Neurosensory Disturbance Research Articles

Radiographic features of anatomic relationship between impacted third molar and inferior alveolar canal on coronal CBCT images: risk factors for nerve injury after tooth extraction.

IntroductionThe present study was aimed to identify the radiographic signs between impacted third molar root and inferior alveolar canal (IAC) on cone-beam CT (CBCT) images as risk factors and prognostic predictors associated with inferior alveolar nerve (IAN) damage following tooth removal.Material and methodsA retrospective clinical study was performed involving 136 patients with 257 impacted lower third molars from January 2013 to December 2014. The neurosensory function of the lower lip and chin was subjectively evaluated and assessed by neurosensory tests before and after surgery. The preoperative CBCT data were retrieved and analyzed to identify the radiographic signs associated with postoperative IAN injury.ResultsThe overall incidence of IAN injury in our patient cohort was 13.2%. Multiple radiographic features on coronal CBCT images including contact between IAC and root, IAC position relative to root, IAC shape and cortication status were found to be significantly associated with IAN damage (p < 0.05, χ2 test). Furthermore, buccolingual position, teardrop/dumbbell shape and cortication status of IAC were identified as independent prognostic predictors for IAN damage.ConclusionsOur findings indicate that radiographic signs including direct contact between IAC and root, buccal/lingual IAC position relative to root, teardrop/dumbbell shape and cortication absence of the IAC on presurgical CBCT images are associated with high risk of IAN injury and postoperative neurosensory disturbance.

Incidence and recovery of neurosensory disturbances after bilateral sagittal split osteotomy in different age groups: a retrospective study of 263 patients

This study aimed to investigate the incidence of neurosensory disturbance (NSD) after bilateral sagittal split osteotomy (BSSO) in different age groups and to assess the probability of sensory recovery in patients aged <19 years, 19–30 years, and >30 years. Hypoaesthesia of the lower lip was assessed subjectively and objectively immediately after BSSO and at 1 week and 1, 6, and 12 months after BSSO. Hypoaesthesia was considered permanent if it was present 1 year after BSSO. The frequency of NSD immediately after surgery was significantly higher in older patients. The cumulative incidence of recovery at 1 year was lower and the mean time to recovery was longer in the older patients, although these differences were not statistically significant. Older age was a significant risk factor for permanent hypoaesthesia, with an incidence of 4.8% per patient aged <19 years, 7.9% per patient aged 19–30 years, and 15.2% per patient aged >30 years. These findings show that the risk of NSD after BSSO is significantly higher in older patients. These results may aid surgeons in preoperative patient counselling and in deciding the optimal age at which to perform BSSO.

Anatomic Variation in Lingual Foramen: A Cone beam Computed Tomography Study

ABSTRACT Background Lingual foramen is usually located in the midline, leveled with or superior to the genial tubercles. The success of implant placements is dependent on the radiological examination, which helps the clinician to determine the parameters of implant placement by revealing the structures like the course of the nerves, location of foramens, height and shape of alveolar bone, etc. The present study was done to assess the appearance, visibility, location, and types of lingual foramen in the mandibular region. Materials and methods A cross-sectional retrospective study was conducted using cone beam computed tomography (CBCT) images of 116 patients who attended the department for various imaging purposes. The examinations were carried out using the Promax three-dimensional (3D) CBCT unit. The cross-sectional images were examined to detect the presence, number, and position of the lingual foramen. Chi-square and Fisher's exact tests were used for comparison of categorical data. Results We observed lingual foramen in 116 patients and their number ranged from 1 to 3. When comparing the position, it was observed that lingual foramen was located at approximately two-thirds (60th percentile from the alveolar crest) distance from the alveolar crest to lower border of the mandible and there was no significant difference in various age groups or between both genders. Conclusion Lingual foramen transmits neurovascular bundles to surrounding structures, hence any damage to the lingual foramen during surgical procedures can result in hemorrhage and/or neurosensory disturbances. It is therefore mandatory for a dentist to be aware of the structures present in the anterior mandible when considering any surgical procedures or implant planning. Hence, CBCT plays a pivotal role during implant planning and surgical procedures in dentistry. How to cite this article Denny CE, Natarajan S, Ahmed J, Binnal A, Jindal R. Anatomic Variation in Lingual Foramen: A Cone beam Computed Tomography Study. World J Dent 2016;7(4):179-181.

Outcome of delayed miniplate osteosynthesis of maxillofacial fractures in a Nigerian tertiary institution

Background: This report describes treatment outcome following delayed miniplate osteosynthesis (MPO) of maxillofacial fractures. Materials and Methods: The records of patients who underwent delayed MPO of facial fractures from January 2011 to December 2014 at the Oral and Maxillofacial surgery Unit of the Federal Medical Centre, Owo, Nigeria were retrospectively reviewed. Data retrieved were age, gender, etiology of trauma, site of fractures, and time lapse from injury to treatment. Follow-up at postoperative intervals consisted of clinical and radiographic examinations. Outcome variables such as wound infection, wound dehiscence, malocclusion, hardware failure, fracture stability, and neurosensory disturbance were recorded. Results: Thirty-one patients with 52 facial fractures were treated. There were 18 (58.1%) mandibular, 8 (25.8%) maxillary fracture while 5 (16.1%) fractures occurred in both jaws. All patients had a stable fixation and normal healing. Thirteen complications occurred in 11 patients representing 35.5% of the total. Malocclusion and wound infection were the most common complication. More complications occurred in late treatment group. Conclusion: MPO with or without postoperative intermaxillary fixation is effective in the delayed facial fracture. Treatment delay may increase the incidence of complications.

Local vs general anaesthesia in the development of neurosensory disturbances after mandibular third molars extraction: A retrospective study of 534 cases.

BackgroundThe choice of the anaesthetic modality is one of the primary steps during planning of third molar surgery. The aim of the present study was to compare the risk of developing neurological injures of the inferior alveolar nerve (IAN) and lingual nerve (LN) in patients treated for wisdom teeth removal under general anaesthesia (GA) with a group treated under local anaesthesia (LA).Material and MethodsThis is an observational retrospective, unicentric study; between September 2013 and September 2014, 534 patients underwent third molar surgery, 194 (36,3%) under GA and 340 (63,7%) under LA by the same oral surgeon. Differences in the incidence of IAN and LN injures between groups have been statistically analyzed with Fisher exact test and estimated odd ratio for development of such complications has been calculated.ResultsIn GA patients the incidence of IAN and LN injures was 4.6% and 2.1%, respectively while in the LA group it was and 0.3% and 0%, respectively. A significant difference in IAN and LN involvement between groups was observed (IAN lesion: Fisher exact test, p<0.001; LN lesions: Fisher exact test, p<0.05). The estimated odd ratio for development of IAN injures after GA was 16.49 (95% CI: 2.07-131.19) and was not calculable for LN injures because no cases were observed in the LA group.ConclusionsSince GA is a perioperative variable that seems to significantly increase the risk of developing IAN and LN lesions, when treating patients that request GA, they must be adequately informed that an higher incidence of post-surgical sensory disturbances is expected. Key words:Third molars, general anaesthesia, local anaesthesia, inferior alveolar nerve, lingual nerve.

Short-term effects of orthognathic surgery on somatosensory function and recovery pattern in the early postoperative period

We examined the short-term surgical effects of orthognathic surgery on somatosensory function. Observations were made over a short period: 3 months postoperatively. In total, 14 patients and 32 healthy controls participated. Among the 14 patients, one underwent bilateral sagittal split osteotomy alone and 13 underwent bilateral sagittal split osteotomy in combination with a Le Fort I osteotomy. A modified quantitative sensory testing (QST) protocol (the German Research Network on Neuropathic Pain, DFNS) was used to evaluate clinically the skin of the chin for sensory disturbances before surgery and at 1 week, 1 month, and 3 months postoperatively. A visual analog scale and the Japanese Version of the McGill Pain Questionnaire were completed by all participants. Both sides of the mandible showed postoperative functional loss in cold detection threshold, warmth detection threshold, thermal sensory limen, and mechanical detection threshold. All function gradually recovered to baseline conditions at 3 months postoperatively. Cold detection threshold, warmth detection threshold, thermal sensory limen, and mechanical detection threshold appeared to be useful QST parameters for evaluating neurosensory disturbances during the early postoperative period. (J Oral Sci 58, 177-184, 2016).

Abnormal Anatomical Location of Root of Second Premolar in Mental Foramen: A Very Rare Case

ABSTRACT Mental foramen is a key factor in many of the surgical procedures. While carrying out surgical procedures in premolar region, the knowledge of anatomy of mental nerve and its foramen is of utmost importance to avoid intraoperative neurovascular damage and to avoid postoperative neurosensory disturbances. The variations of mental foramen with respect to position, size, and number are very well documented. However, in very rare cases, length of the premolar roots may be abnormally long or abnormally positioned, which can impinge on the mental nerve or may enter mandibular canal or mental foramen. We present one such rare case where second premolar root was impinging on the mental nerve and producing symptoms. Extraction of second premolar was done and patient became asymptomatic postoperatively. How to cite this article Khandelwal P, Dubey S, Hajira N. Abnormal Anatomical Location of Root of Second Premolar in Mental Foramen: A Very Rare Case. Int J Experiment Dent Sci 2016;5(1):76-77.

Verlenging van de onderkaak: bilaterale sagittale splijtingsosteotomie versus distractieosteogenese

In the 1990s intra-oral distraction osteogenesis (DO) became available as an alternative for bilateral sagittal splitosteotomy (BSSO) for advancement of the mandible. It was thought that DO would lead to more stability in the results and fewer neurosensory disturbances of the inferior alveolar nerve. However, there was no scientific evidence for this assumption. This article describes a number of recently published, prospective studies that demonstrate that BSSO is not inferior to DO with respect to stability and neurosensory disturbances of the inferior alveolar nerve. They also demonstrate that BSSO leads to less pain in patients and to lower total costs. It can be concluded that BSSO should be considered the standard therapy for mandibular advancement up to 10 mm in non-syndromal patients.

Effect of the use of combination uridine triphosphate, cytidine monophosphate, and hydroxycobalamin on the recovery of neurosensory disturbance after bilateral sagittal split osteotomy: a randomized, double-blind trial

The change in neurosensory lesions that develop after bilateral sagittal split osteotomy (BSSO) was explored, and the influence of the application of combination uridine triphosphate (UTP), cytidine monophosphate (CMP), and hydroxycobalamin (vitamin B12) on patient outcomes was assessed. This was a randomized, controlled, double-blind trial. The study sample comprised 12 patients, each evaluated on both sides (thus 24 sides). All patients fulfilled defined selection criteria. Changes in the lesions were measured both subjectively and objectively. The sample was divided into two patient groups: an experimental group receiving medication and a control group receiving placebo. The statistical analysis was performed using SPSS software. Lesions in both groups improved and no statistically significant difference between the groups was observed at any time. ‘Severe’ injuries in the experimental group were more likely to exhibit a significant improvement after 6 months. Based on the results of the present study, it is concluded that the combination UTP, CMP, and hydroxycobalamin did not influence recovery from neurosensory disorders.

Usefulness of piezoelectric surgery to reduce neurosensory disturbances of inferior alveolar nerve after SSRO

Usefulness of piezoelectric surgery to reduce neurosensory disturbances of inferior alveolar nerve after SSRO

Predicting factors of neurosensory disturbance after sagittal split ramus osteotomy

Predicting factors of neurosensory disturbance after sagittal split ramus osteotomy

Morphological features of the mandible as predictors for neurosensory disturbances after bilateral sagittal split osteotomy.

This retrospective study aimed to identify anatomical predictors of neurosensory disturbance (NSD) after bilateral sagittal split ramus osteotomy (BSSO) by evaluating the morphology of the mandible on lateral cephalograms (LCs) and orthopantomograms (OPTs). The LCs and OPTs of 142 patients who underwent BSSO were reviewed. The influence of the mandibular angle was assessed on LCs, while the following morphological landmarks and subsequent measurements were analysed on OPTs: vertical and horizontal positions of the lingula, ramus width, mandibular body height, mandibular canal position and mandibular angle length. Post-operative NSD (hypoaesthesia) was considered permanent when objective tests or subjective evaluations indicated altered sensation one year after BSSO. Generalised linear mixed models were used to take into account the repeated measurement design (left and right measurements within one patient). Hypoaesthesia was present in 10.6% of the patients (5.6% of sites). After adjusting for age, a small mandibular body height was found to significantly increase the risk of hypoaesthesia. The other measurements showed no significant association with hypoaesthesia. These findings show a relationship between mandibular morphology and hypoaesthesia after BSSO and can aid surgeons in pre-operative assessments of the risk of NSD. Further research is needed to identify risk factors for NSD based on mandibular morphology.

Evidence-based outcomes following inferior alveolar and lingual nerve injury and repair: a systematic review.

The inferior alveolar nerve (IAN) and lingual (LN) are susceptible to iatrogenic surgical damage. Systematically review recent clinical evidence regarding IAN/LN repair methods and to develop updated guidelines for managing injury. Recent publications on IAN/LN microsurgical repair from Medline, Embase and Cochrane Library databases were screened by title/abstract. Main texts were appraised for exclusion criteria: no treatment performed or results provided, poor/lacking procedural description, cohort <3 patients. Of 366 retrieved papers, 27 were suitable for final analysis. Treatment type for injured IANs/LNs depended on injury type, injury timing, neurosensory disturbances and intra-operative findings. Best functional nerve recovery occurred after direct apposition and suturing if nerve ending gaps were <10mm; larger gaps required nerve grafting (sural/greater auricular nerve). Timing of microneurosurgical repair after injury remains debated. Most authors recommend surgery when neurosensory deficit shows no improvement 90days post-diagnosis. Nerve transection diagnosed intra-operatively should be repaired insitu; minor nerve injury repair can be delayed. No consensus exists regarding optimal methods and timing for IAN/LN repair. We suggest a schematic guideline for treating IAN/LN injury, based on the most current evidence. We acknowledge that additional RCTs are required to provide definitive confirmation of optimal treatment approaches.

Neurosensory disturbance after bilateral sagittal split osteotomy: A retrospective study

AimTo retrospectively evaluate neurosensory disturbance (NSD) after bilateral sagittal split osteotomy (BSSO). Material and methodsA retrospective review was carried out to assess inferior alveolar nerve function in patients treated by BSSO from 2010 to 2013. All patients included in the study were assessed using objective (cotton swabs and pin prick testing) and subjective testing (questionnaire) for inferior alveolar nerve function after a minimum of 1 year of follow-up. Medical records of the patients were used to assess the incidence of NSD in the immediate post-operative period. Results15 patients (30 sides) had undergone BSSO during the specified time period. On subjective testing, NSD was reported in 22 operated sides (73.3%) in the immediate post-operative period, while 4 operated sides (13.3%) reported persistent NSD. On objective testing, immediate post-operative NSD was seen in 20 operated sides (66.7%). After a minimum of 1 year follow-up, recovery was seen in 18 operated sides while persistent NSD was seen in 2 operated sides (6.7%). ConclusionNSD of the inferior alveolar nerve is a common complication after BSSO in the immediate post-operative period. However in a long term, nerve function usually recovers.

Inferior Alveolar Nerve Lateralization and Transposition for Dental Implant Placement. Part II: a Systematic Review of Neurosensory Complications.

ABSTRACTObjectivesThis article, the second in a two-part series, continues the discussion of inferior alveolar nerve lateralization/transposition for dental implant placement. The aim of this article is to review the scientific literature and clinical reports in order to analyse the neurosensory complications, risks and disadvantages of lateralization/transposition of the inferior alveolar nerve followed by implant placement in an edentulous atrophic posterior mandible.Material and MethodsA comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed and PMC databases, as well as academic sites and books. The articles were searched from January 1997 to July 2014. Articles in English language, which included adult patients between 18 - 80 years of age who had minimal residual bone above the mandibular canal and had undergone inferior alveolar nerve (IAN) repositioning, with minimum 6 months of follow-up, were included.ResultsA total of 21 studies were included in this review. Ten were related to IAN transposition, 7 to IAN lateralization and 4 to both transposition and lateralization. The IAN neurosensory disturbance function was present in most patients (99.47% [376/378]) for 1 to 6 months. In total, 0.53% (2/378) of procedures the disturbances were permanent.ConclusionsInferior alveolar nerve repositioning is related to initial transient change in sensation in the majority of cases. The most popular causes of nerve damage are spatula-caused traction in the mucoperiosteal flap, pressure due to severe inflammation or retention of fluid around the nerve and subsequent development of transient ischemia, and mandibular body fracture.

Location of Mental Foramen in a Selected Iranian Population: A CBCT Assessment

Mental foramen (MF) is an important anatomic landmark in dentistry and knowledge about its variable locations (L) and type of emergence (TE), has an effect on the sufficiency of local anesthesia and safety of surgical procedures. The aim of this study was to evaluate the L and TE of this radiographic landmark as well as the presence of accessory MF, by means of cone-beam computed tomography (CBCT). In this cross sectional study, a total of 156 CBCT images were retrieved from the archive of a private radiology clinic and were then evaluated for the position of MF and its TE and the existence of accessory foramina in the body of mandible. The extracted information was compared in both genders, in both sides of mandible and among three different age groups (20-29, 30-44 and 45-59 years). The Pearson chi-square and Fisher's Exact tests were used for statistical analysis. The level of significance was set at 0.05. Second premolar was the most common anterolateral L of MF; in general, 48.7% of right and 51.9% of left MFs were located at the apex of second premolar. Anterior and straight ET were more common in right and left side, respectively. Accessory MF was present in only 8 (5.1%) of cases. The possible presence of accessory MF should not be overlooked for avoiding the occurrence of a neurosensory disturbance during surgery and implant insertion.

Inferior Alveolar Nerve Injury in Trauma-Induced Mandible Fractures

This prospective observational cohort study sought to determine the prevalence of inferior alveolar nerve (IAN) injury after mandibular fractures before and after treatment and to elucidate factors associated with the incidence of post-treatment IAN injury and time to normalization of sensation. Consenting patients with mandibular fractures (excluding dentoalveolar, pathologic, previous fractures, or mandibular surgery) were prospectively evaluated for subjective neurosensory disturbance (NSD) and underwent neurosensory testing before treatment and then 1 week, 1.5, 3, 6, and 12 months after treatment. Eighty patients (men, 83.8%; mean age, 30.0 yr; standard deviation, 12.6 yr) with 123 mandibular sides (43 bilateral) were studied. Injury etiology included assault (33.8%), falls (31.3%), motor vehicle accidents (25.0%), and sports injuries (6.3%). Half the fractures (49.6%) involved the IAN-bearing posterior mandible; all condylar fractures (13.0%) had no NSD. Treatment included open reduction and internal fixation (ORIF; 74.8%), closed reduction and fixation (22.0%), or no treatment (3.3%). Overall prevalence of IAN injury was 33.7% (95% confidence interval [CI], 24.8-42.6) before treatment and 53.8% (95% CI, 46.0-61.6) after treatment. In the IAN-bearing mandible, the prevalence was 56.2% (95% CI, 43.2-69.2) before treatment and 72.9% (95% CI, 63.0-82.7) after treatment. In contrast, this prevalence in the non-IAN-bearing mandible was 12.6% (95% CI, 4.1-21.1) before treatment and 31.6% (95% CI, 20.0-43.3) after treatment. Factors associated with the development of post-treatment IAN injury included fracture site and gap distance (a 1-mm increase was associated with a 27% increase in odds of post-treatment sensory alteration). Time to normalization after treatment was associated with type of treatment (ORIF inhibited normalization) and fracture site (IAN-bearing sites took longer to normalize). IAN injury was 4 times more likely in IAN-bearing posterior mandibular fractures (56.2%) than in non-IAN-bearing anterior mandibular fractures (12.6%). After treatment, IAN injury prevalence (in 12 months) was higher (72.9% in posterior mandible, 31.6% in anterior mandible).

Evaluation of the treatment modalities for neurosensory disturbances of the inferior alveolar nerve following retromolar bone harvesting for bone augmentation.

The purpose of this study was to evaluate the treatment modalities for neurosensory disturbances (NSDs) of the inferior alveolar nerve occurring after retromolar bone harvesting for bone augmentation procedures before implant placement. One hundred four patients, of which 49 and 55 exhibited vertical or horizontal alveolar ridge defects in the mandible and maxilla, respectively, were enrolled. Nineteen patients underwent block bone grafting, 38 underwent guided bone generation or autogenous bone grafting combined with titanium mesh reconstruction, and 47 underwent sinus floor augmentation. Using a visual analog scale, we examined subjective symptoms and discomfort related to sensory alteration within the area of the NSDs in these patients. NSDs were clinically investigated using a two-point discrimination test with blunt-tipped calipers. In addition, neurometry was used for evaluation of trigeminal nerve injury. We tested three treatment modalities for NSDs: follow-up observation (no treatment), medication, and stellate ganglion block (SGB). A week after surgery, 26 patients (25.0%) experienced NSDs. Five patients received no treatment, 10 patients received medication, and 11 patients received SGB. Three months after surgery, patients in the medication and SGB group achieved complete recovery. Current perception threshold values recovered to near-baseline values at 3 months: recovery was much earlier in this group than in the other two groups. SGB can accelerate recovery from NSDs. Our results justify SGB as a reasonable treatment modality for NSDs occurring after the harvesting of retromolar bone grafts.

Ginkgo biloba Extract 761: A Review of Basic Studies and Potential Clinical Use in Psychiatric Disorders.

Ginkgo biloba extract 761 (EGb 761) is a well-defined extract obtained from Ginkgo biloba leaves according to a standardized method. It has been used extensively for the treatment of diseases related to the central nervous system including neurosensory disturbances, cerebrovascular insufficiency, peripheral vascular disturbances, and degenerative dementia. The potential use of EGb 761 has also been suggested for the treatment of psychiatric disorders such as anxiety and depression, which is discussed in the current review. These disorders constitute a global epidemic with serious economic and social consequences. Current available treatments with synthetic drugs may have some disadvantages and undesired side effects. There are diverse natural extracts that have been used for the treatment of psychiatric disorders due to their therapeutic action and low rate of side effects, such as EGb 761. EGb 761 has the ability to produce neuroprotection due to its chemical composition and the synergy of its components. We describe several neuroprotective mechanisms of action of EGb 761 such as antioxidant effects, modulation of neurotransmission, neuroendocrine regulation, and upregulation of neurotrophic factors, which underlie its potential therapeutic effect on psychiatric disorders. Furthermore, we discuss the therapeutic effects of EGb 761 both in animal models of psychiatric disorders and in clinical studies that include these pathologies. We focus on depression, anxiety, and schizophrenia, as well as the therapeutic action of EGb 761 on dementia in comorbidity with psychiatric disorders. In the current review, we propose thef potential use of EGb 761, alone or combined with current medication treatment, for psychiatric disorders.

The Incidence of Neurosensory Disturbance after Sagittal Split Ramus Osteotomy Depending on the Path of the Inferior Alveolar Neurovascular Bundle

The Incidence of Neurosensory Disturbance after Sagittal Split Ramus Osteotomy Depending on the Path of the Inferior Alveolar Neurovascular Bundle