What is the correlation between thickness and anterior posterior width of masseter muscle in ultrasonography with intermolar width in maxilla and mandible?

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Mitra Ghazizadeh Ahsaie, Yaser Safi, Mohammad Behnaz, Solmaz Valizadeh, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4872636/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 Background Knowledge of masseter muscle size can be helpful in choosing more successful and stable orthodontic treatment plans. This study aimed to evaluate masseter muscle width and thickness in ultrasonography (USG) and its correlation with dental arch width. Methods In this descriptive-cross-sectional study, 45 participants (25 male (55.5%), and 20 female (45.5%)) were categorized according to their sex and age groups (16–20, 21–25, 26–30 Y.O.). The thickness and anterior-posterior width of the masseter muscle in the rest and clenched states were measured bilaterally using USG with the 7.5 MHz linear probe. Inter-molar width was measured using a metal caliper on dental casts of both jaws. The student t-test analysis was used to compare the means between males and females. The relationship between the width and thickness of masseter muscle and intermolar width was evaluated using Spearman correlation coefficient and Pearson correlation coefficient. Results Males exhibited significantly thicker and wider masseter muscles in rest and clenched states (P < 0.001). They also had wider dental arches in upper and lower jaws (P < 0.001). Intermolar width correlated significantly with muscle dimensions in both states (P 0.05). Conclusion USG can be used to measure muscle thickness as a safe and reproducible method. There is a positive correlation between the masseter muscle width and thickness and intermolar width. Masseter muscle Intermolar width Ultrasonography Muscle Thickness Muscle Width Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Dental arch growth is a multifactorial process that depends on both genetic and environmental components, including muscular, functional and local factors ( 1 ). In the normal dental arch form, the upper and lower jaws are proportional to surrounding muscles and craniofacial structures. ( 2 )In 2005, Pepicelli et al. concluded in their review that individuals with strong/thick mandibular muscles have wider transverse craniofacial dimensions and a tendency toward parallelism between the jaw bases and between the occlusal and mandibular planes.( 3 ) The masticatory muscles play an important role in oral function, three-dimensional jaw movements ,features of the dental arches and alveolar process thickness. ( 4 )Katsaros et al. indicated that changes in masticatory muscle function affects the transversal growth of the skull especially in areas under direct masticatory muscle influence, as the sites of the masseter muscle attachment.( 5 )Bruxism is defined as repeated masticatory muscle activity characterized by clenching, grinding and gnashing teeth. There are a series of studies discussing the relationship between bruxism and personality, psychosocial factors, and anxiety. Bruxism can cause tooth fracture, abrasion, mobility, complications of dentures, temporomandibular disorders (TMD), pain in masticatory muscles, fatigue, and hypertrophy of masseter muscle.( 6 ) Recently, muscle thickness has been recognized as an indicator of jaw muscle activity. The dimensions and functions of the muscles can be evaluated by various modalities, like computed tomography (CT), electromyography, magnetic resonance imaging (MRI) and ultrasonography(USG) .Ultrasound is an accessible ,reliable and noninvasive method compared to others .Additionally, it has an advantage over CT or MRI in assessing the internal echogenic pattern of muscles. ( 7 ) In 1994, Radsheer et al conducted a study to compare MRI and USG in the measurement of mid-belly masseter muscle thickness. They represented USG as an accurate and reproducible imaging technique.( 8 ) Normal muscle tissue shows heterogenic low echogenicity with occasional hyperechoic fascia layers in USG images.( 9 ) Since there is an accepted association between masticatory muscle function and the transverse cranial dimensions in animal experimental studies, a similar relationship might be expected to exist regarding dental arch width in humans.( 10 ) Previous studies have assessed the relation between masseter muscle thickness and arch dimension but to the best of our knowledge no studies have assessed thickness and anterior-posterior(ant-pos) width of masseter muscle with the intermolar width of both jaw. Therefore, this study aimed to measure both masseter muscle thickness and width with USG and assess the impact of this muscle on dental arch width in rest and clenched status. Methods Ethical approval: This was a cross-sectional and analytical-descriptive study. Ethical considerations were taken into account, ensuring that the use of ultrasound waves in USG did not impose radiation or harm on the participants. The study protocol was approved by the ethics committee of the School of Dentistry, Shahid Beheshti University, with code IR.SBMU.DRC.REC.1400.134 and it was conducted following the Declaration of Helsinki and its subsequent revisions. The study was conducted in accordance with the STROBE statement. The institution’s policy includes patients’ consent to participate in any trial and approvals of using their data with full clarification of the benefits and risks of any procedure. Sample size: Subjects undergoing orthodontic treatment at the Orthodontic department of Shahid Beheshti dental school between 2021 and 2022 were referred to the Oral and Maxillofacial Radiology Department and examined. The sample size was calculated to be 45; assuming a minimum desired correlation coefficient of 0.35 (r), with a significance level of 0.05 (α) and a power of 0.84. Inclusion criteria were as follows: 1. Individuals aged 16 to 30; since the finalization of the position of the first molars is stabilized by the age of 16 as a result of the interaction between soft and hard tissues. (11) 2. Normal growth 3. Good physical health Exclusion criteria were as follows: 1. Previous history of systemic diseases. 2. History of orthodontic treatments. 3. Presence of discrepancies and pathological issues. 4. History of trauma to the head and face area. 5. History of muscular paralysis. 6. Neurological disorders. 7. Presence of malocclusion functional and skeletal issues. Patient positioning: Participants were asked to sit upright with their heads positioned naturally, facing a standardized point located 2 meters away. For measurements in the rest position, participants were instructed to relax, gently close their mouth, swallow any saliva, and gently place their posterior teeth in occlusion. For measurements in the clenched position, they were asked to firmly press their posterior teeth together . In both positions, the probe was placed on the masseter muscle area on the face. The probe angle was meticulously adjusted to produce the most robust echo from the ramus of the mandible, a condition achieved when the probe was perpendicular to this specific area. All measurements were taken in the transverse section of the face. To reduce measurement errors, the imaging process was replicated by the operator after a 5-minute interval. The Intraclass Correlation Coefficient (ICC) was then calculated to assess the consistency among the measured values. Measurements Images of the right and left masseter muscles were taken using a linear probe 7.5 MHz ultrasound machine (myLab, Aquasonic100 Ultrasound transmission, Esaote Inc, Italy) with water-soluble gel (gel, USA) by an expert Oral and maxillofacial radiologist. Linear parameters, including thickness and ant-pos width of the masseter muscle, were measured in B-mode and using a linear measuring tool with an accuracy of 0.01 cm. Intra-examiner reliability was assessed by repeating measurements on 10 samples in a two-week interval. Muscle thickness was measured at 2 mm intervals in the posterior, middle, and anterior regions during both rest and clenched states. The measurements were recorded using digital ultrasound software, and the average values were calculated (Figure 1). The posterior and anterior limits of the masseter muscle were identified, and the distance between them was measured (Figure 2, A and B). In some cases, where muscle elongation occurred either at rest or during clenching, the measurement of ant-pos width was conducted taking into account the Ramus index (Figure 2, C and D). To measure the intermolar width between molars, alginate molds of the upper and lower jaws were created and subsequently cast. Electronic calipers were utilized to measure the distance between the central pits of the permanent first molars in the upper jaw and the distance between the distobuccal cusp tips of the permanent first molars in the lower jaw to assess intermolar width (Figure 3). Statistical Analysis: All data were entered into a database system and evaluated using SPSS software version 27 (USA, IL, Chicago, Inc SPSS). Patients’ data were analyzed anonymously, with each case assigned a unique registration number to allow for explicit and anonymous identification. The normal distribution of the data was assessed using the Wilk-Shapiro test and Probability plots. The ICC (Intraclass Correlation Coefficient) was calculated to evaluate intra-rater reliability. Qualitative findings were reported as percentages and compared using the Chi-square test. The level of significance was set at p = 0.05. For quantitative findings, mean and standard deviation were reported, and the student's t-test was used to compare means between female and male patients. Pearson correlation coefficient was utilized to assess the relationship between intermolar width and the thickness and ant-pos width of the masseter muscle on both sides. Results Intra‑operator reliability Measures for the first and second replicates of 10 patients were recorded and intra-class correlation coefficients (ICC) were established for all measurements. Most measures demonstrated a high degree of reliability between the first and second replicates with ICC values exceeding 0.83-0.90. Demographic results In the present study, the thickness and ant-pos width of the masseter muscle in rest and clenched conditions were assessed in 45 participants, including 20 women (44.5%) and 25 men (55.5%). Subjects aged from 16 to 30; divided into 3 groups: (16-20) - (21-25) - (26-30). Masseter muscle measurements The average muscle thickness in the rest condition was 8.94 ± 1.76 mm. The measurements in females were 7.73 ± 1.17 mm on the right side and 7.95 ± 1.23 mm on the left side. These values in males were 9.28 ± 1.63 and 10.39 ± 2.17 mm on the right and left sides, respectively (Table 1). The average muscle thickness in the clenched condition was 13.48 ± 2.59 mm. The measurements in the clenched condition in females was 11.41 ± 1.71 mm on the right side and 12.27 ± 1.59 mm on the left side. These values in males were 14.50 ± 2.79 and 15.07 ± 2.65 mm on the right and left sides, respectively (Table 1). [insert table 1] The average ant-pos width of the muscle in the rest condition was 53.40 ± 5.53 mm. The measurement in females was 50.16 ± 4.48 mm on the right side and 51.06 ± 5.10 mm on the left side. These values in males were 55.09 ± 6.10 and 56.16 ± 5.85 mm on the right and left sides, respectively (Table 2). The average ant-pos width of the muscle in the clenched condition was 45.70 ± 3.90 mm. The measurement in females was 43.11 ± 2.49 mm on the right side and 44.65 ± 5.03 mm on the left side. In men, the average ant-pos width of the muscle was 47.00 ± 3.99 and 47.32 ± 4.13 mm on the right and left sides, respectively (Table 1). [insert table 2] Maxillary and mandibular intermolar width The average intermolar width of both jaws were measured as 47.10 ± 3.10 mm. In females, the average intermolar width of the maxilla and mandible were 45.29 ± 2.28 and 46.13 ± 2.54 mm. In males, it was 48.5 ± 2.4 and 49.49 ± 2.69 mm, respectively (Table 2). The correlation between the masseter muscle measurements and intermolar width with gender The independent t-test revealed a significant correlation between gender and masseter muscle thickness in rest and clenched conditions on both sides (P < 0.001). Additionally, a significant correlation for the ant-pos width of the masseter muscle was observed similarly (P < 0.05). We concluded that the thickness and ant-pos width of the masseter muscle in both rest and clenched conditions was more in men compared to women (Table 3). Based on the results of the independent t-test, there is also a significant relationship between the gender of the participants and the intermolar width in both maxilla and mandible (P<0.001) (Table 3). [insert table 3] The relationship between the masseter muscle measurements and the intermolar width was investigated. The results of Pearson correlation and Spearman correlation coefficient showed that there was no significant relationship between the thickness of the masseter muscle and the intermolar width in the maxilla and mandible and in men and women, in any of the rest and clench conditions, on both sides (P > 0.05). However, with no gender discrimination, the relationship between the thickness of the right and left masseter muscles was significant in both conditions (P<0.05): the thicker the masseter muscle in rest and clench conditions, the greater the intermolar width of maxilla and mandible (Figures 4). Pearson correlation and Spearman correlation coefficients revealed no significant relationship between the ant-post width of the masseter muscle and the intermolar width in both jaws, separately in male and female, in the rest and clenched conditions, on both sides (P > 0.05). In general, regardless of gender, there is a significant positive relationship between the ant-pos width of the masseter muscle and the width of the intermolar in both rest and clenched conditions (P < 0.05); concluding that as the ant-pos width of the masseter muscle in both rest and clenched conditions increase, the intermolar width of both maxilla and mandible also increases. The correlations between the masseter muscle measurements and the intermolar width by jaw and sex in each age group In this research, Subjects were divided in 3 groups: (16-20) - (21-25) - (26-30). The relationship between the thickness of the masseter muscle and the intermolar width by jaw and sex was investigated in each age group. In each of the evaluated age groups, the results of Pearson correlation and correlation coefficient did not show any significant relationship between the thickness of the masseter muscle and the intermolar width in the maxilla and mandible in any of the conditions, in male and female and on both sides (P>0.05). The assessment of the ant-pos width of the masseter muscle was carried out in a manner similar to evaluation of the correlations of masseter muscle thickness. The results of Pearson correlation and Spearman correlation coefficient analyses demonstrated no significant relationship in any of the age groups between the ant-pos width of the masseter muscle and the intermolar width in the maxilla and mandible, in any of the rest and clenched conditions, in both sexes, and on both sides (P > 0.05). Discussion This study aimed to evaluate the relation between masseter muscle thickness / ant-pos width on USG and intermolar width on dental cast. Examining the relationship between the dimensional parameters of the master muscle and the intermolar width in this study, generally indicated that the thickness and width of this muscle both in the rest and clenched mode have a significant relationship with the intermolar width; so that in people who had greater ant-pos width of the masseter muscle and muscle thickness in both rest and clenched phases, the intermolar width of both upper and lower jaws was greater. Jaw musculature has been accepted as one of the possible etiological factors in the development of malocclusion and in relapse after orthodontic treatment. The frequency of relapse after completion of orthodontic treatment ranges from 14 to 70%.(12) Most orthodontic techniques require extrusion of posterior tooth. In patients with high masseteric activity, there appears to be a tendency for depression of the molars during chewing or swallowing. Therefore, it might be difficult to produce permanent extrusion of molars and backward rotation of mandible in these patients. Also, brachyfacial patients with robust masseteric activity tend to reduce the face height and deepen the bite when premolars are extracted. So in these patients, deciding for extraction would be challenging.(13) On the other hand, previous studies found that the masseter muscle thickness influences the growth of the jaws. An increase in masseter muscle size leads to increased growth in transverse and sagittal dimensions and decreased growth in vertical height. (14) The thickness of masticatory muscles has not received much attention when compared with volumes of studies done on skeletal growth of the jaws. In 2018, Park et al concluded that the masseter muscle thickness measured by USG in rest and clenching position were different according to gender. Results of this study and the present study support the thicker masseter muscles in males.(15) In 2016, Biondi et al performed a study to evaluate the relationship between the masseter muscle size, maxillary intermolar width and craniofacial vertical skeletal pattern.(16) Kiliaridis et al investigated the relationship between the ultrasonographic thickness of the masseter muscle and the width of the maxillary dental arch.(17)Unlike the present study, they reported that only in females, the thicker masseter muscle size resulted the wider intermolar width. This controversy may result from the differences between growth stages in various population. Another study evaluated the association between the thickness of masseter muscle and the maxillary dental arch width in both genders. This study proposed a positive linear correlation between masseter muscle thickness and maxillary dental arch width, in both males and females, and this supports the conclusion of the present study.(14) In 2012, Rohila et al evaluated the masseter muscle thickness in different vertical dentofacial patterns. They indicated that posterior facial height, symphysis width, intermolar width of maxillary first molars and facial width had a significant positive relationship with masseter muscle thickness. Results of this study are consistent with the results of the current study.(18) In 2010, Parameswaran et al investigated the effect of masseter muscle thickness on maxillary dental arch width and growth pattern of the face. They concluded that an increase in masseter thickness is along with an increase in the maxillary dental arch width. Thus, it supports the current results.(19) In 2009, Sadeghian et al stated that the thickness of the masseter muscle may be considered as one of the influencing factors on the width of the maxillary dental arch and inter canine mandibular dental arch width. (20) Results of this study support the present results. This study only focused on thickness of masseter not other dimensions. One study provided evidence that the buccolingual inclination of the first and second mandibular molars were affected by masticatory muscle function which indirectly influenced dental arch width.(21) In 1997, Bishara et al studied changes of arch width from 6 weeks to 45 years of age.(22) This study supported the present one by stating that men have wider dental arch than women. The images produced may vary depending on the amount of force exerted on the tissue during imaging, as well as the specific anatomy of each patient. The combination of these factors has caused the ultrasound technique to be more dependent on the operator (subjective) compared to CT and MRI methods, and the measurements made have errors(23,24). In addition, future studies may include larger sample sizes and include muscle elasticity as this study did not assess this variable. Conclusion USG can be used to measure muscle thickness as a safe and reproducible method. There is a positive correlation between the masseter muscle width and thickness and intermolar width. Declarations Ethics approval and consent to participate: This study was performed in line with the principles of the Declaration of Helsinki. The study protocol was approved by the ethics committee of the School of Dentistry, Shahid Beheshti University, with code IR.SBMU.DRC.REC.1400.134. Clinical trial number: Not applicable Consent for publication: Not applicable Availability of data and materials: The data that support the findings of this study are available from the corresponding author upon reasonable request. Competing interests: The authors have no relevant financial or non-financial interest Funding: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript interests to disclose. Authors’ contributions: M.GA. implemented the study idea. Y.S. and M.B. Provided the data. S.V. and Z.M. provided statistical analysis. S.MA. drafted the main manuscript. N.KD. and P.R. revised the manuscript. All authors read and approved the final manuscript. Acknowledgments: Not applicable Statements and Declarations: The authors also confirmed that the manuscript is original and does not contain any unlawful statements and any material, the publication of which would violate any copyright or other personal or proprietary right of any person or entity. They also confirm that they have written permission from copyright owners if their work has been used in this manuscript. The authors declare that the following manuscript has not been published elsewhere (in any format or language) and has not been concomitantly sent to another journal for publication consideration. The authors agree that they are responsible for paying any fees for permissions. References Ciavarella D, Lorusso M, Fanelli C, Cazzolla AP, Maci M, Ferrara D, et al. The Correlation between Mandibular Arch Shape and Vertical Skeletal Pattern. Medicina. 2023;59(11):1926. Alaghbari SSA, Mohmmed BSA, Alalwani NNM, Sobhy MM, Qadi KA, Khawaji SA, et al. 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Can ultrasonography be used to assess capsular distention in the painful temporomandibular joint? BMC Oral Health. 2021;21(1):497. Vasegh Z, Safi Y, Azar MS, Ahsaie MG, Arianezhad SM. Assessment of bony changes in temporomandibular joint in patients using cone beam computed tomography–a cross sectional study. Head & Face Medicine. 2023;19(1):47. Tables Table 1: Masseter muscle thickness in the rest and clenched condition by sex and side Muscle thickness in Rest condition Total (N =45) Male (N = 25) Female (N=20) Thickness rest Max. Min. Std. Mean Max. Min. Std. Mean Max. Min. Std. Mean 12.9 5.6 1.62 8.59 12.9 5.6 1.63 9.28 9.9 5.9 1.17 7.73 Right 15.3 5.5 2.17 9.30 15.3 7.1 2.17 10.39 9.8 5.5 1.23 7.95 Left 13.6 5.7 1.76 8.94 13.6 7.1 1.75 9.83 9.8 5.7 0.994 7.83 Average right and left Muscle thickness in Clenched condition Total Male Female Thickness clenched Max. Min. Std. Mean Max. Min. Std. Mean Max. Min. Std. Mean 20.6 7.8 2.81 13.13 20.6 10.3 2.79 14.5 14.4 7.8 1.71 11.41 Right 21.2 9.6 2.62 13.83 21.2 11.3 2.65 15.07 14.7 9.6 1.59 12.27 Left 20.1 9.6 2.59 13.48 20.1 11.4 2.55 14.78 14.05 9.6 1.52 11.84 Average right and left Ant-pos width of the muscle in Rest Condition Total (N = 45) Male (N = 25) Female (N = 20) width rest Max. Min. Std. Mean Max. Min. Std. Mean Max. Min. Std. Mean 67.1 41.7 5.93 52.9 67.1 45.1 6.10 55.09 56.7 41.7 4.48 50.16 Right 68.1 42.6 6.04 53.896 68.1 45.4 5.85 56.16 61.3 42.6 5.10 51.06 Left 67.6 42.6 5.53 53.40 67.6 46.75 5.31 55.626 58 42.6 4.52 50.61 Average right and left Anterior-posterior width of the muscle in Clenched Condition Total Male Female Width clench Max. Min. Std. Mean Max. Min. Std. Mean Max. Min. Std. Mean 55.5 38.1 3.90 45.27 55.5 38.5 3.99 47.00 48.2 38.1 2.49 43.11 Right 63 39.8 4.70 46.13 55.4 41.4 4.13 47.32 63 39.8 5.03 44.65 Left 54.85 39.1 3.90 45.70 54.5 40.5 3.78 47.16 54.85 39.1 3.30 43.87 Average right and left Table 2: Average intermolar width by sex Total (N = 45) Male (N = 25) Female (N = 20) Intermolar width Max. Min. Std. Mean Max. Min. Std. Mean Max. Min. Std. Mean 54.5 41.2 2.86 47.07 54.5 43 2.46 48.5 49 41.2 2.28 45.29 maxilla 55.1 42 3.10 47.10 55.1 45.5 2.69 49.49 50 42 2.54 46.13 mandible Table 3: The relationship between the masseter muscle thickness, ant-pos width of the muscle, intermolar width, and gender in rest and clenched conditions on both sides Masseter muscle thickness t-test for Equality of Means Levene's Test Independent sample t-test 95% CI Std. Error Diff. Mean Diff. Sig. (2-tailed) Sig. Upper Lower -.67 -2.41 .43 -1.54 .001 .409 Right thickness (rest) -1.40 -3.48 .51 -2.44 .000 .016 Left thickness (rest) -1.16 -2.83 .41 -1.10 .000 .011 Average right and left thickness (rest) -1.72 -4.44 .67 -3.08 .000 .013 Right thickness (clenched) -1.50 -4.08 .63 -2.79 .000 .025 Left thickness (clenched) -1.70 -4.17 .61 -2.94 .000 .005 Average right and left thickness (clenched) Ant-pos width of the muscle t-test for Equality of Means Levene's Test Independent sample T-test 95% CI Std. Error Diff. Mean Diff. Sig. (2- tailed) Sig. Upper Lower -1.63 -8.22 1.63 -4.93 .004 .167 Right width (rest) -1.74 -8.44 1.65 -5.09 .004 .721 Left width (rest) -2.00 -8.02 1.49 -5.01 .002 .556 Average right and left width (rest) -1.83 -5.96 1.02 -3.89 .000 .138 Right width (clenched) .07 -5.43 1.36 -2.67 .056 .851 Left width (clenched) -1.12 -5.45 1.07 -3.30 .004 .185 Average right and left width (clenched) Intermolar width t-test for Equality of Means Levene's Test Independent sample T-test 95% CI Std. Error Diff. Mean Diff. Sig. (2- tailed) Sig. Upper Lower -1.76 -4.65 .71 -3.21 .000 .996 Maxillary intermolar width -1.77 -4.95 .78 -3.36 .000 .794 Mandibular intermolar width -1.82 -4.75 .72 -3.28 .000 .954 Average intermolar width Additional Declarations No competing interests reported. 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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-4872636","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":354498964,"identity":"26eb00a4-7f1a-47e2-98ce-1d0a8ef16ff8","order_by":0,"name":"Mitra Ghazizadeh Ahsaie","email":"","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Mitra","middleName":"Ghazizadeh","lastName":"Ahsaie","suffix":""},{"id":354498965,"identity":"17203dd9-c9d4-4ef9-bc76-e9a33f54d9de","order_by":1,"name":"Yaser Safi","email":"","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Yaser","middleName":"","lastName":"Safi","suffix":""},{"id":354498966,"identity":"0363962c-a53c-4918-911b-dc9e0be5e6e1","order_by":2,"name":"Mohammad Behnaz","email":"","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"","lastName":"Behnaz","suffix":""},{"id":354498967,"identity":"4cb3b0ae-0e26-4276-916c-6da6a21370bb","order_by":3,"name":"Solmaz Valizadeh","email":"","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Solmaz","middleName":"","lastName":"Valizadeh","suffix":""},{"id":354498968,"identity":"199b8dfc-b290-40ac-b9b4-e4f6c9832151","order_by":4,"name":"S. Marjan Arianezhad","email":"","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"Marjan","lastName":"Arianezhad","suffix":""},{"id":354498969,"identity":"1487a544-0ce5-4961-88e6-c2368e86dcaa","order_by":5,"name":"Zakaria Moosavi","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Zakaria","middleName":"","lastName":"Moosavi","suffix":""},{"id":354498970,"identity":"440e2145-9ff1-429b-b4ea-d652eaaa8c04","order_by":6,"name":"Paniz Ranji","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA20lEQVRIiWNgGAWjYDADfvbmA0BKQoZ4LZI9xxJAWniI12Jww8cARBPWYt7Ae/BzQYWNveQMns+vbtRY8DCwHz66AZ8WmQN8ydIzzqQx80v3brPOOQZ0GE9a2g18WiQYeAykedsOs0nOObvNOIcNqEWCx4yQFuPfvP/+8xjcyHlmnPOPOC1m0rwNBySAWpgf57YRo4WZL82a51iyATCQzZhz+yR42Aj6hb338G2eGjt7YFQ+/pzzrU6On/3wMbxaGJgREcEmASbxKgcDhBbmD4RVj4JRMApGwUgEAOq5PnlHnG88AAAAAElFTkSuQmCC","orcid":"","institution":"Shahid Beheshti University of Medical Sciences","correspondingAuthor":true,"prefix":"","firstName":"Paniz","middleName":"","lastName":"Ranji","suffix":""},{"id":354498971,"identity":"808ceb88-354e-49fc-8a4f-2d72097a1189","order_by":7,"name":"Negin Kouchak Dezfouli","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Negin","middleName":"Kouchak","lastName":"Dezfouli","suffix":""}],"badges":[],"createdAt":"2024-08-07 07:15:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4872636/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4872636/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":66644900,"identity":"d3f37854-3e92-44c2-87ab-6a67824c9778","added_by":"auto","created_at":"2024-10-15 06:45:23","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":241791,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of masseter muscle thickness in the middle and 2 mm anterior and posterior to it in the (A) rest state and (B) clenched state\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4872636/v1/bdada087e5011500348fdddc.png"},{"id":66643660,"identity":"dc18f428-abb3-4f3e-8c1c-6038793d6bb7","added_by":"auto","created_at":"2024-10-15 06:37:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":547506,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of ant-posterior width of the masseter muscle in the (A) rest state, (B) clenched state, and (C and D) utilization of the Ramus index (red arrow) for measuring the ant-pos width of the elongated masseter muscle\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4872636/v1/6e4634fade05667c68a930b1.png"},{"id":66643659,"identity":"3bd08a1d-c34b-4559-98e8-25bec63f2217","added_by":"auto","created_at":"2024-10-15 06:37:22","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":845726,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of intermolar width using electronic calipers. (A) Maxillary arch, (B) Mandibular arch\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4872636/v1/5bc77520757cb702a8d36487.png"},{"id":66645516,"identity":"8bfe13bb-3d1d-4b97-a199-f74a603fe796","added_by":"auto","created_at":"2024-10-15 06:53:23","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1190260,"visible":true,"origin":"","legend":"\u003cp\u003eThe relationship between masseter muscle thickness and intermolar width: Muscle with high thickness in US (A1) and corresponding wide intermolar width on dental cast (A2), Muscle with low thickness in US (B1) and corresponding low intermolar width on dental cast(B2)\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4872636/v1/12af4d7a387f33da207865da.png"},{"id":68210940,"identity":"fad44908-0211-4dbe-a838-f2fb4e55fc37","added_by":"auto","created_at":"2024-11-04 17:31:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4476707,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4872636/v1/b3ec2329-f7ea-4b29-b191-15d3481b2079.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"What is the correlation between thickness and anterior posterior width of masseter muscle in ultrasonography with intermolar width in maxilla and mandible?","fulltext":[{"header":"Background","content":"\u003cp\u003eDental arch growth is a multifactorial process that depends on both genetic and environmental components, including muscular, functional and local factors (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). In the normal dental arch form, the upper and lower jaws are proportional to surrounding muscles and craniofacial structures. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e)In 2005, Pepicelli et al. concluded in their review that individuals with strong/thick mandibular muscles have wider transverse craniofacial dimensions and a tendency toward parallelism between the jaw bases and between the occlusal and mandibular planes.(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e The masticatory muscles play an important role in oral function, three-dimensional jaw movements ,features of the dental arches and alveolar process thickness. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)Katsaros et al. indicated that changes in masticatory muscle function affects the transversal growth of the skull especially in areas under direct masticatory muscle influence, as the sites of the masseter muscle attachment.(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)Bruxism is defined as repeated masticatory muscle activity characterized by clenching, grinding and gnashing teeth. There are a series of studies discussing the relationship between bruxism and personality, psychosocial factors, and anxiety. Bruxism can cause tooth fracture, abrasion, mobility, complications of dentures, temporomandibular disorders (TMD), pain in masticatory muscles, fatigue, and hypertrophy of masseter muscle.(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eRecently, muscle thickness has been recognized as an indicator of jaw muscle activity. The dimensions and functions of the muscles can be evaluated by various modalities, like computed tomography (CT), electromyography, magnetic resonance imaging (MRI) and ultrasonography(USG) .Ultrasound is an accessible ,reliable and noninvasive method compared to others .Additionally, it has an advantage over CT or MRI in assessing the internal echogenic pattern of muscles. (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) In 1994, Radsheer et al conducted a study to compare MRI and USG in the measurement of mid-belly masseter muscle thickness. They represented USG as an accurate and reproducible imaging technique.(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) Normal muscle tissue shows heterogenic low echogenicity with occasional hyperechoic fascia layers in USG images.(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e) Since there is an accepted association between masticatory muscle function and the transverse cranial dimensions in animal experimental studies, a similar relationship might be expected to exist regarding dental arch width in humans.(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e) Previous studies have assessed the relation between masseter muscle thickness and arch dimension but to the best of our knowledge no studies have assessed thickness and anterior-posterior(ant-pos) width of masseter muscle with the intermolar width of both jaw.\u003c/p\u003e \u003cp\u003eTherefore, this study aimed to measure both masseter muscle thickness and width with USG and assess the impact of this muscle on dental arch width in rest and clenched status.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cem\u003eEthical approval:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThis was a cross-sectional and analytical-descriptive study. Ethical considerations were taken into account, ensuring that the use of ultrasound waves in USG did not impose radiation or harm on the participants. The study protocol was approved by the ethics committee of the School of Dentistry, Shahid Beheshti University, with code IR.SBMU.DRC.REC.1400.134 and it was conducted following the Declaration of Helsinki and its subsequent revisions. The study was conducted in accordance with the STROBE statement.\u0026nbsp;The institution\u0026rsquo;s policy includes patients\u0026rsquo; consent to participate in any trial and approvals of using their data with full clarification of the benefits and risks of any procedure.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSample size:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eSubjects undergoing orthodontic treatment at the Orthodontic department of Shahid Beheshti dental school between 2021 and 2022 were referred to the Oral and Maxillofacial Radiology Department and examined. The sample size was calculated to be 45; assuming a minimum desired correlation coefficient of 0.35 (r), with a significance level of 0.05 (\u0026alpha;) and a power of 0.84.\u003c/p\u003e\n\u003cp\u003eInclusion criteria were as follows:\u003c/p\u003e\n\u003cp\u003e1. Individuals aged 16 to 30; since the finalization of the position of the first molars is stabilized by the age of 16 as a result of the interaction between soft and hard tissues.\u0026nbsp;(11)\u003c/p\u003e\n\u003cp\u003e2. Normal growth\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3. Good physical health\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eExclusion criteria were as follows:\u003c/p\u003e\n\u003cp\u003e1. Previous history of systemic diseases.\u003c/p\u003e\n\u003cp\u003e2. History of orthodontic treatments.\u003c/p\u003e\n\u003cp\u003e3. Presence of discrepancies and pathological issues.\u003c/p\u003e\n\u003cp\u003e4. History of trauma to the head and face area.\u003c/p\u003e\n\u003cp\u003e5. History of muscular paralysis.\u003c/p\u003e\n\u003cp\u003e6. Neurological disorders.\u003c/p\u003e\n\u003cp\u003e7. Presence of malocclusion functional and skeletal issues.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePatient positioning:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eParticipants were asked to sit upright with their heads positioned naturally, facing a standardized point located 2 meters away. For measurements in the rest position, participants were instructed to relax, gently close their mouth, swallow any saliva, and gently place their posterior teeth in occlusion. For measurements in the clenched position, they were asked to firmly press their posterior teeth together\u003cspan dir=\"RTL\"\u003e.\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eIn both positions, the probe was placed on the masseter muscle area on the face. The probe angle was meticulously adjusted to produce the most robust echo from the ramus of the mandible, a condition achieved when the probe was perpendicular to this specific area. All measurements were taken in the transverse section of the face. To reduce measurement errors, the imaging process was replicated by the operator after a 5-minute interval. The Intraclass Correlation Coefficient (ICC) was then calculated to assess the consistency among the measured values.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMeasurements\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eImages of the right and left masseter muscles were taken using a linear probe 7.5 MHz ultrasound machine (myLab, Aquasonic100 Ultrasound transmission, Esaote Inc, Italy) with water-soluble gel (gel, USA) by an expert Oral and maxillofacial radiologist.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLinear parameters, including thickness and ant-pos width of the masseter muscle, were measured in B-mode and using a linear measuring tool with an accuracy of 0.01 cm. Intra-examiner reliability was assessed by repeating measurements on 10 samples in a two-week interval.\u003c/p\u003e\n\u003cp\u003eMuscle thickness was measured at 2 mm intervals in the posterior, middle, and anterior regions during both rest and clenched states. The measurements were recorded using digital ultrasound software, and the average values were calculated (Figure 1). The posterior and anterior limits of the masseter muscle were identified, and the distance between them was measured (Figure 2, A and B). In some cases, where muscle elongation occurred either at rest or during clenching, the measurement of ant-pos width was conducted taking into account the Ramus index (Figure 2, C and D).\u003c/p\u003e\n\u003cp\u003eTo measure the intermolar width between molars, alginate molds of the upper and lower jaws were created and subsequently cast. Electronic calipers were utilized to measure the distance between the central pits of the permanent first molars in the upper jaw and the distance between the distobuccal cusp tips of the permanent first molars in the lower jaw to assess intermolar width (Figure 3).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eStatistical Analysis:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll data were entered into a database system and evaluated using SPSS software version 27 (USA, IL, Chicago, Inc SPSS). Patients\u0026rsquo; data were analyzed anonymously, with each case assigned a unique registration number to allow for explicit and anonymous identification. The normal distribution of the data was assessed using the Wilk-Shapiro test and Probability plots. The ICC (Intraclass Correlation Coefficient) was calculated to evaluate intra-rater reliability. Qualitative findings were reported as percentages and compared using the Chi-square test. The level of significance was set at \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.05.\u003c/p\u003e\n\u003cp\u003eFor quantitative findings, mean and standard deviation were reported, and the student\u0026apos;s t-test was used to compare means between female and male patients. Pearson correlation coefficient was utilized to assess the relationship between intermolar width and the thickness and ant-pos width of the masseter muscle on both sides.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cem\u003eIntra‑operator reliability\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eMeasures for the first and second replicates of 10 patients were recorded and intra-class correlation coefficients (ICC) were established for all measurements. Most measures demonstrated a high degree of reliability between the first and second replicates with ICC values exceeding 0.83-0.90.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDemographic results\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study, the thickness and ant-pos width of the masseter muscle in rest and clenched conditions were assessed in 45 participants, including 20 women (44.5%) and 25 men (55.5%). Subjects aged from 16 to 30; divided into 3 groups: (16-20) - (21-25) - (26-30).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMasseter muscle measurements\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe average muscle thickness in the rest condition was 8.94 \u0026plusmn; 1.76 mm. The measurements in females were 7.73 \u0026plusmn; 1.17 mm on the right side and 7.95 \u0026plusmn; 1.23 mm on the left side. These values in males were 9.28 \u0026plusmn; 1.63 and 10.39 \u0026plusmn; 2.17 mm on the right and left sides, respectively (Table 1). The average muscle thickness in the clenched condition was 13.48 \u0026plusmn; 2.59 mm. The measurements in the clenched condition in females was 11.41 \u0026plusmn; 1.71 mm on the right side and 12.27 \u0026plusmn; 1.59 mm on the left side. These values in males were 14.50 \u0026plusmn; 2.79 and 15.07 \u0026plusmn; 2.65 mm on the right and left sides, respectively (Table 1).\u003c/p\u003e\n\u003cp\u003e[insert table 1]\u003c/p\u003e\n\u003cp\u003eThe average ant-pos width of the muscle in the rest condition was 53.40 \u0026plusmn; 5.53 mm. The measurement in females was 50.16 \u0026plusmn; 4.48 mm on the right side and 51.06 \u0026plusmn; 5.10 mm on the left side. These values in males were 55.09 \u0026plusmn; 6.10 and 56.16 \u0026plusmn; 5.85 mm on the right and left sides, respectively (Table 2). The average ant-pos width of the muscle in the clenched condition was 45.70 \u0026plusmn; 3.90 mm. The measurement in females was 43.11 \u0026plusmn; 2.49 mm on the right side and 44.65 \u0026plusmn; 5.03 mm on the left side. In men, the average ant-pos width of the muscle was 47.00 \u0026plusmn; 3.99 and 47.32 \u0026plusmn; 4.13 mm on the right and left sides, respectively (Table 1).\u003c/p\u003e\n\u003cp\u003e[insert table 2]\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMaxillary and mandibular intermolar width\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe average intermolar width of both jaws were measured as 47.10 \u0026plusmn; 3.10 mm. In females, the average intermolar width of the maxilla and mandible were 45.29 \u0026plusmn; 2.28 and 46.13 \u0026plusmn; 2.54 mm. In males, it was 48.5 \u0026plusmn; 2.4 and 49.49 \u0026plusmn; 2.69 mm, respectively (Table 2).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe correlation between the masseter muscle measurements and intermolar width with gender\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe independent t-test revealed a significant correlation between gender and masseter muscle thickness in rest and clenched conditions on both sides (P \u0026lt; 0.001). Additionally, a significant correlation for the ant-pos width of the masseter muscle was observed similarly (P \u0026lt; 0.05). We concluded that the thickness and ant-pos width of the masseter muscle in both rest and clenched conditions was more in men compared to women (Table 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBased on the results of the independent t-test, there is also a significant relationship between the gender of the participants and the intermolar width in both maxilla and mandible (P\u0026lt;0.001) (Table 3).\u003c/p\u003e\n\u003cp\u003e[insert table 3]\u003c/p\u003e\n\u003cp\u003eThe relationship between the masseter muscle measurements and the intermolar width was investigated.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThe results of Pearson correlation and Spearman correlation coefficient showed that there was no significant relationship between the thickness of the masseter muscle and the intermolar width in the maxilla and mandible and in men and women, in any of the rest and clench conditions, on both sides (P \u0026gt; 0.05). However, with no gender discrimination, the relationship between the thickness of the right and left masseter muscles was significant in both conditions (P\u0026lt;0.05): the thicker the masseter muscle in rest and clench conditions, the greater the intermolar width of maxilla and mandible (Figures 4).\u003c/p\u003e\n\u003cp\u003ePearson correlation and Spearman correlation coefficients revealed no significant relationship between the ant-post width of the masseter muscle and the intermolar width in both jaws, separately in male and female, in the rest and clenched conditions, on both sides (P \u0026gt; 0.05). In general, regardless of gender, there is a significant positive relationship between the ant-pos width of the masseter muscle and the width of the intermolar in both rest and clenched conditions (P \u0026lt; 0.05); concluding that as the ant-pos width of the masseter muscle in both rest and clenched conditions increase, the intermolar width of both maxilla and mandible also increases.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe correlations between the masseter muscle measurements and the intermolar width by jaw and sex in each age group\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIn this research, Subjects were divided in 3 groups: (16-20) - (21-25) - (26-30). The relationship between the thickness of the masseter muscle and the intermolar width by jaw and sex was investigated in each age group. In each of the evaluated age groups, the results of Pearson correlation and correlation coefficient did not show any significant relationship between the thickness of the masseter muscle and the intermolar width in the maxilla and mandible in any of the conditions, in male and female and on both sides (P\u0026gt;0.05).\u003c/p\u003e\n\u003cp\u003eThe assessment of the ant-pos width of the masseter muscle was carried out in a manner similar to evaluation of the correlations of masseter muscle thickness. The results of Pearson correlation and Spearman correlation coefficient analyses demonstrated no significant relationship in any of the age groups between the ant-pos width of the masseter muscle and the intermolar width in the maxilla and mandible, in any of the rest and clenched conditions, in both sexes, and on both sides (P \u0026gt; 0.05).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study aimed to evaluate the relation between masseter muscle thickness / ant-pos width on USG and intermolar width on dental cast. Examining the relationship between the dimensional parameters of the master muscle and the intermolar width in this study, generally indicated that the thickness and width of this muscle both in the rest and clenched mode have a significant relationship with the intermolar width; so that in people who had greater ant-pos width of the masseter muscle and muscle thickness in both rest and clenched phases, the intermolar width of both upper and lower jaws was greater.\u003c/p\u003e\n\u003cp\u003eJaw musculature has been accepted as one of the possible etiological factors in the development of malocclusion and in relapse after orthodontic treatment. The frequency of relapse after completion of orthodontic treatment ranges from 14 to 70%.(12)\u0026nbsp;Most orthodontic techniques require extrusion of posterior tooth. In patients with high masseteric activity, there appears to be a tendency for depression of the molars during chewing or swallowing. Therefore, it might be difficult to produce permanent extrusion of molars and backward rotation of mandible in these patients. Also, brachyfacial patients with robust masseteric activity tend to reduce the face height and deepen the bite when premolars are extracted. So in these patients, deciding for extraction would be challenging.(13)\u0026nbsp;On the other hand, previous studies found that the masseter muscle thickness influences the growth of the jaws. An increase in masseter muscle size leads to increased growth in transverse and sagittal dimensions and decreased growth in vertical height.\u0026nbsp;(14)\u0026nbsp;The thickness of masticatory muscles has not received much attention when compared with volumes of studies done on skeletal growth of the jaws. In 2018, Park et al concluded that the masseter muscle thickness measured by USG in rest and clenching position were different according to gender. Results of this study and the present study support the thicker masseter muscles in males.(15)\u0026nbsp; In 2016, Biondi et al performed a study to evaluate the relationship between the masseter muscle size, maxillary intermolar width and craniofacial vertical skeletal pattern.(16)\u0026nbsp;Kiliaridis et al investigated the relationship between the ultrasonographic thickness of the masseter muscle and the width of the maxillary dental arch.(17)Unlike the present study, they reported that only in females, the thicker masseter muscle size resulted the wider intermolar width. This controversy may result from the differences between growth stages in various population. Another study evaluated the association between the thickness of masseter muscle and the maxillary dental arch width in both genders. This study proposed a positive linear correlation between masseter muscle thickness and maxillary dental arch width, in both males and females, and this supports the conclusion of the present study.(14)\u003c/p\u003e\n\u003cp\u003eIn 2012, Rohila et al evaluated the masseter muscle thickness in different vertical dentofacial patterns. They indicated that posterior facial height, symphysis width, intermolar width of maxillary first molars and facial width had a significant positive relationship with masseter muscle thickness. Results of this study are consistent with the results of the current study.(18)\u003c/p\u003e\n\u003cp\u003eIn 2010, Parameswaran et al investigated the effect of masseter muscle thickness on maxillary dental arch width and growth pattern of the face. They concluded that an increase in masseter thickness is along with an increase in the maxillary dental arch width. Thus, it supports the current results.(19)\u0026nbsp;In 2009, Sadeghian et al stated that the thickness of the masseter muscle may be considered as one of the influencing factors on the width of the maxillary dental arch and inter canine mandibular dental arch width.\u0026nbsp;(20)\u0026nbsp;Results of this study support the present results. This study only focused on thickness of masseter not other dimensions. One study provided evidence that the buccolingual inclination of the first and second mandibular molars were affected by masticatory muscle function which indirectly influenced dental arch width.(21)\u0026nbsp;In 1997, Bishara et al studied changes of arch width from 6 weeks to 45 years of age.(22)\u0026nbsp;This study supported the present one by stating that men have wider dental arch than women.\u003c/p\u003e\n\u003cp\u003eThe images produced may vary depending on the amount of force exerted on the tissue during imaging, as well as the specific anatomy of each patient. The combination of these factors has caused the ultrasound technique to be more dependent on the operator (subjective) compared to CT and MRI methods, and the measurements made have errors(23,24). In addition, future studies may include larger sample sizes and include muscle elasticity as this study did not assess this variable.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eUSG can be used to measure muscle thickness as a safe and reproducible method. There is a positive correlation between the masseter muscle width and thickness and intermolar width.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e This study was performed in line with the principles of the Declaration of Helsinki. The study protocol was approved by the ethics committee of the School of Dentistry, Shahid Beheshti University, with code IR.SBMU.DRC.REC.1400.134.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e The data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors have no relevant financial or non-financial interest\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;Funding:\u0026nbsp;\u003c/strong\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions:\u003c/strong\u003e M.GA. implemented the study idea. Y.S. and M.B. \u003cstrong\u003e\u003csup\u003e\u0026nbsp;\u003c/sup\u003e\u003c/strong\u003eProvided the data. S.V. and Z.M. provided statistical analysis. S.MA. drafted the main manuscript. N.KD. and P.R. revised the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatements and Declarations:\u0026nbsp;\u003c/strong\u003eThe authors also confirmed that the manuscript is original and does not contain any unlawful statements and any material, the publication of which would violate any copyright or other personal or proprietary right of any person or entity. They also confirm that they have written permission from copyright owners if their work has been used in this manuscript. The authors declare that the following manuscript has not been published elsewhere (in any format or language) and has not been concomitantly sent to another journal for publication consideration. The authors agree that they are responsible for paying any fees for permissions.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCiavarella D, Lorusso M, Fanelli C, Cazzolla AP, Maci M, Ferrara D, et al. The Correlation between Mandibular Arch Shape and Vertical Skeletal Pattern. Medicina. 2023;59(11):1926.\u003c/li\u003e\n\u003cli\u003eAlaghbari SSA, Mohmmed BSA, Alalwani NNM, Sobhy MM, Qadi KA, Khawaji SA, et al. Analysis of the facial measurements and dental arch dimensions for the construction of dental prostheses among adult Yemenis. The Journal of Contemporary Dental Practice. 2023;24(8):595-604.\u003c/li\u003e\n\u003cli\u003ePepicelli A, Woods M, Briggs C. The mandibular muscles and their importance in orthodontics: a contemporary review. Am J Orthod Dentofacial Orthop. 2005;128(6):774-80.\u003c/li\u003e\n\u003cli\u003eIwasaki M, Hirano H, Motokawa K, Shirobe M, Edahiro A, Ohara Y, et al. Interrelationships among whole-body skeletal muscle mass, masseter muscle mass, oral function, and dentition status in older Japanese adults. BMC Geriatrics. 2021;21(1):582.\u003c/li\u003e\n\u003cli\u003eKatsaros C, Berg R, Kiliaridis S. Influence of masticatory muscle function on transverse skull dimensions in the growing rat. J Orofac Orthop. 2002;63(1):5-13.\u003c/li\u003e\n\u003cli\u003eErdil D, Bagis N, Eren H, Camgoz M, Orhan K. The Evaluation of the Relationship between Changes in Masseter Muscle Thickness and Tooth Clenching Habits of Bruxism Patients Treated with Botulinum Toxin A. J Med Ultrasound. 2023;31(1):22-8.\u003c/li\u003e\n\u003cli\u003eKalluvalappil A, Balan A, Chandrabose TB, Venugopal M, Jacob JE, Ramachandran S. Comparative Ultrasonographic Evaluation of the Masseter Muscle in Patients with and without Oral Submucous Fibrosis. Journal of Indian Academy of Oral Medicine and Radiology. 2023;35(1):75-81.\u003c/li\u003e\n\u003cli\u003eRaadsheer MC, Van Eijden TM, Van Spronsen PH, Van Ginkel FC, Kiliaridis S, Prahl-Andersen B. A comparison of human masseter muscle thickness measured by ultrasonography and magnetic resonance imaging. Arch Oral Biol. 1994;39(12):1079-84.\u003c/li\u003e\n\u003cli\u003eLee HJ, Choi YJ, Lee KW, Hu KS, Kim ST, Kim HJ. Ultrasonography of the internal architecture of the superficial part of the masseter muscle in vivo. Clinical Anatomy. 2019;32(3):446-52.\u003c/li\u003e\n\u003cli\u003eOdman A, Bresin A, Kiliaridis S. The effect of retraining hypofunctional jaw muscles on the transverse skull dimensions of adult rats. Acta Odontologica Scandinavica. 2019;77:1-5.\u003c/li\u003e\n\u003cli\u003eRakosi T, Jonas I, Graber TM. Color atlas of dental medicine, Orthodontic-Diagnosis. American Journal of Orthodontics and Dentofacial Orthopedics. 1994;105(6):613.\u003c/li\u003e\n\u003cli\u003eWang M, Wang J, Jin X, Liu D, Bian H, Zhao Y, Li Y. Impact of occlusal contact pattern on dental stability and oromandibular system after orthodontic tooth movement in rats. Sci Rep. 2023;13(1):22276.\u003c/li\u003e\n\u003cli\u003eKumar GS, Pillai B. Masseteric hypertrophy: An orthodontic perspective. Journal of Indian Orthodontic Society. 2012;46(4_suppl1):233-7.\u003c/li\u003e\n\u003cli\u003eTircoveluri S, Singh JR, Rayapudi N, Karra A, Begum M, Challa P. Correlation of masseter muscle thickness and intermolar width - an ultrasonography study. J Int Oral Health. 2013;5(2):28-34.\u003c/li\u003e\n\u003cli\u003ePark KM, Choi E, Kwak EJ, Kim S, Park W, Jeong JS, Kim KD. The relationship between masseter muscle thickness measured by ultrasonography and facial profile in young Korean adults. Imaging Sci Dent. 2018;48(3):213-21.\u003c/li\u003e\n\u003cli\u003eBiondi K, Lorusso P, Fastuca R, Mangano A, Zecca PA, Bosco M, et al. Evaluation of masseter muscle in different vertical skeletal patterns in growing patients. Eur J Paediatr Dent. 2016;17(1):47-52.\u003c/li\u003e\n\u003cli\u003eKiliaridis S, Georgiakaki I, Katsaros C. Masseter muscle thickness and maxillary dental arch width. Eur J Orthod. 2003;25(3):259-63.\u003c/li\u003e\n\u003cli\u003eRohila AK, Sharma VP, Shrivastav PK, Nagar A, Singh GP. An ultrasonographic evaluation of masseter muscle thickness in different dentofacial patterns. Indian J Dent Res. 2012;23(6):726-31.\u003c/li\u003e\n\u003cli\u003eParameshwaran V. Masseter Activity, Arch Width and Facial Type. Journal of Indian Orthodontic Society. 2010;44(1):91-5.\u003c/li\u003e\n\u003cli\u003eSadeghian S. Masseter muscle thickness and dental arch widths. Iranian Journal of Orthodontics. 2009;4(1):33-7.\u003c/li\u003e\n\u003cli\u003eMasumoto T, Hayashi I, Kawamura A, Tanaka K, Kasai K. Relationships among facial type, buccolingual molar inclination, and cortical bone thickness of the mandible. Eur J Orthod. 2001;23(1):15-23.\u003c/li\u003e\n\u003cli\u003eBishara SE, Jakobsen JR, Treder J, Nowak A. Arch width changes from 6 weeks to 45 years of age. Am J Orthod Dentofacial Orthop. 1997;111(4):401-9.\u003c/li\u003e\n\u003cli\u003eKim JH, Park JH, Kim JW, Kim SJ. Can ultrasonography be used to assess capsular distention in the painful temporomandibular joint? BMC Oral Health. 2021;21(1):497.\u003c/li\u003e\n\u003cli\u003eVasegh Z, Safi Y, Azar MS, Ahsaie MG, Arianezhad SM. Assessment of bony changes in temporomandibular joint in patients using cone beam computed tomography\u0026ndash;a cross sectional study. Head \u0026amp; Face Medicine. 2023;19(1):47.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1: Masseter muscle thickness in the rest and clenched condition by sex and side\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable dir=\"rtl\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"744\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"13\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eMuscle thickness in Rest condition\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.451612903225808%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eTotal (N =45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.612903225806452%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMale (N = 25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eFemale (N=20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eThickness\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003erest\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e8.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e15.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e15.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e10.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e13.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e8.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e13.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e0.994\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"13\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eMuscle thickness in Clenched condition\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.451612903225808%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.612903225806452%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eThickness\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eclenched\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.650485436893204%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e20.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e13.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e20.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e10.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e14.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e11.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e21.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e13.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e21.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e11.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e15.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e14.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e12.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.67741935483871%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e20.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e13.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e20.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e14.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e14.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e1.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e11.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable dir=\"rtl\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"744\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"13\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eAnt-pos width of the muscle in Rest Condition\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.451612903225808%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eTotal (N = 45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.612903225806452%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMale (N = 25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eFemale (N = 20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003ewidth\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003erest\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e67.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e41.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e52.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e67.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e6.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e56.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e41.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e4.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e50.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e68.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e6.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e53.896\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e68.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e56.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e61.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e51.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e67.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e53.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e67.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e46.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.626\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e4.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e50.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"13\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eAnterior-posterior width of the muscle in\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eClenched Condition\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"31.451612903225808%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.612903225806452%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eWidth\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eclench\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.679611650485437%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.70873786407767%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.737864077669903%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.796116504854369%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.766990291262136%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e38.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e38.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e47.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e48.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e38.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e43.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e39.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e4.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e46.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e41.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e4.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e47.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e39.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e5.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e44.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.870967741935484%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e54.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e39.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.064516129032258%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e54.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e40.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e47.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e54.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.258064516129032%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e39.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.645161290322581%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.451612903225806%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e43.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.93548387096774%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left\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\u003e\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2: Average intermolar width by sex\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable dir=\"rtl\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"678\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"32.84241531664212%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eTotal (N = 45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.920471281296024%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMale (N = 25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.920471281296024%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eFemale (N = 20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.316642120765833%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eIntermolar width\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.972222222222221%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.465277777777778%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.118055555555555%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.333333333333334%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8125%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.465277777777778%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.944444444444445%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.333333333333334%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8125%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMax.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.465277777777778%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMin.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.944444444444445%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.333333333333334%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.529411764705882%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e54.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e41.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.029411764705882%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e47.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.617647058823529%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e54.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.882352941176471%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e48.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.617647058823529%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e41.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.882352941176471%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.294117647058824%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003emaxilla\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.529411764705882%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.029411764705882%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e3.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e47.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.617647058823529%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e55.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e45.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.882352941176471%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e49.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.617647058823529%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.323529411764706%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.882352941176471%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e2.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.0588235294117645%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e46.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.294117647058824%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003emandible\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\u003e\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 3: The relationship between the masseter muscle thickness, ant-pos width of the muscle, intermolar width, and gender in rest and clenched conditions on both sides\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable dir=\"rtl\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"702\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"11\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eMasseter muscle thickness\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"49.572649572649574%\" colspan=\"9\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003et-test for Equality of Means\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLevene\u0026apos;s Test\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" rowspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eIndependent sample t-test\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.21052631578947%\" colspan=\"5\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.789473684210526%\" colspan=\"2\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd. Error\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eDiff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.842105263157896%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean Diff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.473684210526315%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eSig. (2-tailed)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eSig.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.8974358974359%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eUpper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.1025641025641%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLower\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-2.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.409\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight thickness (rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-3.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-2.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft thickness (rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-2.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left thickness\u0026nbsp;(rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-4.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-3.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight thickness (clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-4.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-2.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.025\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft thickness (clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.532763532763532%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-1.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.68945868945869%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-4.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e-2.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left thickness\u0026nbsp;(clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"11\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eAnt-pos width of the muscle\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"49.572649572649574%\" colspan=\"9\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003et-test for Equality of Means\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLevene\u0026apos;s Test\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" rowspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eIndependent sample T-test\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.21052631578947%\" colspan=\"5\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.789473684210526%\" colspan=\"2\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd. Error Diff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.842105263157896%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean Diff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.473684210526315%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eSig. (2-\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003etailed)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eSig.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"57.69230769230769%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eUpper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"42.30769230769231%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLower\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-8.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-4.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.004\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.167\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight width\u0026nbsp;(rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-8.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-5.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.004\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.721\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft width\u0026nbsp;(rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-2.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-8.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-5.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.002\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.556\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left width\u0026nbsp;(rest)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-5.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-3.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.138\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eRight width (clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-5.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-2.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.056\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.851\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLeft width\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e(clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.820512820512821%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-5.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.6923076923076925%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-3.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.004\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.185\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage right and left width\u0026nbsp;(clenched)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"11\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003eIntermolar width\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"49.572649572649574%\" colspan=\"9\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003et-test for Equality of Means\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLevene\u0026apos;s Test\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" rowspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eIndependent sample T-test\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"32.23684210526316%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.789473684210526%\" colspan=\"2\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eStd. Error\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eDiff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.81578947368421%\" colspan=\"2\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMean Diff.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.473684210526315%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eSig. (2-\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003etailed)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003eSig.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"55.10204081632653%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eUpper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"44.89795918367347%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eLower\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.538461538461538%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-4.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.974358974358974%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-3.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.996\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMaxillary intermolar width\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.538461538461538%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-4.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.974358974358974%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-3.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.794\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eMandibular\u0026nbsp;intermolar width\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.538461538461538%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-1.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-4.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.256410256410257%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.974358974358974%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e-3.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.401709401709402%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e\u003cstrong\u003e.000\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp dir=\"LTR\"\u003e.954\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.042735042735046%\" valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003eAverage intermolar width\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n"}],"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":"Masseter muscle, Intermolar width, Ultrasonography, Muscle Thickness, Muscle Width","lastPublishedDoi":"10.21203/rs.3.rs-4872636/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4872636/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eKnowledge of masseter muscle size can be helpful in choosing more successful and stable orthodontic treatment plans. This study aimed to evaluate masseter muscle width and thickness in ultrasonography (USG) and its correlation with dental arch width.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eIn this descriptive-cross-sectional study, 45 participants (25 male (55.5%), and 20 female (45.5%)) were categorized according to their sex and age groups (16\u0026ndash;20, 21\u0026ndash;25, 26\u0026ndash;30 Y.O.). The thickness and anterior-posterior width of the masseter muscle in the rest and clenched states were measured bilaterally using USG with the 7.5 MHz linear probe. Inter-molar width was measured using a metal caliper on dental casts of both jaws. The student t-test analysis was used to compare the means between males and females. The relationship between the width and thickness of masseter muscle and intermolar width was evaluated using Spearman correlation coefficient and Pearson correlation coefficient.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eMales exhibited significantly thicker and wider masseter muscles in rest and clenched states (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). They also had wider dental arches in upper and lower jaws (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Intermolar width correlated significantly with muscle dimensions in both states (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). However, age and sex categorization revealed no significant correlations between muscle parameters and intermolar widths (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eUSG can be used to measure muscle thickness as a safe and reproducible method. There is a positive correlation between the masseter muscle width and thickness and intermolar width.\u003c/p\u003e","manuscriptTitle":"What is the correlation between thickness and anterior posterior width of masseter muscle in ultrasonography with intermolar width in maxilla and mandible?","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-15 06:37:18","doi":"10.21203/rs.3.rs-4872636/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":"6628617e-0536-4be0-b77f-629a54e0e0d9","owner":[],"postedDate":"October 15th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-11-04T17:23:36+00:00","versionOfRecord":[],"versionCreatedAt":"2024-10-15 06:37:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4872636","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4872636","identity":"rs-4872636","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}