Incidence Of Neurosensory Disturbance Research Articles

POST-SURGICAL NEUROSENSORY DYSFUNCTION OF INFERIOR ALVEOLAR NERVE IN BILATERAL SAGITTAL SPILT OSTEOTOMY OF THE MANDIBLE USING SAW VERSUS PIEZOTOME: A SYSTEMATIC REVIEW AND META-ANALYSIS.

The purpose of this systematic review was to compare neuro-sensory dysfunction incidence between saw and piezotomes in patients requiring bilateral sagittal split osteotomy. Searches were performed electronically in 4 databases (PubMed, LILACS, Cochrane Library, and grey literature) up to September 2020 and manually to identify studies addressing the subject. Randomized and non-randomized clinical trials were included. Six studies met the eligibility criteria with a total number of 284 participants. The risk of bias assessment for randomized clinical trials was high, and for non-randomized clinical trials was critical and serious. Regarding inferior alveolar neuro-sensory dysfunction, the meta-analysis showed no significant difference between saw and piezotome 1 week [RR = 0.99, 95% CI (0.90, 1.08) P = 0.79], and 3 months [RR = 0.39, 95% CI (0.09, 1.75) P = 0.22], post-operatively. For patients requiring bilateral sagittal split osteotomy, piezotomes seem to offer no advantage over conventional saws regarding the incidence of neurosensory disturbance. Follow-up periods longer than 3 months may reveal faster physiologic regain of sensations. They seem to be safer than conventional saws regarding blood loss. However, proper training for using the device is mandatory, while considering the longer operating time required. Further RCTs are still recommended to improve the level of evidence.

Incidence of neurosensory disturbance in mandibular implant surgery - A meta-analysis.

Aim:Implantology has been widely accepted as the mainstay treatment for rehabilitating complete and partial edentulism. However, it is associated with some failures and complications, the most concerning being neurosensory disturbance. Although neurosensory disturbance has been extensively studied, the incidence and cause remains largely variable. Thus, the aim of this systematic review and meta-analysis was to evaluate the incidence, distribution, and recovery rate of neurosensory disturbance.Settings and Design:This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. A structured literature review was conducted using the following databases: PubMed, Science Direct, Cochrane, Ovid, and Google Scholar for reports related to neurosensory disturbance experienced after implant placement in the mandible.Statistical Analysis Used:Incidence and recovery rate for 100 person-years was calculated using the Poisson regression model. The risk difference of incidence between anterior and posterior implants was calculated with a random effects model.Results:Electronic database search yielded 1589 articles; a total of nine articles were selected for the meta-analysis. The risk of neurosensory disturbance was estimated at 13.50/100 person-years (95% confidence interval (CI): 10.98–16.03), with a greater risk with anteriorly placed implants: −0.02 (95% CI: −0.21–0.16) (P = 0.05). The overall recovery rate was estimated at 51.30/100 person-years (95% CI: 31.2–71.4).Conclusions:Within the limitations of the study, it can be concluded that mandibular implant placement is associated with a considerable risk of neurosensory disturbance. A large proportion of these patients present with spontaneous recovery; however, clinicians must take necessary precautions to avoid such complications. More randomized controlled trials are required to quantify the effect of factors leading to altered sensation during implant placement.

Patterns of lingual split and lateral bone cut end and their associations with neurosensory disturbance after bilateral sagittal split osteotomy

The purpose of this study was to characterize the patterns of lingual split and lateral bone cut end (LBCE) after bilateral sagittal split osteotomy (BSSO) in patients and identify their associations with postoperative neurosensory disturbance. This retrospective cohort study recruited 273 patients with skeletal malocclusion who received BSSO. The postoperative cone beam computed tomography data were reconstructed to three-dimensionally view the patterns of lingual split and LBCE. Associations between lingual split and LBCE and their effects on neurosensory disturbance in the lower lip and chin were determined. Six types of lingual split and three types of LBCE were defined based on three-dimensional images. Type I lingual split as a vertical fracture line to the inferior mandibular border was the most common (40.29%). Inferior LBCE was the most prevalent, followed by lingual and buccal types. Significant associations among lingual split, LBCE and skeletal deformities were found (P < 0.05). However, patterns of lingual split and LBCE were not associated with the incidence of neurosensory disturbance. Patterns of lingual split after BSSO significantly associated with types of LBCE and dentomaxillofacial deformities, but not with postoperative neurosensory disturbance.

Evaluation of Neurosensory Function Following Inferior Alveolar Nerve Lateralization for Implant Placement

BackgroundAdequate bone height and width is the most important parameter for success of implants. Prolonged edentulous area in mandibular posterior region is often associated with atrophy precluding the use of dental implants. Inferior alveolar nerve (IAN) lateralization is a challenging surgical procedure as it involves the exposure of the neurovascular bundle from its compact bony compartment and adequate retraction while immediate placement of implant.AimEvaluation of neurosensory disturbances related to IAN lateralization for implant placement in the posterior atrophic edentulous mandible.Materials and MethodsTen patients above the age of 18 years with an edentulous span in mandibular posterior region showing distance from alveolar crest to IAN ≤ 8 mm (CBCT) were included in the study. The postoperative analysis of NDs was done using Semmes–Weinstein Monofilaments (SWM). Readings were made on the 1st and 7th postoperative day and every month thereafter until the neural sensations were restored.ResultsAll patients reported neurosensory disturbance on post-op day 1. None of the patients responded to SWM lesser than 4.56 on first postoperative day, which indicated 100% incidence of neurosensory disturbances. The minimum time required for complete recovery was 2.0 months, and maximum was 4.0 months.ConclusionIAN lateralization is a useful method for managing the atrophic posterior mandible with dental implants. If done precisely with experienced personnel, it can provide a worthy option for surgical restoration of atrophic mandible with minimal temporary NDs.

Transversal Width of Mandibular Bone and Neurosensory Disturbance after Bilateral Sagittal Splitting Ramus Osteotomy

Objective: This study evaluated the condition of mandibular cancellous and cortical bone on computed tomography (CT) images in order to investigate its relationship with the incidence of neurosensory disturbances (NSD) in the mental nerve region after bilateral sagittal splitting ramus osteotomy (BSSRO). Methods: BSSRO was performed on 58 lateral mandibles in 29 patients. From preoperative CT images, the width endpoints of the transversal bone were measured in region I immediately inferior to the mandibular foramen, region II in the mandibular angle region, and region III distal to the lower second molar. The incidence of NSD immediately after surgery and the residual NSD rate at 1, 3, and 6 months after surgery were investigated. The correlation between incidence of NSD in the mental nerve region and each transversal bone width endpoint immediately after and at 6 months after surgery was also comparatively evaluated. Results: The overall incidence of NSD immediately after surgery was 67.2% (39/58 sides) and the overall residual NSD rate at 1, 3, and 6 months after surgery was 53.4% (31/58 sides), 31.0% (18/58 sides), and 17.2% (10/58 sides), respectively. No significant differences were observed for any width endpoints of the transversal bone measured at regions I or III, but the transversal width of the entire mandible was significantly different in region II between patients with and without NSD at 6 months after surgery (p < 0.05). Conclusion: These findings demonstrate that the transversal width of the entire mandible may be an important factor in predicting NSD incidence.

Hypoesthesia associated with mandibular movement after sagittal split ramus osteotomy.

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. Lower lip hypoesthesia was evaluated at 1week, 1month, and 2months after SSRO in 38 patients categorized according to the distance of mandibular movement: S group (0-7mm; n=17, 4 males and 13 females) and L group (7-14mm; 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. 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 1week and 1month 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. 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.

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

Asymmetric mandibular prognathism: Outcome, stability and patient satisfaction after BSSO surgery. A retrospective study

PurposeTo investigate surgical outcome, long-term stability, the time course of relapse, neurosensory disturbances, and patient satisfaction after BSSO for correction of mandibular asymmetry. Another objective was to examine whether osteotomies for transverse rotation of the distal segment represent an increased risk for nerve injury. Subjects and methodsIn a retrospective study lateral and postero-anterior cephalograms, information from patient files and questionnaires were analysed for 38 patients having more than 4 mm asymmetry at the chin pre-treatment (mean 8.4 mm). The radiographs were analysed preoperatively, postoperatively, after 6 months and 3 years. ResultsAsymmetry of the chin to the facial midline improved on average by 56%. Skeletal relapse was about the same for transverse and antero-posterior surgical changes (10–15%). 58% of the patients had asymmetry of more than 3 mm at menton 3 years post-surgery. Discrepancy between upper and lower dental midlines improved on average 80%. Normal or near normal sensation to the lower lip/chin was reported by 44% of the patients which is similar to sensory disturbances after BSSO straight set-back performed by the same surgical team. A difference in the incidence of neurosensory disturbance between the two osteotomy sides was observed. Satisfaction with the treatment result was reported by all patients except for two. ConclusionCorrection of mandibular asymmetry by BSSO is fairly stable. Although the risk for sensory impairment for the individual patient was similar to impairment in a sample having straight setback, rotation of the distal segment during surgery may represent an increased risk for sensory impairment on the deviating side (P = 0.06). Three years after surgery patients were generally satisfied with the result even if more than 3 mm of asymmetry at the chin remained for 58%. The findings have implications for treatment planning and the decision to elect one-jaw, bimaxillary surgery and/or additional genioplasty.

Effectiveness of piezoelectric surgery in reducing surgical complications after bilateral sagittal split osteotomy

Our aim was to investigate the effectiveness of piezoelectric surgery, where the osteotomy is made using ultrasonic vibration, in reducing surgical complications after bilateral sagittal split osteotomy (BSSO). Fifty-nine patients with skeletal mandibular prognathism who had mandibular setback with BSSO between January 2009 and April 2011 were included in the study. Piezosurgery was used in 29 cases, and the bone was split using a separator. In the remaining 30 cases, a Lindeman bur was used for the osteotomy and a chisel was used to split the bone. The amount of intraoperative bleeding and the Semmes Weinstein test scores were used as objective variables to evaluate the degree of neurosensory disturbance, and sex, age, use of piezosurgery, degree of setback, operating time, and method of fixation were used as explanatory variables. We used analysis of covariance (ANCOVA) to assess the significance of differences. Intraoperative bleeding was significantly less with age (p=0.003), and longer when operating time was prolonged (p=0.017), and was not influenced by the use of piezosurgery. The Semmes Weinstein test score significantly increased with age (p=0.01), and was significantly greater when piezoelectric surgery was used (p=0.008), and at 3 months, there were signs of more neurosensory disturbance in older patients and those who had had piezoelectric surgery. In this retrospective non-random study piezoelectric surgery reduced neither blood loss nor the incidence of neurosensory disturbance in BSSO.

Quantitative Evaluation of Cortical Bone Thickness in Mandibular Prognathic Patients With Neurosensory Disturbance After Bilateral Sagittal Split Osteotomy

The buccal cortical thickness (BCT) between the mandibular canal and the corresponding external cortical surface was compared in patients with and without neurosensory disturbance (NSD) after they underwent a bilateral sagittal split osteotomy (BSSO) to correct mandibular prognathism. This prospective cohort study was conducted in 146 patients (95 women, 65.1%; 51 men, 34.9%) 18 to 39 years old who underwent bimaxillary surgery (ie, Le Fort I osteotomy and BSSO) to correct mandibular prognathism. NSD was identified using a light touch test with a Semmes-Weinstein monofilament and a pricking pain test with a sharp dental explorer 1 week after surgery. Preoperative cone-beam computed tomographic (CBCT) imaging was used to visualize the bone contacts or fusion of the mandibular canal to the buccal cortical bone and to decrease injury to the mandibular nerve during surgical dissection. Preoperative CBCT imaging also was used to assess the BCT every 2 mm from the mandibular foramen to the furcation of the mandibular first molar in the NSD group and the sensory normal (N) group. The incidence of NSD was 32.5% at 1 week after surgery. There was no statistically significant difference between men and women, the side affected, or genioplasty at the time of undergoing BSSO. Of the total sample group, decreased BCT was identified throughout the observed length of the mandibular canal in the NSD group compared with the N group. Statistically significant decreased BCTs were 16 to 20 mm and 24 mm in the total sample, 6 to 8 mm in the female group, and 16 to 18 mm in the male group. Compared with the N group, BCTs in the NSD group were always decreased, especially those located at 16 to 20 mm and 24 mm in the total sample, 6 to 8 mm in the female group, and 16 to 18 mm in the male group.

Risk Factors for Neurosensory Disturbance After Bilateral Sagittal Split Osteotomy Based on Position of Mandibular Canal and Morphology of Mandibular Angle

The aim of the present study was to evaluate the potential morphologic risk factors for postoperative neurosensory disturbance (NSD) after bilateral sagittal split osteotomy. The study subjects were 30 skeletal Class III patients (9 males and 21 females), with a mean age of 22.0 years (range, 16-39 years). All patients underwent bilateral sagittal split osteotomy for setback to correct mandibular prognathism. The bone marrow space between the outer mandibular canal and the lateral cortex of the ramus was measured on transaxial computed tomography images, and the length at the mandibular angle between the retromolar and gonion was measured on the lateral cephalograms. The NSD was tested bilaterally using discrimination to touch with the sharp head of a mechanical probe. Each patient was evaluated at 1, 3, and 6 months postoperatively. The median bone marrow space was 1.96 mm (range, 0-4.5 mm), and median length of the mandibular angle was 30.93 mm (range, 23-37 mm). Neurosensory disturbance was present on 15 sides (25.0%) at 1 month postoperatively, 9 sides (15.0%) at 3 months postoperatively, and 7 sides (11.7%) at 6 months postoperatively. The difference in the incidence of NSD with a small bone marrow space and a long mandibular angle from that with a large bone marrow space and short mandibular angle was highly statistically significant (P = .006 and P < .01, respectively). The frequency of NSD after bilateral sagittal split osteotomy in Class III cases was dependent not only on the position of mandibular canal, but also on the length of the mandibular angle. A lateral course of the mandibular canal and a long mandibular angle appeared to result in a high risk of injury to the inferior alveolar nerve, resulting in NSD owing to a compromised splitting procedure.

Poster 188: Neurosensory Disturbance of Genioplasty–Genioplasty Done Alone or in Combination With SSRO

In orthognatic surgery for jaw deformity, we use bimaxillary oteotomy by saggital splitting ramus osteotomy (SSRO) or Le Fort I osteotomy and SSRO to improve occlusion. However, in many cases it is necessary to do genioplasty with SSRO to improve function and esthetics. The purpose of this study is to compare neurosensory distuibance of geniopiasty done alone to in combination with SSRO. The subjects were those who underwent genioplasty. A total of 112 sides (56 patients) underwent preoperative and postoperative (1, 4 and 12 weeks after operation) examinations. Among these cases, 88 sides were done geniopiasty alone, and 24 sides were done in combination with SSRO. The methods of neurosensory examination did constant-touch was assessed using a neurosensory threshold test by Semmes-Weinstein pressure aethesiometer (SW test) and Subjective symptoms were assessed by interview. 1 week after operation, in subjective symptom, the incidence of neurosensory disturbance as detected by in combination with SSRO was 100% and by genioplasty done alone was 82.95%. In SW test, the incidence of neurosensory disturbance as detected in combination with SSRO was 91.67% and by genioplasty done alone was 53.41%. The incidence of neurosensory disturbance was high in combination with SSRO in comparison with genioplasty done alone.

Neurosensory disturbances one year after bilateral sagittal split mandibular ramus osteotomy performed with separators

The most frequently performed osteotomy for correction of mandibular retrognathia is a bilateral sagittal split ramus osteotomy. Permanent neurosensory disturbance of the inferior alveolar nerve is one of the most frequently and severe complications. Many authors have reported this, but the incidence differs widely. In the recent literature, only four authors have reported a percentage of less than 10% after 1 year follow-up. To determine the incidence of permanent neurosensory disturbance of the inferior alveolar nerve after bilateral sagittal split ramus osteotomy, and possible influences of the technique used. A series of 109 patients is reported who underwent a bilateral sagittal split mandibular ramus osteotomy with the use of separators and without the use of chisels. The segments were hold by rigid transbuccal screw fixation. The incidence of neurosensory disturbances 1 year after surgery was 8.3%. The use of sagittal split separators without the use of chisels, may play an important role in the relatively low percentage of persistent hypoaesthesia of the inferior alveolar nerve.

On neurosensory disturbance after sagittal split osteotomy

The purpose of this retrospective study was to assess the incidence of the neurosensory disturbance (NSD) after sagittal split osteotomy and evaluate NSD in relation to patient age, gender, satisfaction, and effect of steroids. Questionnaires were mailed to all patients (31 women, 19 men) who underwent bilateral sagittal split osteotomy between 1995 and 1999, at least 1 year after the operation. Patients were queried about perceived NSD in the distribution of both inferior alveolar and lingual nerves, duration of these changes, and any influence of these changes on their quality of life. Eighty-six percent of the mailed questionnaires were returned and analyzed (27 women, 16 men). Eight patients with 10 affected sides (11.6% of sides) reported long lasting NSD corresponding to the distribution of the inferior alveolar nerve. NSD was reported in 16.7% of the operated sides in women, while 3% of the operated sides in the men had such changes. Fifty percent of the operated sides in patients over 40 years of age were affected. Steroid treatment seemed to decrease NSD. Four patients (9%) were not satisfied, but only 1 attributed the dissatisfaction to sensory impairment. The incidence of NSD after sagittal split osteotomy increases in patients over the age of 40. Steroid regimen might be beneficial in reducing NSD after sagittal split osteotomy, although further investigation is required. The discomfort of the nerve damage seems outweighed by the result of function and esthetics.

Incidence of neurosensory disturbance after sagittal split osteotomy alone or combined with genioplasty

We mailed questionnaires to all patients who had had sagittal split osteotomies alone (n=84) or in combination with genioplasty (n=37) between 1995 and 2000, to find out the incidence of postoperative sensory disturbances.The patients with sagittal split osteotomies alone reported sensory disturbance in 48/131 (37%) operated sides. When combined with genioplasty patients experienced them in 20/54 (37%) operated sides. The incidences were 36/101 (36%) for mandibular advancement and 12/30 (40%) for mandibular setback.Out of the patients with sagittal split osteotomies alone, 59/66 (89%) were satisfied with the result of the operation, and when combined with the genioplasty the corresponding figure was 23/27 (85%).We conclude that differences in the incidence of sensory disturbance after sagittal split osteotomy for mandibular advancement and setback were not significant. The combination with genioplasty did not increase the incidence of sensory disturbance. Sensory changes after the osteotomies do not serve to be the main determinant of the patients’ satisfaction.

Inferior alveolar nerve function after mandibular osteotomies

A total of 1034 patients who had undergone orthognathic surgery were examined after 2 years; 818 had been treated with varying types of mandibular osteotomy such as vertical ramus osteotomy, sagittal split ramus osteotomy, and genioplasty. Neurosensory function in the mental nerve region was assessed by evaluating light touch perception. The incidence of neurosensory deficiency was 216/548 (39%) after sagittal split ramus osteotomy, 26/140 (19%) after extraoral vertical ramus osteotomy, 9/78 (12%) after genioplasty and 60/650 (9%) after intraoral vertical ramus osteotomy. Additional genioplasty increased both the incidence and severity of neurosensory disturbance after intraoral vertical ramus osteotomy but did not significantly influence the neurosensory function after sagittal split ramus osteotomy. The incidences of neurosensory disturbance after mandibular osteotomies in this report correspond well with those previously reported, but the incidence of almost 40% after sagittal split ramus osteotomy must be considered a disquieting drawback of the procedure.

Neurosensory disturbance associated with the anterior mandibular horizontal osteotomy.

Fifteen patients who underwent an anterior mandibular horizontal osteotomy (genioplasty) were retrospectively studied by neurosensory testing to evaluate light touch (LT) and temperature (T) discrimination. Testing was conducted using the two-alternative forced choice method. Density of a neurosensory disturbance (NSD), when it occurred, was also evaluated. A questionnaire was administered to determine if patients with a NSD perceived that their quality of life was adversely affected. The incidence of NSD was 3.4% (one of 30) to LT and 0% (none of 30) to T. The one abnormal mental nerve with a NSD to LT was moderately dense, but was not perceived by the patient as adversely affecting her quality of life.

Neurosensory disturbance with rigid fixation of the bilateral sagittal split osteotomy

Twenty-one patients who underwent bilateral sagittal split osteotomies using rigid fixation were evaluated by neurosensory testing. Neurosensory tests included light touch (LT), brush stroke direction (BSD), two-point discrimination (2-P), and temperature (T). Tests were conducted using the two-alternate forced choice method. The density of neurosensory disturbance was examined as well as the incidence of neurosensory disturbance as it correlated with age of the patient. The incidence of neurosensory disturbance was 45.2% ( 19 42 ) to LT, 52.4% ( 22 42 ) to BSD, 33.3% ( 14 42 ) to 2-P and 7.1% ( 3 42 ) to T. The majority of demonstrable neurosensory disturbances were not dense. Increased age was associated with an increased incidence of neurosensory disturbance.