Clinical study of double occlusal splints combined with manual reduction for the treatment of anterior disc displacement without reduction: a retrospective study

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This study aimed to compare the therapeutic efficacy of modified double occlusal splints with traditional anterior repositioning splints (ARS) in treating ADDWoR, to identify a simple, effective, and stable clinical approach. Materials and Methods: A total of 107 patients were enrolled in this single-center retrospective study. Those using double occlusal splints after successful manual reduction were assigned to observation groups (A, B). Clinical indicators included pain visual analogue score (VAS), maximum mouth opening (MMO), craniomandibular index (CMI), dysfunction index (DI), palpation index (PI), and overall efficacy. Results: At one month post-treatment, groups A and B showed significant improvements in VAS, MMO, CMI, and DI compared to control groups C and D ( P < 0.05). At three and six months, group A had significantly lower CMI and DI than group C, with no significant VAS or MMO difference. Group B showed greater improvement than group D across all parameters ( P < 0.05). Magnetic resonance imaging (MRI) confirmed higher disc reduction rates in the observation groups. Clinical efficacy was 89.3% in experimental groups versus 74.5% in control groups (c 2 = 3.990, P < 0.05). Conclusion: Double occlusal splints demonstrated superior stabilization following early manual repositioning and improved structural outcomes compared to ARS. These findings support their clinical value as a treatment option for ADDWoR. Clinical Relevance: This study demonstrates that modified double occlusal splints provide more effective and stable outcomes than traditional anterior repositioning splints, particularly after early manual disc repositioning. The findings offer clinicians a simplified, non-invasive treatment strategy that enhances long-term joint stabilization and functional recovery in ADDWoR patients. Anterior disc displacement without reduction Anterior repositioning splint Double occlusal splints Manual reduction Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Temporomandibular joint disorder (TMD affects both the masticatory muscles and the structure of the joint and can exert significant impact on a patient’s quality-of-life [ 1 ] . One common structural disorder of TMD is anterior disc displacement without reduction (ADDWoR), which has a reported prevalence ranging from 2–8% across various TMD illnesses [ 2 ] . ADDWoR typically develops from anterior disc displacement of the temporomandibular joint with reduction (ADDWR), which is categorized into acute and chronic stages based on whether the duration exceeds four months [ 3 ] . Despite a variety of treatment options, there is still no consensus on the management of ADDWoR. There are differing opinions as to whether we should combine different therapeutic approaches and the optimal sequence of performing various treatments [ 4 – 6 ] . Although some researchers have proposed that manual reduction combined with an anterior repositioning splint (ARS) could effectively move the condyle forwards to prevent the articular disc from shifting forwards again during the mouth closing process [ 7 , 8 ] . However, throughout clinical diagnosis and treatment, we have found that for some patients with chronic phase and acute ADDWoR with a slightly longer course, the articular disc structure will reoccur in a short period of time following manual reduction. Moreover, some patients complained that the joints became “stuck” again when they awoke in the morning. Currently, there is a lack of sufficient research on how we night reduce the occurrence of such phenomena. Another consideration is that due to the long production cycle and poor stabilization effect of traditional ARS, this strategy might even cause the lower anterior teeth to become loose and dislocated due to excessive lateral occlusal force [ 9 ] . Therefore, in the present study, we modified the traditional ARS into double occlusal splints featuring a daytime-ARS (DARS) and a nighttime-ARS (NARS). ADDWoR was treated by direct manual reduction or by manual reduction after lavage of the joint cavity and the use of a repositioning splint. We then compared the efficacy of manual reduction combined with traditional ARS and double occlusal splints for the treatment of patients with anterior disc displacement without reduction. Material and methods Ethics approval This study was approved by the Ethics Committee of the Affiliated Stomatological Hospital of Nanchang University (Reference: 2022019). All participants provided signed and informed electronic consent in accordance with the principles of the Declaration of Helsinki. All methods were performed in accordance with the relevant regulations and guidelines of the Declaration of Helsinki. Patient Recruitment We enrolled patients diagnosed with ADDWoR according to the diagnostic criteria of Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) [ 10 ] in the Affiliated Stomatological Hospital of Nanchang University between January 2022 and December 2023. Patients who wore double occlusal splints after successful manual reduction were selected as the observation groups (patients who were successfully reduced by direct manipulation and wore double occlusal splints were classified into group A; those who were successfully reduced by manipulation and wore double occlusal splints after supra-articular lavage injection were classified into group B). Patients who wore a traditional ARS were enrolled as the control groups (group C and group D were classified by the same method as for groups A and B). The specific inclusion criteria were as follows: (1) diagnosis of ADDWoR based on the DC/TMD; (2) maximum mouth opening (MMO) < 37mm, and (3) successful manual reduction directly or after arthrocentesis. The exclusion criteria were as follows: (1) osteoarthropathy; (2) acute joint trauma; (3) severe psychiatric and psychological disorders; (4) uncontrolled periodontal disease; and (5) serious systemic diseases. Treatment and outcome evaluation Double occlusal splints incorporated a daytime-ARS (Fig. 1 A) and a Nighttime-ARS (Fig. 1 B). The production process for NARS is shown in Figure S1 A-B. The processes utilized for arthrocentesis and manual reduction are shown in Figure S2 and S3. Mouth opening increased significantly immediately (Fig. 2 A-B). Magnetic resonance imaging (MRI) revealed that the disc-condylar relationship was normal in the opening position (Fig. 3 A-B). The measurement indices included pain visual analogue score (VAS), MMO, craniomandibular index (CMI) [ 11 ] , dysfunction index (DI), palpation index (PI) and clinical efficacy. An effective treatment would reduce local pain, tenderness and joint clicking to varying degrees, and improve the degree of mouth opening when compared to that prior to treatment. If these changes did not occur, then the treatment was considered invalid. MRI images were recorded before and after treatment in order to investigate the relative positions between the articular disc and condyle in both the open and closed positions [ 12 ] . Statistical analysis Data were statistically analyzed using IBM SPSS Statistics version 26.0 software (IBM Corp, Armonk, NY, USA). The Shapiro-Wilk test method was used to detect whether the data were normally distributed. The Levene test was used to detect whether the variance was homogenous. Comparisons of VAS, MMO and CMI (including DI and PI) between groups was conducted using the Mann-Whitney U test (data that conformed to a normal distribution) or the independent sample t test (data that did not conform to a normal distribution). If the data were normally distributed and had uniform variances, then repeated measures analysis of variance (ANOVA) was used to compare the changes of VAS, MMO and CMI (including DI and PI) at multiple time points before and after treatment; otherwise, the Wilcoxon test was used. Inter-group comparisons were conducted using the χ 2 test to evaluate treatment efficacy, the effective MRI joint disc reduction rate and the incidence of disc re-displacement. The significance level was set at P < 0.05. Results Patient Clinical Characteristics As shown in Table 1, 107 ADDWoR patients with 124 joints were included in the study, with a male to female ratio of approximately 1:4. There were no significant differences between the observation groups (group A and B) and the control groups (groups C and D) in terms of gender ratio, mean age, and the number of affected joints ( P > 0.05). Furthermore, there were no significant differences between the two groups in terms of the baseline levels of VAS, MMO and CMI prior to treatment ( P > 0.05). However, the mean treatment course for group B patients (1.95 ± 1.83 months) was longer than that of group A (1.09 ± 1.26 months). The mean duration of group D (1.78 ± 1.71 months) was longer than that of group C (1.06 ± 1.39 months) ( P < 0.05). Table 1 Basic information and baseline data for patients in the four groups Group A (n = 29) Group C (n = 25) P Group B (n = 27) Group D (n = 26) P Gender Male 6 5 0.950 7 6 0.810 Female 23 20 20 20 Joints Unilateral 24 21 0.903 23 22 0.954 Bilateral 5 4 4 4 Age (years) 24.12 ± 6.57 24.28 ± 6.58 0.942 25.72 ± 8.85 25.40 ± 11.31 0.864 Duration (month) 1.09 ± 1.26 a 1.06 ± 1.39 b 0.851 1.95 ± 1.83 1.78 ± 1.71 0.733 VAS 31.32 ± 14.71 30.04 ± 17.61 0.782 36.28 ± 14.85 37.92 ± 15.61 0.705 MMO 25.84 ± 6.71 26.24 ± 4.49 0.805 23.60 ± 5.40 24.68 ± 3.40 0.402 CMI 0.29 ± 0.07 0.27 ± 0.06 0.251 0.25 ± 0.07 0.29 ± 0.08 0.099 a group A compared with group B, P < 0.05; b group C compared with group D, P < 0.05. Abbreviations: VAS, visual analogue score; MMO, maximum mouth opening; CMI, craniomandibular index. VAS score assessment As shown in Figure 4, VAS was significantly lower at one-, three- and six- months after treatment; this was the case in all four groups ( P < 0.01). One month after treatment, the VAS of group A was lower than that of group C ( P < 0.05), but there was no significant difference between the two groups when tested three- and six-months after treatment. The VAS for group B was lower than that of group D at one-, three- and six-months after treatment ( P < 0.05). The VAS score of group B (5.08 ± 10.51) was significantly lower than that of group D (14.88 ± 14.79) when tested six-months after treatment ( P < 0.01). MMO outcome assessment As shown in Figure 5, there was no significant difference in the maximal degree of mouth opening when compared between the four groups before treatment. The results demonstrates that the maximal degree of mouth opening in group A was higher than that in group C when tested one-month after treatment ( P < 0.05). However, there was no significant difference in the maximal degree of mouth opening between group A and group C after three- and six-months of treatment. The maximal degree of mouth opening in group B was significantly higher than that in group D when tested one-, three- and six-months after treatment ( P < 0.05). Within one week of repositioning, 13 cases in the control groups reported being 'stuck' again; only three ‘stuck’ cases were recorded in the observation groups during follow-up (Table S1) ( P = 0.01). CMI, DI and PI outcome assessment As shown in Table 2, there were no significant difference in DI, PI and CMI when compared between the observation groups (A, B) and the control groups (C, D) before treatment, although the DI and CMI in the observation groups were significantly lower than those in the control groups at one-, three- and six-months after treatment ( P < 0.05). There was no significant difference in PI between the two groups before and after treatment. Table 2 Comparison between the observation groups and control groups in terms of CMI Group Stage Before treatment 1st month after treatment 3rd month after treatment 6th month after treatment DI Group A 0.44 ± 0.09 0.11 ± 0.06 a 0.06 ± 0.06 b 0.04 ± 0.06 b Group C 0.42 ± 0.08 0.18 ± 0.14 0.14 ± 0.13 0.14 ± 0.12 PI Group A 0.13 ± 0.09 0.03 ± 0.02 0.03 ± 0.04 0.02 ± 0.03 Group C 0.11 ± 0.05 0.04 ± 0.04 0.03 ± 0.04 0.03 ± 0.04 CMI Group A 0.29 ± 0.07 0.07 ± 0.04 a 0.04 ± 0.05 a 0.03 ± 0.04 a Group C 0.27 ± 0.06 0.09 ± 0.07 0.08 ± 0.08 0.08 ± 0.08 DI Group B 0.42 ± 0.06 0.13 ± 0.12 a 0.07 ± 0.10 a 0.07 ± 0.10 a Group D 0.45 ± 0.09 0.23 ± 0.16 0.17 ± 0.17 0.15 ± 0.18 PI Group B 0.13 ± 0.05 0.04 ± 0.06 0.02 ± 0.04 0.02 ± 0.03 Group D 0.13 ± 0.09 0.07 ± 0.08 0.05 ± 0.07 0.05 ± 0.07 CMI Group B 0.26 ± 0.04 0.08 ± 0.08 a 0.05 ± 0.06 a 0.04 ± 0.06 a Group D 0.29 ± 0.08 0.15 ± 0.10 0.11 ± 0.12 0.10 ± 0.12 Superscript symbols indicate significant differences: a P < 0.05 and b P < 0.01. Abbreviations: DI, dysfunction index; PI, palpation index; CMI, craniomandibular index. MRI image analysis In this study, we collated 58 cases with MRI images from three- to six-months after treatment, including 35 cases in the observation groups and 23 cases in the control groups. As shown in Figure 6, we observed three treatment outcomes using MRI images. The first outcome included the restoration of disc displacement without reduction before treatment to the normal disc-condyle relationship, including 20 cases in the observation groups and nine cases in the control groups (Figure 6A and 6D). The second outcome was the conversion from disc displacement without reduction before treatment to the disc displacement with reduction; there were seven cases in the observation groups and three cases in the control groups (Figure 6B and 6E). The third outcome was no change in the disc-condyle relationship before and after treatment; there were eight cases in the observation groups and 11 cases in the control groups. The first two outcomes, as observed on MRI were considered to be effective in structure reduction (Figure 6C and 6F). The efficacy of structure reduction in the observation groups (77.1%) was significantly higher than that in the control groups (52.2%) ( P < 0.05) (Table 3). Table 3. Comparison of MRI results between the observation groups and the control groups after treatment Results total Efficiency of structural reduction P (a) (b) (c) Observation groups (A+B) 20 7 8 35 77.1% 3.928 0.047 Control groups (C+D) 9 3 11 23 52.2% Abbreviations: MRI, magnetic resonance imaging Clinical outcome assessment Table S2 depicts clinical efficacy, 50 cases (89.3%) in the observation groups were effective and 38 cases (74.5%) in the control groups were effective; there was a significant difference in efficacy between these two groups ( P < 0.05). Discussion Our research showed that for some patients with acute ADDWoR, after manual reduction, double occlusal splints following manual reduction improved symptoms more effectively, offering a new clinical strategy to maintain disc-condyle stability. A previous study showed that 95% of ADDWoR symptoms resolve within three months [13] ,but structural restoration is rare, and worsening disc-condyle deformation can increase the risk of joint degeneration [14,15] . Chronic disc displacement alters joint tissue composition, degrading fibers, proteins, and cartilage, which may lead to osteoarthropathy. In adolescents, it may impair condylar growth, causing facial asymmetry and malocclusion [16] . In the present study, all four groups of patients underwent early manual reduction to restore the normal disc-condylar relationship. This intervention improved mouth opening and alleviated joint pain, thus resulting in effective clinical therapeutic effects. A previous study identified a high proportion of patients with articular disc perforation who had ADDWoR [17] , thus highlighting the importance of early intervention for these patients. The efficacy of manual repositioning is influenced by the degree of disc displacement and the stage of development. Research has demonstrated that patients with acute ADDWoR who have suffered from this condition for less than four months generally have TMJ discs with well-preserved morphology, structure, and function [18] . However, as inflammation progresses, cytokines and proteases promote soft tissue degradation [19] , and synovial proliferation reduces fluid quality, increasing joint friction and adhesion risk [20] .In these cases, manipulation faces stronger resistance. Clinicians must overcome muscle resistance with skillful traction. For high-resistance patients, verbal instruction and timing, combined with supra-articular lavage and sodium hyaluronate injection, can improve outcomes. Supra-articular lavage is advantageous in several respects. First, this method helps to loosen small adhesions in the joint cavity, improve the intra-articular environment, removes inflammatory substances and pain factors (such as matrix metalloproteinases13 (MMP-13) and interleukin-6 (IL-6)) [21] , restore normal intra-articular pressure, and reduce the exudation of inflammatory fluid. Secondly, supra-articular lavage eliminates the 'adsorption effect' and reduces the pressure in the joint cavity [22] . When the load on the TMJ is relieved or removed following irrigation, the middle band of the articular disc and the articular nodes separate. At this point, the injection of sodium hyaluronate gel can compensate for the deficiency of endogenous hyaluronic acid in the joint fluid, enhancing joint lubrication, reducing friction between the articular disc, condyle, and articular fossa, and increasing condyle mobility [23] .These events initiate the manipulative reset of the anteriorly dislocated articular disc [24] . Manual reduction is not typically an urgent measure for some patients with obvious inflammatory exudation and severe tissue edema in the soft tissue surrounding the joint disc. Instead, hot compresses, physical therapy, and oral non-steroidal anti-inflammatory analgesics can be administered initially. Manual reduction and an occlusal splint can be employed when the initial inflammation is under control and the edema has been reduced. Although symptoms may improve even with recurrent disc displacement [25] , failure to maintain disc-condyle alignment can accelerate joint degeneration [8,26,27] . Therefore, it is crucial that clinicians pay attention to maintaining the disc-condylar relationship following manual reduction. According to a previous clinical study, patients with acute ADDWoR should follow certain measures to maintain the reset joint disc within 24 hours to one week after manual reduction [2] . It is important to restrict jaw movement in order to prevent recurrence of the joint ‘stuck’ phenomenon. Therefore, maintaining the disc-condylar relationship following reset is crucial if we are to ensure treatment efficacy [28] . In this study, we observed that the improvement of mouth opening and pain in the short- term after manipulation was slightly worse in the control groups than in the observation groups. Within one week of repositioning, 13 cases in the control groups reported being 'stuck' again; only three ‘stuck’ cases were recorded in the observation groups during follow-up (Table S1). In addition, these patients experienced a longer duration of symptoms (exceeding 3 months) and exhibited greater resistance to manipulation. This necessitated the use of a device with a higher level of stability for transition in the early stage. For patients with ADDwoR, the period of 24-48 hours after manual reduction is crucial for fixation. Following manual reduction, double occlusal splints can be manufactured chair-side to effectively prevent joint symptoms. This can also help to reduce the frequency of patient visits. During regular clinical visits, we observed that some patients who wore a traditional ARS experienced the recurrence of joint stiffness when they awoke in the morning, thus preventing them from opening their mouths. This was mainly attributed to poor sleeping posture and habits, as well as relaxation of the body muscles during sleep, thus leading to involuntary mandibular retraction [29,30] . NARS utilizes retainers to stabilize the maxilla and mandible in the treatment position, effectively addressing the issue of stability following manual reduction. In addition, double occlusal splints can also help to prevent damage to the teeth and periodontal tissues caused by bad sleeping habits such as clenched teeth and bruxism, and allow for the upper and lower dentition to be connected as a whole, evenly distributing the occlusal force and maintaining a stable positional relationship. As a single-center retrospective study, this work has methodological limitations. The population lacked diversity, no power analysis was conducted, and follow-up was short. Larger, multicenter, long-term studies are needed to confirm these findings. Conclusions Double occlusal splints are more beneficial than traditional ARS in terms of symptomatic relief for ADDWoR patients with successful manual reduction, particularly during the first month post-therapy. The efficacy of double occlusal splints was higher than that of traditional ARS. Following early manual reduction, double occlusal splints were more stable. In the future, multi-center randomized controlled trials should be carried out and the follow-up time can be extended to verify the clinical efficacy and stability of this technique; findings from such research will be conducive to the promotion and application of this strategy in clinical practice. Declarations Conflict of Interest The authors declare that they have no competing interests. Author Contributions W.H.X. and C.C. conceived the study and designed the methodology. C.C. and W.C.Z. wrote and edited the manuscript. C.C. conducted the investigation and formal analysis. W.C.Z. and W.H.X. managed the project. S.X.X. conducted investigation and prepared figures. T.B.W. validated the data. Z.C.O. contributed resources and data curation. W.H.X. acquired funding and supervised the work. Funding This work was supported by the Key Project of Research and Development Plan of Jiangxi Province (Grant number: 20203BBG7304). Ethics approval This study was approved by the Ethics Committee of the Affiliated Stomatological Hospital of Nanchang University (Reference: 2022019). All participants provided signed and informed electronic consent in accordance with the principles of the Declaration of Helsinki. All methods were performed in accordance with the relevant regulations and guidelines of the Declaration of Helsinki. Clinical trial number: Not applicable. Consent to publish Not applicable. Availability of data and materials The datasets supporting the conclusions of this article are included within the article and its supplementary materials. Additional anonymized data are available from the corresponding author upon reasonable request. Acknowledgements Not applicable. References Beaumont, S., Garg, K., Gokhale, A., & Heaphy, N. (2020). Temporomandibular Disorder: a practical guide for dental practitioners in diagnosis and management. 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07:35:05","extension":"html","order_by":35,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":126778,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/1e16bd1cf14d60eddd2f8b3f.html"},{"id":92478725,"identity":"45703c89-8501-44ad-95c7-ca31303af93b","added_by":"auto","created_at":"2025-09-30 07:35:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":529144,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of double occlusal splints. \u003cstrong\u003e(A)\u003c/strong\u003e DARS; \u003cstrong\u003e(B)\u003c/strong\u003e NARS (From left to right are the front view, side view and top view of the device). DARS, Daytime anterior repositioning splint; NARS, Nighttime anterior repositioning splint\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/842667aa05acfacad71b430d.png"},{"id":92480754,"identity":"af7a1bdc-6ff0-4796-b6a9-b129a545b95f","added_by":"auto","created_at":"2025-09-30 07:43:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":288077,"visible":true,"origin":"","legend":"\u003cp\u003eMandibular manipulation of a patient. \u003cstrong\u003e(A)\u003c/strong\u003e Restricted mouth opening before treatment; \u003cstrong\u003e(B)\u003c/strong\u003e Mouth opening returned to normal after manual reduction\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/222b01465bf202bbdaa88fec.png"},{"id":92478732,"identity":"de4f8952-1e50-435e-85fb-f5ab5e421afd","added_by":"auto","created_at":"2025-09-30 07:35:04","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":261833,"visible":true,"origin":"","legend":"\u003cp\u003eMRI showed successful manual reduction.\u003cstrong\u003e (A)\u003c/strong\u003e disc displacement without reduction before manual reduction; \u003cstrong\u003e(B)\u003c/strong\u003e the normal disc-condyle relationship in both the closed and open mouth positions after manual reduction. MRI, Magnetic resonance imaging\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/f927cf2b2720e5b5575a74e8.png"},{"id":92478728,"identity":"5bb5d98f-9c81-4b8d-b53e-ea1fa3ba5890","added_by":"auto","created_at":"2025-09-30 07:35:04","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":36854,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of VAS between the observation groups and control groups. \u003cstrong\u003e(A)\u003c/strong\u003e VAS values of observation group A and control group C; \u003cstrong\u003e(B)\u003c/strong\u003e VAS values of observation group B and control group D. The abscissa (0, 1, 2, and 3) represents VAS values before treatment and at one-, three- and six-months after treatment. Superscript symbols indicate significant differences: *\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05 and **\u003cem\u003eP \u003c/em\u003e\u0026lt; 0.01. VAS, visual analogue score\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/9c71f762c687558ba0496b5c.png"},{"id":92481494,"identity":"fa2d961d-d9e7-483f-b3a9-3ed6c02e8c7f","added_by":"auto","created_at":"2025-09-30 07:51:04","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":37806,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of MMO between the observation groups and control groups. \u003cstrong\u003e(A)\u003c/strong\u003e MMO values of observation group A and control group C; \u003cstrong\u003e(B)\u003c/strong\u003e MMO values of observation group B and control group D. The abscissa (0, 1, 2, and 3) represents MMO values before treatment and at one-, three- and six-months after treatment. Superscript symbols indicate significant differences: *\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05 and **\u003cem\u003eP \u003c/em\u003e\u0026lt; 0.01. MMO, maximum mouth opening\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/758ee9cc76fbc2963ff899a3.png"},{"id":92480757,"identity":"8f014de2-600f-47c9-a42b-4f6d16b08c2c","added_by":"auto","created_at":"2025-09-30 07:43:04","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":331278,"visible":true,"origin":"","legend":"\u003cp\u003eThree oblique sagittal MRI images before and after treatment. Before treatment \u003cstrong\u003e(A)\u003c/strong\u003e versus after treatment \u003cstrong\u003e(D)\u003c/strong\u003e the disc-condyle relationship is normalized; Pre-treatment \u003cstrong\u003e(B)\u003c/strong\u003e versus post-treatment \u003cstrong\u003e(E)\u003c/strong\u003e change from anterior displacement of the disc without reduction to anterior displacement of the disc after reduction; There was no significant change between pre-treatment \u003cstrong\u003e(C)\u003c/strong\u003e and post-treatment \u003cstrong\u003e(F)\u003c/strong\u003e. The red arrow indicates the position of the joint disc. MRI, magnetic resonance imaging\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/278b0ff9aa4e0a9ac389820f.png"},{"id":97179460,"identity":"f4cc73ca-b4bc-4f18-9b9b-49b1f9c959b9","added_by":"auto","created_at":"2025-12-01 16:15:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2560291,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/c0b3ef3f-791f-4d56-b870-934b7ed5c15e.pdf"},{"id":92478726,"identity":"561d8579-fdee-4280-a91f-c794a859ea68","added_by":"auto","created_at":"2025-09-30 07:35:04","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":4624779,"visible":true,"origin":"","legend":"","description":"","filename":"supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-7081699/v1/9e4d329a240bad159e608e7d.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical study of double occlusal splints combined with manual reduction for the treatment of anterior disc displacement without reduction: a retrospective study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTemporomandibular joint disorder (TMD affects both the masticatory muscles and the structure of the joint and can exert significant impact on a patient\u0026rsquo;s quality-of-life\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. One common structural disorder of TMD is anterior disc displacement without reduction (ADDWoR), which has a reported prevalence ranging from 2\u0026ndash;8% across various TMD illnesses\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. ADDWoR typically develops from anterior disc displacement of the temporomandibular joint with reduction (ADDWR), which is categorized into acute and chronic stages based on whether the duration exceeds four months\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Despite a variety of treatment options, there is still no consensus on the management of ADDWoR.\u003c/p\u003e\u003cp\u003eThere are differing opinions as to whether we should combine different therapeutic approaches and the optimal sequence of performing various treatments\u003csup\u003e[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Although some researchers have proposed that manual reduction combined with an anterior repositioning splint (ARS) could effectively move the condyle forwards to prevent the articular disc from shifting forwards again during the mouth closing process\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. However, throughout clinical diagnosis and treatment, we have found that for some patients with chronic phase and acute ADDWoR with a slightly longer course, the articular disc structure will reoccur in a short period of time following manual reduction. Moreover, some patients complained that the joints became \u0026ldquo;stuck\u0026rdquo; again when they awoke in the morning. Currently, there is a lack of sufficient research on how we night reduce the occurrence of such phenomena. Another consideration is that due to the long production cycle and poor stabilization effect of traditional ARS, this strategy might even cause the lower anterior teeth to become loose and dislocated due to excessive lateral occlusal force\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eTherefore, in the present study, we modified the traditional ARS into double occlusal splints featuring a daytime-ARS (DARS) and a nighttime-ARS (NARS). ADDWoR was treated by direct manual reduction or by manual reduction after lavage of the joint cavity and the use of a repositioning splint. We then compared the efficacy of manual reduction combined with traditional ARS and double occlusal splints for the treatment of patients with anterior disc displacement without reduction.\u003c/p\u003e"},{"header":"Material and methods","content":"\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003cp\u003eThis study was approved by the Ethics Committee of the Affiliated Stomatological Hospital of Nanchang University (Reference: 2022019). All participants provided signed and informed electronic consent in accordance with the principles of the Declaration of Helsinki. All methods were performed in accordance with the relevant regulations and guidelines of the Declaration of Helsinki.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePatient Recruitment\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWe enrolled patients diagnosed with ADDWoR according to the diagnostic criteria of Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e in the Affiliated Stomatological Hospital of Nanchang University between January 2022 and December 2023. Patients who wore double occlusal splints after successful manual reduction were selected as the observation groups (patients who were successfully reduced by direct manipulation and wore double occlusal splints were classified into group A; those who were successfully reduced by manipulation and wore double occlusal splints after supra-articular lavage injection were classified into group B). Patients who wore a traditional ARS were enrolled as the control groups (group C and group D were classified by the same method as for groups A and B). The specific inclusion criteria were as follows: (1) diagnosis of ADDWoR based on the DC/TMD; (2) maximum mouth opening (MMO)\u0026thinsp;\u0026lt;\u0026thinsp;37mm, and (3) successful manual reduction directly or after arthrocentesis. The exclusion criteria were as follows: (1) osteoarthropathy; (2) acute joint trauma; (3) severe psychiatric and psychological disorders; (4) uncontrolled periodontal disease; and (5) serious systemic diseases.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTreatment and outcome evaluation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eDouble occlusal splints incorporated a daytime-ARS (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA) and a Nighttime-ARS (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). The production process for NARS is shown in Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003eA-B. The processes utilized for arthrocentesis and manual reduction are shown in Figure S2 and S3. Mouth opening increased significantly immediately (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA-B). Magnetic resonance imaging (MRI) revealed that the disc-condylar relationship was normal in the opening position (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA-B).\u003c/p\u003e\u003cp\u003eThe measurement indices included pain visual analogue score (VAS), MMO, craniomandibular index (CMI)\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e, dysfunction index (DI), palpation index (PI) and clinical efficacy. An effective treatment would reduce local pain, tenderness and joint clicking to varying degrees, and improve the degree of mouth opening when compared to that prior to treatment. If these changes did not occur, then the treatment was considered invalid. MRI images were recorded before and after treatment in order to investigate the relative positions between the articular disc and condyle in both the open and closed positions\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eData were statistically analyzed using IBM SPSS Statistics version 26.0 software (IBM Corp, Armonk, NY, USA). The Shapiro-Wilk test method was used to detect whether the data were normally distributed. The Levene test was used to detect whether the variance was homogenous. Comparisons of VAS, MMO and CMI (including DI and PI) between groups was conducted using the Mann-Whitney U test (data that conformed to a normal distribution) or the independent sample t test (data that did not conform to a normal distribution). If the data were normally distributed and had uniform variances, then repeated measures analysis of variance (ANOVA) was used to compare the changes of VAS, MMO and CMI (including DI and PI) at multiple time points before and after treatment; otherwise, the Wilcoxon test was used. Inter-group comparisons were conducted using the χ\u003csup\u003e2\u003c/sup\u003e test to evaluate treatment efficacy, the effective MRI joint disc reduction rate and the incidence of disc re-displacement. The significance level was set at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003ePatient Clinical Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Table 1, 107 ADDWoR patients with 124 joints were included in the study, with a male to female ratio of approximately 1:4. There were no significant differences between the observation groups (group A and B) and the control groups (groups C and D) in terms of gender ratio, mean age, and the number of affected joints (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026gt; 0.05). Furthermore, there were no significant differences between the two groups in terms of the baseline levels of VAS, MMO and CMI prior to treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026gt; 0.05). However, the mean treatment course for group B patients (1.95 \u0026plusmn; 1.83 months) was longer than that of group A (1.09 \u0026plusmn; 1.26 months). The mean duration of group D (1.78 \u0026plusmn; 1.71 months) was longer than that of group C (1.06 \u0026plusmn; 1.39 months) (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Basic information and baseline data for patients in the four groups\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"107%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003eGroup A\u003c/p\u003e\n \u003cp\u003e(n = 29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003eGroup C\u003c/p\u003e\n \u003cp\u003e(n = 25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003eGroup B\u003c/p\u003e\n \u003cp\u003e(n = 27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003eGroup D\u003c/p\u003e\n \u003cp\u003e(n = 26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.950\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.810\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eJoints\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eUnilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.903\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.954\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eBilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003cp\u003e(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e24.12 \u0026plusmn; 6.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e24.28 \u0026plusmn; 6.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.942\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e25.72 \u0026plusmn; 8.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e25.40 \u0026plusmn; 11.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.864\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eDuration\u003c/p\u003e\n \u003cp\u003e(month)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1.09 \u0026plusmn; 1.26\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1.06 \u0026plusmn; 1.39\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.851\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1.95 \u0026plusmn; 1.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1.78 \u0026plusmn; 1.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.733\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e31.32 \u0026plusmn; 14.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e30.04 \u0026plusmn; 17.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.782\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e36.28 \u0026plusmn; 14.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e37.92 \u0026plusmn; 15.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.705\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eMMO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e25.84 \u0026plusmn; 6.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e26.24 \u0026plusmn; 4.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.805\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e23.60 \u0026plusmn; 5.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e24.68 \u0026plusmn; 3.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.402\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003eCMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e0.29 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e0.27 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.251\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e0.25 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e0.29 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e0.099\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003egroup A compared with group B, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05; \u003csup\u003eb\u003c/sup\u003egroup C compared with group D, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05.\u003c/p\u003e\n\u003cp\u003eAbbreviations: VAS, visual analogue score; MMO, maximum mouth opening; CMI, craniomandibular index.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVAS score assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Figure 4, VAS was significantly lower at one-, three- and six- months after treatment; this was the case in all four groups (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01). One month after treatment, the VAS of group A was lower than that of group C (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05), but there was no significant difference between the two groups when tested three- and six-months after treatment. The VAS for group B was lower than that of group D at one-, three- and six-months after treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05). The VAS score of group B (5.08 \u0026plusmn; 10.51) was significantly lower than that of group D (14.88 \u0026plusmn; 14.79) when tested six-months after treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMMO outcome assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Figure 5, there was no significant difference in the maximal degree of mouth opening when compared between the four groups before treatment. The results \u0026nbsp;demonstrates that the maximal degree of mouth opening in group A was higher than that in group C when tested one-month after treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05). However, there was no significant difference in the maximal degree of mouth opening between group A and group C after three- and six-months of treatment. The maximal degree of mouth opening in group B was significantly higher than that in group D when tested one-, three- and six-months after treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05). Within one week of repositioning, 13 cases in the control groups reported being \u0026apos;stuck\u0026apos; again; only three \u0026lsquo;stuck\u0026rsquo; cases were recorded in the observation groups during follow-up (Table S1) (\u003cem\u003eP =\u0026nbsp;\u003c/em\u003e0.01).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCMI, DI and PI outcome assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Table 2, there were no significant difference in DI, PI and CMI when compared between the observation groups (A, B) and the control groups (C, D) before treatment, although the DI and CMI in the observation groups were significantly lower than those in the control groups at one-, three- and six-months after treatment (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05). There was no significant difference in PI between the two groups before and after treatment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003eComparison between the observation groups and control groups in terms of CMI\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 7px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" rowspan=\"2\" style=\"width: 78px;\"\u003e\n \u003cp\u003eStage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"63\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd height=\"63\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003eBefore treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e1st month after treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e3rd month after treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e6th month after treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"72\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eDI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup A\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.44 \u0026plusmn; 0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.11 \u0026plusmn; 0.06\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.06 \u0026plusmn; 0.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"51\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.42 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.18 \u0026plusmn; 0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.14 \u0026plusmn; 0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.14 \u0026plusmn; 0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"54\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup A\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.13 \u0026plusmn; 0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.02 \u0026plusmn; 0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"49\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup C\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.11 \u0026plusmn; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"51\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eCMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup A\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.29 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.07 \u0026plusmn; 0.04\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.05\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.04\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"49\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup C\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.27 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.09 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.08 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.08 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eDI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup B\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.42 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.13 \u0026plusmn; 0.12\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.07 \u0026plusmn; 0.10\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.07 \u0026plusmn; 0.10\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eGroup D\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.45 \u0026plusmn; 0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.23 \u0026plusmn; 0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.17 \u0026plusmn; 0.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e0.15 \u0026plusmn; 0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003ePI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003eGroup B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.13 \u0026plusmn; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.02 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 121px;\"\u003e\n \u003cp\u003e0.02 \u0026plusmn; 0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003eGroup D\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.13 \u0026plusmn; 0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.07 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.05 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 121px;\"\u003e\n \u003cp\u003e0.05 \u0026plusmn; 0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eCMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003eGroup B\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.26 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.08 \u0026plusmn; 0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.05 \u0026plusmn; 0.06\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 121px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.06\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003eGroup D\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.29 \u0026plusmn; 0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.15 \u0026plusmn; 0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.11 \u0026plusmn; 0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 121px;\"\u003e\n \u003cp\u003e0.10 \u0026plusmn; 0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd height=\"46\" style=\"width: 0px;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSuperscript symbols indicate significant differences: \u003csup\u003ea\u003c/sup\u003e\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05 and \u003csup\u003eb\u003c/sup\u003e\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01.\u003c/p\u003e\n\u003cp\u003eAbbreviations: DI, dysfunction index; PI, palpation index; CMI, craniomandibular index.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMRI image analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, we collated 58 cases with MRI images from three- to six-months after treatment, including 35 cases in the observation groups and 23 cases in the control groups. As shown in\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eFigure 6, we observed three treatment outcomes using MRI images. The first outcome included the restoration of disc displacement without reduction before treatment to the normal disc-condyle relationship, including 20 cases in the observation groups and nine cases in the control groups (Figure 6A and 6D). The second outcome was the conversion from disc displacement without reduction before treatment to the disc displacement with reduction; there were seven cases in the observation groups and three cases in the control groups (Figure 6B and 6E). The third outcome was no change in the disc-condyle relationship before and after treatment; there were eight cases in the observation groups and 11 cases in the control groups. The first two outcomes, as observed on MRI were considered to be effective in structure reduction (Figure 6C and 6F). The efficacy of structure reduction in the observation groups (77.1%) was significantly higher than that in the control groups (52.2%) (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05) (Table 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Comparison of MRI results between the observation groups and the control groups after treatment\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"622\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 103px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 218px;\"\u003e\n \u003cp\u003eResults\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 73px;\"\u003e\n \u003cp\u003etotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 83px;\"\u003e\n \u003cp\u003eEfficiency of structural reduction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 73px;\"\u003e\n \u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"25\" height=\"28\"\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 73px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e(a)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e(b)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e(c)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eObservation groups (A+B)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 83px;\"\u003e\n \u003cp\u003e77.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 73px;\"\u003e\n \u003cp\u003e3.928\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.047\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 103px;\"\u003e\n \u003cp\u003eControl groups (C+D)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 83px;\"\u003e\n \u003cp\u003e52.2%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: MRI,\u0026nbsp;magnetic resonance imaging\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical outcome assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable S2 depicts clinical efficacy, 50 cases (89.3%) in the observation groups were effective and 38 cases (74.5%) in the control groups were effective; there was a significant difference in efficacy between these two groups (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur research showed that for some patients with acute ADDWoR, after manual reduction, \u0026nbsp;double occlusal splints following manual reduction improved symptoms more effectively, offering a new clinical strategy to maintain disc-condyle stability. A previous study showed that 95% of ADDWoR symptoms resolve within three months\u003csup\u003e[13]\u003c/sup\u003e,but structural restoration is rare, and worsening disc-condyle deformation can increase the risk of joint degeneration\u003csup\u003e[14,15]\u003c/sup\u003e. Chronic disc displacement alters joint tissue composition, degrading fibers, proteins, and cartilage, which may lead to osteoarthropathy. In adolescents, it may impair condylar growth, causing facial asymmetry and malocclusion\u003csup\u003e[16]\u003c/sup\u003e. In the present study, all four groups of patients underwent early manual reduction to restore the normal disc-condylar relationship. This intervention improved mouth opening and alleviated joint pain, thus resulting in effective clinical therapeutic effects. A previous study identified a high proportion of patients with articular disc perforation who had ADDWoR\u003csup\u003e[17]\u003c/sup\u003e, thus highlighting the importance of early intervention for these patients.\u003c/p\u003e\n\u003cp\u003eThe efficacy of manual repositioning is influenced by the degree of disc displacement and the stage of development. Research has demonstrated that patients with acute ADDWoR who have suffered from this condition for less than four months generally have TMJ discs with well-preserved morphology, structure, and function\u003csup\u003e[18]\u003c/sup\u003e. However, as inflammation progresses, cytokines and proteases promote soft tissue degradation\u003csup\u003e[19]\u003c/sup\u003e, and synovial proliferation reduces fluid quality, increasing joint friction and adhesion risk\u003csup\u003e[20]\u003c/sup\u003e.In these cases, manipulation faces stronger resistance. Clinicians must overcome muscle resistance with skillful traction. For high-resistance patients, verbal instruction and timing, combined with supra-articular lavage and sodium hyaluronate injection, can improve outcomes.\u003c/p\u003e\n\u003cp\u003eSupra-articular lavage is advantageous in several respects. First, this method helps to loosen small adhesions in the joint cavity, improve the intra-articular environment, removes inflammatory substances and pain factors (such as matrix metalloproteinases13 (MMP-13) and interleukin-6 (IL-6))\u003csup\u003e[21]\u003c/sup\u003e, restore normal intra-articular pressure, and reduce the exudation of inflammatory fluid. Secondly, supra-articular lavage eliminates the 'adsorption effect' and reduces the pressure in the joint cavity\u003csup\u003e[22]\u003c/sup\u003e. When the load on the TMJ is relieved or removed following irrigation, the middle band of the articular disc and the articular nodes separate. At this point, the injection of sodium hyaluronate gel can compensate for the deficiency of endogenous hyaluronic acid in the joint fluid, enhancing joint lubrication, reducing friction between the articular disc, condyle, and articular fossa, and increasing condyle mobility\u003csup\u003e[23]\u003c/sup\u003e.These events initiate the manipulative reset of the anteriorly dislocated articular disc\u003csup\u003e[24]\u003c/sup\u003e. Manual reduction is not typically an urgent measure for some patients with obvious inflammatory exudation and severe tissue edema in the soft tissue surrounding the joint disc. Instead, hot compresses, physical therapy, and oral non-steroidal anti-inflammatory analgesics can be administered initially. Manual reduction and an occlusal splint can be employed when the initial inflammation is under control and the edema has been reduced.\u003c/p\u003e\n\u003cp\u003eAlthough symptoms may improve even with recurrent disc displacement\u003csup\u003e[25]\u003c/sup\u003e, failure to maintain disc-condyle alignment can accelerate joint degeneration\u003csup\u003e[8,26,27]\u003c/sup\u003e. Therefore, it is crucial that clinicians pay attention to maintaining the disc-condylar relationship following manual reduction. According to a previous clinical study, patients with acute ADDWoR should follow certain measures to maintain the reset joint disc within 24 hours to one week after manual reduction\u003csup\u003e[2]\u003c/sup\u003e. It is important to restrict jaw movement in order to prevent recurrence of the joint ‘stuck’ phenomenon. Therefore, maintaining the disc-condylar relationship following reset is crucial if we are to ensure treatment efficacy\u003csup\u003e[28]\u003c/sup\u003e. In this study, we observed that the improvement of mouth opening and pain in the short- term after manipulation was slightly worse in the control groups than in the observation groups. Within one week of repositioning, 13 cases in the control groups reported being 'stuck' again; only three ‘stuck’ cases were recorded in the observation groups during follow-up (Table S1). In addition, these patients experienced a longer duration of symptoms (exceeding 3 months) and exhibited greater resistance to manipulation. This necessitated the use of a device with a higher level of stability for transition in the early stage.\u003c/p\u003e\n\u003cp\u003eFor patients with ADDwoR, the period of 24-48 hours after manual reduction is crucial for fixation. Following manual reduction, double occlusal splints can be manufactured chair-side to effectively prevent joint symptoms. This can also help to reduce the frequency of patient visits. During regular clinical visits, we observed that some patients who wore a traditional ARS experienced the recurrence of joint stiffness when they awoke in the morning, thus preventing them from opening their mouths. This was mainly attributed to poor sleeping posture and habits, as well as relaxation of the body muscles during sleep, thus leading to involuntary mandibular retraction\u003csup\u003e[29,30]\u003c/sup\u003e. NARS utilizes retainers to stabilize the maxilla and mandible in the treatment position, effectively addressing the issue of stability following manual reduction. In addition, double occlusal splints can also help to prevent damage to the teeth and periodontal tissues caused by bad sleeping habits such as clenched teeth and bruxism, and allow for the upper and lower dentition to be connected as a whole, evenly distributing the occlusal force and maintaining a stable positional relationship.\u003c/p\u003e\n\u003cp\u003eAs a single-center retrospective study, this work has methodological limitations. The population lacked diversity, no power analysis was conducted, and follow-up was short. Larger, multicenter, long-term studies are needed to confirm these findings.\u0026nbsp;\u003c/p\u003e\n\n"},{"header":"Conclusions","content":"\u003cp\u003eDouble occlusal splints are more beneficial than traditional ARS in terms of symptomatic relief for ADDWoR patients with successful manual reduction, particularly during the first month post-therapy. The efficacy of double occlusal splints was higher than that of traditional ARS. Following early manual reduction, double occlusal splints were more stable. In the future, multi-center randomized controlled trials should be carried out and the follow-up time can be extended to verify the clinical efficacy and stability of this technique; findings from such research will be conducive to the promotion and application of this strategy in clinical practice.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eW.H.X. and C.C. conceived the study and designed the methodology. C.C. and W.C.Z. wrote and edited the manuscript. C.C. conducted the investigation and formal analysis. W.C.Z. and W.H.X. managed the project. S.X.X. conducted investigation and prepared figures. T.B.W. validated the data. Z.C.O. contributed resources and data curation. W.H.X. acquired funding and supervised the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Key Project of Research and Development Plan of Jiangxi Province (Grant number: 20203BBG7304).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of the Affiliated Stomatological Hospital of Nanchang University (Reference: 2022019). All participants provided signed and informed electronic consent in accordance with the principles of the Declaration of Helsinki. All methods were performed in accordance with the relevant regulations and guidelines of the Declaration of Helsinki.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets supporting the conclusions of this article are included within the article and its supplementary materials. Additional anonymized data are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBeaumont, S., Garg, K., Gokhale, A., \u0026amp; Heaphy, N. (2020). Temporomandibular Disorder: a practical guide for dental practitioners in diagnosis and management. Australian dental journal, 65(3), 172\u0026ndash;180. https://doi.org/10.1111/adj.12785.\u003c/li\u003e\n\u003cli\u003eLei, J., Yap, A. U., Li, Y., Liu, M. Q., \u0026amp; Fu, K. Y. (2020). Clinical protocol for managing acute disc displacement without reduction: a magnetic resonance imaging evaluation. International journal of oral and maxillofacial surgery, 49(3), 361\u0026ndash;368. https://doi.org/10.1016/j.ijom.2019.07.005.\u003c/li\u003e\n\u003cli\u003eMa X. C. (2017). 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Long-term results in patients with disk displacement without reduction treated conservatively. Cranio : the journal of craniomandibular practice, 14(4), 301\u0026ndash;305. https://doi.org/10.1080/08869634.1996.11745981.\u003c/li\u003e\n\u003cli\u003eHu, Y. K., Yang, C., \u0026amp; Xie, Q. Y. (2016). Changes in disc status in the reducing and nonreducing anterior disc displacement of temporomandibular joint: a longitudinal retrospective study. Scientific reports, 6, 34253. https://doi.org/10.1038/srep34253.\u003c/li\u003e\n\u003cli\u003ede Souza-Pinto, G. N., Herreira-Ferreira, M., Grossmann, E., Brasil, D. M., Hara, G. F., Groppo, F. C., \u0026amp; Iwaki, L. C. V. (2023). Assessment of temporomandibular joint bone changes associated with anterior disc displacement: An MRI cross-sectional study. Journal of stomatology, oral and maxillofacial surgery, 124(6 Suppl 2), 101657. https://doi.org/10.1016/j.jormas.2023.101657.\u003c/li\u003e\n\u003cli\u003eAl-Baghdadi, M., Durham, J., \u0026amp; Steele, J. (2014). Timing interventions in relation to temporomandibular joint closed lock duration: a systematic review of \u0026apos;locking duration\u0026apos;. Journal of oral rehabilitation, 41(1), 24\u0026ndash;58. https://doi.org/10.1111/joor.12126.\u003c/li\u003e\n\u003cli\u003eDi Paolo, C., Falisi, G., Panti, F., Di Giacomo, P., \u0026amp; Rampello, A. (2020). \u0026quot;RA.DI.CA.\u0026quot; Splint for the Management of the Mandibular Functional Limitation: A Retrospective Study on Patients with Anterior Disc Displacement without Reduction. International journal of environmental research and public health, 17(23), 9057. https://doi.org/10.3390/ijerph17239057.\u003c/li\u003e\n\u003cli\u003eHardy, R. S., \u0026amp; Bonsor, S. J. (2021). The efficacy of occlusal splints in the treatment of bruxism: A systematic review. Journal of dentistry, 108, 103621. https://doi.org/10.1016/j.jdent.2021.103621.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Anterior disc displacement without reduction, Anterior repositioning splint, Double occlusal splints, Manual reduction","lastPublishedDoi":"10.21203/rs.3.rs-7081699/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7081699/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjectives:\u003c/strong\u003e Some patients with anterior disc displacement without reduction (ADDWoR) experience restricted mouth opening after manual reduction. This study aimed to compare the therapeutic efficacy of modified double occlusal splints with traditional anterior repositioning splints (ARS) in treating ADDWoR, to identify a simple, effective, and stable clinical approach.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods: \u003c/strong\u003eA total of 107 patients were enrolled in this single-center retrospective study. Those using double occlusal splints after successful manual reduction were assigned to observation groups (A, B). Clinical indicators included pain visual analogue score (VAS), maximum mouth opening (MMO), craniomandibular index (CMI), dysfunction index (DI), palpation index (PI), and overall efficacy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eAt one month post-treatment, groups A and B showed significant improvements in VAS, MMO, CMI, and DI compared to control groups C and D (\u003cem\u003eP \u003c/em\u003e\u0026lt; 0.05). At three and six months, group A had significantly lower CMI and DI than group C, with no significant VAS or MMO difference. Group B showed greater improvement than group D across all parameters (\u003cem\u003eP \u003c/em\u003e\u0026lt; 0.05). Magnetic resonance imaging (MRI) confirmed higher disc reduction rates in the observation groups. Clinical efficacy was 89.3% in experimental groups versus 74.5% in control groups (c\u003csup\u003e2\u003c/sup\u003e = 3.990, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eDouble occlusal splints demonstrated superior stabilization following early manual repositioning and improved structural outcomes compared to ARS. These findings support their clinical value as a treatment option for ADDWoR.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Relevance:\u003c/strong\u003e This study demonstrates that modified double occlusal splints provide more effective and stable outcomes than traditional anterior repositioning splints, particularly after early manual disc repositioning. The findings offer clinicians a simplified, non-invasive treatment strategy that enhances long-term joint stabilization and functional recovery in ADDWoR patients.\u003c/p\u003e","manuscriptTitle":"Clinical study of double occlusal splints combined with manual reduction for the treatment of anterior disc displacement without reduction: a retrospective study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-30 07:34:59","doi":"10.21203/rs.3.rs-7081699/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-30T08:54:33+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"169493895029573235523703920778050621763","date":"2025-10-09T12:42:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-02T13:36:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-30T11:34:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-28T11:55:14+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-25T22:40:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"97828489935814465584816571926698163774","date":"2025-09-25T16:24:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"127124940235393451101031895018806113799","date":"2025-09-23T20:03:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"271448974114511455447015960970232846542","date":"2025-09-21T20:11:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"185900073491518952889362526773460226040","date":"2025-09-21T11:23:52+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-18T15:35:54+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-16T14:25:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-07-16T11:39:39+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-16T06:15:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-07-16T03:48:47+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b1df2195-601e-41cf-a1b3-a0aa014ec5d2","owner":[],"postedDate":"September 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:11:30+00:00","versionOfRecord":{"articleIdentity":"rs-7081699","link":"https://doi.org/10.1186/s12903-025-07398-w","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2025-11-28 15:57:19","publishedOnDateReadable":"November 28th, 2025"},"versionCreatedAt":"2025-09-30 07:34:59","video":"","vorDoi":"10.1186/s12903-025-07398-w","vorDoiUrl":"https://doi.org/10.1186/s12903-025-07398-w","workflowStages":[]},"version":"v1","identity":"rs-7081699","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7081699","identity":"rs-7081699","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}