Effects of age, amount of advancement, and genioplasty on neurosensory disturbance after a bilateral sagittal split osteotomy

doi:10.1053/joms.2002.34411

Journal of Oral and Maxillofacial Surgery

Volume 60, Issue 9, September 2002, Pages 1012-1017

https://doi.org/10.1053/joms.2002.34411 Get rights and content

Abstract

Purpose: There are numerous risks for developing neurosensory deficits after a bilateral sagittal split osteotomy (BSSO). The purpose of this study was to evaluate the effects of genioplasty, length of advancement, and age and their interactions in a group of patients undergoing BSSO advancement and followed up for 2 years. Materials and Methods: Patients were examined at multiple time intervals during the 2 years. Measuring in the mental nerve distribution assessed damage. 127 subjects were divided into the following 3 age groups: younger than 24 years, 24 to 35 years, and older than 35 years old. They also were divided into small (≤7 mm) and large (>7 mm) advancements and genioplasty and no genioplasty. Change in tactile sensitivity from presurgical to the subsequent time periods is reported as a function of these variable and interactions among the variables. Data were analyzed using the Kruskal-Wallis test and the Friedman test, all at an α level of 0.05. Results: Older subjects had greater sensory losses than younger subjects. Patients with a genioplasty had a greater loss of sensation initially. For all subjects, the sensory function of those receiving large and small advancements was not significantly different. Among subjects receiving small advancements there was no significant difference among the 3 age groups. However, among patients receiving advancements greater than 7 mm, older patients did worse. Among patients not receiving genioplasty, there was no significant difference among the 3 age groups. In contrast, older subjects with a genioplasty had significantly greater sensory deficits. Conclusions: Age at the time of surgery and addition of a genioplasty increases the risk of a neurosensory injury. Large advancements further increase the risk of injury in older patients. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:1012-1017, 2002

Section snippets

Materials and methods

Objective neurosensory evaluations were performed at multiple periods ranging from 2 weeks before surgery to 2 years after surgery. Patients were participating in a multisite randomized, clinical trial at The University of Texas Health Science Center at San Antonio, University of Florida, Gainsville, and Emory University in Atlanta comparing 2 surgical fixation techniques. They were assigned to rigid or wire fixation using a stratified randomized assignment. Three bicortical position screws

Results

In general, there were no differences among the 3 sites of light touch and brush stroke sensitivity scores. As such, all 3 sites were combined. The 3 age groups, 2 genioplasty groups, and 2 advancement groups showed no difference in neurosensory function when tested 2 weeks before surgery (P >.05). These groups also showed no difference in function at the infraorbital site. The postsurgical changes in touch detection threshold and brush stroke direction are displayed (Fig 1).

. Light touch and

Discussion

Pratt et al²¹ compared the labial sensation in 2 groups of patients who underwent a BSSO with either superior border wires or miniplates used to fix the proximal and distal segments. They noted that the incidence of persistent sensory disturbance to be much higher in the group with superior border wires at 2 years. In a previous report from our group, there was no significant difference between inferior border wire and 3 bicortical position screws used to fix the proximal and distal segments

Conclusions

Neurosensory injuries after a BSSO are very common. The vast majority of patients show significant recovery by 2 years after surgery. Age of the patient at the time of surgery and addition of a genioplasty increase the risk of a neurosensory injury. Large advancements further increase the risk of neurosensory injury, especially in older patients.

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Cited by (88)

Relationship of the Degree of Nerve Exposure and Surgical Manipulation and Short-Term Neurosensory Disturbance Following Sagittal Split Ramus Osteotomy: A Prospective Study
2024, Journal of Oral and Maxillofacial Surgery
Neurosensory disturbance (NSD) is a common complication after sagittal split ramus osteotomy (SSRO) due to inferior alveolar nerve (IAN) injury. The impact of intraoperative nerve manipulation on NSD remains debated.
The purpose of this study was to evaluate the influence of IAN exposure and manipulation during SSRO on functional sensory recovery (FSR).
This was a single-center, prospective cohort study of 40 patients undergoing SSRO at Mahidol University from December 2020 to December 2021. The inclusion criteria were patients aged 20-34, ASA Class I-II. The exclusion criteria were patients with systemic bone disease, history of head and neck or neurological pathology, previous SSRO, or incomplete data collection.
Degree of intraoperative nerve manipulation was divided by the attending surgeon as follows; 1) Nerve fully encased in distal segment and not visible (NS); 2) Nerve encased in distal segment but partially visible (DS); and 3) Nerve partially encased in proximal segment and fully dissected free (PS).
The area of interest was divided into the lip and chin. The primary outcome was time to FSR. The secondary outcome was subjective patient report, using a visual analogue scale, compared to FSR.
The covariates were sex, age, skeletal diagnosis, degree of movement, and concomitant genioplasty/subapical procedure.
Kaplan-Meier survival analysis, Cox proportional hazards regression, and Mcnemar test were utilized. P-value < .05 was significant.
In the lip, the median times to FSR were NS, 2 days; DS, 45 days; PS, 102 days. (Interquartile range: 77,127, 114, respectively) In the chin, the median times to FSR were NS, 23 days; DS, 92 days; PS, 87 days. (Interquartile range: 77, 161, 101, respectively.) Nerve manipulation significantly affected FSR in the lip and chin (P = .001, <0.001, respectively. Cox hazard ratios for DS and PS were lower compared to NS. Patients consistently reported more NSD compared to FSR as per Mcnemar test.
After SSRO, FSR in the lip is prolonged when the IAN is partially encased in the proximal segment and released. This raises the question of the efficacy of surgically releasing a partially encased IAN.
Posterior ostectomy of a mandibular distal segment for nerve bundle traction to tensionless anastomosis of an inferior alveolar nerve
2023, Journal of Stomatology, Oral and Maxillofacial Surgery
Tensionless adaptation of nerve ends is a challenging task in the repair of damaged inferior alveolar nerve (IAN). A new technique is introduced with posterior ostectomy of a mandibular distal segment after sagittal splitting for nerve bundle traction to tensionless anastomosis of nerve ends. We were able to create tensionless anastomosis of an IAN defect without autogenous or alloplastic graft using this method. This method is suitable for neurorrhaphy after neuroma removal in cases of IAN damage during dental procedures.
Risk factors of neurosensory disturbances at 1 year postoperatively after bilateral sagittal split osteotomy
2022, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
To investigate morphologic and surgical risk factors causing neurosensory disturbances (NSDs) after bilateral sagittal split osteotomy (BSSO).
A total of 237 patients (with 474 sides) who underwent BSSO were followed up for 1 year. Parameters examined included age, sex, asymmetry, mandibular movement direction, mandible cutting devices, split type, intraoperative exposure of the inferior alveolar nerve (IAN), contact between the IAN and screw, distance between mandibular canal and inner surface of the cortical bone (distance A), distance from lateral osteotomy to mental foramen (distance B), and NSD at 1 year postoperatively.
NSD was observed in 62 (13.1%) sides of 51 patients. Exploratory factor analysis determined 4 factors (factor 1: distance A; factor 2: direction of mandibular movement; factor 3: distance B and cutting devices; factor 4: IAN exposure). Logistic regression analysis was performed using the above factors and age, sex, and asymmetry, making a total of 7 variables. Age, factor 1, and factor 4 were significant predictors of NSD.
Advanced age, close distance between mandibular canal and inner surface of the cortical bone, and IAN intraoperative exposure are risk factors for NSD 1 year postoperatively. Cases at high risk for NSD must be treated with great care.
Influence of Inferior Alveolar Nerve Exposure During Sagittal Split Osteotomy on the Rate and Timing of Baseline Sensory Recovery
2022, Journal of Oral and Maxillofacial Surgery
Neurosensory disturbance is the most common consequence of sagittal split osteotomy (SSO). The purpose of this study is to quantitatively assess neurosensory deficiency and recovery to the preoperative status when the inferior alveolar nerve (IAN) was exposed versus unexposed during SSO.
This is a single-center, prospective, cohort study of all patients undergoing bilateral SSO between August 2018 and July 2019. Patients were included in the study sample if they underwent bilateral SSO with an intact intraoperative IAN and were received follow-up assessment for at least a year. The predictor variable was the intraoperative IAN status (exposed vs unexposed). The outcomes of interest were the rate and timing of recovery to the preoperative status. The covariates were age, sex, and the magnitude and direction of surgical movements. Neurosensory function was quantitatively evaluated using the Semmes-Weinstein monofilament test at follow-up intervals of 1, 3, 6, and 12 months. Descriptive statistics, bivariate statistics, Cox proportional hazards regression, and Kaplan-Meier analyses were performed. P value <.05 was considered statistically significant.
Of 90 patients, 86 patients who underwent 172 SSOs were included in this study. The mean age was 22.95 ± 3.34 years (range, 17 to 30), 65 were women, and the range of surgical movements was 3 to 8.3 mm of advancement and 2 to 12 mm of setback. Eighty-five nerves (49.4%) were allocated to the unexposed group, and 87 (50.6%) to the exposed group, with statistically significant differences in the rate and timing of recovery (hazard ratio = 2.368; 95% confidence interval, 1.662 to 3.376; P < .001). Among those with recovered nerves, the median time to recovery was 90 days in the unexposed group and 364 days in the exposed group (P < .0001).
IAN exposure during SSO is associated with an increased risk of neurosensory deficiency and an increased time of sensory recovery to the baseline threshold in patients aged 17 to 30 years. When the IAN remained fully enclosed in the canal of the distal segment, only 11% of patients had a measurable sensory deficit 1 year after surgery. In those patients with any degree of IAN exposure, 36% had a residual sensory deficit 1 year after surgery.
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
2022, Journal of Evidence-Based Dental Practice
Citation Excerpt :
Long-term neurologic deficit occurs in 10% to 30% of the affected patients, whether annoyed or not.3 Many factors are involved in IAN NSD such as age, sex, bone quality, surgeon's skills, presence of concomitant genioplasty, dissection technique, bad splits, fixation techniques, presence of the third molar tooth, increased amount of mandibular advancements, laterally positioned mandibular canals, and manipulation of the inferior alveolar nerve.7-12 The introduction of piezosurgery decreases the risk of damage to the surrounding soft tissues and other vital structures; namely nerves, vessels, and mucosa, particularly during an osteotomy.13-18
Purpose: The purpose of this systematic review was to compare neuro-sensory dysfunction incidence between saw and piezotomes in patients requiring bilateral sagittal split osteotomy.
Methods: 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.
Results: 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.
Conclusions: 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.
Computed tomography assessment of mandibular morphologic changes and the inferior mandibular border defect after sagittal split ramus osteotomy
2021, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
This study aimed to assess mandibular morphologic changes to the condyle, ramus, mandibular body, and inferior mandibular border defect after sagittal split ramus osteotomy in class II and III patients.
The relationships among the condyle, ramus, and mandibular body measured by computed tomography preoperatively and postoperatively were assessed and factors related to the reduction of the condylar square and mandibular inferior border defect were examined.
Patients included 72 female patients with jaw deformity (36 skeletal class II cases, 36 skeletal class III cases). Postoperative reduction of the condylar square was significantly correlated with preoperative condylar height in patients with class II (P = .0297) vs preoperative condylar height and preoperative mandibular height in patients with class III (P < .0001). A mandibular inferior border defect was found in 18 of 72 class II sides (25.0%) and was significantly related to the position of the osteotomy line and attachment side of the inferior border cortex (P < .0001).
This study's findings suggest that the postoperative reduction of the condyle could be associated with preoperative condylar height. However, the mandibular inferior border defect in class II advancement surgery could be independently associated with technical factors in sagittal split ramus osteotomy.

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^☆: This study was supported by National Institutes of Health Grants DE 09630 and 07282.

^☆☆: Address correspondence and reprint requests to Dr Van Sickels: Professor and Director of Residency Education, Division of Oral and Maxillofacial Surgery, D-512 Chandler Medical Center, College of Dentistry, University of Kentucky, Lexington, KY 40536-0297; e-mail: [email protected]

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Clinical ArticlesEffects of age, amount of advancement, and genioplasty on neurosensory disturbance after a bilateral sagittal split osteotomy☆,☆☆

Abstract

Section snippets

Materials and methods

Results

Discussion

Conclusions

J Oral Maxillofac Surg

J Oral Maxillofac Surg

Oral Surg Oral Med Oral Pathol

Int J Oral Maxillofac Surg

Int J Oral Maxillofac Surg

Br J Oral Maxillofac Surg

J Oral Maxillofac Surg

J Oral Maxillofac Surg

J Oral Maxillofac Surg

J Oral Maxillofac Surg

Oral Surg Oral Med Oral Pathol Oral Radiol Endod

J Oral Maxillofac Surg

Clinical Articles
Effects of age, amount of advancement, and genioplasty on neurosensory disturbance after a bilateral sagittal split osteotomy☆,☆☆