Evaluation of the neurosensory deficiencies of oral and maxillofacial region following surgery

Injury to Anatomic Structures Due to Fixation Device in Management of Mandibular Fracture

INTRODUCTION

ORIF is the gold standard for the management of mandibular fractures. The chances of postoperative complications are due to infection, damage of the inferior alveolar nerve canal, or tooth root during the fixation of the fracture fragments. Fixation hardware placed in the vicinity of the vital structures may encroach on the anatomic structures, leading to postoperative complications.

AIM

The aim of this study is to evaluate the injury to the anatomic structures in the proximity of the fracture line due to the fixation device.

MATERIAL AND METHODS

This retrospective study was conducted in a tertiary care teaching hospital from July 2021 to June 2023. The cases of maxillofacial trauma reported and referred from peripheral centers were considered duly, applying the inclusion and exclusion criteria. Patients having mandibular fractures from one mandibular foramen to another with or without associated other facial fractures were treated by ORIF under general anesthesia. The patient was followed up at 1 week, 1 month, 3 months, and 6 months. The cases of postoperative complications were further investigated by CBCT.

RESULT

There were 67 patients (56 males and 11 females) with 86 fracture lines in the age group of 18-55 years with an average age of 35.2 years. Postoperatively 7 patients presented with unilateral paresthesia of the lower lip and chin region. CBCT revealed that the mean distance of the screw from the inferior alveolar nerve canal was 3.02 mm. None of these cases had injury to the nerve canal or roots of teeth. All the patients recovered from paresthesia within 6 months.

DISCUSSION

Complications like injury to the inferior alveolar nerve (IAN) with sensory disturbances to the lower lip and chin, as well as tooth/tooth root fractures, may occur due to mandibular fracture, surgical manipulation, and fixation devices. The anatomic structures in the vicinity of the fracture line can be damaged during the fixation of the fracture fragments by the bone plates and screws. In the present study, it was found that 7 out of 67 patients presented with unilateral paresthesia of the lower lip and chin. CBCT analysis showed a considerable distance of 3.02 mm from the inferior alveolar nerve canal to the screws. There was no evidence of hardware encroachment on the IAN or tooth roots.

CONCLUSION

Selection and placement of appropriate fixation devices, particularly the length of the bone screws, are crucial to avoid injury to the anatomic structures.

Analysis of Effect of Melatonin on Postoperative Sensory Nerve Recovery Following Open Reduction and Internal Fixation of Anterior Mandible Fractures: A Prospective Randomized Control Trial

Purpose

Open reduction and internal fixation (ORIF) of the anterior mandibular fractures are commonly associated with mental nerve paraesthesia. This study evaluates the efficacy of melatonin on postoperative sensory functional recovery and pain following surgical treatment of anterior mandibular fractures.

Methods

Forty patients were randomly allocated to two groups: Group I-melatonin, and Group II-control group. Postoperative neurosensory recovery was evaluated both subjectively and objectively at 1-week, 1-month, and 3-month intervals. The pain was assessed during the immediate postoperative period, postoperative days 1, 2, 3, and 7 using a visual analog scale. Statistical significance was set at P value < 0.05.

Results

The statistically significant difference was noticed in both subjective and objective recovery of sensory nerve function at 1-month follow-up. All patients in the melatonin group showed complete recovery of nerve function as compared to the control group where 10% of patients showed limited recovery.

Conclusion

Neurosensory recovery following ORIF of mandibular fractures was better in the melatonin group as compared to the control group and therefore the perioperative administration of 10 mg. Melatonin can be recommended for quicker and better nerve recovery in the anterior mandibular fractures requiring close manipulation of the mental nerve during treatment.

Effects of light-emitting diode (LED) therapy on sensory changes in the inferior alveolar nerve after surgical treatment of mandibular fractures: a randomized controlled trial

PURPOSE

A randomized controlled trial was performed to evaluate the effects of light-emitting diode (LED) therapy on sensory changes in the inferior alveolar nerve after surgical treatment of mandibular fractures.

METHODS

Patients admitted with surgically treated mandibular fractures between January 2018 and December 2019 were evaluated. Personal data, fracture location, fracture type, and dislocation degree were obtained. The cases were randomly allocated into two groups: LED therapy (LEDT) (57 points of 660 nm and 74 points of 850 nm, 6.4 mV/cm2, and 7.64 J) with the use of a prototype device and control (CTRL). For 6 months, tactile and thermal tests were used in the mental region. Data were analyzed using the Mann─Whitney U test and likelihood ratio test (p ≤ 0.050).

RESULTS

The study included 42 patients, 25 of whom had bilateral fractures and 17 had unilateral fractures, totaling 67 fractures. The mean values of the tactile and thermal sensitivity tests were lower in the LEDT group in all evaluation periods. There was a significant difference between the groups in the parasymphysis location, displacement < 5 mm, and intraoral access. Sensory changes were observed in 68.7% of all fractures upon admission, with 91.2% in the LEDT group and 78.8% in the CTRL group demonstrating complete remission during the final period of the study.

CONCLUSION

LED photobiomodulation accelerated the process of sensory change remission. There was an influence of the fracture location, degree of displacement, and surgical access, with a better response in the LEDT group.

Time-Lapse Between Presentation and Treatment of Mandibular Fractures: Is There a Correlation With Sensory Loss Recovery or No Recovery?

ABSTRACT

A prospective cohort study composed of 43 patients treated for unilateral mandibular fracture. The primary study variables were the post-traumatic IAN neurosensory score and the score after fracture reduction in two different groups on the basis of time lapse between presentation and treatment and displacement of mandible fracture. Appropriate descriptive and bivariate statistics were computed. The sample was analyzed over a one year period. It was observed that the recovery percentage (80%) was good in Group-A (n = 20) patients as compared to Group-B (n = 23) patients (43.47%) with significant P value of 0.015. Patients with displacement of ≥9 mm have neurosensory deficit of 80% while fracture displacement ≥ 5 mm to 8 mm have the neurosensory deficit of 34.21% which is significant with P value of 0.049. With each millimeter increase of displacement of fracture segments, more neurosensory deficit will be manifested. Delay in seeking in the treatment increases the risk because of continued movement. Where the injury is more severe, excessive displacement with increased time lapse from injury to surgical intervention, there is a higher possibility neurosensory deficit or no recovery. Early management can reduce the risk of permanent neurosensory deficits.

Postoperative neurosensory impairment perception using ultrasonic BoneScalpel and conventional rotary instruments after bilateral split sagittal osteotomy

PURPOSE

Although bilateral sagittal split osteotomy (BSSO) is the most widely used surgical technique for the correction of mandibular dentofacial anomalies, it is associated with lesion of inferior alveolar nerve (IAN) and unwanted neurosensory disorders. The aim of this study was to document the perception of changes in sensitivity and mean recovery time after BSSO, using an ultrasonic BoneScalpel versus the conventional rotary instruments.

PATIENTS AND METHODS

This retrospective observational study included all patients with diagnosis of skeletal anomaly who underwent advancement or setback BSSO of less than 10 mL, using the ultrasonic osteotome or conventional rotary instruments. The patients were operated on at the Hospital Universitario Clínica San Rafael, Bogotá Colombia, between 2017 and 2018. The primary predictor variable was the osteotomy technique. The primary outcome was the presence or absence of postoperative sensory alteration, whereas secondary outcomes were time of appearance and recovery, affected anatomical region, laterality, and disturbance in daily activities. Data were analyzed using Chi-square, Mann-Whitney U, and Fisher's exact test.

RESULTS

Data of 38 patients were retrieved, of which 23 were operated with BoneScalpel and 13 with the conventional technique. Twenty patients were women and 18 were men. All patients reported experiencing at least one type of sensory disturbance immediately after the surgical procedure. There was a significant difference (p = 0.0001) in the time that the alteration was present between the two groups, in favor of the BoneScalpel group. The chin and the lower lip were the anatomical regions with the greatest alteration in sensitivity and persistence of it.

CONCLUSIONS

The results of this study indicate that BoneScalpel is effective in performing BSSO. They also suggest that it may reduce the occurrence of nerve damage during BSSO, although more research on this topic is required.

Health-related quality of life in patients surgically treated for orbital blow-out fracture: a prospective study

Purpose

The purpose of this study was to evaluate patients’ health-related quality of life (HRQoL) before and after surgical treatment of orbital blow-out fracture.

Methods

This prospective study comprises of all adult patients undergoing a surgical reconstruction of an orbital blow-out fracture in 2006–2010. Their HRQoL was evaluated for 6 months postoperatively with the aid of the standardized 15D instrument and was compared with that of an age- and gender-standardized sample of the general Finnish population. A complementary questionnaire for more detailed information was also administered.

Results

Twenty-six patients completed the study. Mean 15D score among the patients preoperatively (0.898) was statistically significantly and clinically importantly worse than the score of the control population (0.936). Six months postoperatively, the mean 15D score was 0.920, with no significant difference compared with the control population and the significant differences on the different dimensions had disappeared. The most common complaint at 6 months postoperatively was diplopia in daily life (19%). Disturbances in facial sensation (27%) and defects in facial appearance (15%) were the most unpleasant subjective outcomes.

Conclusion

The HRQoL is significantly decreased after orbital blow-out fracture compared with the general population but will recover completely in 6 months. Thus, the negative impact of orbital blow-out fracture on HRQoL is only transient. Disturbances in facial sensation, defects in facial appearance, and diplopia are the most common subjective complaints after the injury and its surgical treatment. However, these do not appear to affect the overall quality of life in the long term.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10006-020-00923-x.

Does the Lag Time Between Injury and Treatment Affect Recovery of Infraorbital Nerve Disturbances in Zygomaticomaxillary Complex Fractures?

Study Design

A cross-sectional study.

Objective

Neurosensory disturbances (NSDs) of the infraorbital nerve (ION) are common following orbito-zygomaticomaxillary complex (ZMC) fractures. This study aimed to evaluate the effect of lag time between injury and treatment on recovery of NSDs of the ION following open reduction internal fixation.

Methods

Subjects who had ZMC fracture and paresthesia were studied. The lag time between injury and treatment was considered as the predictive factor. The level of NSDs according to the brush test and two-point discrimination (TPD) test and self-reported NSD were the outcomes of this study. Self-reported NSD was quantified using a visual analog scale.

Results

Forty patients were studied. The lag time between injury and treatment had a significant correlation with the result of the TPD test and the self-reported level of NSD. In 73.6% of patients who had NSD following ZMC fracture, every 1-day delay in treatment increased the incidence of self-reported paresthesia by 0.44.

Conclusions

It seems, a delay in treatment of ZMC fractures increased the risk of NSD.

Comparison of postoperative paresthesia after sagittal split osteotomy among different fixation methods: a one year follow-up study

Objectives

Postoperative paresthesia is a common complication after sagittal split osteotomy (SSO). This study aimed to compare paresthesia among different fixation methods one year postoperative.

Materials and Methods

This prospective cohort study assessed subjects in four groups: class II with miniplate fixation (Group 1), class II with three-screw fixation (Group 2), class III with miniplate fixation (Group 3), and class III with three-screw fixation (Group 4). Paresthesia was evaluated one year postoperative based on a 0-10 visual analogue scale. Pearson correlation was used to evaluate associations of age and mandibular movement with paresthesia. ANOVA was used to compare paresthesia among groups.

Results

A total of 80 subjects were enrolled, with 20 subjects in each of the four groups. The Pearson correlation test demonstrated a significant correlation between mandibular movement and paresthesia (P=0.001). Comparison of paresthesia among the groups showed significant differences among groups 1 and 2, 2 and 3, and 3 and 4 (P<0.05).

Conclusion

The three-screw fixation method led to more paresthesia one year postoperative compared with miniplate fixation. In addition, the magnitude of mandibular movement had a positive correlation with paresthesia.

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

BACKGROUND

The lag time between injury and treatment (LTIT) plays an important role in reduction of complications in mandibular fractures. The aim of this study was to measure the effect of LTIT on recovery of the inferior alveolar nerve (IAN) neurosensory disturbances (NSDs) following surgical management of mandibular body fractures.

METHODS

This was a prospective cohort study. Patients who had a unilateral mandibular body fracture with paresthesia were studied. Paresthesia was evaluated by 2-point discrimination (TPD) test, brush stroke test and self-reporting before and 6 months after the surgical procedure.

RESULTS

Forty-five patients were studied. There was a correlation between LTIT and TPD test result and self-reported paresthesia at 6 months, postoperatively (P = 0.001). Fifteen patients (33.3%) had complete improvement in NSD 6 months after treatments (group 1) and 30 patients (group 2) had hyposthesia (N = 17, 37.77%) and paresthesia (N = 13, 28.88%). There was a significant difference in LTIT between groups 1 and 2 at 6 months postoperatively (P = 0.001). Cox regression model demonstrated the hazard ratio increased significantly for self-reported NSD when treatment was done 10 days after trauma (P = 0.001, confidence level = 95%).

CONCLUSION

It seems that conduction of open reduction with internal rigid fixation shortly after mandibular fracture may shorten the recovery time of NSDs of the IAN following mandibular body fractures.

Bilateral Sagittal Split Osteotomy: Description of Surgical Technique to Complement the Procedural Cognition Simulation in the Craniofacial Interactive Virtual Assistant-Professional Edition

Operative experience for the contemporary trainee has become exceedingly more challenging in the setting of more stringent hospital regulations. Surgical training is thus shifting toward more self-directed, independent learning to maximize operative opportunities as they become available; yet, this can prove difficult for complex surgeries like craniofacial procedures. The intricate anatomy and fine reconstructive techniques employed cannot be readily depicted onto a two-dimensional page. To address this educational gap, the Craniofacial Interactive Virtual Assistant-Pro Edition (CIVA-Pro) was developed as a web-based surgical simulator to aid learners with conceptualizing the surgical principles utilized in these cases. The current work reviews the Bilateral Sagittal Split Osteotomy module of CIVA-Pro, providing detailed narratives for each chapter with expert commentary on broadened indications and future directions.

Risk factors for hypesthesia after repair of facial fractures

OBJECTIVE

The aim of this study was to investigate the incidence of hypesthesia in patients with facial bone fractures and to identify the relationships between posttraumatic hypesthesia and risk factors, including general and fracture-related characteristics.

STUDY DESIGN

A total of 437 patients who underwent surgery for facial bone fractures were included. Clinical neurosensory testing was performed at different time points (immediately after trauma and 1 week, 1 month, and 6 months after surgery). The results of these assessments were compared with regard to characteristics and fracture sites.

RESULTS

The hypesthesia incidences were highest in the mandible (19.1%), maxilla (18.3%), and orbit (8.5%). Sensation was recovered by 97.3% of all patients by 6 months after surgery. Risk factors for hypesthesia were direct nerve injury (P = .002), distance (≤10 mm) between the fracture and nerve foramen (P = .002), the amount of bony displacement (P = .035), and age (P = .004). There were significant differences among the fracture sites.

CONCLUSIONS

Posttraumatic hypesthesia increased temporarily after surgery, but most patients recovered by 6 months postoperatively. Recovery from postoperative hypesthesia was related to the fracture site and pattern. Cases in which the patient did not recover involved direct nerve injury.

Anaesthetic efficacy of 4% articaine compared with 2% mepivacaine: a randomized, double-blind, crossover clinical trial

The aim of this study was to evaluate the clinical efficacy of 4% articaine (Ar4) compared to 2% mepivacaine (Me2), both in combination with 1:100,000 epinephrine, in a unique soft tissue model. This was a randomized, double-blind, crossover clinical trial. The anaesthetic was applied to the lower lip using a computerized local delivery system. The following were evaluated: blood flow, thermal sensation, pressure and proprioception, extent of anaesthesia, gradual elimination, and the final duration of the effect of the anaesthesia. Seventy-two volunteers completed all parts of the study. Significant differences, which indicated better effectiveness of Me2 compared to Ar4, were observed in the following tests: reduction in blood flow (larger in the Me2 group); anaesthetized area at 30min (larger in the Me2 group); pressure tests; temperature tests after 20min; fine and discriminatory proprioception tests after 20min. The volunteers' perception of anaesthesia at 30, 40, 50, and 60min was superior for Me2 at all recorded time points. The duration of anaesthesia was also superior for Me2. The overall performance of Me2 was superior to Ar4, implying that Me2 provides a more effective anaesthesia in terms of depth, extent, and duration.

Interaction between calcitonin gene-related peptide-immunoreactive neurons and satellite cells via P2Y12 R in the trigeminal ganglion is involved in neuropathic tongue pain in rats

The P2Y₁₂ receptor expressed in satellite cells of the trigeminal ganglion is thought to contribute to neuropathic pain. The functional interaction between neurons and satellite cells via P2Y₁₂ receptors and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) underlying neuropathic pain in the tongue was evaluated in this study. Expression of P2Y₁₂ receptor was enhanced in pERK1/2-immunoreactive cells encircling trigeminal ganglion neurons after lingual nerve crush. The administration to lingual nerve crush rats of a selective P2Y₁₂ receptor antagonist, MRS2395, attenuated tongue hypersensitivity to mechanical and heat stimulation and suppressed the increase in the relative numbers of calcitonin gene-related peptide (CGRP)-immunoreactive neurons and neurons encircled by pERK1/2-immunoreactive cells. Administration of the P2Y_1,12,13 receptor agonist, 2-(methylthio)adenosine 5'-diphosphate trisodium salt hydrate (2-MeSADP), to naïve rats induced neuropathic pain in the tongue, as in lingual nerve crush rats. Co-administration of 2-MeSADP + MRS2395 to naïve rats did not result in hypersensitivity of the tongue. The relative number of CGRP-immunoreactive neurons increased following this co-administration, but to a lesser degree than observed in 2-MeSADP-administrated naïve rats, and the relative number of neurons encircled by pERK1/2-immunoreactive cells did not change. These results suggest that the interaction between activated satellite cells and CGRP-immunoreactive neurons via P2Y₁₂ receptors contributes to neuropathic pain in the tongue associated with lingual nerve injury.

Phenotypic change in trigeminal ganglion neurons associated with satellite cell activation via extracellular signal-regulated kinase phosphorylation is involved in lingual neuropathic pain

Iatrogenic trigeminal nerve injuries remain a common and complex clinical problem. Satellite glial cell (SGC) activation, associated phosphorylation of extracellular signal-regulated kinase (ERK), and neuropeptide expression in the trigeminal ganglion (TG) are known to be involved in trigeminal neuropathic pain related to trigeminal nerve injury. However, the involvement of these molecules in orofacial neuropathic pain mechanisms is still unknown. Phosphorylation of ERK1/2 in lingual nerve crush (LNC) rats was observed in SGCs. To evaluate the role of neuron-SGC interactions under neuropathic pain, calcitonin gene-related peptide (CGRP)-immunoreactive (IR), phosphorylated ERK1/2 (pERK1/2)-IR and glial fibrillary acidic protein (GFAP)-IR cells in the TG were studied in LNC rats. The number of CGRP-IR neurons and neurons encircled with pERK1/2-IR SGCs was significantly larger in LNC rats compared with sham rats. The percentage of large-sized CGRP-IR neurons was significantly higher in LNC rats. The number of CGRP-IR neurons, neurons encircled with pERK1/2-IR SGCs, and neurons encircled with GFAP-IR SGCs was decreased following CGRP receptor blocker CGRP_8-37 or mitogen-activated protein kinase/ERK kinase 1 inhibitor PD98059 administration into the TG after LNC. Reduced thresholds to mechanical and heat stimulation to the tongue in LNC rats were also significantly recovered following CGRP_8-37 or PD98059 administration. The present findings suggest that CGRP released from TG neurons activates SGCs through ERK1/2 phosphorylation and TG neuronal activity is enhanced, resulting in the tongue hypersensitivity associated with lingual nerve injury. The phenotypic switching of large myelinated TG neurons expressing CGRP may account for the pathogenesis of tongue neuropathic pain.

Hypoesthesia associated with mandibular movement after sagittal split ramus osteotomy

PURPOSE

This retrospective study investigated the relationship between the degree of neurosensory disturbance (NSD) and mandibular movement distance after sagittal split ramus osteotomy (SSRO) and assessed sensory recovery.

METHODS

Lower lip hypoesthesia was evaluated at 1 week, 1 month, and 2 months after SSRO in 38 patients categorized according to the distance of mandibular movement: S group (0-7 mm; n = 17, 4 males and 13 females) and L group (7-14 mm; n = 21, 7 males, 14 females). Symptoms were evaluated by visual analog scale (VAS), tactile-threshold (SW) test, static 2-point discrimination (s-2PD) test, and current perception threshold (CPT) test.

RESULTS

The two groups did not differ significantly in gender and age. The Aβ fiber results of the CPT test differed significantly between the groups at 1 week and 1 month postsurgery (P < 0.05). There were no significant differences between the groups throughout the period in terms of VAS, SW, s-2PD, Aδ fiber, and C fiber of CPT.

CONCLUSIONS

Post-SSRO, the incidence of NSD in terms of tactile sensation may be greater in the L group early postoperatively. This may assist surgeons in explaining postoperative hypoesthesia to patients preoperatively.

Dexamethasone promotes regeneration of crushed inferior alveolar nerve by inhibiting NF-κB activation in adult rats

PURPOSE

Nuclear factor kappa B (NF-κB), which is closely related to inflammation, has become a topic of interest for research. The aim of this study is to investigate the effects of dexamethasone (Dex), an inhibitor of NF-κB, on inferior alveolar nerve injury in adult rats.

MATERIALS AND METHODS

The crushed inferior alveolar model is established in Wistar rats and they are randomly divided into three groups according to treatment: pyrrolidine dithiocarbamate (PDTC), dexamethasone (Dex), and saline (physiological saline). After treatment, the rats are respectively sacrificed at 3, 7, and 14d, and inferior alveolar nerves are extracted for histochemical and western blot analysis.

RESULT

Compared with the PDTC and saline groups, nerve fibers in the Dex group are regularly arranged with few vacuoles, which is similar to normal inferior alveolar nerves. Immunofluorescent results show significantly decreased NF-κB expression in the Dex group. Western bolt shows higher expression of GAP-43 and lower expression of NF-κB.

CONCLUSION

Taken together, all results show that dexamethasone significantly improved the regeneration of crushed inferior alveolar nerves by inhibiting NF-κB activation in adult rats.

Post-traumatic and postoperative neurosensory deficits of the inferior alveolar nerve in mandibular fracture: a prospective study

Objectives

We evaluated and recorded post-traumatic and postoperative neurosensory deficits of the inferior alveolar nerve (IAN) in mandibular fracture in order to identify associated risk factors.

Materials and Methods

This was a prospective cohort study composed of 60 patients treated for mandibular fracture. The primary study variable was the change between the post-traumatic IAN neurosensory examination score and the score after fracture reduction. Risk factors were categorized as demographic, anatomic, fracture displacement, and treatment. Appropriate descriptive and bivariate statistics were computed.

Results

Sixty patients with unilateral mandibular fracture reported within 24 hours of injury were evaluated over a one-year period. A post-traumatic neurosensory deficit was observed in 52 patients (86.7%), the percentage of which was reduced to 23.3% over the follow-up period. Abnormal postoperative neurosensory scores were significantly higher in angle fracture cases (33.3%) compared to body fracture cases (11.1%). When recovered and non-recovered neurosensory scores were compared by fracture location, 88.9% of body fracture cases showed significant recovery compared to 66.7% of mandibular angle fracture cases. Cases with less than 5 mm fracture displacement showed statistically significantly higher neurosensory recovery scores (90.6%) compared to those with more than 5 mm fracture displacement (60.7%).

Conclusion

Use of a miniplate with mono-cortical screws does not play a role in increasing IAN post-traumatic neurosensory deficit. Early management can reduce the chances of permanent neurosensory deficit. Mandibular fracture displacement of 5 mm or more and fracture location were found to be associated with an increased risk of post-traumatic IAN neurosensory score worsening.

Systematic Review and Meta-Analysis on Incidence of Altered Sensation of Mandibular Implant Surgery

Altered sensation (including paresthesia, dysesthesia and hypoesthesia) after mandibular implant surgery may indicate transient or permanent injury of the inferior alveolar nerve and the mental branch, and considerably lower patients’ satisfaction about the therapy. Previous studies have shown a great degree of variability on the incidence of altered sensation. We here reported the incidence of altered sensation after mandibular implant surgery based on a meta-analysis of 26 articles published between 1990.1.1 and 2016.1.1. Study quality and risk of bias was assessed and the studies with a lower score were excluded in the meta-analysis. Data synthesis was performed using the logistic-normal random-effect model. The meta-analyses revealed that the short-term (10 days after implant placement) and long-term (1 year after implant placement) incidence was 13% (95% CI, 6%-25%) and 3% (95% CI, 1%-7%), respectively. (2) For the patients who initially reported altered sensation, 80% (95% CI, 52%-94%) of them would return to normal sensation within 6 months after surgery, and 91% (95% CI, 78%-96%) of them would return to normal sensation one year after surgery. We concluded that dentist-patient communication about the risk of altered sensation is critical to treatment planning, since the short-term incidence of altered sensation is substantial (13%). When a patient reports altered sensation, regular assessment for 6 months would help tracing the changes of symptoms. In terms of long-term follow-up (1 year after surgery), the incidence is much lower (3%) and most patients (91%) would return to normal sensation.

Neurosensory disturbance after bilateral sagittal split osteotomy: A retrospective study

AIM

To retrospectively evaluate neurosensory disturbance (NSD) after bilateral sagittal split osteotomy (BSSO).

MATERIAL AND METHODS

A 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.

RESULTS

15 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%).

CONCLUSION

NSD 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.

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 <10 mm; 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 90 days post-diagnosis. Nerve transection diagnosed intra-operatively should be repaired in situ; 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.

Inferior alveolar and mental nerve injuries associated with open reduction and internal fixation of mandibular fractures: a Seven Year retrospective study

PURPOSE

To document adverse neurosensory changes in the inferior alveolar nerve (IAN) and mental nerve (MN) after surgical mandibular fracture treatment and to identify risk factors associated with these changes.

MATERIALS AND METHODS

A retrospective study of patients surgically treated for mandibular fractures. The primary study variable was the postoperative change in IAN/MN neurosensory examination after fracture fixation. Risk factors were categorized as demographic, anatomic, experience of the operator, fracture displacement and number of miniplates placed at each fracture site. Appropriate statistics were computed.

RESULTS

209 patients with 293 fractures were analysed. One hundred twenty fractures (41%) were located between the lingula and mental foramen, and 173 fractures (59%) were located distal to the mental foramen. Two hundred seventeen (41%) were displaced by 5 mm or more. In 38 fractures (13%), the IAN/MN neurosensory status worsened after treatment. In a multivariate model, fracture displacement, operator inexperience and two plate fixation were associated with a statistically significant risk (P ≤ 0.05) for postoperative deterioration of IAN/MN sensation.

CONCLUSION

Fixation with two miniplates, fracture displacement of 5 mm or more and operator inexperience were associated with an increased risk for deterioration of the IAN/MN neurosensory status after treatment of mandibular fractures.

Effects of lip revision surgery on long-term orosensory function in patients with cleft lip/palate

OBJECTIVE : To determine whether secondary lip revision surgery impacts sensitivity of the upper lip. DESIGN : A three-group, parallel, prospective, nonrandomized clinical trial. SETTING : University of North Carolina School of Dentistry. PATIENTS, PARTICIPANTS : Three groups: (1) patients with repaired cleft lip/palate who were scheduled for lip revision (revision; N = 20); (2) patients with repaired cleft lip/palate who did not receive a lip revision (non-revision; N = 13); and (3) non-cleft control subjects (non-cleft; N = 22). Interventions : Lip revision surgery. MAIN OUTCOME MEASURES : Measures of (1) two-point perception threshold (two-point), (2) warmth detection threshold (warm), and (3) cool detection threshold (cool) were obtained from two sites on the upper lip vermilion. The revision participants were tested approximately 1 week before surgery and then approximately 3 and 12 months after surgery. The non-revision and non-cleft participants were tested at similar times. RESULTS : There were no significant differences among the three groups at baseline for two-point, warm, or cool. The main effects of group, age, sex, and time were not statistically significant for the two-point or warm (p > .05). The mean differences between the 3- and 12-month follow-up visits and baseline for two-point and warm were small for all three groups. For cool, group was statistically significant (p = .04), the difference in the non-revision group between follow-up and baseline was 31% to 34% higher than in the non-cleft group (p = .01). CONCLUSIONS : Although at postsurgery revision participants exhibited threshold values comparable to presurgical values, the sensory differences observed among subgroups of participants with cleft lip are complex.

Prospective study of postoperative sensory disturbances after surgical treatment of mandibular fractures

INTRODUCTION

This present study's purpose is to evaluate the degree of paresthesia and recovery of inferior alveolar nerve in patients with mandible fractures who underwent surgical treatment.

MATERIAL AND METHODS

Nineteen patients were evaluated (27 hemimandibles) at six different times: preoperative (T1), postoperative 1 week (T2), postoperative 1 month (T3), postoperative 3 months (T4), postoperative 6 months (T5), and postoperative 1 year (T6). Subjective and objective methods were used for this evaluation.

RESULTS

The results were analyzed using likelihood ratio chi-square test for the hypothesis of no association between indicators of sensitivity and responses to the questionnaire, and the Cochran-Mantel-Haenszel test for equality hypothesis. All objective tests showed a statistically significant worsening in sensitivity at T2 (p < 0.0001) and a significant improvement after T4 (α < 0.05). The subjective tests showed an association with the objectives tests, and improvement in sensitivity after T4 (p < 0.0001) was noted.

DISCUSSION

The first postoperative week is the period in which there are major changes with respect to sensitivity, and after 3 months postoperatively, the recovery reaches its apex with little difference observed after this period. In this research 100 % of the patients analyzed recovered all sensibility until T6.

Evaluation of neurosensory alterations via clinical neurosensory tests following anterior maxillary osteotomy (Bell technique)

Neurosensory deficits are the most common complication following orthognathic surgery. Le Fort I and sagittal split ramus osteotomies have been widely studied but there is a lack of data about the neurosensory alterations resulting from anterior maxillary osteotomy (AMO). This paper evaluates the neurosensory alterations in cutaneous regions including lower eyelid, cheek, nose, upper lip and vestibular and palatal mucosal areas using simple clinical tests following AMO performed with Bell's incision so patients can be properly informed about the extent of sensory loss and its rate of recovery following AMO. Twenty-four sides of 12 patients (eight females; four males) with a mean age of 14.20 ± 1.86 years (range 12-17 years) were examined. Pin prick sensation, light touch sensation, static and dynamic two-point discrimination tests were used. Following AMO, vestibular mucosa, upper lip, nose and cheek were the most commonly affected sites. No alterations were detected in lower eyelid and palatal mucosa. The neurosensory deficits in cheek, nose and upper lip resolved 10 days after surgery. The vestibular mucosa showed normal sensation on day 30. In conclusion, following AMO, neurosensory alterations can occur, but it will resolve spontaneously in 30 days.

Evaluation of Neurosensory Changes in the Infraorbital Nerve following Zygomatic Fractures

PURPOSE

To evaluate the incidence and recovery of persistent sensory disturbances of the infraorbital (IO) nerve after isolated zygomatic complex fractures with various treatment methods.

METHODS AND RESULTS

The study was inclusive of isolated unilateral zygomatic complex fractures and fractures of IO rim .Tests performed were Pin prick and Electrical detection threshold test. The evaluation was done preoperatively, after 1 month and after 6 months of surgery. The results suggested that neurosensory disturbance was present in all the patients with zygomatic complex fractures. At 1 month post-operatively some sensory deficit was present in all the patients on the affected side. After 6 months all the patients showed near to normal improvement comparable to normal side.

CONCLUSION

Study shows that earlier the surgical intervention, more the recovery of the nerve injury is appreciable during the 1 and 6  months follow up period.

Inferior alveolar nerve injury in implant dentistry: diagnosis, causes, prevention, and management

Inferior alveolar nerve injury is one of the most serious complications in implant dentistry. This nerve injury can occur during local anesthesia, implant osteotomy, or implant placement. Proper understanding of anatomy, surgical procedures, and implant systems and proper treatment planning is the key to reducing such an unpleasant complication. This review discusses the causes of inferior alveolar nerve injury and its diagnosis, prevention, and management.

Functional outcomes of cleft lip surgery. Part IV: Between- and within-participant variables affecting lip vermilion sensory thresholds

OBJECTIVE

Compare neurosensory assessments for participants with and without a cleft lip; identify between- and within-participant variables affecting sensory thresholds on the vermilion of participants with cleft lip.

DESIGN

A parallel group, nonrandomized clinical trial.

SUBJECTS

There were 56 participants with cleft lip and 37 noncleft participants.

ANALYSIS

Two-point perception and warmth and cool detection thresholds were measured on the right and left sides of the upper and lower vermilion. A cotton-tip stick, stroked across the skin, was used to identify altered sensation. Linear mixed effects modeling was used to examine the effects of between- and within-participant variables on the thresholds.

RESULTS

Threshold values on the upper and lower vermilion were similar for cleft and noncleft participants and were unaffected by the presence of a cleft on the side tested. Participants with cleft lip who reported hyposensitive altered sensations had higher two-point thresholds on the upper lip than those who reported hypersensitivity. Participants with cleft lip who reported altered midface sensation had lower warmth detection, but higher cool detection thresholds, on the lower vermilion than participants with cleft lip who did not report altered sensation. Participants with bilateral cleft lip had lower warmth detection thresholds on the upper vermilion than participants with unilateral cleft lip.

CONCLUSIONS

Although participants with cleft lip and noncleft participants exhibit similar thermal and two-point discrimination, on average, differences exist among subgroups of participants with cleft lip that may reflect central disturbances in the processing of somatosensory stimuli.

Clinical and Histopathologic Study of the Use of Gangliosides for Nerve Regeneration in Rats After Axonotmesis

PURPOSE

This study involved a clinical and histopathologic evaluation of the use of gangliosides in nerve regeneration, using an experimental model with higher vertebrates.

MATERIALS AND METHODS

Forty Sprague Dawley rats had their right sciatic nerve crushed for 1 minute in a hemostatic tweezer. The animals were divided into experimental and control groups. The animals in the experimental group received an intramuscular injection of gangliosides in the left thigh for 25 days, whereas those in the control group received infiltrations of distilled water. A clinical evaluation of gait was made 24 hours and then 45 days after the surgical intervention, and a histopathologic evaluation of the sciatic nerves was performed after 45 days.

RESULTS

There were no signs that the use of gangliosides significantly altered the animals' gait after 45 days. The animals in the experimental group had a greater frequency and intensity of inflammatory response than seen in the control group.

CONCLUSION

The systemic use of gangliosides produced no improvement in gait and led to a more frequent and intense inflammatory response at the site of injury.

Iatrogenic injury to oral branches of the trigeminal nerve: records of 449 cases

The aims of this study were threefold: (1) to describe iatrogenic lesions to oral branches of the trigeminal nerve, signs and symptoms, and functional status, (2) to report on a simple neurosensory examination method, and (3) to discuss means of prevention of iatrogenic injury. The etiology and functional status of 449 injuries to oral branches collected over 18 years were retrospectively reviewed. A simple scheme of a clinical neurosensory examination was applied to enable a quantified rating of the perception. Injury to the lingual nerve (n = 261) is not only the most prevalent type of lesion, it also seems to be the most devastating type of lesion. Third molar surgery (n = 319) counts for the majority of injuries to the lingual, inferior alveolar, and buccal nerves. Lesions related to the injection of local analgesics was the second most frequent etiology (n = 78), and the lingual nerve was affected more frequently and severely than other oral branches of the trigeminal nerve. The female gender was overrepresented in incidence of injured nerves but no difference was found in the severity of affection between females and males. All grades of loss of neurosensory functions were found, and a range of neurogenic malfunctions was reported. Methodological obstacles in clinical neurosensory examination of trigeminal nerve injury and the magnitude of neurosensory impairment are discussed. Many nerve injuries are avoidable by critical reevaluation of indications, increased awareness of potential hazards, and modified surgical procedures.

Neurosensory function of the inferior alveolar nerve after bilateral sagittal ramus osteotomy: a retrospective study of 68 patients

The aim of the present study was to report the incidence of neurosensory dysfunction in the lower lip and chin after bilateral sagittal split osteotomy at four postoperative time points, and the relation of impairment to factors connected with the operation. Sixty-eight patients who had undergone the procedure (at 136 operated sites) were reviewed, and neurosensory recovery was studied at 2, 6, 18 and finally 30 months postoperatively. A change in neurosensory recovery was seen over this period of time. Two months postoperatively, 84 sites had reduced sensitivity (62%). The incidence of disorder decreased to 52 sites (38%) at 6 months, 43 sites (32%) at 1.5 years and 32 sites (24%) at the final 2.5-year check up. The patient age at the time of surgery, the type of osteosynthesis and the perioperative position of the inferior alveolar nerve were variables that influenced the neurosensory outcome. In conclusion, this retrospective study shows that the most important factors influencing postoperative nerve function are patient age, fixation method and the perioperative position of the inferior alveolar nerve.

Report of altered sensation in patients with cleft lip

OBJECTIVE

To determine whether patients with cleft lip have normal perioral sensation.

DESIGN

Each subject was carefully questioned about the following: sensation in the face at rest, light touch of different areas, and sensation in natural situations (e.g., exposure to cold weather) that reveal sensory abnormalities. A cotton-tip applicator stick was stroked lightly across the facial skin. The subject's descriptions of the evoked sensations were used to identify and outline areas with abnormal sensation.

SETTING

Data were obtained from subjects participating in a longitudinal, university-based study of the functional outcomes of lip revision surgery.

PATIENTS

Seventeen patients with cleft lip and 12 control subjects (aged 7 to 22 years, mean 12.9 years) participated.

RESULTS

In contrast to control subjects, 9 of 16 patients (56%) reported loss in sensation, described as decreased touch, scratch, tickle, or tingle intensity. Six other patients (38%) reported additional sensation, described as increased scratch, tickle, or tingle intensity. In eight patients, the altered sensation was restricted to the skin area flanking and including the visible scar, encompassing no more than 25% of the total area bound by the inferior nose, nasolabial grooves and inferior vermilion. In seven patients (unilateral cleft), the altered area extended to the contralateral, noncleft side of the upper lip or onto the philtrum.

CONCLUSIONS

In contrast to the literature, sensation in the upper lip of many patients with cleft lip is not normal. Loss in sensation is exhibited most commonly and limited largely to the skin overlying tissues traumatized during reconstructive surgery.

Perioperative neurosensory changes associated with treatment of mandibular fractures

PURPOSE

The purpose of this study was to document perioperative neurosensory changes in the inferior alveolar nerve (IAN) after mandibular fracture treatment and to identify risk factors associated with these changes.

MATERIALS AND METHODS

This was a prospective cohort study composed of patients treated for mandibular fractures. The primary study variable was the change between the postinjury/pretreatment IAN neurosensory examination score and the score after fracture reduction. Risk factors were categorized as demographic, anatomic, and treatment. Appropriate descriptive, bivariate, and multivariate statistics were computed.

RESULTS

The cohort was composed of 61 patients with 97 fractured sides. Forty-seven fractures (49%) were located between the lingula and mental foramen, and 50 fractures (51%) were located distal to the mental foramen. Thirty-nine fractures (41%) were displaced by 5 mm or more. Abnormal preoperative IAN neurosensory examinations were documented in 81% of the fractured sides. Fifty-three fractures (54%) were treated by closed reduction and 44 (46%) by open reduction and internal fixation. In 82 fractures (85%), the IAN neurosensory score was unchanged or improved after treatment. In a multivariate model, preoperative neurosensory score, displacement, and treatment were associated with a statistically significant risk (P < or =.05) for postoperative deterioration of IAN sensation.

CONCLUSION

Open reduction and internal fixation, fracture displacement of 5 mm or more, and a normal preoperative IAN neurosensory examination were associated with an increased risk for deterioration of the IAN neurosensory score after treatment of mandibular fractures. Additional studies are indicated to determine long-term IAN neurosensory function after mandibular fracture treatment and the factors that affect prognosis.