Effect of temporomandibular joint anterior disc displacement on condylar height in different age groups

Effect of temporomandibular joint anterior disc displacement on condylar height in different age groups | 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 Effect of temporomandibular joint anterior disc displacement on condylar height in different age groups Siyu Wu, Dahe Zhang, Simo Xia, Pei Shen, Chi Yang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5877385/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 04 Jul, 2025 Read the published version in BMC Oral Health → Version 1 posted 4 You are reading this latest preprint version Abstract Background: Temporomandibular joint ADD is highly prevalent and harmful, and some patients have no obvious clinical symptoms, but it can cause facial asymmetry, mandibular retrusion and other dental and maxillofacial deformities. Nevertheless, the impact of ADD on condylar height in individuals of varying age groups remains uncertain particularly with regard to condylar heights at different stages of development. The aim of this retrospective self-controlled study was to investigate the association between condylar height and temporomandibular joint anterior disc displacement (ADD) in different age groups. Materials and Methods: Patient characteristics, condylar height, disc length, and displacement distance at the baseline (T0) and the second follow-up visit (T1) were collected, and the differences between the two-time points were analyzed. Results: A total of 149 patients who were diagnosed with unilateral ADD were included in the study. In comparison to T0, the affected condylar height decreased 0.66 mm, whereas the non-affected condylar height increased 1.37 mm at T1. The further subgroup analysis revealed no statistically significant change in the affected condylar height of the 11-17 age group. However, a considerable reduction in height was observed on the ADD side in the subgroup above 18 years, when compared to the T0 period. Conclusions: ADD disrupts the normal development of condylar bone and cartilage in all age groups. Clinician recognises that ADD results in condylar growth inhibition in the young and condylar resorption in the adult. Temporomandibular Joint Disorders Temporomandibular Joint Disc Mandibular Condyle Age Groups Adolescent Development Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Temporomandibular joint anterior disc displacement (TMJ ADD) is one of the most common TMJ diseases, which can lead to a range of clinical symptoms, including joint sounds, pain and limitation of mouth opening. It can occur in all age groups with a prevalence of 18–25%[ 1 , 2 ]. Nebble et al [ 3 ]found that nearly 50% pre-orthodontic juveniles were diagnosed with ADD, revealing the prevalence and insidious nature of ADD in the adolescent population. In addition to these clinical symptoms, Boering (1966) followed 400 patients and found a close relationship between ADD and condylar resorption, ramus height reduction, noticeable chin point deviation and mandibular retrusion[ 4 ]. Subsequent studies revealed that patients with unilateral ADD were two or three times more likely to develop mandibular asymmetry (MA) than the general population, and the chin was always deviated towards the ADD side[ 5 , 6 ]. A 12- to 14-month follow-up of patients with ADD indicated a reduction in condylar height of 0.41 to 1.1 mm, with an increase in menton deviation of 2 mm and in incisor overjet of 0.73mm[ 7 – 10 ]. Consistent with these studies, Xie et al demonstrated that ADDwoR group exhibited a 0.4mm reduction in condylar height growth in comparison to the ADDwR group after > 3-month follow-up[ 6 ]. These studies indicated that ramus height continued to shorten as ADD progresses. It's evident that the condyle, as the center of mandibular growth, is strongly connected to the jaw development. Cortical bone begins to form around the periphery of the condyle and the development of the mandible peaks at around 12–14 years of age[ 11 ]. ADD has been demonstrated to negatively affect condylar growth and age may be an important factor in this process[ 6 – 8 ]. A significant negative correlation was oberserved between the dgree of mandibular deviation and age, with a correlation coefficient of -0.76, which meant that the earlier ADD occurs, the more severe facial deviation is likely to be[ 6 ]. And after receiving arthroscopic treatment, younger patients exhibited a greater potential for new bone formation in the condyle[ 12 ]. Nevertheless, the impact of ADD on condylar height in individuals of varying age groups remains uncertain particularly with regard to condylar heights at different stages of development. Therefore, a retrospective self-controlled study was designed and conducted to explore the changes in condylar height and disc status in patients with unilateral ADD. Our study aimed to explore the influence of ADD on condylar development in patients of different age groups. The hypothesis is that ADD can inhibit condylar development in patients, especially in the young age groups. We hope this study can give an insight into the process of ADD, and provide evidence to guide the therapeutic strategy of ADD. Materials and methods Study design This was a retrospective self-controlled clinical study based on the patients who were diagnosed with unilateral ADD at Shanghai Ninth People’s Hospital between January 2017 and December 2022. The study was designed in accordance with the Declaration of Helsinki for research. Ethics approval was obtained from the Human Research Ethics Committee of Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine (approval no.SH9H-2020-T7–1). Written informed consent was obtained from all participants. In the case of adolescent patients under the age of 18, informed consent was obtained from both the patients themselves and their legal guardians. Study participants and data collection The inclusion criteria were as follows: (1) aged between 11 and 29 years old; (2) diagnosed with unilateral TMJ-ADD based on MRI; (3) at least 2 sets of MRI, as follows: images at the beginning of the natural course (T0) and at the follow-up visit (T1). The interval between T0 and T1 was at least 3 months. The exclusion criteria were as follows: (1) history of orthognathic treatment or surgery involving the TMJ before the first visit; (2) history of trauma or rheumatoid arthritis; (3) history of orthodontic treatment during the follow-up interval. Study variables The predictor variable was the ADD (affected vs non-affected). The primary outcome variables were the changes in the condylar height, and the secondary outcome variables were the disc length and the disc anterior distance at the beginning of the natural course (T0) and the follow-up visit (T1). Outcome measurements The outcomes were measured based on the magnetic resonance imaging (MRI) results as shown in Figure 1, which was considered as the standard to diagnose ADD[13]. The image in the middle, with the largest sectional area of condylar, was chosen for mearsuring. The posterior border of the ramus (MN) was defined, and two horizontal lines perpendicular to MN were drawn: DE through the most cranial point of the condyle (P) and LT through the deepest point of the sigmoid notch (L). The condylar height was measured as the distance between DE and LT (PH). The midpoint of the intermediate zone of the disc (O) could always be clearly located. A and B were the most anterior and posterior points according to the point C, respectively. The disc length was the sum of AO and OB. The anterior distance of disc relative to the condyle was defined as the distance between point B and point P. Statistical analysis All data were analyzed by R version 4.1.0. Data are presented as frequencies (percentages) for categorical variables and as the mean ± standard deviation or median (interquartile range) for continuous variables, or as frequencies (percentages) for categorical variables. A paired t test was used to compare the variables within each period, and a generalized estimating equation (GEE) [14] was used to compare the change in the variables between the two time points. Subgroup analysis was performed by GEE. Pearson correlation analysis was calculated to define the relationship between the changes of condylar height, disc length, and disc displacement distance. The 95% confidence intervals (CI) and p values were calculated. A level of p < 0.05 was considered statistically significant. Results A total of 715 patients were diagnosed with unilateral ADD between 2017 January and 2022 December. Initially, 562 patients were between 10 to 29 years of age. For the final analysis, 149 patients (30 male and 119 female) had the complete information of follow-up period. The median age was 18.0 years and the median follow-up duration was 10 months. The participant characteristics at T0 are presented in Table 1. Here, a representative case of MRI images obtained within 8 months was shown (Fig. 2). Condylar height of affected side was measured as 19.4mm at T0 and 19.2mm at T1 (Fig. 2A), while the condylar height of non-affected side was 19.6 mm at T0 and 20.6mm at T1 (Fig. 2B). Condylar height changes between the groups Changes in condylar height between the ADD affected side and the non-affected side during the follow-up period are shown in Figure 3 and Table 2. During the follow-up period, condylar height decreased by 0.71 mm on the ADD side ( p < 0.001), and increased by 0.66 mm on the other side ( p < 0.001), with a significant difference of 1.37 mm between the two sides ( p < 0.001). Subgroup analysis in the condylar height changes To further investigate the effect of ADD on condylar height growth in different age groups, the change of condylar height in different age subgroups were analyzed (Figure 4 and Table 3). The participants were divided into four groups: 11-14 years (n = 43), 15-17 years (n = 27), 18-20 years (n = 32), and 21-29 years (n = 47). There was no significant condylar height reduction on the affected side in 11-14 and 15-17 age groups, but there was significant growth in height on the non-affected side ( p <0.001). Both the 18-20 and 21-29 age groups had significant reductions in condylar height on the ADD side ( p < 0.001). Disc length and anterior displacement distance changes in the interval As shown in Table 4 and Table 5, the disc length of the affected side was shortened by an average of 0.88mm ( p <0.001), and the disc of the affected side shifted forward by 0.95mm ( p <0.001). The difference was significant in both the overall group and in the subgroups ( p <0.001). Correlations between the condylar height and articular disc Pearson correlation analysis between the condylar height change, disc length and disc displacement distance are presented in Figure 5 and Table 6. The changes in overall condylar height were positively correlated with the disc length ( p < 0.001) and were negatively correlated with the disc anterior displacement ( p < 0.05 ). Discussion The mandibular condyle, disc, and fossa–eminence complex form the two-compartment articulation of the TMJ. The articular disc serve as a cushion to relieve stress during joint movement and stimulate the joint development. When the disc shifts forward, the abnormal pressure during mandibular movement results in the condylar bone remodelling and ramus height decreasing[ 15 , 16 ]. Although a substantial number of studies indicated that ADD was associated with condylar resorption[ 6 , 7 , 17 ], it is important to recognize that age also plays a role in the progression of condylar resorption in individuals with ADD. PH Buschang et al collected cephalograms of aged 6–16 years in the United States and found that condylar height growth reached its peak at the age of 12–14 years, with an average increase of 2 mm per year and a maximum increase of 4 ~ 5mm[ 18 ]. Lei et al evaluated the subchondral formation of cortical bone and condylar development at the ages of 10–30 years, and concluded that cortical bone formation began at 12–14 years of age, with most formation occurring after 20 years of age[ 11 ]. In light of the impact of individual and age-related factors on bone growth, we included patients with unilateral ADD, employing their own contralateral side as control, and analyzed changes in bone growth at varying ages. MRI is considered the gold standard for the diagnosis of temporomandibular joint (TMJ) disease due to its ability to provide comprehensive assessment of both soft tissue and condylar bone[ 19 ]. The present study used MRI to measure changes of condylar height and articular disc at two follow-up visits greater than 3 months. Condylar height growth on the ADD side was 1.37mm less than the health side at a mean follow-up time of 10 months. The increase in condylar height difference was accompanied by a shortening of disc length and an increase in anterior displacement distance on the ADD side, with these changes being statistically significant. Although some studies have demonstrated that the clinical symptoms tend to be relieved during the natural ADD course[ 20 , 21 ], prolonged ADD accompanied by abnormal mechanical stress may lead to degenerative changes in the condyle and even osteoarthritis[ 22 ]. Thus, a normal disc position is of great importance. This is the reason why disc repositioning can exert a significant protective influence on the condyles in ADD and condylar resorption[ 23 ]. In the present study, the impact of ADD on condylar height varied across different age subgroups. No notable alteration in condylar height was observed in patients aged 11–17 years. However, a considerable increase in condylar height on the contralateral side was evident, indicating a potential inhibitory effect on condylar growth. Patients over 18-year were more inclined to have a reduced condylar height in ADD side, which suggested a bone destruction.This intergroup variability may be due to the mechanical stress induced by ADD, resulting in the condylar cartilage degeneration and bone destruction[ 24 – 26 ]. This upshot manifests as condylar growth inhibition in adolescent patients, and bone destruction in adult patients. Moreover, a positive correlation was demonstrated between the degree of mandibular deviation, the articular disc shortage, disc anterior displacement, and reduced condylar height in the ADD side[ 6 ]. In line with previous studies, it showed that the difference in condylar height between the two time points was positively correlated with the disc length. This finding indicated that the disc condition is also important for the condyle. In the previous studies, it proved that disc repositioning surgery can be an effective surgery to relieve condylar resorption and facial deformities [28]. Thus, clinicians should pay more attention to the younger ADD patients with a short disc. For these patients, an early and appropriate intervention is necessary. Conclusion The study examined the condylar height changes over time in individuals with unilateral ADD across different age groups. In patients with ADD aged between 11 and 17 years, the non-affected condyle demonstrates relatively accelerated growth in comparison to the affected condylar. Whereas, in the higher age groups, the affected condyle exhibites significant resorption. These findings indicated that ADD disrupts the normal physiological state of condyle in all age groups. In conclusion, ADD results in condylar growth inhibition in the young patients, and condylar resorption in the adult patients. Clincians should pay more attention to the condylar condition in ADD patients, and appropriate intervention is necessary, especially in the young patients. Declarations Ethics approval and consent to participate: The Ethics Committee of the Ninth People's Hospital affiliated to the Shanghai Jiao Tong University School of Medicine approved this study (SH9H-2020-T7–1). The ethical approval has been submitted. All participants have signed informed consent Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests: The authors declare that they have no competing interests. Funding: National Natural Science Foundation of China (82071134，82401148); Dominant disease biological sample project of the Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (YBKA202201) Authors' contributions: Siyu Wu, Pei Shen and Chi Yang provided conception and design of study, analyzed data; Siyu Wu and Dahe Zhang drafted the manuscript, all authors reviewed and approved the manuscript. Acknowledgements: Not applicable References Naeije M, Te Veldhuis AH, Te Veldhuis EC, Visscher CM, Lobbezoo F. Disc displacement within the human temporomandibular joint: a systematic review of a “noisy annoyance.” J Oral Rehabil. 2013;40:139–58. Manfredini D, Guarda-Nardini L, Winocur E, Piccotti F, Ahlberg J, Lobbezoo F. Research diagnostic criteria for temporomandibular disorders: a systematic review of axis I epidemiologic findings. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011;112:453–62. Nebbe B, Major PW. Prevalence of TMJ disc displacement in a pre-orthodontic adolescent sample. Angle Orthod. 2000;70:454–63. Hall HD. Intra-articular disc displacement part II: Its significant role in temporomandibular joint pathology. Journal of Oral and Maxillofacial Surgery. 1995;53:1073–9. K O, N I, K M, T M, K M, S K, et al. Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. The British journal of oral & maxillofacial surgery. 2020;58. Xie Q, Yang C, He D, Cai X, Ma Z. Is mandibular asymmetry more frequent and severe with unilateral disc displacement? J Craniomaxillofac Surg. 2015;43:81–6. Zhuo Z, Cai X, Xie Q. Is anterior disc displacement without reduction associated with temporomandibular joint condylar height in juvenile patients younger than 20 years? J Oral Maxillofac Surg. 2015;73:843–9. Xie Q, Yang C, He D, Cai X, Ma Z, Shen Y, et al. Will unilateral temporomandibular joint anterior disc displacement in teenagers lead to asymmetry of condyle and mandible? A longitudinal study. J Craniomaxillofac Surg. 2016;44:590–6. Zhu H, He D, Yang Z, Song X, Ellis E. The effect of disc repositioning and post-operative functional splint for the treatment of anterior disc displacement in juvenile patients with Class II malocclusion. J Craniomaxillofac Surg. 2019;47:66–72. Liu Z, Xie Q, Yang C, Chen M, Bai G, Abdelrehem A. The effect of arthroscopic disc repositioning on facial growth in juvenile patients with unilateral anterior disc displacement. J Craniomaxillofac Surg. 2020;48:765–71. Lei J, Liu M-Q, Yap AUJ, Fu K-Y. Condylar subchondral formation of cortical bone in adolescents and young adults. Br J Oral Maxillofac Surg. 2013;51:63–8. Zhang D, Abdelrehem A, Luo Y, Shen P, Yang C. Effect of arthroscopic discopexy on condylar growth in adolescents with temporomandibular joint disc displacement without reduction: A retrospective self-controlled case series study. J Craniomaxillofac Surg. 2024;52:157–64. Manfredini D, Guarda-Nardini L. Agreement between Research Diagnostic Criteria for Temporomandibular Disorders and magnetic resonance diagnoses of temporomandibular disc displacement in a patient population. Int J Oral Maxillofac Surg. 2008;37:612–6. Residuals analysis of the generalized linear models for longitudinal data - PubMed. https://pubmed.ncbi.nlm.nih.gov/10814977/. Accessed 20 Jul 2024. Part I: Development and Physiology of the Temporomandibular Joint - PubMed. https://pubmed.ncbi.nlm.nih.gov/29948821/. Accessed 20 Jul 2024. Wu Y, Cisewski SE, Coombs MC, Brown MH, Wei F, She X, et al. Effect of Sustained Joint Loading on TMJ Disc Nutrient Environment. J Dent Res. 2019;98:888–95. Zhang X, Sun J, He D. Review of the studies on the relationship and treatment of anterior disk displacement and dentofacial deformity in adolescents. Oral Surg Oral Med Oral Pathol Oral Radiol. 2023;135:470–4. Buschang PH, Santos-Pinto A, Demirjian A. Incremental growth charts for condylar growth between 6 and 16 years of age. Eur J Orthod. 1999;21:167–73. Montesinos GA, de Castro Lopes SLP, Trivino T, Sánchez JA, Maeda FA, de Freitas CF, et al. Subjective analysis of the application of enhancement filters on magnetic resonance imaging of the temporomandibular joint. Oral Surg Oral Med Oral Pathol Oral Radiol. 2019;127:552–9. Sato S, Kawamura H, Nagasaka H, Motegi K. The natural course of anterior disc displacement without reduction in the temporomandibular joint: follow-up at 6, 12, and 18 months. J Oral Maxillofac Surg. 1997;55:234–8; discussion 238-239. Kurita K, Westesson PL, Yuasa H, Toyama M, Machida J, Ogi N. Natural course of untreated symptomatic temporomandibular joint disc displacement without reduction. J Dent Res. 1998;77:361–5. Zou L, Yang K, Yu Y, Wang C, Zhao J, Lu C, et al. Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA. Oral Dis. 2024. https://doi.org/10.1111/odi.14871. Shen P, Bai G, Xie Q, Fang Y, Pan L, Geng Y, et al. Efficacy of Arthroscopic Discopexy on Condylar Growth in Temporomandibular Joint Anterior Disc Displacement: A Randomized Clinical Trial. Plast Reconstr Surg. 2023. https://doi.org/10.1097/PRS.0000000000010966. Mirahmadi F, Koolstra JH, Lobbezoo F, van Lenthe GH, Ghazanfari S, Snabel J, et al. Mechanical stiffness of TMJ condylar cartilage increases after artificial aging by ribose. Arch Oral Biol. 2018;87:102–9. Rahmati M, Nalesso G, Mobasheri A, Mozafari M. Aging and osteoarthritis: Central role of the extracellular matrix. Ageing Res Rev. 2017;40:20–30. Cai S, Zou Y, Zhao Y, Lin H, Zheng D, Xu L, et al. Mechanical stress reduces secreted frizzled-related protein expression and promotes temporomandibular joint osteoarthritis via Wnt/β-catenin signaling. Bone. 2022;161:116445. Tables Table 1. Participant characteristics at T0 . Variables Value (n = 149) Sex, n (%) Male 30 (20.1) Female 119(79.9) Age(years) 18(14, 23) Site, n (%) Left 100(67.1) Right 49(32.9) Follow-up duration, mon, median (IQR) 10(7, 15) Joint sounds, n (%) Yes 125(83.9) No 24(16.1) Pre-auricular pain, n (%) Yes 58(38.9) No 91(61.1) Opening restriction, n (%) Yes 56(37.6) No 93(62.4) MIO (mm) 38.2±1.8 Mandibular asymmetry, n (%) Yes 79(53.0) No 24(47.0) MIO: maximum interincisal opening Table 2. Condylar height changes in the follow-up period. Side Estimate (95% CI) P -value Affected (n = 149) -0.71(-0.91 to -0.51) <0.001 a Non-affected (n = 149) 0.66(0.51 to 0.80) <0.001 a Affected VS Non-affected -1.37(-1.50 to -1.24) <0.001 b a Mean change differences within groups were calculated by Paired t -test. b Mean change differences between groups were calculated by GEE. Table 3. Condylar height changes of subgroups in the follow-up period. Age n Affected Non-affected Affected VS Non-affected group T1-T0 (95% CI) P -value a T1-T0 (95% CI) P -value a Estimate (95% CI) P-value b 11~14 43 -0.08(-0.39 to 0.23) 0.597 1.19(0.90 to 1.49) <0.001 -1.27(-1.48 to -1.07) <0.001 15~17 27 -0.49(-0.86 to -0.23) 0.110 0.82(0.11 to 0.59) <0.001 -1.32(-1.52 to -1.11) <0.001 18~20 32 -0.64(-0.95 to -0.33) <0.001 0.66(0.41 to 0.90) <0.001 -1.29(-1.49 to -1.10) <0.001 21~29 47 -1.46(-1.88 to -1.33) <0.001 0.07(-0.18 to 0.32) 0.567 -1.54(-1.78 to -1.30) <0.001 Total 149 -0.71(-0.91 to -0.51) <0.001 0.66(0.51 to 0.80) <0.001 -1.37(-1.50 to -1.24) <0.001 a Mean change differences within groups were calculated by Paired t -test. b Mean change differences between groups were calculated by GEE. Table 4. Disc length and disc anterior distance changes in overall. Disc length(mm) Anterior distance(mm) T0 7.97±1.60 5.24±2.75 T1 7.09±2.03 6.20±3.00 Mean difference of T1 vs T0 (95%CI) -0.88(-1.03 to -0.73) 0.95( 0.76 to 1.14) P a < 0.001 < 0.001 a Mean change differences between groups were calculated by Paired t -test Table 5. Disc length and disc anterior distance changes among subgroup. Age n Disc length Anterior distance T0 T1 Mean difference of T1 vs T0 (95% CI) p a T0 T1 Mean difference of T1 vs T0 (95% CI) p a 11~14 43 8.30±1.12 7.34±1.49 -0.96(-1.31 to -0.61) <0.001 4.70(4.00,5.55) 4.70(4.60,5.00) 0.65(0.30 to 1.00) <0.001 15~17 27 7.84±1.30 7.31±1.21 -0.53(-0.81 to -0.25) <0.001 4.67±1.29 5.66±1.28 0.98(0.50 to 1.45) <0.001 18~20 32 8.10±1.24 6.83±1.37 -1.27(-1.66 to 0.89) <0.001 4.30(3.80, 6.35) 5.95(4.95,7.10) 1.11(0.68 to 1.53) <0.001 21~29 47 7.66±1.33 6.91±1.50 -0.75(-0.93 to -0.57) <0.001 6.30(5.00,7.15) 7.30(6.25,8.45) 1.09(0.77 to 1.41) <0.001 a Mean change differences between groups were calculated by Paired t -test Table 6. Correlations between the condylar height and articular disc among the subgroups. variables T0 T1 PC p PC p 11-14 △H-disc length 0.41 <0.05 0.48 <0.05 △H-anterior distance -0.01 0.95 0.08 0.59 15-17 △H-disc length 0.58 <0.05 0.39 <0.05 △H-anterior distance -0.15 0.45 0.01 0.96 18-20 △H-disc length 0.29 0.10 0.47 <0.05 △H-anterior distance 0.27 0.12 0.13 0.46 21-29 △H-disc length 0.32 <0.05 0.28 0.05 △H-anterior distance -0.03 0.87 0.01 0.94 PC: Pearson correlation △H: Height difference between T1 and T0 of ADD side in MRI Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 04 Jul, 2025 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Revision requested 30 Jan, 2025 Editor assigned by journal 22 Jan, 2025 Submission checks completed at journal 22 Jan, 2025 First submitted to journal 21 Jan, 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5877385","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":405593146,"identity":"3c7d546f-bacd-489f-90f2-a60168d1433e","order_by":0,"name":"Siyu Wu","email":"","orcid":"","institution":"Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Siyu","middleName":"","lastName":"Wu","suffix":""},{"id":405593147,"identity":"6ef2f84c-700b-42f0-ad31-b592d3b0fb16","order_by":1,"name":"Dahe Zhang","email":"","orcid":"","institution":"Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Dahe","middleName":"","lastName":"Zhang","suffix":""},{"id":405593148,"identity":"5e67278e-cbd9-4aee-b250-6d04623fb3d5","order_by":2,"name":"Simo Xia","email":"","orcid":"","institution":"Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Simo","middleName":"","lastName":"Xia","suffix":""},{"id":405593149,"identity":"af34f383-6d6e-4cd6-9ff4-405775fd3bf0","order_by":3,"name":"Pei Shen","email":"","orcid":"","institution":"Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Pei","middleName":"","lastName":"Shen","suffix":""},{"id":405593150,"identity":"f79c20c3-dbaf-492a-beef-683fb5f3f79a","order_by":4,"name":"Chi Yang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYLACxgYJHn729oOPwTxm5gaitMhI9pxJNmZgMABqYSRKC4ONwQ0HM2mwFgYCWgyOnz384ucOCx6DGwxp1QUVf6L524FaflRsw63lTF6aZe8ZCR7J243Hbs84Y5A74zBjA2PPmdu4tRzIMTNmbJPg4btzIO02b5tBbgNQCzNjGx4t599AtDDcSDArBmmZT1DLjRzjxyAtAkAtzCAtGwhpkbzxxoyxF6gFFMjSPGeMczcCtRzE5xe+8znGH3621dmDovIzT4Vc7rzzhw8++FGBW4vCAQY2CQzRAzjVA4F8AwPzB3wKRsEoGAWjYBQwAAAGgly0VGN+AAAAAABJRU5ErkJggg==","orcid":"","institution":"Shanghai Jiao Tong University School of Medicine","correspondingAuthor":true,"prefix":"","firstName":"Chi","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2025-01-22 04:38:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5877385/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5877385/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12903-025-06121-z","type":"published","date":"2025-07-04T15:57:21+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":74680237,"identity":"d9e0f75e-be08-4fa6-8793-fd02604b1820","added_by":"auto","created_at":"2025-01-24 15:42:54","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":160066,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of condylar height, disc length, and disc position based on MRI. The condylar height was determined to be the length of PH. The disc length was the sum of AO and OB. The disc position relative to the condyle was defined as the distance between point B and point P. MN represents the border of the ramus; DE, a line perpendicular to MN through the most cranial point of the condyle; LT, a line perpendicular to MN through the deepest point of the sigmoid notch; PH, the distance between DE and LT; A, the most anterior point of the disc; O, the midpoint of the intermediate zone of the disc; B, the most posterior point of the disc\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/931c0c09dfd9b11bbee5f3c3.png"},{"id":74680242,"identity":"9fc8b9df-9447-4656-9d3e-663f59aa4fe5","added_by":"auto","created_at":"2025-01-24 15:42:55","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":278670,"visible":true,"origin":"","legend":"\u003cp\u003eMRI images of patient with unilateral ADD. Affected side: (A) T0, (A) T1.Non-affected side: (B) T0, (B) T1. The red line show the condylar height and the white lines indicate the contour of the condyle and the disc morphology.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/5e0856f6d5a1acc40a34e507.png"},{"id":74680238,"identity":"64964573-50a3-4ff8-9a8d-5034262dbc86","added_by":"auto","created_at":"2025-01-24 15:42:54","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":82490,"visible":true,"origin":"","legend":"\u003cp\u003eCondylar height change on the two sides from T0 to T1.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/677855e303aecff78b00488c.png"},{"id":74680243,"identity":"4deda8d0-6292-487a-a281-0ce745b81ac3","added_by":"auto","created_at":"2025-01-24 15:42:55","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":87280,"visible":true,"origin":"","legend":"\u003cp\u003eSubgroup analysis of condylar heights changes in follow-up period.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/d71dd43caa44766113331873.png"},{"id":74680246,"identity":"069d3be8-6601-4a6b-9425-a297ca621a64","added_by":"auto","created_at":"2025-01-24 15:42:55","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":492482,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelations between condylar height and articular disc. (A). Correlations between change in overall condylar height and disc anterior displacement distance , (B). Correlations between change in overall condylar height and disc length.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/d17b632ff46f09dc7cef1857.png"},{"id":86179165,"identity":"05cd20f9-23ff-4238-956d-519a3bbb95dd","added_by":"auto","created_at":"2025-07-07 16:16:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2106871,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5877385/v1/e6d87dfb-006f-4207-b032-0c0075152463.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of temporomandibular joint anterior disc displacement on condylar height in different age groups","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTemporomandibular joint anterior disc displacement (TMJ ADD) is one of the most common TMJ diseases, which can lead to a range of clinical symptoms, including joint sounds, pain and limitation of mouth opening. It can occur in all age groups with a prevalence of 18\u0026ndash;25%[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Nebble et al [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]found that nearly 50% pre-orthodontic juveniles were diagnosed with ADD, revealing the prevalence and insidious nature of ADD in the adolescent population.\u003c/p\u003e \u003cp\u003eIn addition to these clinical symptoms, Boering (1966) followed 400 patients and found a close relationship between ADD and condylar resorption, ramus height reduction, noticeable chin point deviation and mandibular retrusion[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Subsequent studies revealed that patients with unilateral ADD were two or three times more likely to develop mandibular asymmetry (MA) than the general population, and the chin was always deviated towards the ADD side[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. A 12- to 14-month follow-up of patients with ADD indicated a reduction in condylar height of 0.41 to 1.1 mm, with an increase in menton deviation of 2 mm and in incisor overjet of 0.73mm[\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Consistent with these studies, Xie et al demonstrated that ADDwoR group exhibited a 0.4mm reduction in condylar height growth in comparison to the ADDwR group after \u0026gt;\u0026thinsp;3-month follow-up[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. These studies indicated that ramus height continued to shorten as ADD progresses.\u003c/p\u003e \u003cp\u003eIt's evident that the condyle, as the center of mandibular growth, is strongly connected to the jaw development. Cortical bone begins to form around the periphery of the condyle and the development of the mandible peaks at around 12\u0026ndash;14 years of age[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. ADD has been demonstrated to negatively affect condylar growth and age may be an important factor in this process[\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. A significant negative correlation was oberserved between the dgree of mandibular deviation and age, with a correlation coefficient of -0.76, which meant that the earlier ADD occurs, the more severe facial deviation is likely to be[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. And after receiving arthroscopic treatment, younger patients exhibited a greater potential for new bone formation in the condyle[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Nevertheless, the impact of ADD on condylar height in individuals of varying age groups remains uncertain particularly with regard to condylar heights at different stages of development.\u003c/p\u003e \u003cp\u003eTherefore, a retrospective self-controlled study was designed and conducted to explore the changes in condylar height and disc status in patients with unilateral ADD. Our study aimed to explore the influence of ADD on condylar development in patients of different age groups. The hypothesis is that ADD can inhibit condylar development in patients, especially in the young age groups. We hope this study can give an insight into the process of ADD, and provide evidence to guide the therapeutic strategy of ADD.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eStudy design\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis was a retrospective self-controlled clinical study based on the patients who were diagnosed with unilateral ADD at Shanghai Ninth People\u0026rsquo;s Hospital between January 2017 and December 2022. The study was designed in accordance with the Declaration of Helsinki for research. Ethics approval was obtained from the Human Research Ethics Committee of Shanghai Ninth People\u0026rsquo;s Hospital, Shanghai Jiao Tong University School of Medicine (approval no.SH9H-2020-T7\u0026ndash;1). Written informed consent was obtained from all participants. In the case of adolescent patients under the age of 18, informed consent was obtained from both the patients themselves and their legal guardians.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy participants and data collection\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe inclusion criteria were as follows: (1) aged between 11 and 29 years old; (2) diagnosed with unilateral TMJ-ADD based on MRI; (3) at least 2 sets of MRI, as follows: images at the beginning of the natural course (T0) and at the follow-up visit (T1). The interval between T0 and T1 was at least 3 months. The exclusion criteria were as follows: (1) history of orthognathic treatment or surgery involving the TMJ before the first visit; (2) history of trauma or rheumatoid arthritis; (3) history of orthodontic treatment during the follow-up interval.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy variables\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe predictor variable was the ADD (affected vs non-affected). The primary outcome variables were the changes in the condylar height, and the secondary outcome variables were the disc length and the disc anterior distance at the beginning of the natural course (T0) and the follow-up visit (T1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcome measurements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe outcomes were measured based on the magnetic resonance imaging (MRI) results as shown in Figure 1, which was considered as the standard to diagnose ADD[13]. The image in the middle, with the largest sectional area of condylar, was chosen for mearsuring. The posterior border of the ramus (MN) was defined, and two horizontal lines perpendicular to MN were drawn: DE through the most cranial point of the condyle (P) and LT through the deepest point of the sigmoid notch (L). The condylar height was measured as the distance between DE and LT (PH). The midpoint of the intermediate zone of the disc (O) could always be clearly located. A and B were the most anterior and posterior points according to the point C, respectively.\u0026nbsp;The disc length was the sum of AO and OB. The anterior distance of disc relative to the condyle was defined as the distance between point B and point P.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data were analyzed by R version 4.1.0. Data are presented as frequencies (percentages) for categorical variables and as the mean \u0026plusmn;\u0026thinsp;standard deviation or median (interquartile range) for continuous variables, or as frequencies (percentages) for categorical variables. A paired\u003cem\u003e\u0026nbsp;t\u0026nbsp;\u003c/em\u003etest was used to compare the variables within each period, and a generalized estimating equation (GEE) [14] was used to compare the change in the variables between the two time points. Subgroup analysis was performed by GEE. Pearson correlation analysis was calculated to define the relationship between the changes of condylar height, disc length, and disc displacement distance. The 95% confidence intervals (CI) and \u003cem\u003ep\u003c/em\u003e values were calculated. A level of \u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 715 patients were diagnosed with unilateral ADD between 2017 January and 2022 December. Initially, 562 patients were between 10 to 29 years of age. For the final analysis, 149 patients (30 male and 119 female) had the complete information of follow-up period. The median age was 18.0 years and the median follow-up duration was 10 months. The participant characteristics at T0 are presented in Table 1. Here, a representative case of MRI images obtained within 8 months was shown (Fig. 2).\u0026nbsp;Condylar height of affected side was measured as 19.4mm at T0 and 19.2mm at T1 (Fig. 2A), while the condylar height of non-affected side was 19.6 mm at T0 and 20.6mm at T1 (Fig. 2B).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCondylar height changes between the groups\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eChanges in condylar height between the ADD affected side and the non-affected side during the follow-up period are shown in Figure 3 and Table 2. During the follow-up period, condylar height decreased by 0.71 mm on the ADD side (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001), and increased by 0.66 mm on the other side (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001), with a significant difference of 1.37 mm between the two sides (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSubgroup analysis in the condylar height changes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo further investigate the effect of ADD on condylar height growth in different age groups, the change of condylar height in different age subgroups were analyzed (Figure 4 and Table 3). The participants were divided into four groups: 11-14 years (n = 43), 15-17 years (n = 27), 18-20 years (n = 32), and 21-29 years (n = 47). There was no significant condylar height reduction on the affected side in 11-14 and 15-17 age groups, but there was significant growth in height on the non-affected side (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt;0.001). Both the 18-20 and 21-29 age groups had significant reductions in condylar height on the ADD side ( \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisc length and anterior displacement distance changes in the interval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Table 4 and Table 5, the disc length of the affected side was shortened by an average of 0.88mm ( \u003cem\u003ep\u003c/em\u003e \u0026lt;0.001), and the disc of the affected side shifted forward by 0.95mm ( \u003cem\u003ep\u003c/em\u003e \u0026lt;0.001). The difference was significant in both the overall group and in the\u0026nbsp;\u003c/p\u003e\n\u003cp\u003esubgroups ( \u003cem\u003ep\u003c/em\u003e \u0026lt;0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelations between the condylar height and articular disc\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePearson correlation analysis between the condylar height change, disc length and disc displacement distance are presented in Figure 5 and Table 6. The changes in overall condylar height were positively correlated with the disc length (\u003cem\u003e\u0026nbsp;p\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001) and were negatively correlated with the disc anterior displacement (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05 ).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe mandibular condyle, disc, and fossa\u0026ndash;eminence complex form the two-compartment articulation of the TMJ. The articular disc serve as a cushion to relieve stress during joint movement and stimulate the joint development. When the disc shifts forward, the abnormal pressure during mandibular movement results in the condylar bone remodelling and ramus height decreasing[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Although a substantial number of studies indicated that ADD was associated with condylar resorption[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], it is important to recognize that age also plays a role in the progression of condylar resorption in individuals with ADD. PH Buschang et al collected cephalograms of aged 6\u0026ndash;16 years in the United States and found that condylar height growth reached its peak at the age of 12\u0026ndash;14 years, with an average increase of 2 mm per year and a maximum increase of 4\u0026thinsp;~\u0026thinsp;5mm[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Lei et al evaluated the subchondral formation of cortical bone and condylar development at the ages of 10\u0026ndash;30 years, and concluded that cortical bone formation began at 12\u0026ndash;14 years of age, with most formation occurring after 20 years of age[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In light of the impact of individual and age-related factors on bone growth, we included patients with unilateral ADD, employing their own contralateral side as control, and analyzed changes in bone growth at varying ages.\u003c/p\u003e \u003cp\u003eMRI is considered the gold standard for the diagnosis of temporomandibular joint (TMJ) disease due to its ability to provide comprehensive assessment of both soft tissue and condylar bone[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The present study used MRI to measure changes of condylar height and articular disc at two follow-up visits greater than 3 months. Condylar height growth on the ADD side was 1.37mm less than the health side at a mean follow-up time of 10 months. The increase in condylar height difference was accompanied by a shortening of disc length and an increase in anterior displacement distance on the ADD side, with these changes being statistically significant. Although some studies have demonstrated that the clinical symptoms tend to be relieved during the natural ADD course[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], prolonged ADD accompanied by abnormal mechanical stress may lead to degenerative changes in the condyle and even osteoarthritis[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Thus, a normal disc position is of great importance. This is the reason why disc repositioning can exert a significant protective influence on the condyles in ADD and condylar resorption[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the present study, the impact of ADD on condylar height varied across different age subgroups. No notable alteration in condylar height was observed in patients aged 11\u0026ndash;17 years. However, a considerable increase in condylar height on the contralateral side was evident, indicating a potential inhibitory effect on condylar growth. Patients over 18-year were more inclined to have a reduced condylar height in ADD side, which suggested a bone destruction.This intergroup variability may be due to the mechanical stress induced by ADD, resulting in the condylar cartilage degeneration and bone destruction[\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. This upshot manifests as condylar growth inhibition in adolescent patients, and bone destruction in adult patients.\u003c/p\u003e \u003cp\u003eMoreover, a positive correlation was demonstrated between the degree of mandibular deviation, the articular disc shortage, disc anterior displacement, and reduced condylar height in the ADD side[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In line with previous studies, it showed that the difference in condylar height between the two time points was positively correlated with the disc length. This finding indicated that the disc condition is also important for the condyle. In the previous studies, it proved that disc repositioning surgery can be an effective surgery to relieve condylar resorption and facial deformities [28]. Thus, clinicians should pay more attention to the younger ADD patients with a short disc. For these patients, an early and appropriate intervention is necessary.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe study examined the condylar height changes over time in individuals with unilateral ADD across different age groups. In patients with ADD aged between 11 and 17 years, the non-affected condyle demonstrates relatively accelerated growth in comparison to the affected condylar. Whereas, in the higher age groups, the affected condyle exhibites significant resorption. These findings indicated that ADD disrupts the normal physiological state of condyle in all age groups. In conclusion, ADD results in condylar growth inhibition in the young patients, and condylar resorption in the adult patients. Clincians should pay more attention to the condylar condition in ADD patients, and appropriate intervention is necessary, especially in the young patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThe Ethics Committee of the Ninth People\u0026apos;s Hospital affiliated to the Shanghai Jiao Tong University School of Medicine approved this study (SH9H-2020-T7\u0026ndash;1). The ethical approval has been submitted. All participants have signed informed consent\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e National Natural Science Foundation of China (82071134，82401148); Dominant disease biological sample project of the Ninth People\u0026apos;s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (YBKA202201)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eSiyu Wu, Pei Shen and Chi Yang provided conception and design of study, analyzed data;\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eSiyu Wu and Dahe Zhang drafted the manuscript, all authors reviewed and approved the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eNaeije M, Te Veldhuis AH, Te Veldhuis EC, Visscher CM, Lobbezoo F. Disc displacement within the human temporomandibular joint: a systematic review of a \u0026ldquo;noisy annoyance.\u0026rdquo; J Oral Rehabil. 2013;40:139\u0026ndash;58.\u003c/li\u003e\n\u003cli\u003eManfredini D, Guarda-Nardini L, Winocur E, Piccotti F, Ahlberg J, Lobbezoo F. Research diagnostic criteria for temporomandibular disorders: a systematic review of axis I epidemiologic findings. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011;112:453\u0026ndash;62.\u003c/li\u003e\n\u003cli\u003eNebbe B, Major PW. Prevalence of TMJ disc displacement in a pre-orthodontic adolescent sample. Angle Orthod. 2000;70:454\u0026ndash;63.\u003c/li\u003e\n\u003cli\u003eHall HD. Intra-articular disc displacement part II: Its significant role in temporomandibular joint pathology. Journal of Oral and Maxillofacial Surgery. 1995;53:1073\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eK O, N I, K M, T M, K M, S K, et al. Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. The British journal of oral \u0026amp; maxillofacial surgery. 2020;58.\u003c/li\u003e\n\u003cli\u003eXie Q, Yang C, He D, Cai X, Ma Z. Is mandibular asymmetry more frequent and severe with unilateral disc displacement? J Craniomaxillofac Surg. 2015;43:81\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eZhuo Z, Cai X, Xie Q. Is anterior disc displacement without reduction associated with temporomandibular joint condylar height in juvenile patients younger than 20 years? J Oral Maxillofac Surg. 2015;73:843\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eXie Q, Yang C, He D, Cai X, Ma Z, Shen Y, et al. Will unilateral temporomandibular joint anterior disc displacement in teenagers lead to asymmetry of condyle and mandible? A longitudinal study. J Craniomaxillofac Surg. 2016;44:590\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eZhu H, He D, Yang Z, Song X, Ellis E. The effect of disc repositioning and post-operative functional splint for the treatment of anterior disc displacement in juvenile patients with Class II malocclusion. J Craniomaxillofac Surg. 2019;47:66\u0026ndash;72.\u003c/li\u003e\n\u003cli\u003eLiu Z, Xie Q, Yang C, Chen M, Bai G, Abdelrehem A. The effect of arthroscopic disc repositioning on facial growth in juvenile patients with unilateral anterior disc displacement. J Craniomaxillofac Surg. 2020;48:765\u0026ndash;71.\u003c/li\u003e\n\u003cli\u003eLei J, Liu M-Q, Yap AUJ, Fu K-Y. Condylar subchondral formation of cortical bone in adolescents and young adults. Br J Oral Maxillofac Surg. 2013;51:63\u0026ndash;8.\u003c/li\u003e\n\u003cli\u003eZhang D, Abdelrehem A, Luo Y, Shen P, Yang C. Effect of arthroscopic discopexy on condylar growth in adolescents with temporomandibular joint disc displacement without reduction: A retrospective self-controlled case series study. J Craniomaxillofac Surg. 2024;52:157\u0026ndash;64.\u003c/li\u003e\n\u003cli\u003eManfredini D, Guarda-Nardini L. Agreement between Research Diagnostic Criteria for Temporomandibular Disorders and magnetic resonance diagnoses of temporomandibular disc displacement in a patient population. Int J Oral Maxillofac Surg. 2008;37:612\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eResiduals analysis of the generalized linear models for longitudinal data - PubMed. https://pubmed.ncbi.nlm.nih.gov/10814977/. Accessed 20 Jul 2024.\u003c/li\u003e\n\u003cli\u003ePart I: Development and Physiology of the Temporomandibular Joint - PubMed. https://pubmed.ncbi.nlm.nih.gov/29948821/. Accessed 20 Jul 2024.\u003c/li\u003e\n\u003cli\u003eWu Y, Cisewski SE, Coombs MC, Brown MH, Wei F, She X, et al. Effect of Sustained Joint Loading on TMJ Disc Nutrient Environment. J Dent Res. 2019;98:888\u0026ndash;95.\u003c/li\u003e\n\u003cli\u003eZhang X, Sun J, He D. Review of the studies on the relationship and treatment of anterior disk displacement and dentofacial deformity in adolescents. Oral Surg Oral Med Oral Pathol Oral Radiol. 2023;135:470\u0026ndash;4.\u003c/li\u003e\n\u003cli\u003eBuschang PH, Santos-Pinto A, Demirjian A. Incremental growth charts for condylar growth between 6 and 16 years of age. Eur J Orthod. 1999;21:167\u0026ndash;73.\u003c/li\u003e\n\u003cli\u003eMontesinos GA, de Castro Lopes SLP, Trivino T, S\u0026aacute;nchez JA, Maeda FA, de Freitas CF, et al. Subjective analysis of the application of enhancement filters on magnetic resonance imaging of the temporomandibular joint. Oral Surg Oral Med Oral Pathol Oral Radiol. 2019;127:552\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eSato S, Kawamura H, Nagasaka H, Motegi K. The natural course of anterior disc displacement without reduction in the temporomandibular joint: follow-up at 6, 12, and 18 months. J Oral Maxillofac Surg. 1997;55:234\u0026ndash;8; discussion 238-239.\u003c/li\u003e\n\u003cli\u003eKurita K, Westesson PL, Yuasa H, Toyama M, Machida J, Ogi N. Natural course of untreated symptomatic temporomandibular joint disc displacement without reduction. J Dent Res. 1998;77:361\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eZou L, Yang K, Yu Y, Wang C, Zhao J, Lu C, et al. Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA. Oral Dis. 2024. https://doi.org/10.1111/odi.14871.\u003c/li\u003e\n\u003cli\u003eShen P, Bai G, Xie Q, Fang Y, Pan L, Geng Y, et al. Efficacy of Arthroscopic Discopexy on Condylar Growth in Temporomandibular Joint Anterior Disc Displacement: A Randomized Clinical Trial. Plast Reconstr Surg. 2023. https://doi.org/10.1097/PRS.0000000000010966.\u003c/li\u003e\n\u003cli\u003eMirahmadi F, Koolstra JH, Lobbezoo F, van Lenthe GH, Ghazanfari S, Snabel J, et al. Mechanical stiffness of TMJ condylar cartilage increases after artificial aging by ribose. Arch Oral Biol. 2018;87:102\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eRahmati M, Nalesso G, Mobasheri A, Mozafari M. Aging and osteoarthritis: Central role of the extracellular matrix. Ageing Res Rev. 2017;40:20\u0026ndash;30.\u003c/li\u003e\n\u003cli\u003eCai S, Zou Y, Zhao Y, Lin H, Zheng D, Xu L, et al. Mechanical stress reduces secreted frizzled-related protein expression and promotes temporomandibular joint osteoarthritis via Wnt/\u0026beta;-catenin signaling. Bone. 2022;161:116445.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e \u003cstrong\u003eParticipant characteristics at T0\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 217px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eValue (n = 149)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eSex, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e30 (20.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e119(79.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eAge(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e18(14, 23)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eSite, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 217px;\"\u003e\n \u003cp\u003eLeft\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e100(67.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 217px;\"\u003e\n \u003cp\u003eRight\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;49(32.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eFollow-up duration, mon, median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e10(7, 15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eJoint sounds, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;125(83.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;24(16.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003ePre-auricular pain, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;58(38.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;91(61.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eOpening restriction, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;56(37.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;93(62.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eMIO (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e38.2\u0026plusmn;1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003eMandibular asymmetry, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\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: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;79(53.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 217px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;24(47.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eMIO: maximum interincisal opening\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Condylar height changes in the follow-up period.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 245px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSide \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEstimate (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 245px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAffected (n = 149)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e-0.71(-0.91 to -0.51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u0026nbsp;\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 245px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNon-affected (n = 149)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e0.66(0.51 to 0.80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u0026nbsp;\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 245px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAffected VS Non-affected\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 198px;\"\u003e\n \u003cp\u003e-1.37(-1.50 to -1.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 109px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u0026nbsp;\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea Mean change differences within groups were calculated by Paired \u003cem\u003et\u003c/em\u003e-test.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eb Mean change differences between groups were calculated by GEE.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Condylar height changes of subgroups in the follow-up period.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"646\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 38px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 27.709%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAffected\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 29.7213%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNon-affected\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAffected VS Non-affected\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u003cstrong\u003egroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT1-T0 (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003ca href=\"https://www.sciencedirect.com/science/article/pii/S101051822300104X#tbl2fna\"\u003e\u003cstrong\u003e\u003csup\u003e\u003c/sup\u003e\u003c/strong\u003e\u003c/a\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT1-T0 (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEstimate (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003eP-value\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e11~14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 38px;\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.08(-0.39 to 0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e0.597\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e1.19(0.90 to 1.49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e-1.27(-1.48 to -1.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e15~17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 38px;\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.49(-0.86 to -0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e0.110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e0.82(0.11 to 0.59)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e-1.32(-1.52 to -1.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e18~20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 38px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.64(-0.95 to -0.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e0.66(0.41 to 0.90)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e-1.29(-1.49 to -1.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e21~29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 38px;\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-1.46(-1.88 to -1.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e0.07(-0.18 to 0.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e0.567\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e-1.54(-1.78 to -1.30)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 38px;\"\u003e\n \u003cp\u003e149\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.71(-0.91 to -0.51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.8236%;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8854%;\"\u003e\n \u003cp\u003e0.66(0.51 to 0.80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e-1.37(-1.50 to -1.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea Mean change differences within groups were calculated by Paired \u003cem\u003et\u003c/em\u003e-test.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eb Mean change differences between groups were calculated by GEE.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eTable 4. Disc length and disc anterior distance changes in overall.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"581\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 141px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 227px;\"\u003e\n \u003cp\u003eDisc length(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 212px;\"\u003e\n \u003cp\u003eAnterior distance(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 141px;\"\u003e\n \u003cp\u003eT0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 227px;\"\u003e\n \u003cp\u003e7.97\u0026plusmn;1.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 212px;\"\u003e\n \u003cp\u003e5.24\u0026plusmn;2.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 141px;\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 227px;\"\u003e\n \u003cp\u003e7.09\u0026plusmn;2.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 212px;\"\u003e\n \u003cp\u003e6.20\u0026plusmn;3.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 141px;\"\u003e\n \u003cp\u003eMean difference of T1 vs T0 (95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 227px;\"\u003e\n \u003cp\u003e-0.88(-1.03 to -0.73)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 212px;\"\u003e\n \u003cp\u003e0.95( 0.76 to 1.14)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 141px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 227px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 212px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea\u0026nbsp;Mean change differences between groups were calculated by Paired\u003cem\u003e\u0026nbsp;t\u003c/em\u003e-test\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Disc length and disc anterior distance changes among subgroup.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"794\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 28px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 331px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDisc length\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 378px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnterior distance\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003eMean difference of T1 vs T0\u003cstrong\u003e\u0026nbsp;(95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003csup\u003e\u0026nbsp;a\u003c/sup\u003e \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eMean difference of T1 vs T0 \u003cstrong\u003e(95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e11~14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e8.30\u0026plusmn;1.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e7.34\u0026plusmn;1.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.96(-1.31 to -0.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e4.70(4.00,5.55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e4.70(4.60,5.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0.65(0.30 to 1.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e15~17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e7.84\u0026plusmn;1.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e7.31\u0026plusmn;1.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.53(-0.81 to -0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e4.67\u0026plusmn;1.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e5.66\u0026plusmn;1.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0.98(0.50 to 1.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e18~20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e8.10\u0026plusmn;1.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e6.83\u0026plusmn;1.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-1.27(-1.66 to 0.89)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e4.30(3.80, 6.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e5.95(4.95,7.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.11(0.68 to 1.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e21~29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e7.66\u0026plusmn;1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e6.91\u0026plusmn;1.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 123px;\"\u003e\n \u003cp\u003e-0.75(-0.93 to -0.57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e6.30(5.00,7.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e7.30(6.25,8.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.09(0.77 to 1.41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea\u0026nbsp;Mean change differences between groups were calculated by Paired\u003cem\u003e\u0026nbsp;t\u003c/em\u003e-test\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6. Correlations between the condylar height and articular disc among the subgroups.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"671\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003evariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 66px;\"\u003e\n \u003cp\u003e11-14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-disc length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-anterior distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e-0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 66px;\"\u003e\n \u003cp\u003e15-17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-disc length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-anterior distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e-0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 66px;\"\u003e\n \u003cp\u003e18-20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-disc length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-anterior distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 66px;\"\u003e\n \u003cp\u003e21-29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-disc length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e△H-anterior distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e-0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ePC: Pearson correlation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e△H: Height difference between T1 and T0 of ADD side in MRI\u003c/p\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":"Temporomandibular Joint Disorders, Temporomandibular Joint Disc, Mandibular Condyle, Age Groups, Adolescent Development","lastPublishedDoi":"10.21203/rs.3.rs-5877385/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5877385/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003eTemporomandibular joint ADD is highly prevalent and harmful, and some patients have no obvious clinical symptoms, but it can cause facial asymmetry, mandibular retrusion and other dental and maxillofacial deformities. Nevertheless, the impact of ADD on condylar height in individuals of varying age groups remains uncertain particularly with regard to condylar heights at different stages of development. The aim of this retrospective self-controlled study was to investigate the association between condylar height and temporomandibular joint anterior disc displacement (ADD) in different age groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods:\u003c/strong\u003e Patient characteristics, condylar height, disc length, and displacement distance at the baseline (T0) and the second follow-up visit (T1) were collected, and the differences between the two-time points were analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eA total of 149 patients who were diagnosed with unilateral ADD were included in the study. In comparison to T0, the affected condylar height decreased 0.66 mm, whereas the non-affected condylar height increased 1.37 mm at T1. The further subgroup analysis revealed no statistically significant change in the affected condylar height of the 11-17 age group. However, a considerable reduction in height was observed on the ADD side in the subgroup above 18 years, when compared to the T0 period.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e ADD disrupts the normal development of condylar bone and cartilage in all age groups. Clinician recognises that ADD results in condylar growth inhibition in the young and condylar resorption in the adult.\u003c/p\u003e","manuscriptTitle":"Effect of temporomandibular joint anterior disc displacement on condylar height in different age groups","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-24 15:42:50","doi":"10.21203/rs.3.rs-5877385/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-01-30T10:41:26+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-22T11:48:12+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-01-22T11:47:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-01-22T04:33:04+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":"86900bb1-7632-4beb-9683-4d7e2db8e365","owner":[],"postedDate":"January 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-07T16:06:40+00:00","versionOfRecord":{"articleIdentity":"rs-5877385","link":"https://doi.org/10.1186/s12903-025-06121-z","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2025-07-04 15:57:21","publishedOnDateReadable":"July 4th, 2025"},"versionCreatedAt":"2025-01-24 15:42:50","video":"","vorDoi":"10.1186/s12903-025-06121-z","vorDoiUrl":"https://doi.org/10.1186/s12903-025-06121-z","workflowStages":[]},"version":"v1","identity":"rs-5877385","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5877385","identity":"rs-5877385","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}