The impact of tonsillar hypertrophy on skeletal relapse in skeletal Class III patients treated with two-jaw orthognathic surgery

The impact of tonsillar hypertrophy on skeletal relapse in skeletal Class III patients treated with two-jaw orthognathic surgery | 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 The impact of tonsillar hypertrophy on skeletal relapse in skeletal Class III patients treated with two-jaw orthognathic surgery Chenxing Lv, Liu Yang, Xuewen Yang, Tingting Zhao, Fang Hua, Xiong Chen, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6479982/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective: This study aimed to determine if tonsillar hypertrophy (TH) influenced the postsurgical skeletal stability of Class III patients receiving two-jaw orthognathic surgery. Materials and Methods: Sixty patients with skeletal Class III malocclusion corrected by conventional two-jaw surgery were included in the study. Patients were divided into the TH group (n=30) and normal tonsil (NT) group (n=30) depending on tonsil size on the presurgical cone beam computed tomography. Serial lateral cephalograms were traced and analyzed at 3 stages: before surgery (T0), within 2 weeks of surgery (T1), and 1 year after surgery (T2). Linear and angular cephalometric parameters were used to evaluate the surgical change (T0-T1) and postsurgical relapse (T1-T2). The data were analyzed with the paired t-test, independent t-test, chi-square test and Pearson correlation analysis. Results: From T0 to T1, the TH and NT groups showed a similar surgical pattern of the maxilla and mandible for repositioning. From T1 to T2, significant differences in skeletal relapse were observed in the mandible horizontally but not in the maxilla between the 2 groups. Compared to the NT group, the TH group exhibited significantly more forward movement at point B and Pog as well as a greater increase in SNB angle one year after surgery. Conclusions/ Clinical relevance: Skeletal Class III patients with TH presented considerably different skeletal relapses in the mandible following two-jaw orthognathic surgery compared to those with NT. The factor of TH needs to be considered when orthognathic surgery is indicated in Class III patients. Tonsillar hypertrophy Class III malocclusion Skeletal stability Relapse Orthognathic surgery Figures Figure 1 Figure 2 Figure 3 Introduction Skeletal Class III malocclusion presents with skeletal imbalances in the size of the maxilla and mandible or their position, which is commonly corrected by combined orthognathic surgery and orthodontic treatment [ 1 ]. Though the efficacy of orthognathic surgery is time-tested in terms of improving facial aesthetics and occlusion in Class III malocclusions, the issue of possible postsurgical relapse has always bothered clinicians. Various factors have been suggested to influence the stability of surgical results, including the surgical procedures, type of fixation, amount of surgical movement, and maxillomandibular counterclockwise rotation[ 2 ]. Breathing, swallowing, and alteration of the functional matrix such as the tongue may also contribute to the occurrence of relapse[ 3 , 4 ]. In recent years, the narrowing of the pharyngeal airway after mandibular setback surgery has gained increased attention because of its possible relationship to snoring and sleep apnea[ 5 ]. Studies have shown that the correction of Class III malocclusion with either single-jaw or two-jaw surgery caused a notable reduction in the oropharyngeal and hypopharyngeal airways[ 6 – 8 ], with the changes in the positions of the hyoid bone and tongue[ 9 ]. However, the degree of airway reduction was smaller in two-jaw than in single-jaw surgery[ 10 ]. There is still a great deal of controversy regarding whether these airway changes cause the induction of obstructive sleep apnea (OSA), with some studies reporting the development of postsurgical OSA and the decline of sleep quality[ 11 – 13 ], whereas others claiming that these reductions were not accompanied by signs or symptoms of OSA[ 8 , 14 , 15 ]. The palatine tonsils are lymphatic tissues located on the lateral walls of the oropharynx. As one of the known causes of OSA in both children and adults, tonsillar hypertrophy (TH) plays an important role in the obstruction of the upper airway. The previous literature reported that children with isolated TH had a more forward position of the mandible and a higher rate of Class III malocclusion [ 16 ]. The evidence of an association between TH and the mandibular protrusion suggested that children with hypertrophic tonsils are forced into a more anterior position of the tongue and mandible to increase the airway volume for the function of breathing. It was reported that the prevalence of TH in adult patients seeking orthodontic treatment was 23.2%, and the proportion of adults with TH in Class Ⅲ group was significantly higher than that in Class Ⅰ and Class Ⅱ groups[ 17 ]. For adult Class III patients receiving mandibular setback surgery, hypertrophic tonsil tissues may contribute to the forward movement of the mandible to compensate for the loss of airway after surgery and thus influence the final skeletal position. Previous studies have shown that the airway adapts to these surgical changes and returns to presurgical values during the follow-up period [ 18 ]. Additionally, it is reported that dimensional recovery of the pharyngeal airway was correlated with postsurgical skeletal relapse[ 7 , 18 ]. However, very few studies are available that consider TH as one of the potential risk factors influencing skeletal stability after surgery. Therefore, the purpose of this study was to compare the skeletal stability after correction of Class III malocclusion by two-jaw surgery between the patients with and without TH. This study tested the hypothesis that there would be a difference in skeletal relapse between these 2 groups of patients. Materials and Methods In this retrospective cohort study, the patients were recruited from a population with skeletal Class III malocclusion who underwent orthognathic surgery at the XXX from January 2016 to June 2022. This study was reviewed and approved by the Ethics Committees of XXX (No. XXX). Consecutive adult patients were selected based on the following inclusion criteria: 1) bilateral Class III canine and molar relationships with ANB angle lower than 0°, 2) completion of conventional surgical-orthodontic treatment, 3) orthodontic treatment with no extraction, except for the third molars, 4) one-piece Le Fort I osteotomy with maxillary advancement and bilateral sagittal split osteotomy (BSSO) with mandibular setback performed, 5) no significant facial asymmetry and transverse discrepancy (< 3 mm midline deviation, < 5 mm arch width discordance), and 6) patients with a complete series of identifiable lateral cephalograms and presurgical cone-beam computed tomography (CBCT). Patients were excluded as study subjects if they were treated with surgery-first approaches without presurgical orthodontics or had cleft lip and palate, or other craniofacial syndromes. Patients were classified into 2 groups according to the tonsil size evaluated by the presurgical CBCT: TH group with grade 3 and 4 tonsils, and normal tonsil (NT) group with grade 0, 1, and 2 tonsils[ 19 , 20 ]. The narrowest distance between the tonsils in the horizontal and coronal plane of CBCT was used to classify relative tonsil sizes into 5 grades (Fig. 1 ), and the measurement of tonsil size was carried out by an otolaryngologist and an orthodontist. Surgical and orthodontic procedures In surgical and orthodontic treatment, the 3 general stages were presurgical orthodontic treatment, the surgical procedure, and postsurgical orthodontic treatment. A team of 2 experienced surgeons and 2 experienced orthodontists was involved in performing the orthognathic surgeries and orthodontic treatments. Fixed appliances were normally used in presurgical and postsurgical orthodontic stages. No expansion protocol except orthodontic wires was performed in either group. During the Le Fort I osteotomy and BSSO, metal plates and monocortical screws were used for rigid internal fixation of the osteotomized bony segments. After the operation, the elastics between stainless steel wires and an interocclusal splint were used to maintain the maxillomandibular positions for 2 to 4 weeks. Functional training was prescribed to patients for 2 weeks after intermaxillary fixation release. Cephalometric analysis Lateral cephalograms were obtained for each patient with the same cephalostat (Soredex, Tuusula, Finland) before orthognathic surgery (T0), within 2 weeks of surgery (T1), and 1 year after surgery (T2, defined as 10–14 months after the operation). All cephalograms were digitized for cephalometric analysis with Dolphin software (Dolphin Imaging and Management Solutions, Chatsworth, CA, USA) by the same researcher blinded to the patient details. Definitions of the landmarks, reference planes, and measured variables are shown in Fig. 2 . The measurements were not corrected for magnification (5.6%). An x–y coordinate system was constructed for serial linear measurements, with sella as the origin coordinate. The x-axis passed through sella and rotated 7° below the sella-nasion plane. The y-axis was perpendicular to the x-axis and passed through sella. The vertical and horizontal positions of the landmarks were recorded as linear measurements in relation to the x- and y-axes, respectively. Surgical change and postsurgical relapse were measured by superimposing traced serial lateral cephalograms along the sella–nasion line and cranial base structures. Sample size determination A sample size calculation was performed based on the primary outcome, that is, postsurgical horizontal changes of point B. Since no published study with the same design was available, the sample size was calculated based on the data from the pre-trial study and reasonable assumptions. It was assumed that the mean value of relapse of point B in the TH group was 1 mm more than the NT group, and standard deviation (SD) values were the same in both groups. To detect a 1-mm difference with a 1.3-mm SD (calculated from 10 patients with TH in the pre-trial study) between groups and reach an 80% power using PASS software 15 (Version 15.0, NCSS, Kaysville, UT), at least 26 subjects in each group were required. Statistical analysis For analysis of the method error, 20 randomly selected radiographs from the 7 patients were retraced and digitized at a 2-week interval. Dahlberg’s method was used to determine the error between the double measurements [ 21 ]. The method error of the linear measurements ranged from 0.17 to 0.58 mm and angular measurements ranged from 0.1 to 0.5 °, which were statistically minor. Descriptive statistics, including means and SDs, were used to describe each variable analyzed in the study. The Shapiro–Wilk test was conducted to evaluate the normal distribution of variables. The independent t-test test was used to compare the initial measurements, surgical changes (T0 to T1), and postsurgical relapse (T1 to T2) between the TH and NT groups. The paired t-test was used to evaluate surgical and postsurgical changes of related variables in each group. chi-square test and correlation analysis. Within each group, Pearson correlation coefficients were calculated to analyze whether skeletal relapse was related to surgical repositioning. Differences were considered significant at a P value lower than 0.05. Statistical analysis was performed using SPSS software (Version 24.0, IBM, Armonk, NY). Results Patients’ characteristics and presurgical morphology The present study consisted of 60 patients: 30 patients were in the TH group (12 males, 18 females; average age, 22.0 ± 2.8 years) and 30 patients were in the NT group (10 males, 20 females; average age, 22.3 ± 3.3 years). Fourteen patients received the genioplasty combined with two-jaw surgery, 7 in each group. Demographic characteristics and cephalometric variables describing the presurgical skeletal and dentofacial morphology of both groups were similar at T0 (Table I), without significant differences between the groups. The measurement of tonsil sizes of the patients participating in this study is shown in Supplementary Table I. Table I. Comparison of age and cephalometric measurements at T0 between 2 groups. Variables TH group NT group P Value a Mean SD Mean SD Age (yr) at T0 22.04 2.76 22.34 3.30 0.712 SNA (°) 80.35 3.06 79.51 4.16 0.380 SNB (°) 86.27 3.84 85.46 4.43 0.454 ANB (°) -5.93 3.09 -5.96 2.39 0.963 SN-MP (°) 32.68 6.25 33.39 7.76 0.698 U1-SN (°) 111.10 8.02 109.23 8.05 0.272 IMPA (°) 87.97 6.41 87.36 7.36 0.736 Overjet (mm) -5.17 3.62 -5.85 2.14 0.362 Overbite (mm) 0.97 1.93 0.83 1.92 0.779 A-x(mm) 58.83 3.71 58.97 5.02 0.905 ANS-x(mm) 64.16 3.69 64.22 5.17 0.959 PNS-x(mm) 17.00 3.17 17.95 3.20 0.251 B-x(mm) 67.25 6.56 66.72 7.72 0.775 Pog-x(mm) 68.34 7.67 68.16 8.84 0.932 A-y(mm) 51.82 4.03 51.34 3.34 0.616 ANS-y(mm) 45.15 3.70 44.44 2.24 0.374 PNS-y(mm) 44.22 3.63 44.07 3.09 0.869 B-y(mm) 88.67 7.90 87.08 6.76 0.405 Pog-y(mm) 103.53 9.03 103.23 9.11 0.896 Note. SNA, angle of lines connecting the sella, nasion, and A point; SNB, angle of lines connecting the sella, nasion, and B point; ANB, angle of lines connecting A point, nasion, and B point; SN-MP, angle of SN plane to mandibular plane; U1-SN, angle between upper incisor axis and SN plane; IMPA, angle between lower incisor axis and mandibular plane; Overjet, distance between tips of upper central incisor and lower central incisor parallel to x-axis; Overbite, distance between tips of upper central incisor and lower central incisor parallel to y-axis; A-x, horizontal position of A point; A-y, vertical position of A point; ANS-x, horizontal position of ANS; ANS-y, vertical position of ANS; PNS-x, horizontal position of PNS; PNS-y, vertical position of PNS; B-x, horizontal position of B point; B-y, vertical position of B point; Pog-x, horizontal position of Pog; Pog-y, vertical position of Pog. T0, before surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation. a by independent t test Comparison of surgical changes (T0 to T1) in each group and between the 2 groups Table 2 shows the surgical changes in cephalometric variables in both groups. For maxilla from T0 to T1, the TH and NT groups showed significant increases in horizontal linear measurements (A-x, ANS-x, PNS-x, all P < 0.001). For mandibular measurements, both groups showed significant decreases in horizontal linear measurements (B-x, Pog-x, all P < 0.001) and significant increases in vertical linear measurements (B-y, Pog-y, all P < 0.01) from T0 to T1. Regarding the angular measurements, both groups exhibited significant changes in the SNA, SNB, and ANB from T0 to T1, which tended to be within the normal range. Regarding the dental changes, the TH and NT groups showed significant increases in overjet and overbite. In contrast, all horizontal, vertical, and angular changes of the maxilla and mandible and dental changes for surgical repositioning did not show relevant differences between the 2 groups (all P > 0.05). Table II. Comparison of surgical changes in cephalometric measurements between 2 groups. Variables (T0 to T1) TH Group (Mean ± SD) NT Group (Mean ± SD) P value a Horizontal changes (mm) A-x 3.26 ± 1.42*** 3.11 ± 1.02*** 0.647 ANS-x 2.95 ± 1.82*** 2.95 ± 1.03*** 0.999 PNS-x 2.00 ± 1.55*** 2.18 ± 0.81*** 0.568 B-x -6.44 ± 4.16*** -6.28 ± 3.15*** 0.796 Pog-x -6.37 ± 4.11*** -6.26 ± 3.64*** 0.779 Overjet 8.25 ± 3.90*** 8.82 ± 2.34*** 0.394 Vertical changes (mm) A-y 0.36 ± 1.64 0.17 ± 1.55 0.379 ANS-y 0.29 ± 1.45 0.31 ± 1.44 0.918 PNS-y 0.41 ± 1.29 0.32 ± 0.92 0.446 B-y 1.54 ± 2.37*** 1.33 ± 2.69** 0.682 Pog-y 1.61 ± 2.49*** 1.31 ± 3.29** 0.579 Overbite -1.04 ± 1.90** -0.71 ± 1.92* 0.502 Angular changes (°) SNA 3.25 ± 1.55*** 2.99 ± 0.96*** 0.428 SNB -3.80 ± 2.20*** -3.67 ± 1.60*** 0.912 ANB 7.05 ± 2.87*** 6.66 ± 1.94*** 0.537 Note. Definitions of cephalometric terms are provided in Table I. Horizontal changes, positive values indicate forward movement; Vertical changes, positive values indicate downward movement; Angular changes, positive values indicate increase; Overjet, positive values indicate increase; Overbite, positive values indicate increase. T0, before surgery; T1, within 2 weeks of surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation. *P < 0.05, **P < 0.01, ***P < 0.001, significant difference between T0 and T1 by paired t test. a by independent t test Comparison of postsurgical changes (T1 to T2) in each group and between the 2 groups As shown in Table 3, the TH and NT groups showed significant relapse in horizontal linear measurements of the maxilla (A-x, ANS-x, PNS-x), with no significant differences between the groups. Both groups showed significant relapse in horizontal and vertical linear measurements of the mandible, but significant between-group differences were only found horizontally. The TH group showed significantly greater increases in the B-x (2.24 vs 1.57 mm, P < 0.05) and the Pog-x (2.57 vs 1.87 mm, P 0.05; -2.76 vs -2.35 mm for the Pog- y, P > 0.05) than the NS group, but the between-group difference was not statistically significant. From T1 to T2, both groups exhibited significant changes in 3 angular measurements and the between-group differences were statistically significant at SNB (1.40 vs 0.97 °, P < 0.05) and ANB (-2.23 vs -1.66 °, P < 0.05). Horizontally, significant between-group differences in the relapse ratio were observed in the mandible (37.13 vs 27.47%, P 0.05). In addition, the TH group showed greater decreases in overjet (-0.81 vs -0.39 mm, P > 0.05) than the NT group for postsurgical dental changes, but the between-group difference was not significant. Table III. Comparison of postsurgical changes in cephalometric measurements and ratio of relapse between 2 groups. Variables (T1 to T2) TH Group (Mean ± SD) NT Group (Mean ± SD) P value a Horizontal changes (mm) A-x -0.73 ± 0.35*** -0.67 ± 0.31*** 0.450 ANS-x -0.75 ± 0.64*** -0.66 ± 0.38*** 0.584 PNS-x -0.61 ± 0.63*** -0.54 ± 0.34*** 0.433 B-x 2.24 ± 1.47*** 1.57 ± 1.12*** 0.037 Pog-x 2.57 ± 1.66*** 1.87 ± 1.19*** 0.040 Overjet -0.81 ± 0.84*** -0.39 ± 1.07 0.142 Vertical changes (mm) A-y -0.15 ± 0.73 -0.11 ± 0.55 0.801 ANS-y -0.14 ± 0.72 -0.12 ± 0.57 0.880 PNS-y -0.21 ± 0.54 -0.17 ± 0.41 0.551 B-y -2.99 ± 1.81*** -2.57 ± 1.34*** 0.261 Pog-y -2.76 ± 1.92*** -2.35 ± 1.50*** 0.395 Overbite 1.40 ± 1.16*** 1.53 ± 1.09*** 0.647 Angular changes (°) SNA -0.83 ± 0.48*** -0.69 ± 0.38*** 0.320 SNB 1.40 ± 0.83*** 0.97 ± 0.62*** 0.042 ANB -2.23 ± 0.85*** -1.66 ± 0.74*** 0.015 Ratio of relapse (%) A-x:(T1-T2)/(T0-T1) 25.14 ± 11.43 22.99 ± 10.81 0.457 B-x:(T1-T2)/(T0-T1) 37.13 ± 15.66 27.47 ± 17.15 0.026 Note. Definitions of cephalometric terms are provided in Table I. Horizontal changes, positive values indicate forward movement; Vertical changes, positive values indicate downward movement. Angular changes, positive values indicate increase; Overjet, positive values indicate increase; Overbite, positive values indicate increase. T1, within 2 weeks of surgery T2, 1 year after surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation. ***P < 0.001, significant difference between T1 and T2 by paired t test. a by independent t test. The distribution of relapse at the B point was categorized into 2 groups: less than or equal to 2 mm and greater than 2 mm. The results showed that 17 (57%) and 6 (20%) subjects of the TH and NT groups, respectively, relapsed greater than 2 mm. The relapse less than or equal to 2 mm was more dominant in the NT group (80%) than in the TH group (43%; P < 0.05; Fig. 3 ). Relation between surgical changes and postsurgical changes in each group In the 2 groups, horizontal relapses at point A and point B were significantly correlated with the amounts of mandibular setback and maxillary advancement (Supplementary Table II). Discussion This retrospective cohort study was performed to test the hypothesis that the TH group would present a different degree of skeletal stability compared to the NT group. In this study, the 2 groups appeared to have similar presurgical conditions and surgical skeletal changes, which presented a homogeneity for the evaluation of the postsurgical relapse. During the postsurgical period (T1 to T2), the TH and NT groups showed the backward and upward movement of the maxilla and there were no differences in the amount of relapse at point A, ANS, and PNS, SNA between the 2 groups. Although the horizontal and angular relapses of the maxilla were statistically significant in both groups, these changes might be clinically insignificant because they were less than 1 mm or 1° on average. Consistent with previous studies that showed good stability of the maxilla in bimaxillary surgery to correct Class III malocclusion[ 1 , 22 ], both groups in this study showed a stable position of the maxilla from T1 to T2 with a similar relapse ratio at point A. This suggested that the presence of TH did not affect the skeletal relapse of the maxilla in bimaxillary surgery during the postsurgical phase. It can be explained that hypertrophic tonsils occupy the airway at the level of the oropharynx, which is close to the root of the tongue and mandible and may have a limited effect on the skeletal relapse of the maxilla. Stable maintenance of the postsurgical mandibular position is very important when treating Class III malocclusion through the surgical-orthodontic approach. In accordance with some studies showing that the mandible displaced in the forward and upward direction postsurgically[ 23 , 24 ], both groups in this study had a similar relapse pattern of the mandible 1 year after surgery. However, significant differences in skeletal relapse were observed in the mandible between the groups. The TH group showed significantly greater increases in horizontal measurements of point B and Pog, greater increases in SNB, and greater decreases in ANB than the NT group from T1 to T2, indicating more forward movement of the mandible as relapse. Significant differences between groups in ANB were mainly linked to changes in SNB rather than SNA. Proffit et al.[ 25 ] suggested that postsurgical changes exceeding 2 mm or 2° could be considered clinically significant. The results showed that patients with a relapse greater than 2 mm comprised 57% of the TH group versus only 20% of the NT group. In addition, the TH group showed a higher relapse ratio in the mandible than the NT group. These results suggested that TH might be a risk factor for horizontal relapse after the mandibular setback in two-jaw surgery, which could be explained by the enlarged tonsil tissues pushing forward the tongue and mandible that had been retracted during the operation. The dependent functions such as breathing attempt to compensate for the encountered alterations in the oral environment and influence the skeletal stability of hard tissues. The genioplasty could influence the actual changes of the pogonion position during and after the surgery, so we chose the postsurgical changes of point B as the primary outcome in terms of mandible relapse. In addition to the group difference, relapse at point B can also be triggered by various factors including the amount of mandibular setback, counterclockwise rotation of the mandible, and condylar position[ 22 , 26 ]. A correlation has been established between the amount of mandibular setback and skeletal relapse in both groups, as reported in previous studies[ 24 ]. Considering the presence of the interocclusal splint during the immediate postsurgical radiograph (T1), it was expected that the mandible would rotate forward and upward because of autorotation after the removal of surgical splints. During the postsurgical phase, the mandible moved upward more in the TH group, but the between-group difference was not statistically significant, suggesting that the counterclockwise rotation of the mandible did not significantly contribute to the greater horizontal relapse at point B in the TH group. Besides, significant differences between groups in horizontal relapse at Pog were still observed with some patients undergoing the genioplasty. The role of postsurgical orthodontics is to adjust the occlusal relationship and maintain a stable postsurgical outcome, which primarily affects the position of teeth rather than jaws. Therefore, only overbite and overbite were used to analyze the changes in dental stability in this study. Horizontal skeletal relapses at point B were larger than the dental changes in the overjet in both groups. This was obviously due to dentoalveolar compensation during the postsurgical orthodontic treatment. Despite the mandibular skeletal relapse, there was no significant difference in the overjet between groups, indicating the importance of postsurgical orthodontic treatment. Traditionally, skeletal Class III malocclusion was treated by mandibular setback surgery alone. The increasing prevalence of two-jaw surgery is attributed to its better profile and less chance of airway reduction. Isolated mandibular setback surgery may provide a more direct indication of the impact of TH on the stability of the mandible, as it may minimize the influence of the maxillary movements on the mandibular position. Due to the low rate of isolated mandibular surgery in our hospital (around 16% of all Class III orthognathic procedures), relatively limited patients are available to evaluate the impact of TH on relapse of single-jaw surgery in this study. Although bimaxillary surgery increases nasopharynx volume and has less chance of airway reduction, it still does not appear to cannot compensate for the influence of TH on mandibular relapse. Further studies are needed to examine the skeletal relapse when performing the isolated mandibular setback in patients with TH. Various diagnostic methods such as clinical examination, lateral cephalograms, magnetic resonance imaging (MRI), and CBCT could be used for measuring tonsil size [ 27 – 29 ]. As a reliable and accurate tool for evaluating oropharyngeal obstruction, CBCT image could be a ready reference for patients undergoing orthognathic surgery and offer a three-dimensional (3D) solution to evaluate tonsil size. Besides, a collaborative approach was established between the otolaryngologist and orthodontist to aid in properly grouping samples. Our results suggested that the presence of TH might lead to less skeletal stability of the mandible, indicating the assessment of tonsil size was required for Class III patients undergoing orthognathic surgery. Patients with TH should be referred to otolaryngologists for further clinical or radiographic examination in the presurgical stages. In terms of postsurgical relapse, the surgical removal of obstructive tonsils might be recommended for patients with TH. Predicting these changes at the diagnostic and treatment planning stage may prevent potential adverse events on skeletal stability or airway problems. Limitation This study has some limitations. First, 2-dimensional cephalometric radiographs were used to assess skeletal changes that occurred 3-dimensionally. Second, due to the inability of cephalograms for volumetric measurements, we were unable to compare the volumetric relapse of the airway in 2 groups. Third, the condylar position which might affect the postsurgical mandibular position was not evaluated. 3D analysis using CBCT may allow for a more accurate assessment of skeletal and airway changes stability, but the radiation dosages and the possibility of errors caused by the movement during scans should be taken into consideration. Moreover, due to its retrospective nature, the quality of life and polysomnography of participants were not evaluated. Therefore, further prospective longitudinal studies comprehensively monitoring a wide array of parameters were recommended. Conclusions In conclusion, the hypothesis that the presence of TH in Class III patients would affect skeletal stability after orthognathic surgery was accepted. Skeletal Class III patients with TH presented considerably different postoperative skeletal changes compared to patients with NT, with more forward movement position of the mandible during the 1-year postsurgical period. Orthodontists and surgeons might preoperatively consider the factor of TH when two-jaw orthognathic surgery is indicated in Class III patients. Declarations Conflict of Interest The authors declare that they have no conflict of interest. Ethical Approval Ethical approval for this study was granted by the Ethics Committees of the Hospital of Stomatology, Wuhan University, China (No.2023-B31). Informed consent Not Applicable. 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J Oral Maxillofac Surg 80:1340–1353 Baroni M, Ballanti F, Franchi L, Cozza P (2011) Craniofacial features of subjects with adenoid, tonsillar, or adenotonsillar hypertrophy. Prog Orthod 12:38–44 Zhao TT, Wang M, Yang Z, Zhang J, Hua F, He H (2022) Percentage of tonsil hypertrophy in orthodontic patients with different sagittal skeletal relationship. Zhonghua kouqiang yixue zazhi 57:266–271 Kim H, Lee KC (2021) Sequential Changes in Pharyngeal Airway Dimensions After Mandibular Setback Surgery and Its Correlation With Postsurgical Stability in Patients With Mandibular Prognathism. J Oral Maxillofac Surg 79:2540–2547 Mohamed AS, Habumugisha J, Cheng B, Zhao M, Bu W, Liu L et al (2023) A cone-beam computed tomography study of hyoid bone position and airway volume in subjects with obstructive and nonobstructive adenotonsillar hypertrophy. Angle Orthod 93:467–475 Enciso R, Shigeta Y, Manuel N, Clark GT (2012) Comparison of cone-beam computed tomography incidental findings between patients with moderate/severe obstructive sleep apnea and mild obstructive sleep apnea/healthy patients. Oral Surg Oral Med Oral Pathol Oral Radiol 114:373–381 Houston W, ERRORS IN ORTHODONTIC MEASUREMENTS (1983) Am J Orthod Dentofac Orthop 83:382–390 Proffit WR, Phillips C, Turvey TA (2012) Stability After Mandibular Setback: Mandible-Only Versus 2-Jaw Surgery. J Oral Maxillofac Surg 70:E408–E414 Larson BE, Lee NK, Jang MJ, Yun PY, Kim JW, Kim YK (2017) Comparing Stability of Mandibular Setback Versus 2-Jaw Surgery in Class III Patients With Minimal Presurgical Orthodontics. J Oral Maxillofac Surg 75:1240–1248 Rizk MZ, Torgersbråten N, Mohammed H, Franzen TJ, Vandevska-Radunovic V (2021) Stability of single-jaw vs two-jaw surgery following the correction of skeletal class III malocclusion: A systematic review and meta-analysis. Orthod Craniofac Res 24:314–327 Proffit WR, Bailey LJ, Phillips C, Turvey TA (2000) Long-term stability of surgical open-bite correction by Le fort I osteotomy. Angle Orthod 70:112–117 Abeltins A, Jakobsone G, Urtane I, Bigestans A (2011) The stability of bilateral sagittal ramus osteotomy and vertical ramus osteotomy after bimaxillary correction of class III malocclusion. J Cranio-Maxillofacial Surg 39:583–587 Brodsky L, MODERN ASSESSMENT OF TONSILS, AND ADENOIDS (1989) Pediatr Clin North Am 36:1551–1569 Lv CX, Yang L, Ngan P, Xiao WJ, Zhao TT, Tang BJ et al (2023) Role of the tonsil-oropharynx ratio on lateral cephalograms in assessing tonsillar hypertrophy in children seeking orthodontic treatment. BMC Oral Health ; 23 Iwasaki T, Sugiyama T, Yanagisawa-Minami A, Oku Y, Yokura A, Yamasaki Y (2020) Effect of adenoids and tonsil tissue on pediatric obstructive sleep apnea severity determined by computational fluid dynamics. J Clin Sleep Med 16:2021–2028 Additional Declarations No competing interests reported. Supplementary Files SupplementaryTableI.docx SupplementaryTableII.docx Cite Share Download PDF Status: Posted Version 1 posted 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-6479982","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":450711730,"identity":"58c438c4-e2d7-404e-b2a3-917ae7818b38","order_by":0,"name":"Chenxing Lv","email":"","orcid":"","institution":"School and Hospital of Stomatology, Zhejiang Chinese Medical University, Hangzhou","correspondingAuthor":false,"prefix":"","firstName":"Chenxing","middleName":"","lastName":"Lv","suffix":""},{"id":450711731,"identity":"9cff3657-0f18-4fe6-b414-834662201165","order_by":1,"name":"Liu Yang","email":"","orcid":"","institution":"Department of Stomatology, Hangzhou Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou","correspondingAuthor":false,"prefix":"","firstName":"Liu","middleName":"","lastName":"Yang","suffix":""},{"id":450711732,"identity":"6443f5be-e6c5-4f2a-8ed0-3f6ae630fb72","order_by":2,"name":"Xuewen Yang","email":"","orcid":"","institution":"State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan","correspondingAuthor":false,"prefix":"","firstName":"Xuewen","middleName":"","lastName":"Yang","suffix":""},{"id":450711733,"identity":"edb6ab04-87cd-493c-8905-d9260650c8fe","order_by":3,"name":"Tingting Zhao","email":"","orcid":"","institution":"State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan","correspondingAuthor":false,"prefix":"","firstName":"Tingting","middleName":"","lastName":"Zhao","suffix":""},{"id":450711734,"identity":"9f4c4006-91c9-4ba3-954c-1a04114a21d1","order_by":4,"name":"Fang Hua","email":"","orcid":"","institution":"State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan","correspondingAuthor":false,"prefix":"","firstName":"Fang","middleName":"","lastName":"Hua","suffix":""},{"id":450711735,"identity":"f07b8d47-cf5a-4909-a63e-b13d30fbed46","order_by":5,"name":"Xiong Chen","email":"","orcid":"","institution":"Department of Otorhinolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan","correspondingAuthor":false,"prefix":"","firstName":"Xiong","middleName":"","lastName":"Chen","suffix":""},{"id":450711736,"identity":"a2aef583-4b8b-4594-9aad-2522c738a042","order_by":6,"name":"Hong He","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYDCCAzwMzCCan4EHRDGToEWygWQtBgeI1cJ3++zBxwUVd+w238g9JsFQYZ3YwH72AF4tkufyko1nnHmWvO1GXpoEw5n0xAaevAS8WgzO8JhJ87YdTja7nWMmwdh2OLFBgseAkBbz3yAtxrNBWv4Rp8WMGajFzkAapKWBCC2SZ3iMpXnOHE6QuP/G2CLhWLpxG08Ofi18Z3gMP/NUHLbn7zljeONDjbVsP/sZ/FpgILEBRCYAMRtR6oHAnliFo2AUjIJRMAIBAJHoQwDu/5ROAAAAAElFTkSuQmCC","orcid":"","institution":"State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan","correspondingAuthor":true,"prefix":"","firstName":"Hong","middleName":"","lastName":"He","suffix":""}],"badges":[],"createdAt":"2025-04-18 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2","display":"","copyAsset":false,"role":"figure","size":417701,"visible":true,"origin":"","legend":"","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6479982/v1/2e73c129473162980740f0d0.png"},{"id":81975536,"identity":"a5ee682c-2ed7-4c16-a031-ade8e2564f07","added_by":"auto","created_at":"2025-05-05 13:35:18","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":442578,"visible":true,"origin":"","legend":"","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6479982/v1/0e05701cd593e8e79a3f4095.png"},{"id":95527870,"identity":"24e9ba13-cf0b-440f-be39-145c8e390731","added_by":"auto","created_at":"2025-11-10 10:15:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2246996,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6479982/v1/530d07b6-e506-4cba-896d-28bad9be770a.pdf"},{"id":81950339,"identity":"00e223ed-03e6-4773-a1e4-c5ceb5193158","added_by":"auto","created_at":"2025-05-05 09:08:30","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":16365,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTableI.docx","url":"https://assets-eu.researchsquare.com/files/rs-6479982/v1/96ec5f180250542a2930bd49.docx"},{"id":81949627,"identity":"ef9e28bf-ba78-415b-81b2-a1603f4b8551","added_by":"auto","created_at":"2025-05-05 09:00:30","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":19876,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTableII.docx","url":"https://assets-eu.researchsquare.com/files/rs-6479982/v1/bbd3aec45bf2d8e2ded7e181.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The impact of tonsillar hypertrophy on skeletal relapse in skeletal Class III patients treated with two-jaw orthognathic surgery","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSkeletal Class III malocclusion presents with skeletal imbalances in the size of the maxilla and mandible or their position, which is commonly corrected by combined orthognathic surgery and orthodontic treatment [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Though the efficacy of orthognathic surgery is time-tested in terms of improving facial aesthetics and occlusion in Class III malocclusions, the issue of possible postsurgical relapse has always bothered clinicians. Various factors have been suggested to influence the stability of surgical results, including the surgical procedures, type of fixation, amount of surgical movement, and maxillomandibular counterclockwise rotation[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Breathing, swallowing, and alteration of the functional matrix such as the tongue may also contribute to the occurrence of relapse[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn recent years, the narrowing of the pharyngeal airway after mandibular setback surgery has gained increased attention because of its possible relationship to snoring and sleep apnea[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Studies have shown that the correction of Class III malocclusion with either single-jaw or two-jaw surgery caused a notable reduction in the oropharyngeal and hypopharyngeal airways[\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], with the changes in the positions of the hyoid bone and tongue[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, the degree of airway reduction was smaller in two-jaw than in single-jaw surgery[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. There is still a great deal of controversy regarding whether these airway changes cause the induction of obstructive sleep apnea (OSA), with some studies reporting the development of postsurgical OSA and the decline of sleep quality[\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], whereas others claiming that these reductions were not accompanied by signs or symptoms of OSA[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe palatine tonsils are lymphatic tissues located on the lateral walls of the oropharynx. As one of the known causes of OSA in both children and adults, tonsillar hypertrophy (TH) plays an important role in the obstruction of the upper airway. The previous literature reported that children with isolated TH had a more forward position of the mandible and a higher rate of Class III malocclusion [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The evidence of an association between TH and the mandibular protrusion suggested that children with hypertrophic tonsils are forced into a more anterior position of the tongue and mandible to increase the airway volume for the function of breathing.\u003c/p\u003e \u003cp\u003eIt was reported that the prevalence of TH in adult patients seeking orthodontic treatment was 23.2%, and the proportion of adults with TH in Class Ⅲ group was significantly higher than that in Class Ⅰ and Class Ⅱ groups[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. For adult Class III patients receiving mandibular setback surgery, hypertrophic tonsil tissues may contribute to the forward movement of the mandible to compensate for the loss of airway after surgery and thus influence the final skeletal position. Previous studies have shown that the airway adapts to these surgical changes and returns to presurgical values during the follow-up period [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Additionally, it is reported that dimensional recovery of the pharyngeal airway was correlated with postsurgical skeletal relapse[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. However, very few studies are available that consider TH as one of the potential risk factors influencing skeletal stability after surgery. Therefore, the purpose of this study was to compare the skeletal stability after correction of Class III malocclusion by two-jaw surgery between the patients with and without TH. This study tested the hypothesis that there would be a difference in skeletal relapse between these 2 groups of patients.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eIn this retrospective cohort study, the patients were recruited from a population with skeletal Class III malocclusion who underwent orthognathic surgery at the XXX from January 2016 to June 2022. This study was reviewed and approved by the Ethics Committees of XXX (No. XXX).\u003c/p\u003e \u003cp\u003eConsecutive adult patients were selected based on the following inclusion criteria: 1) bilateral Class III canine and molar relationships with ANB angle lower than 0\u0026deg;, 2) completion of conventional surgical-orthodontic treatment, 3) orthodontic treatment with no extraction, except for the third molars, 4) one-piece Le Fort I osteotomy with maxillary advancement and bilateral sagittal split osteotomy (BSSO) with mandibular setback performed, 5) no significant facial asymmetry and transverse discrepancy (\u0026lt;\u0026thinsp;3 mm midline deviation, \u0026lt;\u0026thinsp;5 mm arch width discordance), and 6) patients with a complete series of identifiable lateral cephalograms and presurgical cone-beam computed tomography (CBCT). Patients were excluded as study subjects if they were treated with surgery-first approaches without presurgical orthodontics or had cleft lip and palate, or other craniofacial syndromes.\u003c/p\u003e \u003cp\u003ePatients were classified into 2 groups according to the tonsil size evaluated by the presurgical CBCT: TH group with grade 3 and 4 tonsils, and normal tonsil (NT) group with grade 0, 1, and 2 tonsils[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The narrowest distance between the tonsils in the horizontal and coronal plane of CBCT was used to classify relative tonsil sizes into 5 grades (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and the measurement of tonsil size was carried out by an otolaryngologist and an orthodontist.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSurgical and orthodontic procedures\u003c/h2\u003e \u003cp\u003eIn surgical and orthodontic treatment, the 3 general stages were presurgical orthodontic treatment,\u003c/p\u003e \u003cp\u003ethe surgical procedure, and postsurgical orthodontic treatment. A team of 2 experienced surgeons and 2 experienced orthodontists was involved in performing the orthognathic surgeries and orthodontic treatments. Fixed appliances were normally used in presurgical and postsurgical orthodontic stages. No expansion protocol except orthodontic wires was performed in either group. During the Le Fort I osteotomy and BSSO, metal plates and monocortical screws were used for rigid internal fixation of the osteotomized bony segments. After the operation, the elastics between stainless steel wires and an interocclusal splint were used to maintain the maxillomandibular positions for 2 to 4 weeks. Functional training was prescribed to patients for 2 weeks after intermaxillary fixation release.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eCephalometric analysis\u003c/h3\u003e\n\u003cp\u003eLateral cephalograms were obtained for each patient with the same cephalostat (Soredex, Tuusula, Finland) before orthognathic surgery (T0), within 2 weeks of surgery (T1), and 1 year after surgery (T2, defined as 10\u0026ndash;14 months after the operation). All cephalograms were digitized for cephalometric analysis with Dolphin software (Dolphin Imaging and Management Solutions, Chatsworth, CA, USA) by the same researcher blinded to the patient details.\u003c/p\u003e \u003cp\u003eDefinitions of the landmarks, reference planes, and measured variables are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The measurements were not corrected for magnification (5.6%). An x\u0026ndash;y coordinate system was constructed for serial linear measurements, with sella as the origin coordinate. The x-axis passed through sella and rotated 7\u0026deg; below the sella-nasion plane. The y-axis was perpendicular to the x-axis and passed through sella. The vertical and horizontal positions of the landmarks were recorded as linear measurements in relation to the x- and y-axes, respectively. Surgical change and postsurgical relapse were measured by superimposing traced serial lateral cephalograms along the sella\u0026ndash;nasion line and cranial base structures.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eSample size determination\u003c/h3\u003e\n\u003cp\u003eA sample size calculation was performed based on the primary outcome, that is, postsurgical horizontal changes of point B. Since no published study with the same design was available, the sample size was calculated based on the data from the pre-trial study and reasonable assumptions. It was assumed that the mean value of relapse of point B in the TH group was 1 mm more than the NT group, and standard deviation (SD) values were the same in both groups. To detect a 1-mm difference with a 1.3-mm SD (calculated from 10 patients with TH in the pre-trial study) between groups and reach an 80% power using PASS software 15 (Version 15.0, NCSS, Kaysville, UT), at least 26 subjects in each group were required.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eFor analysis of the method error, 20 randomly selected radiographs from the 7 patients were retraced and digitized at a 2-week interval. Dahlberg\u0026rsquo;s method was used to determine the error between the double measurements [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The method error of the linear measurements ranged from 0.17 to 0.58 mm and angular measurements ranged from 0.1 to 0.5 \u0026deg;, which were statistically minor.\u003c/p\u003e \u003cp\u003eDescriptive statistics, including means and SDs, were used to describe each variable analyzed in the study. The Shapiro\u0026ndash;Wilk test was conducted to evaluate the normal distribution of variables. The independent t-test test was used to compare the initial measurements, surgical changes (T0 to T1), and postsurgical relapse (T1 to T2) between the TH and NT groups. The paired t-test was used to evaluate surgical and postsurgical changes of related variables in each group. chi-square test and correlation analysis.\u003c/p\u003e \u003cp\u003eWithin each group, Pearson correlation coefficients were calculated to analyze whether skeletal relapse was related to surgical repositioning. Differences were considered significant at a P value lower than 0.05. Statistical analysis was performed using SPSS software (Version 24.0, IBM, Armonk, NY).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003ePatients\u0026rsquo; characteristics and presurgical morphology\u003c/h2\u003e\n \u003cp\u003eThe present study consisted of 60 patients: 30 patients were in the TH group (12 males, 18 females; average age, 22.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8 years) and 30 patients were in the NT group (10 males, 20 females; average age, 22.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3 years). Fourteen patients received the genioplasty combined with two-jaw surgery, 7 in each group. Demographic characteristics and cephalometric variables describing the presurgical skeletal and dentofacial morphology of both groups were similar at T0 (Table I), without significant differences between the groups. The measurement of tonsil sizes of the patients participating in this study is shown in Supplementary Table I.\u003c/p\u003e\n \u003cp\u003eTable I. Comparison of age and cephalometric measurements at T0 between 2 groups.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Taba\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth rowspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/th\u003e\n \u003cth colspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eTH group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth colspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eNT group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth rowspan=\"2\" align=\"left\"\u003e\n \u003cp\u003eP Value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (yr) at T0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.712\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNA (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e80.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.380\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNB (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e86.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e85.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.454\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANB (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-5.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-5.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.963\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSN-MP (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e32.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e33.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.698\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eU1-SN (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e111.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e109.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.272\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIMPA (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e87.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e87.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.736\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverjet (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-5.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-5.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.362\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverbite (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.779\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-x(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.905\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-x(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e64.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e64.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.959\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-x(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e17.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e17.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.251\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-x(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e67.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e66.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.775\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-x(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e68.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e68.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.932\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-y(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e51.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e51.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.616\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-y(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e45.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e44.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.374\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-y(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e44.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e44.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.869\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-y(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e88.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e87.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.405\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-y(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e103.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e103.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.896\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eNote. SNA, angle of lines connecting the sella, nasion, and A point; SNB, angle of lines connecting the sella, nasion, and B point; ANB, angle of lines connecting A point, nasion, and B point; SN-MP, angle of SN plane to mandibular plane; U1-SN, angle between upper incisor axis and SN plane; IMPA, angle between lower incisor axis and mandibular plane; Overjet, distance between tips of upper central incisor and lower central incisor parallel to x-axis; Overbite, distance between tips of upper central incisor and lower central incisor parallel to y-axis; A-x, horizontal position of A point; A-y, vertical position of A point; ANS-x, horizontal position of ANS; ANS-y, vertical position of ANS; PNS-x, horizontal position of PNS; PNS-y, vertical position of PNS; B-x, horizontal position of B point; B-y, vertical position of B point; Pog-x, horizontal position of Pog; Pog-y, vertical position of Pog.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eT0, before surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation.\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ea\u003c/sup\u003e by independent t test\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eComparison of surgical changes (T0 to T1) in each group and between the 2 groups\u003c/h3\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\n \u003cp\u003eTable 2 shows the surgical changes in cephalometric variables in both groups. For maxilla from T0 to T1, the TH and NT groups showed significant increases in horizontal linear measurements (A-x, ANS-x, PNS-x, all P \u0026lt; 0.001). For mandibular measurements, both groups showed significant decreases in horizontal linear measurements (B-x, Pog-x, all P \u0026lt; 0.001) and significant increases in vertical linear measurements (B-y, Pog-y, all P \u0026lt; 0.01) from T0 to T1. Regarding the angular measurements, both groups exhibited significant changes in the SNA, SNB, and ANB from T0 to T1, which tended to be within the normal range. Regarding the dental changes, the TH and NT groups showed significant increases in overjet and overbite. In contrast, all horizontal, vertical, and angular changes of the maxilla and mandible and dental changes for surgical repositioning did not show relevant differences between the 2 groups (all P \u0026gt; 0.05).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable\u0026nbsp;II.\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of surgical changes in cephalometric measurements between 2 groups.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003cp\u003e(T0 to T1)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTH Group\u003c/p\u003e\n \u003cp\u003e(Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNT Group\u003c/p\u003e\n \u003cp\u003e(Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eHorizontal changes (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.26\u0026thinsp;\u0026plusmn;\u0026thinsp;1.42***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.647\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;1.82***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.999\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.81***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.568\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-6.44\u0026thinsp;\u0026plusmn;\u0026thinsp;4.16***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;3.15***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.796\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-6.37\u0026thinsp;\u0026plusmn;\u0026thinsp;4.11***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-6.26\u0026thinsp;\u0026plusmn;\u0026thinsp;3.64***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.779\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverjet\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.25\u0026thinsp;\u0026plusmn;\u0026thinsp;3.90***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.82\u0026thinsp;\u0026plusmn;\u0026thinsp;2.34***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.394\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eVertical changes (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;1.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.379\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.31\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.918\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.446\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.54\u0026thinsp;\u0026plusmn;\u0026thinsp;2.37***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.69**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.682\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.61\u0026thinsp;\u0026plusmn;\u0026thinsp;2.49***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.31\u0026thinsp;\u0026plusmn;\u0026thinsp;3.29**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.579\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverbite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-1.04\u0026thinsp;\u0026plusmn;\u0026thinsp;1.90**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.71\u0026thinsp;\u0026plusmn;\u0026thinsp;1.92*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.502\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eAngular changes (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.99\u0026thinsp;\u0026plusmn;\u0026thinsp;0.96***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.428\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.20***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-3.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.912\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.05\u0026thinsp;\u0026plusmn;\u0026thinsp;2.87***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.66\u0026thinsp;\u0026plusmn;\u0026thinsp;1.94***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.537\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eNote. Definitions of cephalometric terms are provided in Table I. Horizontal changes, positive values indicate forward movement; Vertical changes, positive values indicate downward movement; Angular changes, positive values indicate increase; Overjet, positive values indicate increase; Overbite, positive values indicate increase. T0, before surgery; T1, within 2 weeks of surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation.\u003c/p\u003e\n\u003cp\u003e*P\u0026thinsp;\u0026lt;\u0026thinsp;0.05, **P\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ***P\u0026thinsp;\u0026lt;\u0026thinsp;0.001, significant difference between T0 and T1 by paired t test.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e by independent t test\u003c/p\u003e\n\u003ch3\u003eComparison of postsurgical changes (T1 to T2) in each group and between the 2 groups\u003c/h3\u003e\n\u003cp\u003eAs shown in Table\u0026nbsp;3, the TH and NT groups showed significant relapse in horizontal linear measurements of the maxilla (A-x, ANS-x, PNS-x), with no significant differences between the groups. Both groups showed significant relapse in horizontal and vertical linear measurements of the mandible, but significant between-group differences were only found horizontally. The TH group showed significantly greater increases in the B-x (2.24 vs 1.57 mm, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) and the Pog-x (2.57 vs 1.87 mm, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) than the NT group. The TH group showed greater decreases in vertical linear measurements of the mandible (-2.99 vs -2.57 mm for the B-y, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05; -2.76 vs -2.35 mm for the Pog- y, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) than the NS group, but the between-group difference was not statistically significant.\u003c/p\u003e\n\u003cp\u003eFrom T1 to T2, both groups exhibited significant changes in 3 angular measurements and the between-group differences were statistically significant at SNB (1.40 vs 0.97 \u0026deg;, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) and ANB (-2.23 vs -1.66 \u0026deg;, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Horizontally, significant between-group differences in the relapse ratio were observed in the mandible (37.13 vs 27.47%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) but not in the maxilla (25.14 vs 22.99%, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In addition, the TH group showed greater decreases in overjet (-0.81 vs -0.39 mm, P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) than the NT group for postsurgical dental changes, but the between-group difference was not significant.\u003c/p\u003e\n\u003cp\u003eTable III. Comparison of postsurgical changes in cephalometric measurements and ratio of relapse between 2 groups.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tabb\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003cp\u003e(T1 to T2)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTH Group\u003c/p\u003e\n \u003cp\u003e(Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNT Group\u003c/p\u003e\n \u003cp\u003e(Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eHorizontal changes (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.450\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.584\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.433\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.24\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.12***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.037\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-x\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.66***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.19***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.040\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverjet\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.142\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eVertical changes (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.801\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANS-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.880\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.551\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.261\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePog-y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.76\u0026thinsp;\u0026plusmn;\u0026thinsp;1.92***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.50***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.395\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOverbite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.16***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.09***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.647\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eAngular changes (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.320\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSNB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.042\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eANB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.015\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" align=\"left\"\u003e\n \u003cp\u003eRatio of relapse (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA-x:(T1-T2)/(T0-T1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.14\u0026thinsp;\u0026plusmn;\u0026thinsp;11.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.99\u0026thinsp;\u0026plusmn;\u0026thinsp;10.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.457\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB-x:(T1-T2)/(T0-T1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e37.13\u0026thinsp;\u0026plusmn;\u0026thinsp;15.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e27.47\u0026thinsp;\u0026plusmn;\u0026thinsp;17.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.026\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003eNote. Definitions of cephalometric terms are provided in Table I. Horizontal changes, positive values indicate forward movement; Vertical changes, positive values indicate downward movement. Angular changes, positive values indicate increase; Overjet, positive values indicate increase; Overbite, positive values indicate increase.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eT1, within 2 weeks of surgery T2, 1 year after surgery; TH, tonsillar hypertrophy; NT, normal tonsil; SD, standard deviation.\u003c/p\u003e\n\u003cp\u003e***P\u0026thinsp;\u0026lt;\u0026thinsp;0.001, significant difference between T1 and T2 by paired t test.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e by independent t test.\u003c/p\u003e\n\u003cp\u003eThe distribution of relapse at the B point was categorized into 2 groups: less than or equal to 2 mm and greater than 2 mm. The results showed that 17 (57%) and 6 (20%) subjects of the TH and NT groups, respectively, relapsed greater than 2 mm. The relapse less than or equal to 2 mm was more dominant in the NT group (80%) than in the TH group (43%; P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eRelation between surgical changes and postsurgical changes in each group\u003c/h2\u003e\n \u003cp\u003eIn the 2 groups, horizontal relapses at point A and point B were significantly correlated with the amounts of mandibular setback and maxillary advancement (Supplementary Table II).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis retrospective cohort study was performed to test the hypothesis that the TH group would present a different degree of skeletal stability compared to the NT group. In this study, the 2 groups appeared to have similar presurgical conditions and surgical skeletal changes, which presented a homogeneity for the evaluation of the postsurgical relapse.\u003c/p\u003e \u003cp\u003eDuring the postsurgical period (T1 to T2), the TH and NT groups showed the backward and upward movement of the maxilla and there were no differences in the amount of relapse at point A, ANS, and PNS, SNA between the 2 groups. Although the horizontal and angular relapses of the maxilla were statistically significant in both groups, these changes might be clinically insignificant because they were less than 1 mm or 1° on average. Consistent with previous studies that showed good stability of the maxilla in bimaxillary surgery to correct Class III malocclusion[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], both groups in this study showed a stable position of the maxilla from T1 to T2 with a similar relapse ratio at point A. This suggested that the presence of TH did not affect the skeletal relapse of the maxilla in bimaxillary surgery during the postsurgical phase. It can be explained that hypertrophic tonsils occupy the airway at the level of the oropharynx, which is close to the root of the tongue and mandible and may have a limited effect on the skeletal relapse of the maxilla.\u003c/p\u003e \u003cp\u003eStable maintenance of the postsurgical mandibular position is very important when treating Class III malocclusion through the surgical-orthodontic approach. In accordance with some studies showing that the mandible displaced in the forward and upward direction postsurgically[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], both groups in this study had a similar relapse pattern of the mandible 1 year after surgery. However, significant differences in skeletal relapse were observed in the mandible between the groups. The TH group showed significantly greater increases in horizontal measurements of point B and Pog, greater increases in SNB, and greater decreases in ANB than the NT group from T1 to T2, indicating more forward movement of the mandible as relapse. Significant differences between groups in ANB were mainly linked to changes in SNB rather than SNA. Proffit et al.[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] suggested that postsurgical changes exceeding 2 mm or 2° could be considered clinically significant. The results showed that patients with a relapse greater than 2 mm comprised 57% of the TH group versus only 20% of the NT group. In addition, the TH group showed a higher relapse ratio in the mandible than the NT group. These results suggested that TH might be a risk factor for horizontal relapse after the mandibular setback in two-jaw surgery, which could be explained by the enlarged tonsil tissues pushing forward the tongue and mandible that had been retracted during the operation. The dependent functions such as breathing attempt to compensate for the encountered alterations in the oral environment and influence the skeletal stability of hard tissues.\u003c/p\u003e \u003cp\u003eThe genioplasty could influence the actual changes of the pogonion position during and after the surgery, so we chose the postsurgical changes of point B as the primary outcome in terms of mandible relapse. In addition to the group difference, relapse at point B can also be triggered by various factors including the amount of mandibular setback, counterclockwise rotation of the mandible, and condylar position[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. A correlation has been established between the amount of mandibular setback and skeletal relapse in both groups, as reported in previous studies[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Considering the presence of the interocclusal splint during the immediate postsurgical radiograph (T1), it was expected that the mandible would rotate forward and upward because of autorotation after the removal of surgical splints. During the postsurgical phase, the mandible moved upward more in the TH group, but the between-group difference was not statistically significant, suggesting that the counterclockwise rotation of the mandible did not significantly contribute to the greater horizontal relapse at point B in the TH group. Besides, significant differences between groups in horizontal relapse at Pog were still observed with some patients undergoing the genioplasty.\u003c/p\u003e \u003cp\u003eThe role of postsurgical orthodontics is to adjust the occlusal relationship and maintain a stable postsurgical outcome, which primarily affects the position of teeth rather than jaws. Therefore, only overbite and overbite were used to analyze the changes in dental stability in this study. Horizontal skeletal relapses at point B were larger than the dental changes in the overjet in both groups. This was obviously due to dentoalveolar compensation during the postsurgical orthodontic treatment. Despite the mandibular skeletal relapse, there was no significant difference in the overjet between groups, indicating the importance of postsurgical orthodontic treatment.\u003c/p\u003e \u003cp\u003eTraditionally, skeletal Class III malocclusion was treated by mandibular setback surgery alone. The increasing prevalence of two-jaw surgery is attributed to its better profile and less chance of airway reduction. Isolated mandibular setback surgery may provide a more direct indication of the impact of TH on the stability of the mandible, as it may minimize the influence of the maxillary movements on the mandibular position. Due to the low rate of isolated mandibular surgery in our hospital (around 16% of all Class III orthognathic procedures), relatively limited patients are available to evaluate the impact of TH on relapse of single-jaw surgery in this study. Although bimaxillary surgery increases nasopharynx volume and has less chance of airway reduction, it still does not appear to cannot compensate for the influence of TH on mandibular relapse. Further studies are needed to examine the skeletal relapse when performing the isolated mandibular setback in patients with TH.\u003c/p\u003e \u003cp\u003eVarious diagnostic methods such as clinical examination, lateral cephalograms, magnetic resonance imaging (MRI), and CBCT could be used for measuring tonsil size [\u003cspan additionalcitationids=\"CR28\" citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e–\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. As a reliable and accurate tool for evaluating oropharyngeal obstruction, CBCT image could be a ready reference for patients undergoing orthognathic surgery and offer a three-dimensional (3D) solution to evaluate tonsil size. Besides, a collaborative approach was established between the otolaryngologist and orthodontist to aid in properly grouping samples.\u003c/p\u003e \u003cp\u003eOur results suggested that the presence of TH might lead to less skeletal stability of the mandible, indicating the assessment of tonsil size was required for Class III patients undergoing orthognathic surgery. Patients with TH should be referred to otolaryngologists for further clinical or radiographic examination in the presurgical stages. In terms of postsurgical relapse, the surgical removal of obstructive tonsils might be recommended for patients with TH. Predicting these changes at the diagnostic and treatment planning stage may prevent potential adverse events on skeletal stability or airway problems.\u003c/p\u003e "},{"header":"Limitation","content":"\u003cp\u003eThis study has some limitations. First, 2-dimensional cephalometric radiographs were used to assess skeletal changes that occurred 3-dimensionally. Second, due to the inability of cephalograms for volumetric measurements, we were unable to compare the volumetric relapse of the airway in 2 groups. Third, the condylar position which might affect the postsurgical mandibular position was not evaluated. 3D analysis using CBCT may allow for a more accurate assessment of skeletal and airway changes stability, but the radiation dosages and the possibility of errors caused by the movement during scans should be taken into consideration. Moreover, due to its retrospective nature, the quality of life and polysomnography of participants were not evaluated. Therefore, further prospective longitudinal studies comprehensively monitoring a wide array of parameters were recommended.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn conclusion, the hypothesis that the presence of TH in Class III patients would affect skeletal stability after orthognathic surgery was accepted. Skeletal Class III patients with TH presented considerably different postoperative skeletal changes compared to patients with NT, with more forward movement position of the mandible during the 1-year postsurgical period. Orthodontists and surgeons might preoperatively consider the factor of TH when two-jaw orthognathic surgery is indicated in Class III patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval for this study was granted by the Ethics Committees of the Hospital of Stomatology, Wuhan University, China (No.2023-B31).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Wuhan University School \u0026amp; Hospital of Stomatology Clinical Research Project (No. LYZX202101) and the International Orthodontics Foundation Research Grants Program (No. IOF2022C01).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eJakobsone G, Stenvik A, Sandvik L, Espeland L (2011) Three-year follow-up of bimaxillary surgery to correct skeletal Class 111 malocclusion: Stability and risk factors for relapse. Am J Orthod Dentofac Orthop 139:80\u0026ndash;89\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRizk MZ, Torgersbraten N, Mohammed H, Franzen TJ, Vandevska-Radunovic V (2021) Stability of single-jaw vs two-jaw surgery following the correction of skeletal class III malocclusion: A systematic review and meta-analysis. Orthod Craniofac Res 24:314\u0026ndash;327\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHwang S, Chung CJ, Choi YJ, Huh JK (2010) Kim. Changes of Hyoid, Tongue and Pharyngeal Airway after Mandibular Setback Surgery by Intraoral Vertical Ramus Osteotomy. Angle Orthod 80:302\u0026ndash;308\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFoletti JM, Antonarakis GS, Galant C, Courvoisier DS, Scolozzi P (2018) Is Atypical Swallowing Associated With Relapse in Orthognathic Patients? A Retrospective Study of 256 Patients. J Oral Maxillofac Surg 76:1084\u0026ndash;1090\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCanellas JVD, Barros HLM, Medeiros PJD, Ritto FG (2016) Sleep-disordered breathing following mandibular setback: a systematic review of the literature. Sleep Breath 20:387\u0026ndash;394\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMattos CT, Vilani GNL, Sant'Anna EF, Ruellas ACO, Maia LC (2011) Effects of orthognathic surgery on oropharyngeal airway: a meta-analysis. Int J Oral Maxillofac Surg 40:1347\u0026ndash;1356\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark SB, Kim YI, Son WS, Hwang DS, Cho BH (2012) Cone-beam computed tomography evaluation of short- and long-term airway change and stability after orthognathic surgery in patients with Class III skeletal deformities: bimaxillary surgery and mandibular setback surgery. Int J Oral Maxillofac Surg 41:87\u0026ndash;93\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTepecik T, Ertas U, Akgun M (2018) Effects of bimaxillary orthognathic surgery on pharyngeal airway and respiratory function at sleep in patients with class III skeletal relationship. J Cranio-Maxillofacial Surg 46:645\u0026ndash;653\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim SH, Choi SK (2020) Changes in the hyoid bone, tongue, and oropharyngeal airway space after mandibular setback surgery evaluated by cone-beam computed tomography. Maxillofacial Plast Reconstr Surg ; 42\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHatab NA, Konstantinovic VS, Mudrak JKH (2015) Pharyngeal airway changes after mono- and bimaxillary surgery in skeletal class III patients: Cone-beam computed tomography evaluation. 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Angle Orthod 70:112\u0026ndash;117\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbeltins A, Jakobsone G, Urtane I, Bigestans A (2011) The stability of bilateral sagittal ramus osteotomy and vertical ramus osteotomy after bimaxillary correction of class III malocclusion. J Cranio-Maxillofacial Surg 39:583\u0026ndash;587\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrodsky L, MODERN ASSESSMENT OF TONSILS, AND ADENOIDS (1989) Pediatr Clin North Am 36:1551\u0026ndash;1569\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLv CX, Yang L, Ngan P, Xiao WJ, Zhao TT, Tang BJ et al (2023) Role of the tonsil-oropharynx ratio on lateral cephalograms in assessing tonsillar hypertrophy in children seeking orthodontic treatment. BMC Oral Health ; 23\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIwasaki T, Sugiyama T, Yanagisawa-Minami A, Oku Y, Yokura A, Yamasaki Y (2020) Effect of adenoids and tonsil tissue on pediatric obstructive sleep apnea severity determined by computational fluid dynamics. J Clin Sleep Med 16:2021\u0026ndash;2028\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Tonsillar hypertrophy, Class III malocclusion, Skeletal stability, Relapse, Orthognathic surgery","lastPublishedDoi":"10.21203/rs.3.rs-6479982/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6479982/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective: \u003c/strong\u003eThis study aimed to determine if tonsillar hypertrophy (TH) influenced the postsurgical skeletal stability of Class III patients receiving two-jaw orthognathic surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods: \u003c/strong\u003eSixty patients with skeletal Class III malocclusion corrected by conventional two-jaw surgery were included in the study. Patients were divided into the TH group (n=30) and normal tonsil (NT) group (n=30) depending on tonsil size on the presurgical cone beam computed tomography. Serial lateral cephalograms were traced and analyzed at 3 stages: before surgery (T0), within 2 weeks of surgery (T1), and 1 year after surgery (T2). Linear and angular cephalometric parameters were used to evaluate the surgical change (T0-T1) and postsurgical relapse (T1-T2). The data were analyzed with the paired t-test, independent t-test, chi-square test and Pearson correlation analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e From T0 to T1, the TH and NT groups showed a similar surgical pattern of the maxilla and mandible for repositioning. From T1 to T2, significant differences in skeletal relapse were observed in the mandible horizontally but not in the maxilla between the 2 groups. Compared to the NT group, the TH group exhibited significantly more forward movement at point B and Pog as well as a greater increase in SNB angle one year after surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions/\u003c/strong\u003e \u003cstrong\u003eClinical relevance: \u003c/strong\u003eSkeletal Class III patients with TH presented considerably different skeletal relapses in the mandible following two-jaw orthognathic surgery compared to those with NT. The factor of TH needs to be considered when orthognathic surgery is indicated in Class III patients.\u003c/p\u003e","manuscriptTitle":"The impact of tonsillar hypertrophy on skeletal relapse in skeletal Class III patients treated with two-jaw orthognathic surgery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-05 09:00:25","doi":"10.21203/rs.3.rs-6479982/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3b4797f4-1875-4c77-9dab-1a230a14f050","owner":[],"postedDate":"May 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-11-09T21:53:26+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-05 09:00:25","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6479982","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6479982","identity":"rs-6479982","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}