Dentoalveolar, skeletal, pharyngeal airway, cervical posture, hyoid bone position, and soft palate changes with Myobrace and Twin-block: a retrospective study

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The second aim was compare the appliances in terms of ease of use by assessing the factors that may influence patient compliance. Methods: : The study included thirty-six Class II division 1 patients (19 females, 17 males; mean age, 12.14 ± 1.23) who had previously been treated in the Orthodontic clinic at Sivas Cumhuriyet University Faculty of Dentistry. The patients were divided into two groups: Group 1: myobrace (n=18), Group 2: twin block (n=18). The effects of the appliances on the skeletal, dentoalveolar, soft tissue, craniocervical, and other anotomic structures were assessed using 46 measurements, 22 linear and 24 angular, on pre and post-treatment cephalometric radiographs. AudaxCeph 5.0 software (Ljubljana, Slovenia) was used for the analysis. To analyze the changes after one year of treatment, a paired sample t-test and Wilcoxon signed-rank test were used. Intergroup comparison was performed by using the Student t-test and the Mann–Whitney U test. Results: In the myobrace and twin block groups, there was a significant increase in SNB 0 (p=0.004, p=0.001), IMPA 0 (p=0.005, p=0.001), and a significant drop in U1/SN 0 (p=0.021, p=0.005). The lengths of Cd-Gn (mm), Go-Pg (mm), and Cd-Go (mm) increased significantly in the twin block group (p=0.003, p=0.010, p=0.001), whereas there was no change in the myobrace group. Similarly, there was no significant difference in pharyngeal and soft palate measurements in the Myobrace group, but there was a statistically significant decrease in SP length and SP angle in the twin block group (p=0.001, p=0.006). Increases in SN/OPT 0 (p=0.032, p=0.001) and SN/CVT 0 (p=0.012, p=0.001) were statistically significant in both groups. Myobrace was more difficult to use while sleeping, whereas twin block caused more nausea. Conclusions: Both appliances can be used for mandibular advancement. The twin block appliance, on the other hand, was more effective and patient-friendly. Functional orthodontic appliances Myobrace Twin block Class 2 div 1 malocclusion Figures Figure 1 Figure 2 Figure 3 Background Functional orthopedic appliances are used to manage mandibular retrognathia in Skeletal class 2 cases by stimulating condylar growth [1]. Since the first functional appliances were introduced by Robin in 1902 and Andresen in 1908, a wide range of new functional appliances have been designed by other clinicians [2-5]. Following conventional functional appliances such as bionator and activator, a new device called Pre-Orthodontic Trainer for Kids TM was developed in 1992 at the Myofunctional Research Center in Australia. It is now claimed that the trainer guides tooth eruption in the early mixed dentition, stimulates mandibular growth, and corrects abnormal myofunctional habits [6,7]. In 2004, the same company launched the Myobrace System, which was developed as a different version of the first introduced trainer. This system, which has different appliance designs based on age groups, is available on the market in a variety of sizes. The myobrace, unlike the first type of trainer appliance, facilitates dental arch development by applying light forces to the teeth via its dynamicore structure. The dynamicore structure is claimed to improve the arch shape and expand the dental arch [8]. Functional appliances increase oropharyngeal dimensions by forcing the mandible, tongue, soft palate and hyoid bone forward [9,10]. Early orthodontic treatment of mandibular retrognathia has been reported to improve insufficient airway dimension in previous studies [11,12]. Some researchers discovered that both the myobrace and twin block appliances have improvement effects on airway dimensions [1,13,14]. However, there are very limited clinical studies in the literature comparing the skeletal, dental, soft tissue and airway effects of these two appliances. On the other hand, clinicians are hesitant about the use of the Myobrace appliance, since its effectiveness is controversial and there are some difficulties in its use. The primary aim of this retrospective study was to compare the effects of twin block and myobrace appliance on skeletal, dental, soft tissue and changes in hyoid bone, cervical posture, soft palate and airway. The secondary goal was to compare the appliances in terms of ease of use by assessing the factors that may influence patient compliance. Methods Participants The current study involved thirty-six (19 females, 17 males; mean age, 12.14 ± 1.23) class 2 growing patients who had been treated at the Orthodontic department of Sivas Cumhuriyet University Dentistry Faculty. Written and verbal informed consent were obtained from the patients and their legal guards separately, and approval was obtained from the Clinical Research Ethics Committee of Sivas Cumhuriyet University (ID: 2020-02/05). This study was prepared in accordance with the Declaration of Helsinki. The sample size calculation using the G Power software revealed that at least 32 patients were required (effect size = 0.8, α = 0.05, and 1- β = 0.90) [15]. The inclusion criteria were as follows: [16,17] overjet > 4 mm, ANB>4, class 2 molar and canine relationships, normal or decreased lower facial height, C3 cervical vertebral maturation stage, no previous orthodontic treatment history. The exclusion criteria were as follows: post-pubertal growth period [18], lack of cooperation. The orthodontic archive provided information on 87 patients. Patients who did not meet the inclusion criteria (21), had radiograph artifacts (14), or had missing form data (16) were excluded from the study. Data from 36 patients treated with twin blocks and myobraces (18 in each group) who met the inclusion criteria were analyzed in this study. The upper and lower parts of the twin block, whose effects were evaluated and routinely used in the orthodontic clinic, had labial bows and adams clasps. Slow expansion screws were added to the upper part of the appliances in 16 patients with relative maxillary narrowness. Lateral cephalograms taken in the natural head position using the Orthoceph OC200D (Instrumentarium Dental, Tuusula, Finland) device were evaluated. AudaxCeph Version 5X software was used to perform cephalometric measurements (Ljubljana, Slovenia) (Table 1), (Figure 1, Figure 2, Figure 3). Patients undergoing functional treatment are routinely asked to complete a form called the 'Pain and Discomfort Level Determination.' The data on this form, which the patients filled out at the first week, first month, third month, and sixth month of treatment, were analyzed in the current study. Measurements were performed by a single investigator (Hasan Camcı) without knowing which group each x-ray belonged to. Error of the method The measurements of ten randomly selected patients were repeated 15 days later by the same investigator (Hasan Camcı). Repeated measurements were compared with the intra-correlation test. Correlation coefficient values for all measurements were greater than 0.762. Statistical analysis SPSS statistical software (version 21.0; IBM Corp, Armonk, NY) was used for all analyzes. The homogeneity of the data was evaluated with the Shapiro-Wilk test. Paired-sample t-test and the Wilcoxon signed-rank test were used for intra-group comparison of pre- and post-treatment data. The Student's t-test and the Mann–Whitney U test were used for inter-group comparison of data at T0 and T1. A p value <0.05 was considered statistically significant. Results The standard deviations and mean values of the T0 and T1 periods of the patients in both groups were calculated. Pre-treatment and post-treatment cephalometric values, intra-group and inter-group comparisons were presented in Table 2 and Table 3. Skeletal and Dental Measurements In the myobrace group's skeletal and dental measurements, there was a statistically significant increase in SNB (0) , L1/NB (0) and L1-NB (mm), IMPA (0) (p=0.004, p=0.003, p=0.026), and a significant decrease in U1/NA (0) and U1-NA (mm) (p=0.020, p=0.020). U1/SN (0) and overjet showed statistically significant decreases (p=0.021, p=0.001) while NAPg (0) and SNPg (0) showed statistically significant increases (p=0.042, p=0.003). In the twin-block group, skeletal and dental measurements showed a statistically significant decrease for SNA (0) and ANB (0) (p=0.001, p=0.001), and a statistically significant increase for SNB (0) (p=0.001). IMPA showed statistically significant increase (p=0.001). Increases in SN/GoGn ( 0 ), FMA ( 0 ) were significant (p=0.001, p=0.001). A statistically significant decrease was observed in the interincisal angle (p=0.010). The increase in the lengths of Cd-Gn (mm), Go-Pg (mm), Cd-Go (mm) was statistically significant (p=0.003, p=0.010, p=0.001). Soft Tissue Measurements Gla-Sub-Pg (0) and labiomental angle increased statistically in the myobrace group (p=0.011, p=0.005). The nasolabial angle, as well as the Gla-Sub-Pg (0) and Mentolabial angles, increased significantly in the twin block group (p=0.001, p=0.002, p=0.003). Pharyngeal and Soft Palate Measurements In the myobrace group, no statistically significant differences in pharyngeal and soft palate measurements were found (p>0.05). In the twin block group, the decrease in SP length and SP angle (0) was statistically significant (p=0.001, p=0.006). Craniocervical and hyoid measurements In both the myobrace and twin block groups, the increases in SN/OPT (0) (p=0.032, p=0.001) and SN/CVT (0) (p=0.012, p=0.001) were statistically significant. CVT/HR (0) and Hi-HR (mm) in the twin block group showed statistically significant increases (p=0.001, p=0.001). When the alterations that occurred in the T0-T1 interval were compared between groups, the changes in FH/MP (0) and PNS-AD1 (mm), and CVT/HR (0) measurements were found to be statistically significant (Table 4) (p=0.041, p=0.009, p=0.038). Findings of the questionnaire The 1st week, 1st month, 3rd month and 6th-month survey data mean, standard deviations, and intergroup comparison results of the groups were shown in Table 4. In the first week, there was a significant difference between the groups in terms of speech disorder and nausea (p=0.020, p=0.001). When the first month data were analyzed in terms of nausea, difficulty using while sleeping, pain, and speech impairments, the difference between the groups was statistically significant (p=0.014, p=0.019, p=0.027, p=0.035). Variations such as using in sleep, appliance discomfort, and gingival bleeding showed a significant difference in the third month (p=0.003, p=0.001). Discussion The present study was quite comprehensive as it simultaneously evaluated skeletal, dental, soft tissue, pharyngeal airway, soft palate, craniocervical posture, and hyoid bone effects of twin block and myobrace appliances. In addition, the two appliances were compared in terms of ease of use. To the best of our knowledge, no comprehensive research on the effects of these two appliances has ever been conducted. At the end of the treatment, both groups showed statistically significant changes in skeletal and dental measurements, but the twin block treatment appeared to be more effective in several categories. [15,20]. In the twin block group, the increase in SNB angle, decrease in ANB, and changes in mandibular length were more noticeable. Ghodke et al. [13] found comparable results in terms of twin block effectiveness. In the current study, no significant change in mandibular length was seen in the myobrace group, similar to the findings of Idris et al. [17] and Ushumez et al. [21]. There was a significant increase in the lower incisor angle in both groups, consistent with the study results of Elhamouly et al. [15] However, several studies found that using a trainer or activator had little effect on the angle of the lower incisors [17]. Twin block was a more effective mandibular advancement technique compared to myobrace. While previous research showed the ability of myobrace in mandibular advancement to be limited, the current study found that it plays an active role in mandibular advancement. In general, the Myobrace appliance is made of a more flexible material than the twin block. This may make it difficult for patients to keep their mandibles in a forward position [17]. The medium hard form of the myobrace was used in the current study to make it easier for patients to hold their mandible forward. Unlike previous studies [17,22], soft tissue measurements of mybroce showed a significant improvement (Gla-Sub-Pg and mentolabial angle). The improvement in the twin block group, on the other hand, was greater than in the mybroce group. The widening of the nasopharyngeal and hypopharyngeal regions after mandibular advancement using orthopedic appliances indicates that the airway is affected by the mandibular position [9]. Pavoni et al. [23] found that using a conventional functional appliance for mandibular advancement increased the dimensions of the pharyngeal airway, PNS-AD1 and PNS-AD2. However, in this study, they found a significant decrease in upper adenoid dimensions (AD2-H). Myobrace has been shown to have similar airway widening effects by some researches [14]. In the current study, both groups showed an increase in airway measurements, which was not statistically significant. The discrepancies in the results could be attributed to a variety of factors, including the severity of the malocclusion, age variations, treatment periods, and appliance type. Chewing, breathing, and phonation are all influenced by the relationships between soft palate and pharyngeal airway diameters. Similar to the findings of the current investigation, Ghodke et al. [13] observed that the SP angle in the twin block group decreased significantly. Jena et al. reported that SP length and angle decreased significantly in both groups in their study comparing two different mandibular advancement devices, whereas SP thickness increased in the twin block group. In the current study, no significant change was observed in soft palate measurements in neither the twin bock group nor the myobrace group. The hyoid bone's position is clinically significant since it is essential for maintaining upper airway dimensions. Ozdemir et al. [24] found no change in hyoid bone position after fixed functional treatment of class II malocclusion. Rizk et al. [25] reported that mandibular advancement causes anterior movement of the hyoid bone. Bavbek et al. [10] observed that after forsus treatment, the hyoid bone moved forward significantly, but there was no significant change in the vertical direction. The hyoid bone moved significantly in the sagittal direction in the twin block group in the current study, however there was no significant change in the vertical direction. In the myobrace group, no significant movement was observed in the hyoid bone in the sagittal and vertical directions. In the current study, a statistically significant increase was observed in the SN/OPT and SN/CVT angles in both the twin block and myobrace groups. In other words, both treatment methods resulted in a more upright craniocervical posture. According to Alsheikho et al. [26], functional orthopedic treatment had no effect on craniocervical posture. Kamal et al. [27] also suggested that functional treatment had no effect on cranio-cervical angles. Significant changes in the CVT/HR and OPT/CVT angles were detected in the twin block group in the current study, which is consistent with other cervical vertebral changes. Similarly, Aglarci [28] observed a significant change in mid-cervical posture (OPT-CVT) with the use of twin blocks. The ease of use of orthodontic appliances is critical to patient compliance. Nausea was detected at a higher rate in the twin block group than in the myobrace group during the early stages of treatment (1st week and 1st month). This could be because the twin block appliance covers a larger area of the palate. In the first and third months of treatment, patients in the myobrace group had significantly more difficulty using it while sleeping than patients in the twin block group. In terms of retention, the customized produced twin block was already expected to outperform the myobrace. Pain was found to be higher in the myobrace group in the first month of the current study. Idris et al. found moderate pain in both the trainer and activator groups during the first months of treatment, but the pain was greater in the activator group [16]. In this study, the medium hard form of the myobrace appliance was used. This could explain the increased level of pain. Speech difficulty was significantly higher in the myobrace appliance than in the twin block appliance. Similarly, in a previous study, less speech difficulties were reported in the twin block group [16]. The myobrace contains a double barrier (lingual and buccal oral screens) and additionally includes tongue tag and tongue guard. The current study's authors suggest that the structure of the myobrace cause to the speech difficulty. There was no significant difference between the groups in terms of temporomandibular joint pain. Limitations In the current study, 3D structures were evaluated using 2D cephalometric X-rays. Three-dimensional image evaluations generate more reliable results. However, in terms of radiation dose, the use of 3D imaging techniques in children is debatable. Because of its low cost and low radiation dose, cephalometric X-ray is more convenient. The results of myobrace and twin block appliances after a year were analyzed in the current study. Another limitations of the study include not knowing the long-term effects of the appliances and not being able to assess the possibility of relapse. Conclusions Both appliances can be used for mandibular advancement. However, the twin block appliance was more effective. The twin block appliance was convenient to use and more widely accepted by patients. Because the long-term effects of myobrace on mandibular advancement are unknown, generalizations should not be made based on the current study's findings. Abbreviations None Declarations Ethics approval and consent to participate Written and verbal informed consent were obtained from the patients and their legal guards separately, and approval was obtained from the Clinical Research Ethics Committee of Sivas Cumhuriyet University (ID: 2020-02/05). All experiments were performed in accordance with the Declaration of Helsinki. Consent for publication Not applicable. Availability of data and materials The datasets created and/or analyzed during the current study are not publicly available due to [Ethics committee decision], but are available from the corresponding author upon reasonable request. Competing interests The authors declare that they have no competing interests. Funding None Authors' contributions Zeynep Çoban Büyükbayraktar wrote the main manuscript text and Hasan Camcı prepared figures 1-3. Zeynep Çoban Büyükbayraktar collected the data. Hasan Camcı carried out the statistical analysis. The literature review was completed by Zeynep Çoban Büyükbayraktar. The critical assessments were completed by Hasan Camcı and Zeynep Çoban Büyükbayraktar. Acknowledgement None References Baka ZM and Fidanboy MO. Pharyngeal airway, hyoid bone, and soft palate changes after Class II treatment with Twin-block and Forsus appliances during the postpeak growth period. Am J Orthod Dentofacial Orthop 2021;159:148-157. Stockfisch H. The principles and practice of dentofacial orthopaedics: Quintessence Puplishing Co, Inc., New Malden, United Kingdom; 1995. Fränkel R. Possibilities of a late basal development of the mandible through the rearrangement of the bite by means of a functional regulator. Deutsche Stomatologie 1971;21:198-202. Clark W. 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Evaluation of cervical spine posture after functional therapy with twin-block appliances. Journal of Orthodontic Research 2016;4:8. Efendiyeva R, Aydemir H, Karasu H and Toygar-Memikoğlu U. Pharyngeal airway space, hyoid bone position, and head posture after bimaxillary orthognathic surgery in Class III patients: long-term evaluation. Angle Orthod 2014;84:773-781. Tables Updated tables can be found in the supplementary file section. Additional Declarations No competing interests reported. Supplementary Files updatedtables.pdf Cite Share Download PDF Status: Published Journal Publication published 30 Jan, 2023 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Major revision 19 Dec, 2022 Reviews received at journal 16 Dec, 2022 Reviewers agreed at journal 06 Dec, 2022 Reviews received at journal 26 Nov, 2022 Reviewers agreed at journal 15 Nov, 2022 Reviews received at journal 15 Nov, 2022 Reviews received at journal 07 Nov, 2022 Reviewers agreed at journal 02 Nov, 2022 Reviewers agreed at journal 01 Nov, 2022 Reviewers invited by journal 29 Oct, 2022 Editor assigned by journal 26 Oct, 2022 Editor invited by journal 26 Oct, 2022 Submission checks completed at journal 26 Oct, 2022 First submitted to journal 04 Oct, 2022 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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AD1-Ba (mm), distance from AD1 to Ba; \u003cstrong\u003e3\u003c/strong\u003e. AD2-H (mm), distance between AD2 and H; \u003cstrong\u003e4. \u003c/strong\u003ePNS-Ba (mm), distance from PNS to Ba; \u003cstrong\u003e5\u003c/strong\u003e. Ptm-Ba (mm), distance from Ptm to Ba; \u003cstrong\u003e6. \u003c/strong\u003ePNS-H (mm), distance between PNS and H.\u003c/p\u003e","description":"","filename":"1Pharyngealairwaylinearmeasurements1.png","url":"https://assets-eu.researchsquare.com/files/rs-2131812/v1/ed1377237250c73d00082408.png"},{"id":28373330,"identity":"3d9008b3-81a4-436f-a9ba-a68fa6398afe","added_by":"auto","created_at":"2022-10-28 15:06:51","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":722594,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSoft palate measurements:\u003c/strong\u003e \u003cstrong\u003e1.\u003c/strong\u003e SP length, \u003cstrong\u003e2.\u003c/strong\u003e SP thickness, and \u003cstrong\u003e3.\u003c/strong\u003eSP angle. ANS, anterior nasal spine; PNS, posterior nasal spine, posterior limit of bony palate; P, lower tip of the uvula.\u003c/p\u003e","description":"","filename":"2SPmeasurements.png","url":"https://assets-eu.researchsquare.com/files/rs-2131812/v1/f51b9877e45b59e80dc50215.png"},{"id":28374401,"identity":"801aa1a8-14e2-4603-833e-0400a5533218","added_by":"auto","created_at":"2022-10-28 15:11:51","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":798408,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCraniocervical and hyoid measurements: \u003c/strong\u003eCVT, cervical vertebra tangent: posterior tangent to the odontoid process through Cv4ip; OPT,odontoid process tangent: posterior tangent to the odontoid process through Cv2ip; HR, horizontal reference plane; VR, vertical reference plane; \u003cstrong\u003e1.\u003c/strong\u003eSN-OPT (0), angle between SN and OPT; \u003cstrong\u003e2.\u003c/strong\u003eSN-CVT (0), angle between SN and CVT; \u003cstrong\u003e3.\u003c/strong\u003eOPT-HR (0), angle between OPT and HR; \u003cstrong\u003e4.\u003c/strong\u003eCVT-HR (0), angle between CVT and HR; \u003cstrong\u003e5.\u003c/strong\u003eOPT-CVT (0), angle between OPT and CVT;\u003cstrong\u003e6.\u003c/strong\u003e Hi-VR (mm), sagittal distance from point Hi to VR; \u003cstrong\u003e7.\u003c/strong\u003e Hi-HR (mm), vertical distance of Hi point to HR\u003c/p\u003e","description":"","filename":"3Craniocervicalandhyoidmeasurements.png","url":"https://assets-eu.researchsquare.com/files/rs-2131812/v1/86a4445f722fdb8c492dfbe0.png"},{"id":44718922,"identity":"a856b1f0-9c1d-4a9e-8bb4-63d676bb6331","added_by":"auto","created_at":"2023-10-16 18:52:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3079947,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2131812/v1/d242122d-7015-4349-bae6-4aad0da84e7d.pdf"},{"id":28806705,"identity":"e7e2acfb-22a1-42fd-b2e2-b6a4391329d8","added_by":"auto","created_at":"2022-11-08 14:30:28","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":364884,"visible":true,"origin":"","legend":"","description":"","filename":"updatedtables.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2131812/v1/2ce9834f19bf2e55565058e9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Dentoalveolar, skeletal, pharyngeal airway, cervical posture, hyoid bone position, and soft palate changes with Myobrace and Twin-block: a retrospective study","fulltext":[{"header":"Background","content":"\u003cp\u003eFunctional orthopedic appliances are used to manage mandibular retrognathia in Skeletal class 2 cases by stimulating condylar growth [1]. Since the first functional appliances were introduced by Robin in 1902 and Andresen in 1908, a wide range of new functional appliances have been designed by other clinicians [2-5].\u003c/p\u003e\n\u003cp\u003eFollowing conventional functional appliances such as bionator and activator, a new device called Pre-Orthodontic Trainer for Kids\u003csup\u003eTM\u003c/sup\u003e was developed in 1992 at the Myofunctional Research Center in Australia. It is now claimed that the trainer guides tooth eruption in the early mixed dentition, stimulates mandibular growth, and corrects abnormal myofunctional habits [6,7]. In 2004, the same company launched the Myobrace System, which was developed as a different version of the first introduced trainer. This system, which has different appliance designs based on age groups, is available on the market in a variety of sizes. The myobrace, unlike the first type of trainer appliance, facilitates dental arch development by applying light forces to the teeth via its dynamicore structure. The dynamicore structure is claimed to improve the arch shape and expand the dental arch [8].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFunctional appliances increase oropharyngeal dimensions by forcing the mandible, tongue, soft palate and hyoid bone forward [9,10]. Early orthodontic treatment of mandibular retrognathia has been reported to improve\u0026nbsp;insufficient airway dimension in previous studies [11,12]. Some researchers discovered that both the myobrace and twin block appliances have improvement effects on airway dimensions [1,13,14]. However, there are very limited clinical studies in the literature comparing the skeletal, dental, soft tissue and airway effects of these two appliances. On the other hand, clinicians are hesitant about the use of the Myobrace appliance, since its effectiveness is controversial and there are some difficulties in its use.\u003c/p\u003e\n\u003cp\u003eThe primary aim of this retrospective study was to compare the effects of twin block and myobrace appliance on skeletal, dental, soft tissue and changes in hyoid bone, cervical posture, soft palate and airway. The secondary goal was to compare the appliances in terms of ease of use by assessing the factors that may influence patient compliance.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eParticipants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe current study involved thirty-six\u0026nbsp;(19 females, 17 males; mean age, 12.14 \u0026plusmn; 1.23) \u0026nbsp;class 2 growing patients who had been treated at the Orthodontic department of Sivas Cumhuriyet \u0026nbsp;University Dentistry Faculty.\u0026nbsp;Written and verbal informed consent were obtained from the patients and their legal guards separately, and approval was obtained from the Clinical Research Ethics Committee of Sivas Cumhuriyet University (ID: 2020-02/05). This study was prepared in accordance with the Declaration of Helsinki. The sample size calculation using the G Power software revealed that at least 32 patients were required (effect size = 0.8, \u003cem\u003e\u0026alpha;\u003c/em\u003e = 0.05, and 1-\u003cem\u003e\u0026beta;\u003c/em\u003e = 0.90) [15].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe inclusion criteria were as follows: [16,17] overjet \u0026gt; 4 mm, ANB\u0026gt;4, class 2 molar and canine relationships, normal or decreased lower facial height, C3 cervical vertebral maturation stage, no previous orthodontic treatment history. The exclusion criteria were as follows: post-pubertal growth period\u0026nbsp;[18], lack of cooperation. The orthodontic archive provided information on 87 patients. Patients who did not meet the inclusion criteria (21), had radiograph artifacts (14), or had missing form data (16) were excluded from the study. Data from 36 patients treated with twin blocks and myobraces (18 in each group) who met the inclusion criteria were analyzed in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe upper and lower parts of the twin block, whose effects were evaluated and routinely used in the orthodontic clinic, had labial bows and adams clasps. Slow expansion screws were added to the upper part of the appliances in 16 patients with relative maxillary narrowness.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLateral cephalograms taken in the natural head position using the Orthoceph OC200D (Instrumentarium Dental, Tuusula, Finland) device were evaluated. AudaxCeph Version 5X software was used to perform cephalometric measurements (Ljubljana, Slovenia) (Table 1), (Figure 1, Figure 2, Figure 3).\u003c/p\u003e\n\u003cp\u003ePatients undergoing functional treatment are routinely asked to complete a form called the \u0026apos;Pain and Discomfort Level Determination.\u0026apos; The data on this form, which the patients filled out at the first week, first month, third month, and sixth month of treatment, were analyzed in the current study.\u003c/p\u003e\n\u003cp\u003eMeasurements were performed by a single investigator (Hasan Camcı) without knowing which group each x-ray belonged to.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eError of the method\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe measurements of ten randomly selected patients were repeated 15 days later by the same investigator (Hasan Camcı). Repeated measurements were compared with the intra-correlation test. Correlation coefficient values for all measurements were greater than 0.762.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS statistical software (version 21.0; IBM Corp, Armonk, NY) was used for all analyzes. The homogeneity of the data was evaluated with the Shapiro-Wilk test. Paired-sample t-test and the Wilcoxon signed-rank test were used for intra-group comparison of pre- and post-treatment data. The Student\u0026apos;s t-test and the Mann\u0026ndash;Whitney U test were used for inter-group comparison of data at T0 and T1. A p value \u0026lt;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results ","content":"\u003cp\u003eThe standard deviations and mean values of the T0 and T1 periods of the patients in both groups were calculated. Pre-treatment and post-treatment cephalometric values, intra-group and inter-group comparisons were presented in Table 2 and Table 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSkeletal and Dental Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the myobrace group\u0026apos;s skeletal and dental measurements, there was a statistically significant increase in SNB\u003csup\u003e(0)\u003c/sup\u003e, L1/NB \u003csup\u003e(0)\u003c/sup\u003e and L1-NB (mm), IMPA\u003csup\u003e(0)\u003c/sup\u003e (p=0.004, p=0.003, p=0.026), and a significant decrease in U1/NA\u003csup\u003e(0)\u003c/sup\u003e and U1-NA (mm) (p=0.020, p=0.020).\u0026nbsp;U1/SN\u003csup\u003e(0)\u0026nbsp;\u003c/sup\u003eand overjet showed statistically significant decreases (p=0.021, p=0.001) while NAPg\u003csup\u003e(0)\u003c/sup\u003e and SNPg\u003csup\u003e(0)\u003c/sup\u003e showed statistically significant increases\u0026nbsp;(p=0.042, p=0.003).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the twin-block group, skeletal and dental measurements showed a statistically significant decrease for SNA\u003csup\u003e(0)\u003c/sup\u003e and ANB\u003csup\u003e(0)\u003c/sup\u003e (p=0.001, p=0.001), and a statistically significant increase for SNB\u003csup\u003e(0)\u003c/sup\u003e (p=0.001). IMPA showed\u0026nbsp;statistically significant increase\u0026nbsp;(p=0.001).\u0026nbsp;Increases in SN/GoGn (\u003csup\u003e0\u003c/sup\u003e), FMA (\u003csup\u003e0\u003c/sup\u003e) were significant\u0026nbsp;(p=0.001, p=0.001). A statistically significant decrease was observed in the interincisal angle\u0026nbsp;(p=0.010). The increase in the lengths of Cd-Gn (mm), Go-Pg (mm), Cd-Go (mm) was statistically significant (p=0.003, p=0.010, p=0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSoft Tissue Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGla-Sub-Pg\u003csup\u003e(0)\u0026nbsp;\u003c/sup\u003eand labiomental angle increased statistically in the myobrace group\u0026nbsp;(p=0.011, p=0.005). The nasolabial angle, as well as the Gla-Sub-Pg \u003csup\u003e(0)\u0026nbsp;\u003c/sup\u003eand Mentolabial angles, increased significantly in the twin block group\u0026nbsp;(p=0.001, p=0.002, p=0.003).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePharyngeal and Soft Palate Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the myobrace group, no statistically significant differences in pharyngeal and soft palate measurements were found (p\u0026gt;0.05). \u0026nbsp;In the twin block group, the decrease in SP length and SP angle\u003csup\u003e(0)\u003c/sup\u003e was statistically significant\u0026nbsp;(p=0.001, p=0.006).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCraniocervical and hyoid measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn both the myobrace and twin block groups, the increases in SN/OPT\u003csup\u003e(0)\u003c/sup\u003e (p=0.032, p=0.001) and SN/CVT\u003csup\u003e(0)\u003c/sup\u003e (p=0.012, p=0.001) were statistically significant. CVT/HR \u003csup\u003e(0)\u003c/sup\u003e and Hi-HR (mm) in the twin block group showed statistically significant increases\u0026nbsp;(p=0.001, p=0.001).\u003c/p\u003e\n\u003cp\u003eWhen the alterations that occurred in the T0-T1 interval were compared between groups, the changes in FH/MP\u003csup\u003e(0)\u003c/sup\u003e and PNS-AD1 (mm), and CVT/HR\u003csup\u003e(0)\u0026nbsp;\u003c/sup\u003emeasurements were found to be statistically significant (Table 4) (p=0.041, p=0.009, p=0.038).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFindings of the questionnaire\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe 1st week, 1st month, 3rd month and 6th-month survey data mean, standard deviations, and intergroup comparison results of the groups were shown in Table 4.\u003c/p\u003e\n\u003cp\u003eIn the first week, there was a significant difference between the groups in terms of speech disorder and nausea (p=0.020, p=0.001). When the first month data were analyzed in terms of nausea, difficulty using while sleeping, pain, and speech impairments, the difference between the groups was statistically significant (p=0.014, p=0.019, p=0.027, p=0.035). Variations such as using in sleep, appliance discomfort, and gingival bleeding showed a significant difference in the third month (p=0.003, p=0.001).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe present study was quite comprehensive as it simultaneously evaluated skeletal, dental, soft tissue, pharyngeal airway, soft palate, craniocervical posture, and hyoid bone effects of twin block and myobrace appliances. In addition, the two appliances were compared in terms of ease of use. To the best of our knowledge, no comprehensive research on the effects of these two appliances has ever been conducted.\u003c/p\u003e\n\u003cp\u003eAt the end of the treatment, both groups showed statistically significant changes in skeletal and dental measurements, but the twin block treatment appeared to be more effective in several categories. [15,20]. In the twin block group, the increase in SNB angle, decrease in ANB, and changes in mandibular length were more noticeable. Ghodke et al.\u0026nbsp;[13] found comparable results in terms of twin block effectiveness. In the current study, no significant change in mandibular length was seen in the myobrace group, similar to the findings of Idris et al.\u0026nbsp;[17] and Ushumez et al. [21]. There was a significant increase in the lower incisor angle in both groups, consistent with the study results of Elhamouly et al. [15]\u0026nbsp; However, several studies found that using a trainer or activator had little effect on the angle of the lower incisors [17]. Twin block was a more effective mandibular advancement technique compared to myobrace. While previous research showed the ability of myobrace in mandibular advancement to be limited, the current study found that it plays an active role in mandibular advancement. In general, the Myobrace appliance is made of a more flexible material than the twin block. This may make it difficult for patients to keep their mandibles in a forward position [17]. The medium hard form of the myobrace was used in the current study to make it easier for patients to hold their mandible forward.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUnlike previous studies [17,22], soft tissue measurements of mybroce showed a significant improvement (Gla-Sub-Pg and mentolabial angle). The improvement in the twin block group, on the other hand, was greater than in the mybroce group.\u003c/p\u003e\n\u003cp\u003eThe widening of the nasopharyngeal and hypopharyngeal regions after mandibular advancement using orthopedic appliances indicates that the airway is affected by the mandibular position\u0026nbsp;[9]. Pavoni et al. [23] found that using a conventional functional appliance for mandibular advancement increased the dimensions of the pharyngeal airway, PNS-AD1 and PNS-AD2. However, in this study, they found a significant decrease in upper adenoid dimensions (AD2-H). Myobrace has been shown to have similar airway widening effects by some researches [14]. In the current study, both groups showed an increase in airway measurements, which was not statistically significant. The discrepancies in the results could be attributed to a variety of factors, including the severity of the malocclusion, age variations, treatment periods, and appliance type.\u003c/p\u003e\n\u003cp\u003eChewing, breathing, and phonation are all influenced by the relationships between soft palate and pharyngeal airway diameters. Similar to the findings of the current investigation, Ghodke et al. [13]\u0026nbsp;observed that the SP angle in the twin block group decreased significantly. Jena et al. reported that SP length and angle decreased significantly in both groups in their study comparing two different mandibular advancement devices, whereas SP thickness increased in the twin block group. In the current study, no significant change was observed in soft palate measurements in neither the twin bock group nor the myobrace group.\u003c/p\u003e\n\u003cp\u003eThe hyoid bone\u0026apos;s position is clinically significant since it is essential for maintaining upper airway dimensions. Ozdemir et al. [24] found no change in hyoid bone position after fixed functional treatment of class II malocclusion. Rizk et al. [25] reported that mandibular advancement causes anterior movement of the hyoid bone. Bavbek et al. [10] observed that after forsus treatment, the hyoid bone moved forward significantly, but there was no significant change in the vertical direction. The hyoid bone moved significantly in the sagittal direction in the twin block group in the current study, however there was no significant change in the vertical direction. In the myobrace group, no significant movement was observed in the hyoid bone in the sagittal and vertical directions.\u003c/p\u003e\n\u003cp\u003eIn the current study, a statistically significant increase was observed in the SN/OPT and SN/CVT angles in both the twin block and myobrace groups. In other words, both treatment methods resulted in a more upright craniocervical posture. According to Alsheikho et al. [26], functional orthopedic treatment had no effect on craniocervical posture.\u0026nbsp;Kamal et al. [27] also suggested that functional treatment had no effect on cranio-cervical angles.\u0026nbsp;Significant changes in the CVT/HR and OPT/CVT angles were detected in the twin block group in the current study, which is consistent with other cervical vertebral changes. Similarly, Aglarci [28] observed a significant change in mid-cervical posture (OPT-CVT) with the use of twin blocks.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe ease of use of orthodontic appliances is critical to patient compliance. Nausea was detected at a higher rate in the twin block group than in the myobrace group during the early stages of treatment (1st week and 1st month). This could be because the twin block appliance covers a larger area of the palate. In the first and third months of treatment, patients in the myobrace group had significantly more difficulty using it while sleeping than patients in the twin block group. In terms of retention, the customized produced twin block was already expected to outperform the myobrace.\u003c/p\u003e\n\u003cp\u003ePain was found to be higher in the myobrace group in the first month of the current study. Idris et al. found moderate pain in both the trainer and activator groups during the first months of treatment, but the pain was greater in the activator group [16]. In this study, the medium hard form of the myobrace appliance was used. This could explain the increased level of pain.\u003c/p\u003e\n\u003cp\u003eSpeech difficulty was significantly higher in the myobrace appliance than in the twin block appliance. Similarly, in a previous study, less speech difficulties were reported in the twin block group [16]. The myobrace contains a double barrier (lingual and buccal oral screens) and additionally includes tongue tag and tongue guard. The current study\u0026apos;s authors suggest that the structure of the myobrace cause to the speech difficulty. There was no significant difference between the groups in terms of temporomandibular joint pain.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the current study, 3D structures were evaluated using 2D cephalometric X-rays. Three-dimensional image evaluations generate more reliable results. However, in terms of radiation dose, the use of 3D imaging techniques in children is debatable. Because of its low cost and low radiation dose, cephalometric X-ray is more convenient.\u003c/p\u003e\n\u003cp\u003eThe results of myobrace and twin block appliances after a year were analyzed in the current study. Another limitations of the study include not knowing the long-term effects of the appliances and not being able to assess the possibility of relapse.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cul\u003e\n \u003cli\u003eBoth appliances can be used for mandibular advancement. However, the twin block appliance was more effective.\u003c/li\u003e\n \u003cli\u003eThe twin block appliance was convenient to use and more widely accepted by patients.\u003c/li\u003e\n \u003cli\u003eBecause the long-term effects of myobrace on mandibular advancement are unknown, generalizations should not be made based on the current study\u0026apos;s findings.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eNone\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten and verbal informed consent were obtained from the patients and their legal guards separately, and approval was obtained from the Clinical Research Ethics Committee of Sivas Cumhuriyet University (ID: 2020-02/05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll experiments were performed in accordance with the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets created and/or analyzed during the current study are not publicly available due to [Ethics committee decision], but are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eZeynep \u0026Ccedil;oban B\u0026uuml;y\u0026uuml;kbayraktar wrote the main manuscript text and Hasan Camcı prepared figures 1-3. Zeynep \u0026Ccedil;oban B\u0026uuml;y\u0026uuml;kbayraktar collected the data. Hasan Camcı carried out the statistical analysis. The literature review was completed by Zeynep \u0026Ccedil;oban B\u0026uuml;y\u0026uuml;kbayraktar. The critical assessments were completed by Hasan Camcı and Zeynep \u0026Ccedil;oban B\u0026uuml;y\u0026uuml;kbayraktar.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBaka ZM and Fidanboy MO. Pharyngeal airway, hyoid bone, and soft palate changes after Class II treatment with Twin-block and Forsus appliances during the postpeak growth period. Am J Orthod Dentofacial Orthop 2021;159:148-157.\u003c/li\u003e\n\u003cli\u003eStockfisch H. The principles and practice of dentofacial orthopaedics: Quintessence Puplishing Co, Inc., New Malden, United Kingdom; 1995.\u003c/li\u003e\n\u003cli\u003eFr\u0026auml;nkel R. Possibilities of a late basal development of the mandible through the rearrangement of the bite by means of a functional regulator. Deutsche Stomatologie 1971;21:198-202.\u003c/li\u003e\n\u003cli\u003eClark W. The twin block technique. A functional orthopedic appliance system. American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 1988;93:1-18.\u003c/li\u003e\n\u003cli\u003eCozza P, Baccetti T, Franchi L, De Toffol L and McNamara Jr JA. Mandibular changes produced by functional appliances in Class II malocclusion: a systematic review. Am J Orthod Dentofacial Orthop 2006;129:599. e591-599. e512.\u003c/li\u003e\n\u003cli\u003eTallgren A, Christiansen RL, Ash Jr MM and Miller RL. Effects of a myofunctional appliance on orofacial muscle activity and structures. Angle Orthod 1998;68:249-258.\u003c/li\u003e\n\u003cli\u003eHashish DI and Mostafa YA. Effect of lip bumpers on mandibular arch dimensions. Am J Orthod Dentofacial Orthop 2009;135:106-109.\u003c/li\u003e\n\u003cli\u003eAnastasi G and Dinnella A. Myobrace System: A no-braces approach to malocclusion and a myofunctional therapy device. WebmedCentral Orthodontics 2014;5:WMC004492.\u003c/li\u003e\n\u003cli\u003eRestrepo C, Santamar\u0026iacute;a A, Pel\u0026aacute;ez S and Tapias A. Oropharyngeal airway dimensions after treatment with functional appliances in class II retrognathic children. J Oral Rehabil 2011;38:588-594.\u003c/li\u003e\n\u003cli\u003eBavbek NC, Tuncer BB, Turkoz C, Ulusoy C and Tuncer C. Changes in airway dimensions and hyoid bone position following class II correction with forsus fatigue resistant device. Clin Oral Investig 2016;20:1747-1755.\u003c/li\u003e\n\u003cli\u003eH\u0026auml;nggi MP, Teuscher UM, Roos M and Peltom\u0026auml;ki TA. Long-term changes in pharyngeal airway dimensions following activator-headgear and fixed appliance treatment. Eur J Orthod 2008;30:598-605.\u003c/li\u003e\n\u003cli\u003eKannan A, Sathyanarayana HP and Padmanabhan S. Effect of functional appliances on the airway dimensions in patients with skeletal class II malocclusion: A systematic review. J Orthod Sci 2017;6:54.\u003c/li\u003e\n\u003cli\u003eGhodke S, Utreja AK, Singh SP and Jena AK. Effects of twin-block appliance on the anatomy of pharyngeal airway passage (PAP) in class II malocclusion subjects. Prog Orthod 2014;15:1-8.\u003c/li\u003e\n\u003cli\u003eEun-Suk A, Ah-Hyeon K, Youn-Soo S and So-Youn A. Oropharyngeal Airway Three-dimensional Changes after Treatment with Myobrace in Class II Retrognathic Children. Iran J Public Health 2017;46:265.\u003c/li\u003e\n\u003cli\u003eElhamouly Y, El-Housseiny AA, Ismail HA and El Habashy LM. Myofunctional trainer versus twin block in developing class II division I malocclusion: A randomized comparative clinical trial. Dentistry Journal 2020;8:44.\u003c/li\u003e\n\u003cli\u003eIdris G, Hajeer M and Al-Jundi A. Acceptance and discomfort in growing patients during treatment with two functional appliances: a randomised controlled trial. Eur J Paediatr Dent 2012;13:219-224.\u003c/li\u003e\n\u003cli\u003eIdris G, Hajeer MY and Al-Jundi A. Soft-and hard-tissue changes following treatment of Class II division 1 malocclusion with Activator versus Trainer: A randomized controlled trial. Eur J Orthod 2019;41:21-28.\u003c/li\u003e\n\u003cli\u003eMandall N, Matthew S, Fox D, Wright J, Conboy F and O\u0026apos;Brien K. Prediction of compliance and completion of orthodontic treatment: are quality of life measures important? Eur J Orthod 2008;30:40-45.\u003c/li\u003e\n\u003cli\u003eSergl HG, Klages U and Zentner A. Functional and social discomfort during orthodontic treatment-effects on compliance and prediction of patients\u0026apos; adaptation by personality variables. Eur J Orthod 2000;22:307-315.\u003c/li\u003e\n\u003cli\u003eAntonarakis GS and Kiliaridis S. Short-term anteroposterior treatment effects of functional appliances and extraoral traction on class II malocclusion: a meta-analysis. Angle Orthod 2007;77:907-914.\u003c/li\u003e\n\u003cli\u003eUsumez S, Uysal T, Sari Z, Basciftci FA, Karaman AI and Guray E. The effects of early preorthodontic trainer treatment on Class II, division 1 patients. Angle Orthod 2004;74:605-609.\u003c/li\u003e\n\u003cli\u003eČirgić E, Kjellberg H and Hansen K. Treatment of large overjet in Angle Class II: division 1 malocclusion with Andresen activators versus prefabricated functional appliances\u0026mdash;a multicenter, randomized, controlled trial. Eur J Orthod 2016;38:516-524.\u003c/li\u003e\n\u003cli\u003ePavoni C, Cretella Lombardo E, Franchi L, Lione R and P C. Treatment and post-treatment effects of functional therapy on the sagittal pharyngeal dimensions in Class II subjects. Int J Pediatr Otorhinolaryngol 2017;101:47-50.\u003c/li\u003e\n\u003cli\u003eOzdemir F, Ulkur F and Nalbantgil D. Effects of fixed functional therapy on tongue and hyoid positions and posterior airway. Angle Orthod 2014;84:260-264.\u003c/li\u003e\n\u003cli\u003eRizk S, Kulbersh VP and Al-Qawasmi R. Changes in the oropharyngeal airway of Class II patients treated with the mandibular anterior repositioning appliance. Angle Orthod 2016;86:955-961.\u003c/li\u003e\n\u003cli\u003eAlsheikho HO, Jomah DH, Younes M, Tizini M, Hassan H and Khalil F. Evaluation of head and cervical spine posture after functional therapy with Twin‑Block and Bionator appliances: A pilot randomized controlled trial. CRANIO\u0026reg; 2021;1-10.\u003c/li\u003e\n\u003cli\u003eKamal AT and Fida M. Evaluation of cervical spine posture after functional therapy with twin-block appliances: a retrospective cohort study. Am J Orthod Dentofacial Orthop 2019;155:656-661.\u003c/li\u003e\n\u003cli\u003eAglarci C. Evaluation of cervical spine posture after functional therapy with twin-block appliances. Journal of Orthodontic Research 2016;4:8.\u003c/li\u003e\n\u003cli\u003eEfendiyeva R, Aydemir H, Karasu H and Toygar-Memikoğlu U. Pharyngeal airway space, hyoid bone position, and head posture after bimaxillary orthognathic surgery in Class III patients: long-term evaluation. Angle Orthod 2014;84:773-781.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eUpdated tables can be found in the supplementary file section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Functional orthodontic appliances, Myobrace, Twin block, Class 2 div 1 malocclusion","lastPublishedDoi":"10.21203/rs.3.rs-2131812/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2131812/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e The primary aim of this study was to evaluate the dentoalveolar, skeletal, pharyngeal airway, cervical posture,hyoid bone position, and soft palate effects of myobrace and twin block appliances. The second aim was compare the appliances in terms of ease of use by assessing the factors that may influence patient compliance.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e \u003cstrong\u003e:\u003c/strong\u003e The study included thirty-six Class II division 1 patients (19 females, 17 males; mean age, 12.14 ± 1.23) who had previously been treated in the Orthodontic clinic at Sivas Cumhuriyet University Faculty of Dentistry. The patients were divided into two groups: Group 1: myobrace (n=18), Group 2: twin block (n=18).\u0026nbsp; The effects of the appliances on the skeletal, dentoalveolar, soft tissue, craniocervical, and other anotomic structures were assessed using 46 measurements, 22 linear and 24 angular, on pre and post-treatment cephalometric radiographs. AudaxCeph 5.0 software (Ljubljana, Slovenia) was used for the analysis. To analyze the changes after one year of treatment, a paired sample t-test and Wilcoxon signed-rank test were used. Intergroup comparison was performed by using the Student t-test and the Mann–Whitney U test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e In the myobrace and twin block groups, there was a significant increase in SNB\u003csup\u003e0 \u003c/sup\u003e(p=0.004, p=0.001), IMPA\u003csup\u003e0\u003c/sup\u003e (p=0.005, p=0.001), and a significant drop in U1/SN\u003csup\u003e0\u003c/sup\u003e (p=0.021, p=0.005). The lengths of Cd-Gn (mm), Go-Pg (mm), and Cd-Go (mm) increased significantly in the twin block group (p=0.003, p=0.010, p=0.001), whereas there was no change in the myobrace group. Similarly, there was no significant difference in pharyngeal and soft palate measurements in the Myobrace group, but there was a statistically significant decrease in SP length and SP angle in the twin block group (p=0.001, p=0.006). Increases in SN/OPT\u003csup\u003e0\u003c/sup\u003e (p=0.032, p=0.001) and SN/CVT\u003csup\u003e0\u003c/sup\u003e (p=0.012, p=0.001) were statistically significant in both groups. Myobrace was more difficult to use while sleeping, whereas twin block caused more nausea.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Both appliances can be used for mandibular advancement. The twin block appliance, on the other hand, was more effective and patient-friendly.\u003c/p\u003e","manuscriptTitle":"Dentoalveolar, skeletal, pharyngeal airway, cervical posture, hyoid bone position, and soft palate changes with Myobrace and Twin-block: a retrospective study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-10-28 15:06:49","doi":"10.21203/rs.3.rs-2131812/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2022-12-19T11:25:42+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-12-16T16:21:06+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"537207b6-b9a9-4ea4-9126-8c80730380ec","date":"2022-12-06T08:03:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-11-26T17:46:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"3ce197e1-0e13-4948-af9f-918879780be0","date":"2022-11-16T04:20:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-11-15T08:02:37+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-11-07T21:55:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"0179456e-3837-42fa-a970-b6023ecbdee1","date":"2022-11-02T19:56:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"69b654de-98e5-4ced-99bf-2d53685aa461","date":"2022-11-01T09:22:02+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-10-29T08:58:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-10-26T10:00:43+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2022-10-26T09:50:13+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2022-10-26T09:45:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2022-10-04T12:34:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"68657e4b-7b64-46bb-9f1d-b3a8a567d75b","owner":[],"postedDate":"October 28th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T18:48:57+00:00","versionOfRecord":{"articleIdentity":"rs-2131812","link":"https://doi.org/10.1186/s12903-023-02773-x","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2023-01-30 18:39:52","publishedOnDateReadable":"January 30th, 2023"},"versionCreatedAt":"2022-10-28 15:06:49","video":"","vorDoi":"10.1186/s12903-023-02773-x","vorDoiUrl":"https://doi.org/10.1186/s12903-023-02773-x","workflowStages":[]},"version":"v1","identity":"rs-2131812","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2131812","identity":"rs-2131812","version":["v1"]},"buildId":"GqpaHPwrfC8PjnIFayRh5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}