Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy.

Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy. Tomonari Kajita, Shinnosuke Nogami, Yuki sugai, Mai Yazaki, Hikari Suzuki, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7526389/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Purpose : Inferior alveolar nerve transection (IANT) is a severe complication of sagittal split osteotomy (SSO). This study aimed to retrospectively evaluate the long-term sensory recovery in patients who experienced intraoperative IANT compared to those who did not. Materials and methods : This retrospective cohort study reviewed patients who underwent SSO from 2016 to 2022. Patients were divided into Group A (with IANT, 11 sides) and Group B (without IANT, 151 sides). Sensory perception was assessed using the Semmes-Weinstein (SW) test, static two-point discrimination (s-2PD) test, and a Numerical Rating Scale (NRS) at preoperative baseline and at 1, 3, 6, and 12 months postoperatively. Mann-Whitney U and Dunnett's tests were used for statistical analysis (p < 0.05). Results : Group A demonstrated significantly worse sensory outcomes than Group B on all tests at all postoperative time points (p < 0.01). In Group B, SW and s-2PD values were significantly worse than baseline at 1 and 3 months but showed no significant difference at 6 and 12 months. In contrast, Group A outcomes remained significantly impaired compared to their own preoperative baseline throughout the 12-month follow-up. Conclusions : Complete IANT during SSO results in a profound and likely permanent neurosensory deficit. While patients without nerve transection typically recover baseline sensory perception by 6 months, those with IANT experience only minimal improvement and remain significantly impaired at a year post-surgery. inferior alveolar nerve transection sagittal split osteotomy neurosensory disturbance jaw deformity sagittal split osteotomy Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Bilateral sagittal split osteotomy (SSO), first introduced by Trauner and Obwegeser, is one of the most frequently performed orthognathic procedures for the correction of mandibular deformity.[ 1 ] While SSO is an established and effective surgical method for treating mandibular hypo- and hyperplasia, it is associated with several potential complications, including bleeding, swelling, and pain. Among these, neurosensory disturbance (NSD) of the inferior alveolar nerve (IAN), which results in hypoesthesia of the lower lip and chin, is a major concern. The reported incidence of NSD following SSO varies widely, from 9–85%. A systematic review by Colella et al. revealed that neurosensory impairment was detected in 63.3% of patients with objective tests and 83% with subjective tests at 7 days postoperatively.[ 2 ] Numerous factors are known to influence the risk of NSD, including patient age,[ 3 ] the magnitude of mandibular movement, the degree of nerve manipulation, and the surgeon's experience.[ 2 , 4 ] Furthermore, specific anatomical features, such as the transversal width of the mandible,[ 5 ] the lateral course of the mandibular canal,[ 6 ] and female gender,[ 7 , 8 ] have been identified as significant risk factors. While sensory impairment after SSO is often temporary, with recovery typically occurring within 6 to 12 months, persistent NSD beyond one year is considered permanent.[ 9 ] Although many studies have investigated risk factors for NSD, a critical gap exists in the literature regarding the long-term prognosis following a complete inferior alveolar nerve transection (IANT) during SSO. To the best of our knowledge, no studies have longitudinally compared the sensory recovery trajectory between patients with intraoperative IANT and those without. Therefore, the objective of this study was to investigate the postoperative recovery of sensory perception in patients who experienced IANT during SSO. Additionally, we aimed to compare their perceptual changes with those of a cohort who also experienced postoperative NSD but without intraoperative nerve transection. Materials and Methods 2.1. Study Design and Patient Selection This retrospective cohort study was approved by the Ethical Review Board of Tohoku University (No. 2017-03-015) and followed the Declaration of Helsinki. We reviewed the records of all patients who underwent SSO, either alone or combined with Le Fort I osteotomy, at our institution between January 2016 and December 2022. Inclusion criteria were patients with postoperative hypoesthesia in the lower lip and chin region at one-month follow-up and at least one year of postoperative follow-up data. Patients were divided into two groups based on intraoperative findings: Group A (patients with documented complete or partial IANT) and Group B (patients without IANT but with postoperative NSD). Exclusion criteria included patients who underwent concomitant procedures that could influence NSD (e.g., intraoral inverted L ramus osteotomy, genioplasty), those with no complaints of hypoesthesia at 1 month postoperatively, and those with incomplete data. 2.2. Surgical Procedure All operations were performed under general anesthesia. The surgical technique was a modification of the Trauner-Obwegeser method as described by Hunsuck and Dal Pont.¹¹ A mucoperiosteal flap was raised to expose the ramus and body of the mandible. After protecting the neurovascular bundle, osteotomies were performed. The fragments were separated, and the distal segment was positioned using an occlusal splint. Fixation was achieved using 6-hole titanium miniplates and monocortical screws (Stryker, Freiburg, Germany)(Figure.1). Intermaxillary fixation was maintained for approximately 5 days. 2.3. Management of Nerve Transection In cases of IANT, nerve repair was performed by an experienced oral and maxillofacial surgeon using 6 − 0 nylon sutures. 2.4. Neurosensory Evaluation Subjective and objective neurosensory evaluations were performed preoperatively and at 1, 3, 6, and 12 months postoperatively (Figure.2). Subjective Evaluation: The Numerical Rating Scale (NRS) was used, where patients rated their sensation from 0 (complete anesthesia) to 10 (normal sensation). Objective Evaluation: Two tests were performed: Semmes-Weinstein (SW) monofilament test: Assessed light touch threshold. Static two-point discrimination (s-2PD) test: Measured spatial acuity using blunt-tipped calipers. All evaluations were conducted by trained examiners following a standardized protocol.¹² All patients with hypoesthesia were prescribed mecobalamin (1,500 mg/day). 2.5. Data Analysis Dunnett's test was used to compare postoperative measurements with preoperative baseline values within each group. The Mann-Whitney U test was used to compare the outcomes between Group A and Group B at each time point. All statistical analyses were performed using JMP version 17 (SAS Institute Inc, Cary, NC). A p-value less than 0.05 was considered statistically significant. Results The study sample was initially composed of patients who underwent SSO alone or combined with Le Fort I osteotomy between January 2016 and December 2022. Of these, patients who underwent intraoral inverted L ramus and sagittal splitting ramus osteotomy (ILRO) or genioplasty, which can influence postoperative NSD and patients with incomplete data were excluded. Furthermore, patients with no complaints of hypoesthesia at 1 month after the operation were excluded. Therefore, the final study subjects were consecutive patients with hypoesthesia in the lips and cheeks (35 males and 66 females). The results of sample date were shown in Table.1. Group A consisted of the 11 side in 11 patients (8 males and 3 females), with a mean age of 25.4 ± 7.2 years. Group B consisted of the 151 side in 90 patients (27 males and 63 females), with a mean age of 24.9 ± 9.2 years. Figure.3 shows the results of Group A. Assessments were carried out at pre-operation, 1, 3, 6, 12 months postoperatively, respectively. NRS was 10.0, 3.36± 2.83, 5.18± 2.60, 6.86± 1.88, 7.14± 1.78. The SW test was 1.85 ± 0.33, 3.31 ± 1.96, 2.86 ± 1.28, 2.15 ± 0.66, 2.02 ± 0.59, respectively. S-2PD test was 8.0 ± 2.13,16.3 ± 5.34, 15.0 ± 5.12, 12.8 ± 4.0, 11.3 ± 2.30, respectively. The NRS showed significant differences at all time points compared to the preoperative period ( p< .05). On the other hand, the results of SW tests showed significant differences at 1 month postoperatively ( p< .05), but no significant differences at 3, 6 and 12 months postoperatively ( p= .16, p= .94, p= .99, respectively). Moreover, the results of s-2PD tests showed significant differences at 1, 3 and 6 months postoperatively ( p< .05), but no significant differences at 12 months postoperatively ( p= .22). The results of NRS, SW and s-2PD compared with those of Group A and Group B was shown in Figure.4. In all assessment time points, Comparison between Group A and Group B showed significant differences at 1, 3, 6, and 12 months ( p< .05). Discussion NSD is one of the most uncomfortable postoperative complications of SSO for patients. This is mainly caused by direct or indirect intraoperative damage to the IAN.[4] Hypoesthesia of the lower lip and chin area is reported to occur temporary for up to 12 months after surgery in most cases, on the other hand, some cases are reported to occur residual permanent hypoesthesia with a frequency of 1-48%.[2, 7, 8] Several previous studies have evaluated the perception of the lower lip and chin area following SSO.[10–12] Various kind of sensory test after SSO were carried out so far. Both objective and subjective tests are available for perceptual evaluation. For example, SW test, s-2PD test, light touch sensation test, thermal stimulation test, vibratory sensitivity test were typical inspections which are objective tests. Authors used the SW test and s-2PD test as objective assessment methods. SW test is a reliable, inexpensive, and easy-to- apply tool, which can be used for clinical evaluation.[9] Several papers noted that the tests that present satisfactory evidence for the intention of sensitive evaluation are the tests carried out with standardized monofilaments that increase gradually in thickness, like SW test. The reason why SW test is very useful and trustworthy method to evaluate sensory disturbances at the mental nerve are after SSO, authors this evaluation method. With regard to subjective tests, NSD was evaluated using NRS and visual analog scale (VAS) by questioning the patient about altered sensation in the lower lip in the previous reports.[11] Although, a lot of studies reported the qualitative evaluations of sensory disturbance or partial observation of tactile and pressure sensation,[13] subjective symptoms and sense are often difficult to evaluate quantitatively. Assessment methods, such as NRS and VAS are very meaningful for pre- and post-operative sensory assessment because these are quantified. In the present study, postoperative time points of evaluation of sensory disturbance were carried out pre-operation, 1, 3, 6, 12 months postoperatively, respectively with reference to the study by Kajita et al.[14, 15] From the results of figure.1, objective evaluation suggested that the patient's perception had improved to a level close to the preoperative level at 12 months postoperatively. On the other hand, subjective evaluation indicated that the patient`s perception improved over time, but their symptoms were fixed at a level that deviated from that of the preoperative level. These findings suggest that detailed perceptual assessment is difficult using objective examination alone. Surgeons should understand that this difference between subjective and objective assessment makes it difficult to assess the sensory impact of nerve damage on the patient postoperatively. The present case of nerve transection is classified as neurotmesis in the Seddon classification, which is a severe grade for mechanical nerve injury.[16, 17] Nerve repair with sutures was performed in all cases, and it is thought that a certain degree of sensory recovery could be achieved. From the results of Figure.2, the significant differences in both objective and subjective evaluations suggest that the nerve transection has a significant effect on the postoperative dysesthesia of the lower lip and mentum area, and that there is a limit to the degree of improvement in the perception compared to the non-neurotmesis group. However, there was a statistically significant difference between Group A and Group B at all assessment time points. These results clearly shows that nerve suture allows sensory recovery, while the sensory loss due to nerve transection is irreversible. Several papers have been published describing measures to prevent nerve transection. For example, Verweij et al.[18] showed that a small mandibular body height significantly increased the risk of hypoesthesia. Furthermore, Kuroyanagi et al.[19] found a significantly increased risk of NSD in patients with a smaller lingula-mandibular notch length and scant surgical space on the medial side of the mandibular ramus. Also, some paper noted that older age was a significant risk factor for permanent hypoesthesia.[20, 21] These reports were focused on the presence or absence of NSD after SSO. In contrast, the present study is focused on the intraoperative item, which means the direct damage of nerve or not influence the long -term neurosensory disturbance. A longitudinal evaluation was carried out in cases with sensory abnormalities, with and without nerve transection. To our knowledge, no previous paper has compared the presence or absence of nerve transection, which makes this paper unique. Moreover, this paper is valuable because nerve transection is incidental and evaluating postoperative perception may reaffirm the importance of nerve preservation and may be useful in explaining this to patients。 One limitation of this study is potential bias due to dependence on the surgeon's technique. There have been no previous reports on hypoesthesia caused by nerve transection and there are no comparisons, so more cases need to be collected in the future. Another limitation is that nerve sutures were used in all cases, but in recent years, the development of treatment methods for nerve damage has become more active, and there are repair methods using materials such as PGA-collagen tube,[22] so it was considered necessary to investigate treatment methods in the future. The third limitation of this study include its retrospective design, a small sample size, and insufficient analysis of confounding factors. It's considered necessary to accumulate more cases and increase the number of evaluation items to investigate long-term sensory changes in the future. In conclusion, this study's data clearly indicated that objective indicators recovered close to pre-operative levels; however, subjective assessments maintained a significant residual difference. It is important not to damage the IAN intraoperatively. However, even if the nerve is damaged, it is possible to approach the preoperative state by performing as much treatment as possible, such as nerve suture. Further long-term evaluation of cases of IANT during SSO is needed in the future. Conclusion Complete IANT during SSO, even with immediate nerve repair, leads to a profound and likely permanent neurosensory deficit. While patients with an intact nerve can expect sensory recovery to baseline levels within a year, patients with a transected nerve experience only limited improvement and remain subjectively and objectively impaired. These findings underscore that the utmost care must be taken to preserve the integrity of the IAN during SSO, as the consequences of transection are severe and largely irreversible. Declarations Ethics approval This retrospective study followed the Declaration of Helsinki for medical protocol and ethics, and received approval from the regional Ethical Review Board of Tohoku University No. 2017-03-015). Consent to participate Each subject participated voluntarily in each examination after signing an informed consent. Competing interests The authors declare no competing interests. Authors’ contributions Tomonari Kajita. was the primary researcher for this study. Shinnosuke Nogami, Kensuke Yamauchi. performed the surgical procedures. Tomonari Kajita, Shinnosuke Nogami, Hikari Suzuki, Mai Yazaki and Yuki Sugai. performed the Data collection procedure and analysis. Tomonari Kajita, Shinnosuke Nogami., and performed a literature review and revisions of the manuscript. All authors read and approved the final version submitted for publication. Data and/or code availability The datasets generated and/or analyzed during the current study are not publicly available due to includes personal patient information but are available from the corresponding author on reasonable request. Funding The authors declare that no funds, grants, or other support were received during the preparation of this manuscript References Trauner R, Obwegeser H (1957) The surgical correction of mandibular prognathism and retrognathia with consideration of genioplasty. Oral Surgery. Oral Med Oral Pathol 10:677–689. https://doi.org/10.1016/s0030-4220(57)80063-2 Colella G, Cannavale R, Vicidomini A, Lanza A (2007) Neurosensory Disturbance of the Inferior Alveolar Nerve After Bilateral Sagittal Split Osteotomy: A Systematic Review. J Oral Maxillofac Surg 65:1707–1715. https://doi.org/10.1016/j.joms.2007.05.009 Teerijoki-Oksa T, Jääskeläinen SK, Forssell K, Forssell H (2004) Recovery of nerve injury after mandibular sagittal split osteotomy. Diagnostic value of clinical and electrophysiologic tests in the follow-up. 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Gynecol Oncol Rep 41:100977. https://doi.org/10.1016/j.gore.2022.100977 Tables Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table.1.jpg Table. 1 Number of patients with neurosensory disturbance following bilateral sagittal split osteotomy (Group A) or without neurosensory disturbance following bilateral sagittal split osteotomy (Group B). Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 25 Sep, 2025 Reviewers agreed at journal 22 Sep, 2025 Reviewers invited by journal 17 Sep, 2025 Editor assigned by journal 03 Sep, 2025 Submission checks completed at journal 03 Sep, 2025 First submitted to journal 03 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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16:09:24","extension":"html","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":73570,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/3daa6aa962a2bd14a2ce530f.html"},{"id":92280802,"identity":"3546baf4-5948-4331-9e0b-44e85e634e4d","added_by":"auto","created_at":"2025-09-26 16:17:24","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":102493,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative images of intraoperative photograph.\u003c/p\u003e\n\u003cp\u003eA, Cross-section of a severed nerve. B, suture of a severed nerve. Arrowheads\u003c/p\u003e\n\u003cp\u003eindicate the suture site.\u003c/p\u003e\n\u003cp\u003eC, The fragment were stabilized utilizing a 6-hole titanium miniplate and screw.\u003c/p\u003e\n\u003cp\u003eD, Panoramic x-ray image.\u003c/p\u003e","description":"","filename":"Figure.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/f7a09d0b2804314337765d59.jpg"},{"id":92280804,"identity":"db5a1902-9970-4096-9f7d-7c5ae73c3206","added_by":"auto","created_at":"2025-09-26 16:17:24","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":34028,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative images of SW test (A) and s-2PD test (B).\u003c/p\u003e","description":"","filename":"Figure.2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/8324b80acec829796c68e4b0.jpg"},{"id":92280803,"identity":"e7011889-1451-4480-8605-3298d691838c","added_by":"auto","created_at":"2025-09-26 16:17:24","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":87107,"visible":true,"origin":"","legend":"\u003cp\u003ePerceptual changes in patients with neurotmesis of IAN (Group A).\u003c/p\u003e\n\u003cp\u003e(A) NRS, (B) SW test, (C) s-2PD test.\u003c/p\u003e","description":"","filename":"Figure.3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/6600bdedc14a26c70f3f9bd8.jpg"},{"id":92280293,"identity":"a7eab643-25dd-4165-ac9f-c312efd0bade","added_by":"auto","created_at":"2025-09-26 16:09:24","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":84976,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of perceptual changes between neurotmesis of IAN cases (Group A) and non-neurotmesis of IAN cases (Group B). (A) NRS, (B) SW test, (C) s-2PD test.\u003c/p\u003e","description":"","filename":"Figure.4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/9c8361aa73cc2ebb36850597.jpg"},{"id":92281453,"identity":"1df28fa2-2cf5-4462-8e29-9c8a1900ff45","added_by":"auto","created_at":"2025-09-26 16:33:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":741765,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/6b27cafa-6a02-4c72-b51a-b2679b31b5c1.pdf"},{"id":92280288,"identity":"fec97811-e9a9-4b28-bf5f-fb9cdbf02f52","added_by":"auto","created_at":"2025-09-26 16:09:24","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":36269,"visible":true,"origin":"","legend":"\u003cp\u003eTable. 1 Number of patients with neurosensory disturbance following bilateral sagittal split osteotomy (Group A) or without neurosensory disturbance following bilateral sagittal split osteotomy (Group B).\u003c/p\u003e","description":"","filename":"Table.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7526389/v1/c9512365b479e0da2b7ec4a1.jpg"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy.","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBilateral sagittal split osteotomy (SSO), first introduced by Trauner and Obwegeser, is one of the most frequently performed orthognathic procedures for the correction of mandibular deformity.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] While SSO is an established and effective surgical method for treating mandibular hypo- and hyperplasia, it is associated with several potential complications, including bleeding, swelling, and pain. Among these, neurosensory disturbance (NSD) of the inferior alveolar nerve (IAN), which results in hypoesthesia of the lower lip and chin, is a major concern.\u003c/p\u003e\u003cp\u003eThe reported incidence of NSD following SSO varies widely, from 9\u0026ndash;85%. A systematic review by Colella et al. revealed that neurosensory impairment was detected in 63.3% of patients with objective tests and 83% with subjective tests at 7 days postoperatively.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] Numerous factors are known to influence the risk of NSD, including patient age,[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] the magnitude of mandibular movement, the degree of nerve manipulation, and the surgeon's experience.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] Furthermore, specific anatomical features, such as the transversal width of the mandible,[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] the lateral course of the mandibular canal,[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] and female gender,[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] have been identified as significant risk factors.\u003c/p\u003e\u003cp\u003eWhile sensory impairment after SSO is often temporary, with recovery typically occurring within 6 to 12 months, persistent NSD beyond one year is considered permanent.[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] Although many studies have investigated risk factors for NSD, a critical gap exists in the literature regarding the long-term prognosis following a complete inferior alveolar nerve transection (IANT) during SSO. To the best of our knowledge, no studies have longitudinally compared the sensory recovery trajectory between patients with intraoperative IANT and those without.\u003c/p\u003e\u003cp\u003eTherefore, the objective of this study was to investigate the postoperative recovery of sensory perception in patients who experienced IANT during SSO. Additionally, we aimed to compare their perceptual changes with those of a cohort who also experienced postoperative NSD but without intraoperative nerve transection.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e\u003ch2\u003e2.1. Study Design and Patient Selection\u003c/h2\u003e\u003cp\u003e This retrospective cohort study was approved by the Ethical Review Board of Tohoku University (No. 2017-03-015) and followed the Declaration of Helsinki. We reviewed the records of all patients who underwent SSO, either alone or combined with Le Fort I osteotomy, at our institution between January 2016 and December 2022.\u003c/p\u003e\u003cp\u003eInclusion criteria were patients with postoperative hypoesthesia in the lower lip and chin region at one-month follow-up and at least one year of postoperative follow-up data. Patients were divided into two groups based on intraoperative findings: Group A (patients with documented complete or partial IANT) and Group B (patients without IANT but with postoperative NSD).\u003c/p\u003e\u003cp\u003eExclusion criteria included patients who underwent concomitant procedures that could influence NSD (e.g., intraoral inverted L ramus osteotomy, genioplasty), those with no complaints of hypoesthesia at 1 month postoperatively, and those with incomplete data.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.2. Surgical Procedure\u003c/h2\u003e\u003cp\u003eAll operations were performed under general anesthesia. The surgical technique was a modification of the Trauner-Obwegeser method as described by Hunsuck and Dal Pont.\u0026sup1;\u0026sup1; A mucoperiosteal flap was raised to expose the ramus and body of the mandible. After protecting the neurovascular bundle, osteotomies were performed. The fragments were separated, and the distal segment was positioned using an occlusal splint. Fixation was achieved using 6-hole titanium miniplates and monocortical screws (Stryker, Freiburg, Germany)(Figure.1). Intermaxillary fixation was maintained for approximately 5 days.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.3. Management of Nerve Transection\u003c/h2\u003e\u003cp\u003eIn cases of IANT, nerve repair was performed by an experienced oral and maxillofacial surgeon using 6\u0026thinsp;\u0026minus;\u0026thinsp;0 nylon sutures.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.4. Neurosensory Evaluation\u003c/h2\u003e\u003cp\u003eSubjective and objective neurosensory evaluations were performed preoperatively and at 1, 3, 6, and 12 months postoperatively (Figure.2).\u003c/p\u003e\u003cp\u003eSubjective Evaluation: The Numerical Rating Scale (NRS) was used, where patients rated their sensation from 0 (complete anesthesia) to 10 (normal sensation).\u003c/p\u003e\u003cp\u003eObjective Evaluation: Two tests were performed:\u003c/p\u003e\u003cp\u003eSemmes-Weinstein (SW) monofilament test: Assessed light touch threshold.\u003c/p\u003e\u003cp\u003eStatic two-point discrimination (s-2PD) test: Measured spatial acuity using blunt-tipped calipers.\u003c/p\u003e\u003cp\u003eAll evaluations were conducted by trained examiners following a standardized protocol.\u0026sup1;\u0026sup2; All patients with hypoesthesia were prescribed mecobalamin (1,500 mg/day).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.5. Data Analysis\u003c/h2\u003e\u003cp\u003eDunnett's test was used to compare postoperative measurements with preoperative baseline values within each group. The Mann-Whitney U test was used to compare the outcomes between Group A and Group B at each time point. All statistical analyses were performed using JMP version 17 (SAS Institute Inc, Cary, NC). A p-value less than 0.05 was considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe study sample was initially composed of patients who underwent SSO alone or combined with Le Fort I osteotomy between January 2016 and December 2022. Of these, patients who underwent intraoral inverted L ramus and sagittal splitting ramus osteotomy (ILRO) or genioplasty, which can influence postoperative NSD and patients with\u0026nbsp;incomplete data were excluded. Furthermore, patients with no complaints of hypoesthesia at 1 month after the operation were excluded. Therefore, the final study subjects were consecutive patients with hypoesthesia in the lips and cheeks (35 males and 66 females). The results of sample date were shown in Table.1. Group A consisted of the 11 side in 11 patients (8 males and 3 females), with a mean age of 25.4 \u0026plusmn; 7.2 years. Group B consisted of the 151 side in 90 patients (27 males and 63 females), with a mean age of 24.9 \u0026plusmn; 9.2 years. Figure.3 shows the results of Group A. Assessments were carried out at pre-operation, 1, 3, 6, 12 months postoperatively, respectively. NRS was 10.0, 3.36\u0026plusmn; 2.83, 5.18\u0026plusmn; 2.60, 6.86\u0026plusmn; 1.88, 7.14\u0026plusmn; 1.78. The SW test was 1.85 \u0026plusmn; 0.33, 3.31 \u0026plusmn; 1.96, 2.86 \u0026plusmn; 1.28, 2.15 \u0026plusmn; 0.66, 2.02 \u0026plusmn; 0.59, respectively. S-2PD test was 8.0 \u0026plusmn; 2.13,16.3 \u0026plusmn; 5.34, 15.0 \u0026plusmn; 5.12, 12.8 \u0026plusmn; 4.0, 11.3 \u0026plusmn; 2.30, respectively. The NRS showed significant differences at all time points compared to the preoperative period (\u003cem\u003ep\u0026lt;\u003c/em\u003e .05). On the other hand, the results of SW tests showed significant differences at 1 month postoperatively (\u003cem\u003ep\u0026lt;\u0026nbsp;\u003c/em\u003e.05), but no significant differences at 3, 6 and 12 months postoperatively (\u003cem\u003ep=\u003c/em\u003e.16, \u003cem\u003ep=\u003c/em\u003e.94, \u003cem\u003ep=\u003c/em\u003e.99, respectively). Moreover, the results of s-2PD tests showed significant differences at 1, 3 and 6 months postoperatively (\u003cem\u003ep\u0026lt;\u003c/em\u003e .05), but no significant differences at 12 months postoperatively (\u003cem\u003ep=\u0026nbsp;\u003c/em\u003e.22).\u003c/p\u003e\n\u003cp\u003eThe results of NRS, SW and s-2PD compared with those of Group A and Group B was shown in Figure.4. In all assessment time points, Comparison between Group A and Group B showed significant differences at 1, 3, 6, and 12 months (\u003cem\u003ep\u0026lt;\u0026nbsp;\u003c/em\u003e.05).\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eNSD is one of the most uncomfortable postoperative complications of SSO for patients. This is mainly caused\u0026nbsp;by direct or indirect intraoperative damage to the IAN.[4]\u0026nbsp;Hypoesthesia of the lower lip and chin area is reported to occur temporary for up to 12 months after surgery in most cases, on the other hand, some cases are reported to occur residual permanent hypoesthesia with a frequency of 1-48%.[2, 7, 8]\u0026nbsp;Several previous studies have evaluated the perception of the lower lip and chin area following SSO.[10\u0026ndash;12]\u0026nbsp;Various kind of sensory test after SSO were carried out so far. Both objective and subjective tests are available for perceptual evaluation.\u0026nbsp;For example, SW test, s-2PD test,\u0026nbsp;light touch sensation test, thermal stimulation test, vibratory sensitivity test\u0026nbsp;were typical inspections which are objective tests. Authors used the SW test and s-2PD test as objective assessment methods. SW test is a reliable, inexpensive, and easy-to- apply tool, which can be used for clinical evaluation.[9] Several papers noted that the tests that present satisfactory evidence for the intention of sensitive evaluation are the tests carried out with standardized monofilaments that increase gradually in thickness, like SW test. The reason why SW test is very useful and trustworthy method to evaluate sensory disturbances at the mental nerve are after SSO, authors this evaluation method.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;With regard to subjective tests, NSD was evaluated using NRS and visual analog scale (VAS) by questioning the patient about altered sensation in the lower lip in the previous reports.[11]\u0026nbsp;Although,\u0026nbsp;a lot of studies reported the qualitative evaluations of sensory disturbance or partial observation of tactile and pressure sensation,[13]\u0026nbsp;subjective symptoms and sense are often difficult to evaluate quantitatively. Assessment methods, such as NRS and VAS are very meaningful for pre- and post-operative sensory assessment because these are quantified. In the present study, postoperative time points of evaluation of sensory disturbance were carried out\u0026nbsp;pre-operation, 1, 3, 6, 12 months postoperatively, respectively\u0026nbsp;with reference to the study by Kajita et al.[14, 15]\u003c/p\u003e\n\u003cp\u003eFrom the results of figure.1, objective evaluation suggested that the patient\u0026apos;s perception had improved to a level close to the preoperative level at 12 months postoperatively. \u0026nbsp;On the other hand, subjective evaluation indicated that the patient`s perception improved over time, but their symptoms were fixed at a level that deviated from that of the preoperative level. These findings suggest that detailed perceptual assessment is difficult using objective examination alone. Surgeons should understand that this difference between subjective and objective assessment makes it difficult to assess the sensory impact of nerve damage on the patient postoperatively. The present case of nerve transection is classified as neurotmesis in the Seddon classification, which is a severe grade for mechanical nerve injury.[16, 17] Nerve repair with sutures was performed in all cases, and it is thought that a certain degree of sensory recovery could be achieved.\u003c/p\u003e\n\u003cp\u003eFrom the results of Figure.2, the significant differences in both objective and subjective evaluations suggest that the nerve transection has a significant effect on the postoperative dysesthesia of the lower lip and mentum area, and that there is a limit to the degree of improvement in the perception compared to the non-neurotmesis group. However, there was a statistically significant difference between Group A and Group B at all assessment time points. These results clearly shows that nerve suture allows sensory recovery, while the sensory loss due to nerve transection is irreversible.\u003c/p\u003e\n\u003cp\u003eSeveral papers have been published describing measures to prevent nerve transection.\u0026nbsp;For example, Verweij et al.[18] showed that a small mandibular body height significantly increased the risk of hypoesthesia. Furthermore, Kuroyanagi et al.[19] found a significantly increased risk of NSD in patients with a smaller lingula-mandibular notch length and scant surgical space on the medial side of the mandibular ramus.\u0026nbsp;Also, some paper noted that older age was a significant risk factor for permanent hypoesthesia.[20, 21] These reports were focused on the presence or absence of NSD after SSO. In contrast, the present study is focused on the intraoperative item, which means the direct damage of nerve or not influence the long -term\u0026nbsp;neurosensory disturbance.\u0026nbsp;A longitudinal evaluation was carried out in cases with sensory abnormalities, with and without nerve transection. To our knowledge, no previous paper has compared the presence or absence of nerve transection, which makes this paper unique. Moreover, this paper is valuable because nerve transection is incidental and evaluating postoperative perception may reaffirm the importance of nerve preservation and may be useful in explaining this to patients。\u003c/p\u003e\n\u003cp\u003eOne limitation of this study is potential bias due to dependence on the surgeon\u0026apos;s technique.\u0026nbsp;There have been no previous reports on hypoesthesia caused by nerve transection and there are no comparisons, so more cases need to be collected in the future. Another limitation is that nerve sutures were used in all cases, but in recent years, the development of treatment methods for nerve damage has become more active, and there are repair methods using materials such as PGA-collagen tube,[22] so it was considered necessary to investigate treatment methods in the future. The third limitation of this study include its retrospective design, a small sample size, and insufficient analysis of confounding factors. It\u0026apos;s considered necessary to accumulate more cases and increase the number of evaluation items to investigate long-term sensory changes in the future.\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study\u0026apos;s data clearly indicated that objective indicators recovered close to pre-operative levels; however, subjective assessments maintained a significant residual difference. It is important not to damage the IAN intraoperatively. However, even if the nerve is damaged, it is possible to approach the preoperative state by performing as much treatment as possible, such as nerve suture. Further long-term evaluation of cases of IANT during SSO is needed in the future.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eComplete IANT during SSO, even with immediate nerve repair, leads to a profound and likely permanent neurosensory deficit. While patients with an intact nerve can expect sensory recovery to baseline levels within a year, patients with a transected nerve experience only limited improvement and remain subjectively and objectively impaired. These findings underscore that the utmost care must be taken to preserve the integrity of the IAN during SSO, as the consequences of transection are severe and largely irreversible.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval\u003c/p\u003e\n\u003cp\u003eThis retrospective study followed the Declaration of Helsinki for medical protocol and ethics, and received approval from the regional Ethical Review Board of Tohoku University\u0026nbsp;No. 2017-03-015).\u003c/p\u003e\n\u003cp\u003eConsent to participate\u003c/p\u003e\n\u003cp\u003eEach subject participated voluntarily in each examination after signing an informed consent.\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026rsquo; contributions\u003c/p\u003e\n\u003cp\u003eTomonari Kajita. was the primary researcher for this study. Shinnosuke Nogami, Kensuke Yamauchi. performed the surgical procedures. Tomonari Kajita, Shinnosuke Nogami, Hikari Suzuki, Mai Yazaki and Yuki Sugai. performed the Data collection procedure and analysis. Tomonari Kajita, Shinnosuke Nogami., and performed a literature review and revisions of the manuscript. All authors read and approved the final version submitted for publication.\u003c/p\u003e\n\u003cp\u003eData and/or code availability\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are not publicly available due to includes personal patient information but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eTrauner R, Obwegeser H (1957) The surgical correction of mandibular prognathism and retrognathia with consideration of genioplasty. Oral Surgery. 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J Hand Surg Am 39:1216\u0026ndash;1222\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeddon HJ (1942) A Classification of Nerve Injuries. BMJ 2:237\u0026ndash;239. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/bmj.2.4260.237\u003c/span\u003e\u003cspan address=\"10.1136/bmj.2.4260.237\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeddon HJ (1943) Three types of nerve injury. Brain 66:237\u0026ndash;288. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/brain/66.4.237\u003c/span\u003e\u003cspan address=\"10.1093/brain/66.4.237\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVerweij JP, Mensink G, Fiocco M, Van Merkesteyn JPR (2015) Morphological features of the mandible as predictors for neurosensory disturbances after bilateral sagittal split osteotomy. J Cranio-Maxillofacial Surg 43:1710\u0026ndash;1715. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jcms.2015.07.013\u003c/span\u003e\u003cspan address=\"10.1016/j.jcms.2015.07.013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKuroyanagi N, Miyachi H, Ochiai S et al (2013) Prediction of neurosensory alterations after sagittal split ramus osteotomy. Int J Oral Maxillofac Surg 42:814\u0026ndash;822. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijom.2012.11.016\u003c/span\u003e\u003cspan address=\"10.1016/j.ijom.2012.11.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVerweij JP, Mensink G, Fiocco M, Van Merkesteyn JPR (2016) Incidence and recovery of neurosensory disturbances after bilateral sagittal split osteotomy in different age groups: A retrospective study of 263 patients. Int J Oral Maxillofac Surg 45:898\u0026ndash;903. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijom.2016.01.011\u003c/span\u003e\u003cspan address=\"10.1016/j.ijom.2016.01.011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUpton LG, Rajvanakarn M, Hayward JR (1997) Evaluation of the Regenerative Capacity of the Inferior Alveolar Nerve Following Surgical Trauma. J Oral Maxillofac Surg 45:212\u0026ndash;216\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIwao A, Yagi M, Imamura Y et al (2022) Intraoperative obturator nerve injury reconstructed using a PGA-collagen tube: Three case reports. Gynecol Oncol Rep 41:100977. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.gore.2022.100977\u003c/span\u003e\u003cspan address=\"10.1016/j.gore.2022.100977\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"oral-and-maxillofacial-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"omfs","sideBox":"Learn more about [Oral and Maxillofacial Surgery](http://link.springer.com/journal/10006)","snPcode":"10006","submissionUrl":"https://submission.nature.com/new-submission/10006/3","title":"Oral and Maxillofacial Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"inferior alveolar nerve transection, sagittal split osteotomy, neurosensory disturbance, jaw deformity, sagittal split osteotomy","lastPublishedDoi":"10.21203/rs.3.rs-7526389/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7526389/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e: Inferior alveolar nerve transection (IANT) is a severe complication of sagittal split osteotomy (SSO). This study aimed to retrospectively evaluate the long-term sensory recovery in patients who experienced intraoperative IANT compared to those who did not.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and methods\u003c/strong\u003e: This retrospective cohort study reviewed patients who underwent SSO from 2016 to 2022. Patients were divided into Group A (with IANT, 11 sides) and Group B (without IANT, 151 sides). Sensory perception was assessed using the Semmes-Weinstein (SW) test, static two-point discrimination (s-2PD) test, and a Numerical Rating Scale (NRS) at preoperative baseline and at 1, 3, 6, and 12 months postoperatively. Mann-Whitney U and Dunnett's tests were used for statistical analysis (p \u0026lt; 0.05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: Group A demonstrated significantly worse sensory outcomes than Group B on all tests at all postoperative time points (p \u0026lt; 0.01). In Group B, SW and s-2PD values were significantly worse than baseline at 1 and 3 months but showed no significant difference at 6 and 12 months. In contrast, Group A outcomes remained significantly impaired compared to their own preoperative baseline throughout the 12-month follow-up.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e: Complete IANT during SSO results in a profound and likely permanent neurosensory deficit. While patients without nerve transection typically recover baseline sensory perception by 6 months, those with IANT experience only minimal improvement and remain significantly impaired at a year post-surgery.\u003c/p\u003e","manuscriptTitle":"Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-26 16:09:19","doi":"10.21203/rs.3.rs-7526389/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-09-25T13:38:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"268961755357624358100781630401610197545","date":"2025-09-22T09:43:14+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-17T17:42:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-04T01:17:55+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-04T01:17:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"Oral and Maxillofacial Surgery","date":"2025-09-03T11:07:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"oral-and-maxillofacial-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"omfs","sideBox":"Learn more about [Oral and Maxillofacial Surgery](http://link.springer.com/journal/10006)","snPcode":"10006","submissionUrl":"https://submission.nature.com/new-submission/10006/3","title":"Oral and Maxillofacial Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"58ac707c-a2e2-4fd7-9379-9fa123ac8d85","owner":[],"postedDate":"September 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-09-26T16:09:19+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-26 16:09:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7526389","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7526389","identity":"rs-7526389","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}