeks in the Ob group and 11.3 +/- 13.7 weeks in the OD group. There were significant differences between the Ob group and the OD group (P < .0001). The OD group showed significantly greater SSA and PM than the Ob group (P < 0.0001)., Conclusion: This study suggested that recovery period of hypoesthesia of the lower lip after SSRO was strongly associated with SSA and PM.

Damage to the inferior alveolar nerve is a relatively infrequent complication in dental practice. When root canal treatment of a lower molar or premolar surpasses and/or overextends beyond the apical foramen and invades the periapical zone, the foreign material introduced within such a sensitive anatomical space may mechanically or even chemically affect the inferior alveolar nerve. We describe a case of endodontic treatment of a permanent right lower first molar in which the sealer cement overextended in large amounts and damaged the right inferior alveolar nerve. The condition reverted a few months after the surgical removal of the material. Evaluation of the removed material, using powder x-ray diffraction and scanning electron microscopy with coupled dispersive energy spectroscopy, showed it to consist of calcium tungstate (scheelite [CaWO4]) and zirconium oxide (baddeleyite [ZrO2]), which were chemical components of the sealer cement.

The inferior alveolar nerve (IAN) contains mainly sensory fibers. Within the mandibular canal, the IAN runs forward in company of the inferior alveolar artery, and together they are called the inferior alveolar neurovascular bundle. Disturbances of the IAN and mental nerve will predominantly give sensitivity symptoms in the soft tissue of the lower lip and chin. We present a case report of endodontic overfilling involving the mandibular canal. A 52-year-old woman was seen in our outpatient clinic for pain and numbness in the left lower lip and chin, which developed following an endodontic treatment for her mandibular left second premolar. The panoramic radiograph showed radiopaque material in the inferior alveolar canal region, with an extension from the left canine to the second premolar. This case report shows an unusual complication of mandibular second premolar root canal overfilling. The patient underwent treatment with corticosteroids, and after 2 months, the clinical examination revealed an improved clinical situation with a disappearance of the hypoesthesia but with a persistence of the pain. After 4 months, the pain had almost entirely disappeared. In conclusion, even if in our case no surgical treatment was used and although spontaneous resorption has been described for some materials, early surgical exploration with removal of the material and decompression of the IAN is suggested, irrespective of the material used, because the severity of nerve damage can increase with the duration of the injury.

Current management of painful trigeminal neuropathies relies on pharmacological (topical and systemic), surgical, and complementary modalities. There is, however, a lack of quality research relating to the effectiveness of these modalities. In this review we analyze the available data that relates to the therapy of trigeminal neuralgia, postherpetic neuralgia, and posttraumatic neuropathies and provide clinical guidelines. The review focuses on medical management, as well as surgical and other interventions for painful neuropathies.

Removal of third molars is one of the most common operations performed in oral surgery. A well recognized serious complication of mandibular third molar extraction is injury to the inferior alveolar nerve (IAN). We describe a case of an unusual nerve passage discovered after the extraction of a completely erupted third molar. The likelihood of direct damage to the IAN can be predicted with more specific information obtained by the use of a preoperative computerized tomography scan when conventional radiography does not clearly show the nerve canal.

Purpose: The purpose of this study was to objectively evaluate hypoesthesia of the upper lip following Le Fort I osteotomy in combination with mandibular osteotomy with trigeminal somatosensory evoked potential (TSEP)., Subjects and Methods: The subjects consisted of 25 patients with mandibular prognathism with maxillary retrognathism mandibular prognathism with or without asymmetry, who underwent Le Fort I osteotomy in combination with sagittal split ramus osteotomy (SSRO) or intraoral vertical ramus osteotomy (IVRO). Trigeminal nerve hypoesthesia at the region of the upper lip was assessed bilaterally by the TSEP method. The electrodes were placed exactly above the highest point of the vermilion border and on the mucosa of the upper lip. An electroencephalograph recording system (Neuropack Sigma; Nihon Koden Corp., Tokyo, Japan) was used to analyze the potentials. Each patient was evaluated preoperatively and then postoperatively at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year., Results: The average measurable period and standard deviation of TSEP of the upper lip was 7.8 +/- 10.7 weeks following Le Fort I osteotomy, TSEP of the lower lip was 4.6 +/- 9.2 weeks in the patients who underwent SSRO with Le Fort I osteotomy, and 1.2 +/- 0.4 weeks in the patients who underwent IVRO with Le Fort I osteotomy., Conclusion: This study objectively proved that hypoesthesia could appear in the upper lips following Le Fort I osteotomy with TSEP. The measurable period for the upper lip following Le Fort I osteotomy tended to be longer than that for the lower lip in the patients who underwent SSRO and IVRO with Le Fort I osteotomy.

Background: Endodontic treatment of mandibular molar teeth has the potential to damage the inferior alveolar nerve via direct trauma, pressure or neurotoxicity., Methods: The author reviewed all cases of involvement of the inferior alveolar nerve resulting from root canal therapy in patients seen in a tertiary referral center during an eight-year period (1998 through 2005). The author had encouraged practitioners to refer patients immediately to a university clinic., Results: The author saw 61 patients during the eight-year period. Eight patients were asymptomatic and received no treatment. Forty-two patients exhibited only mild symptoms or were seen more than three months after undergoing root canal therapy, and they received no surgical treatment. Only 10 percent of these patients experienced any resolution of symptoms. Eleven patients underwent surgical exploration. Five of these patients underwent exploration and received treatment within 48 hours, and all recovered completely. The remaining six patients underwent surgical exploration and received treatment between 10 days and three months after receiving endodontic therapy. Of these patients, four experienced partial recovery and two experienced no recovery at all., Conclusions: Early surgical exploration and débridement may reverse the side effects of endodontic treatment on the inferior alveolar nerve., Clinical Implications: If the radiograph obtained after endodontic therapy shows sealant in the inferior alveolar canal, then immediate referral to an oral and maxillofacial surgeon is indicated if the patient has continued symptoms of paresthesia or pain once the local anesthetic should have worn off. Immediate surgical exploration and débridement may provide satisfactory results.

Objective: To examine neurosensory changes in the chin following bilateral sagittal split ramus osteotomy (BSSRO) using the heat flux technique., Study Design: Twelve healthy adults (C-group) and 23 patients undergoing BSSRO (P-group) were examined. The warm sense threshold (WHF) and cold sense threshold (CHF) in the chin of these patients were measured by the heat flux technique. In the P-group, touch sensation also was measured with a visual analog scale (VAS) and the Semmes-Weinstein monofilament test (SW test)., Results: Both WHF and CHF were significantly larger in the P-group than in the C-group (P = .024). Touch sensation (VAS and SW test) were damaged in some patients of the P-group. However, no correlation was revealed between thermal sensation (WHF and CHF) and touch sensation (VAS and SW test) in the P-group., Conclusions: These results suggest that the thermal sensation in the chin was damaged after BSSRO. The heat flux technique appears to be one of the useful methods for the examination of neurosensory disturbance in the chin.

The present study describes a case of endodontic paste (Endomethasone) penetration within and along the mandibular canal from the periapical zone of a lower first premolar following endodontic treatment of the latter. The clinical manifestations comprised anesthesia of the right side of the lower lip and paresthesia of the gums in the fourth quadrant, appearing immediately after endodontic treatment. The lip anesthesia was seen to decrease, with persistence of the gingival paresthesia, after 7 months.

Surgical removal of impacted lower third molars is widely carried out in general dental practice and in many institutional clinics. Despite the fact that there are well established indications for the removal of impacted lower third molars, prophylactic removal of these teeth is still being universally practiced. Some reports have estimated that the proportion of impacted third molars that are removed when no clinically sound justification for surgery is present is between 18% and 50.7%. Justifications for prophylactic surgery include the need to minimize the risk of disease (cysts and tumors) development, reduction of the risk of mandibular angle fracture, increased difficulty of surgery with age, and that third molars have no definite role in the mouth. This article critically examines the literature regarding the relationship between impacted lower wisdom teeth, cysts and tumor development, and mandibular fractures.

Objective: This prospective study reports the proportion of permanent sensory impairment of the inferior alveolar and lingual nerves and the factors influencing such prevalence after the removal of mandibular third molars under local anesthesia., Study Design: There were 1,087 patients with 1,087 mandibular third molars removed under local anesthesia from 1998 to 2003. Standardized data collection included the patient's name, age, gender, radiographic position of extracted tooth, grade of surgeon, proximity of the inferior alveolar nerve, and the prevalence of lingual and/or inferior alveolar nerve paresthesia., Results: Inferior alveolar nerve injury was 4.1% 1 week after surgery and decreased to 0.7% after 2 years of follow-up, and alteration in tongue sensation occurred in 6.5% of patients 1 week after surgery and decreased to 1.0% after 2 years of follow-up., Conclusion: The experience of the operator was found to be a significant factor in determining both permanent lingual nerve (P=.022) and permanent inferior alveolar nerve paresthesia (P=.026).

Labiomandibular paresthesia after root canal treatment is an accident that is still too frequent despite the development of new endodontic techniques. The aim of this anatomical and clinical study is to advance the understanding of how accidents occur so as to avoid them. This anatomical study made it possible to determine the variability of proximity of the apex of the tooth root to the mandibular bundle, as well as the relationship between the nerve and its satellite artery, and to understand how endodontic filling material spreads into the cancellous bone. The clinical study, which included examination with conventional radiology as well as with imaging techniques, enabled us to identify the exact location of the filling material in relation to the mandibular bundle and to correlate this to the occurrence of clinical symptoms and their diverse manifestations.

Objective: To determine the panoramic radiographic distance from the mandibular third molar tooth to the inferior alveolar canal., Study Design: Five hundred sixty mandibular third molars were evaluated by panoramic radiography. The teeth were grouped into erupted vs unerupted and further subdivided by tooth angulation. The distance from the most inferior aspect of the mandibular third molar tooth to the superior border of the inferior alveolar canal was measured with digital calipers. A t test was performed to compare erupted and unerupted teeth, and ANOVA was used to determine if a significant difference exists based upon tooth angulation. A record review was performed to assess the incidence of inferior alveolar nerve paresthesia based upon measured distances., Results: The mean distance from erupted mandibular third molar teeth to the inferior alveolar canal is 0.88 mm. This distance was significantly different from unerupted teeth (P=.002). The mean values for unerupted teeth indicated that the most inferior portion of all teeth measured was below the superior border of the canal (negative values) as follows: mesioangular (-0.97 mm), vertical (-0.61 mm), distoangular (-0.31 mm), and horizontal (-0.24 mm). The position of mesioangular impactions were significantly different than all other impaction groups (P=.0125). The incidence of inferior alveolar nerve paresthesia was 3.33% (18/541), most commonly associated with mesioangular impactions (-0.66 mm) in female patients., Conclusions: Unerupted mandibular third molar teeth are closer to the inferior alveolar canal than are erupted teeth. Mesioangular mandibular third molar impactions are most closely positioned to the inferior alveolar canal, and this may represent an independent risk factor for postoperative paresthesia.

Introduction: The aim of this study was to review complications in a series of 1264 consecutive patients who were operated in a single centre during a 20-year-period., Material and Methods: Complications were documented, their incidences calculated and compared with data from the literature., Results: In 35 patients (2.8%) infection developed requiring extraoral incision and drainage; in 27 patients (2.1%) the inferior alveolar nerve was inadvertently cut; 18 patients (1.4%) had to undergo re-operation due to bending or fracture of osteosynthesis material; 15 patients (1.2%) suffered from bleeding complications; in 12 patients (0.9%) an unfavourable split occurred. In 8 patients (0.6%) foreign bodies were left in situ; in 7 patients a partial weakness of the facial nerve occurred, which was permanent in 1 patient. Six patients (0.5%) with a significantly higher age than average (mean: 33.6 years in comparison with 23.1 years) developed non-union at the site of osteotomy, and the mandible had to be bone grafted. Two patients (0.2%) developed osteomyelitis, and in one patient airway problems led to a need for tracheostomy (0.1%)., Conclusion: Although some of these complications of bilateral sagittal split with osteotomy carry severe limitations in health related quality of life, it remains an overall safe procedure, demanding, however, comprehensive informed consent. Good knowledge of technical reasons for these complications should help to reduce their incidence.

Objectives: To calculate the incidence of inferior alveolar nerve (IAN) damage due to lower third molar extraction and to describe the evolution of IAN sensitivity and the prognosis of IAN damage based on preoperative data., Study Design: A retrospective study of 4995 lower third molar extractions in 3513 outpatients., Results: Fifty-five extractions (1.1%) resulted in IAN impairment. Cox regression analysis showed age to be a risk factor for the persistence of IAN injury due to lower third molar extraction. The sensation recovery rate was higher in the first 3 months. Fifty percent of the patients showed full recovery after 6 months., Conclusions: Most cases of IAN impairment following lower third molar extraction recover within 6 months, though in some cases recovery takes more than 1 year. Older patients are at an increased risk of incomplete recovery of chin and lip sensibility after third molar extraction.

Endodontic overfilling involving the mandibular canal may cause an injury of the inferior alveolar nerve (IAN) resulting in disabling sensory disturbances such as pain, dysesthesia, paresthesia, hypoesthesia, or anesthesia. Two fundamental mechanisms are responsible for the injury: the chemical neurotoxicity and the mechanical compression caused by the extruded material. Although spontaneous resorption has been described for some materials, early surgical exploration with removal of the material and decompression of the IAN should be performed, irrespective of the material used, given that the importance of nerve damage increases with the duration of the injury. We report 4 cases of disabling dysesthesia and paresthesia following endodontic treatment of lower molars in which sagittal osteotomy was used to remove the endodontic paste and to perform nerve decompression. All the patients experienced immediate relief of dysesthesia and paresthesia.