Significant Difference In Muscle Thickness Research Articles

Assessment of forearm muscles with ultrasound shear wave elastography in patients with acromegaly.

The effects of acromegaly on soft tissues, bones and joints are well-documented, but information on its effects on muscle mass and quality remains limited. The primary goal of this study is to assess the sonoelastographic features of forearm muscles in patients with acromegaly. Forty-five patients with acromegaly and 45 healthy controls similar in terms of gender, age, and body mass index (BMI) were included in a single-center, multidisciplinary, cross-sectional study. The body composition was analyzed using bioelectrical impedance analysis (BIA), and height-adjusted appendicular skeletal muscle index (hSMI) was calculated. The dominant hand's grip strength was also measured. Two radiologists specialized in the musculoskeletal system employed ultrasound shear wave elastography (SWE) to assess the thickness and stiffness of brachioradialis and biceps brachii muscles. The acromegaly group had significantly higher thickness of both the biceps brachii (p = 0.034) and brachioradialis muscle (p = 0.046) than the control group. However, the stiffness of the biceps brachii (p = 0.001) and brachioradialis muscle (p = 0.001) was lower in the acromegaly group than in the control group. Disease activity has not caused a significant difference in muscle thickness and stiffness in the acromegaly group (p > 0.05). The acromegaly group had a higher hSMI (p = 0.004) than the control group. The hand grip strength was similar between the acromegaly and control group (p = 0.594). The patients with acromegaly have an increased muscle thickness but decreased muscle stiffness in the forearm muscles responsible for elbow flexion. Acromegaly can lead to a permanent deterioration of the muscular structure regardless of the disease activity.

A Multivariable Model Based on Ultrasound Imaging Features of Gastrocnemius Muscle to Identify Patients With Sarcopenia.

Low skeletal muscle mass, strength, or somatic function are used to diagnose sarcopenia; however, effective assessment methods are still lacking. Therefore, we evaluated the effectiveness of ultrasound in identifying patients with sarcopenia. This study included 167 patients, 78 with sarcopenia and 89 healthy participants, from two hospitals. We evaluated clinical factors and five ultrasound imaging features, of which three ultrasound imaging features were used to create the model. In both the training and validation datasets, the sarcopenia detection performances of chosen ultrasonic characteristics and the constructed model were evaluated using receiver operating characteristic (ROC) curves. The predictive performance was evaluated by area under the ROC (AUROC), calibration, and decision curves. There were statistically significant differences in muscle thickness (MT) of gastrocnemius medialis muscle (GM), flaky myosteatosis echo (FE), pennation angle (PA), average shear wave velocity (SWV) in the relaxed state (RASWV), and average SWV in the passive stretched state (PASWV) between sarcopenic and normal subjects. PA, RASWV, and PASWV were effective predictors of sarcopenia. The AUROC (95% confidence interval) for these three parameters were 0.930 (0.882-0.978), 0.865 (0.791-0.940), and 0.849 (0.770-0.928), respectively, in the training set, and 0.873 (0.777-0.969), 0.936 (0.878-0.993), and 0.826 (0.716-0.935), respectively, in the validation set. The combined model had better detection power. Finally, the calibration curve showed that the combined model had good prediction accuracy. Our model can be used to identify sarcopenia in primary medical institutions, which is valuable for the early recognition and management of sarcopenia patients.

The architectural characteristics of the hamstring muscles do not differ between male and female elite-level rugby union players.

Purpose: To determine whether differences exist in the architectural characteristics of the hamstring muscles of elite-level male and female rugby union players. Methods: Forty elite-level rugby union players (male n = 20, female n = 20) participated in this cross-sectional study. A sonographer acquired static ultrasound images using a 92mm linear transducer to quantify (via a semi-automated tracing software tool) the architectural characteristics (muscle length, fascicle length, pennation angle, and muscle thickness) of the biceps femoris long head and semimembranosus muscles of participants' left limb. Muscle length and muscle thickness of the biceps femoris short head and semitendinosus muscles of participants' left limb were also quantified. Bonferroni adjusted independent samples t-tests were performed to evaluate whether differences exist in the architectural characteristics of the hamstring muscles of elite-level male and female rugby union players. Results: There were no significant differences in fascicle length or pennation angle of the hamstring muscles of elite-level male and female rugby union players. Some significant differences in muscle thickness (biceps femoris short head, and semimembranosus) and muscle length (biceps femoris short head, biceps femoris long head, semitendinosus, and semimembranosus) were observed; in all cases the male players had thicker and longer muscles. Conclusion: At a group level, hamstring muscle fascicle length and pennation angle are unlikely to be a sex-specific intrinsic risk factor for Hamstring strain injuries.

Intervertebral Disc Degeneration: Functional Analysis of Bite Force and Masseter and Temporal Muscles Thickness.

Intervertebral disc degeneration is a pathological condition associated with the intervertebral disc and is related to functional alterations in the human body. This study aimed to evaluate the maximum molar bite force and masseter and temporal muscles thickness in individuals with intervertebral disc degeneration. Thirty-two individuals were divided into two groups: those with degeneration of intervertebral discs (n=16) and those without degeneration (n=16). The maximum molar bite force (on the right and left sides) was measured using a dynamometer. Masseter and temporal muscle thickness during mandibular task rest and dental clenching in maximum voluntary contraction were analysed using ultrasound. Significant differences in the left molar bite force (p=0.04) were observed between the groups (Student's t-test, p<0.05). The intervertebral disc degeneration group had a lower maximum molar bite force. No significant differences in muscle thickness were observed between the masseter and temporal muscles in either group. However, based on clinical observations, the group with intervertebral disc degeneration presented less masseter muscle thickness and greater temporal muscle thickness in both mandibular tasks. Degenerative disease of the intervertebral discs promoted morphofunctional changes in the stomatognathic system, especially in maximum molar bite force and masticatory muscle thickness. This study provides insight into the interaction between spinal pathology and the stomatognathic system, which is important for healthcare professionals who treat patients with functional degeneration.

Comparison of Kinesio Taping and manual therapy in the treatment of patients with bruxism using shear-wave elastography-A randomised clinical trial.

Bruxism is significantly associated with craniofacial pain, feeling of stiffness or fatigue of the jaw and neck pain.Various physiotherapeutic strategies are used in the treatment of bruxism; however, it is not clear which method leads to greater decrease in pain. The aim of this study is to compare the effects of two physiotherapy methods (manual therapy [MT] and Kinesio taping with manual therapy [KTMT]) in patients with bruxism. Patients were randomised into MT or KTMT groups. Evaluations were performed at baseline and following 4weeks of physiotherapy. Muscle thickness and stiffness were assessed via shear wave elastography; pain thresholds were evaluated using algometer. Sleep quality was assessed using Pittsburgh Sleep Quality Index, and quality of life was assessed with Likert scales regarding the associated symptoms. Significant decreases were found in muscle stiffness, pain threshold, sleep quality and quality of life (P<.05) in both MT and KTMT groups. Pain in bilateral temporalis and right occipital region of the trapezius muscle decreased more in the KTMT group compared with the MT group (P<.05). No significant differences in muscle thickness (P>.05) were found in either of the groups. Both MT and KTMT methods were effective in the treatment of bruxism. Kinesio Tape used in conjunction with MT has additionally decreased jaw pain and temporal region pain compared with MT intervention only. Therefore, if jaw pain is the primary complaint of a patient, our results recommend including Kinesio Tape application in the physiotherapeutic treatment program.

Multifidus Thickness Comparison between the Effectiveness of Abdominal Bracing and Maximum Expiration Maneuvers in Lumbo-Pelvic Upright Sitting Posture

Background: Trunk flexor-extensor muscles’ co-activation and upright posture are important for spinal stability. Abdominal bracing and maximal expiration are being used as exercises to excel torso co-contraction. However, no study has on comparison of the effect of this exercise on multifidus in the upright sitting posture.Objectives: This study aims to verify the effectiveness of abdominal bracing and expiration maneuvers in lumbo-pelvic upright sitting.Design: Cross-sectional study.Methods: Eighteen healthy women were recruited for this study. The multifidus muscle thickness of all subjects was measured in three sitting conditions (lumbo-pelvic upright sitting, lumbo-pelvic upright sitting with abdominal bracing, and lumbo-pelvic upright sitting with maximum expiration) using ultrasound. One-way repeated measure analysis of variance was used for the evaluation.Results: Compared to lumbo-pelvic upright sitting, lumbo-pelvic upright sitting with abdominal bracing and lumbo-pelvic upright sitting with maximum expiration were associated with significantly increment of muscle thickness. There was no significant difference in muscle thickness between lumbo-pelvic upright sitting with abdominal bracing and lumbo-pelvic upright sitting with maximum expiration.Conclusion: Abdominal bracing and maximum expiration could be beneficial to increasing lumbar multifidus thickness in lumbo-pelvic upright sitting.

Application of muscle ultrasound for the evaluation of patients with amyotrophic lateral sclerosis: An observational cross-sectional study.

We evaluated the association between muscle ultrasound, number of motor units, and clinical parameters, and assessed their utility for distinguishing amyotrophic lateral scleorisis (ALS) patients from healthy individuals. Three muscle pairs (abductor pollicis brevis, abductor digiti minimi, and tibialis anterior) of 18 ALS patients and 18 controls underwent muscle ultrasound (echointensity and thickness) and assessment of motor unit number index (MUNIX). The clinical and functional status of participants were also assessed. Mean age of the patients was 53.8 ± 12.1 years, and score on the ALS Functional Rating Scale-Revised was 38.9 ± 4.1. Echointensity of all tested muscles of ALS participants was significantly higher than that of controls, but there was no significant difference in muscle thickness. Muscle echointensity correlated significantly with clinical and electrophysiological parameters. Echointensity of muscles was highly associated with clinical scales and MUNIX, confirming its relevance as an ancillary diagnostic test in ALS patients.

Effect of milk fat globule membrane supplementation on motor unit adaptation following resistance training in older adults.

This study aimed to investigate the effect of milk fat globule membrane (MFGM) supplementation on motor unit adaptation following resistance training in older adults. Twenty‐five older males and females took MFGM (n = 12) or a placebo (PLA; n = 12) while performing 8 weeks of isometric knee extension training. During the training, the motor unit firing pattern during submaximal contractions, muscle thickness, and maximal muscle strength of knee extensor muscles were measured every 2 weeks. None of the measurements showed significant differences in muscle thickness or maximal muscle strength (MVC) between the two groups (p > .05). Significant decreases in motor unit firing rate following the intervention were observed in PLA, that is, 14.1 ± 2.7 pps at 0 weeks to 13.0 ± 2.4 pps at 4 weeks (p = .003), but not in MFGM (14.4 ± 2.5 pps to 13.8 ± 1.9 pps). Motor unit firing rates in MFGM were significantly higher than those in PLA at 2, 4, 6, and 8 weeks of the intervention, that is, 15.1 ± 2.3 pps in MFGM and 14.5 ± 3.3 pps in PLA at 70% of MVC for motor units recruited at 40% of MVC at 6 weeks (p = .034). Significant differences in firing rates among motor units with different recruitment thresholds were newly observed following the resistance training intervention in MFGM, indicating that motor unit firing pattern is changed in this group. These results suggest that motor unit adaptation following resistance training is modulated by MFGM supplementation in older adults.

Evaluation of effects of aging on skeletal muscle elasticity using shear wave elastography

PurposeTo evaluate the effects of aging on skeletal muscle stiffness in relaxed and contracted status using shear wave elastography (SWE). Materials and methodsA total of 57 participants were enrolled to this institutional review board approved prospective study. Medial head of the gastrocnemius muscle (GM) of all participants were examined bilaterally by a single radiologist in prone position. Muscle thickness, stiffness values in both relaxed and contracted status were measured. Stiffness increase rate (SIR) was calculated for all muscles. The Spearman’s correlation test was used for correlation analyses. Mann-Whitney U test was used to compare subgroups. ResultsThe mean age of the participants was 41.15 ± 16.19 (range, 18−74). The means of stiffness values of medial head of GM were 12.51 ± 2.56 kPa and 81.74 ± 15.77 kPa in relaxed and contracted status, respectively. The mean of SIR values was 5.62 ± 1.05 (range, 3.18–8.66). The stiffness values of relaxed and contracted medial head of GM had moderate to strong inverse correlations with age for both dominant and non-dominant extremities (r range: −0.703 to −0.590). Age subgroup analyses revealed significant differences in muscle thickness and stiffness values, whereas no significant difference was found in SIR values. ConclusionIn conclusion, despite the decrease in stiffness of skeletal muscle with advancing age, SIR remained similar. Any improvement in stiffness values of skeletal muscle in relaxed status may play pivotal role in the management of sarcopenia.

Lower Extremity Muscle Morphology and Plantar Loading During Squatting with Different Heel Heights

Objective: Although it is widely reported that high-heeled changes gait pattern in terms of motions and forces throughout the body, the biomechanics while high-heeled squatting has not been examined. This study aimed to explore the acute effects of different heel heights on muscle morphology and plantar loading during high-heeled squatting. Methods: Fourteen healthy females performed squats on high-heeled shoes with different heights: flat (0.8 cm), moderate (4.0 cm), and high (7.0 cm). Muscle thickness and pennation angle of selected lower limb muscles were measured by ultrasound imaging. Plantar pressure distribution and COP trajectory during an entire squatting motion were recorded. Results: As the heel height increased, the average and peak pressure consistently increased in the heel and hallux regions, while reversely changed in MF and LF regions. In addition, the selected lower limb muscles except for the lateral gastrocnemius and vastus medialis showed significant differences in muscle thickness and pennation angle between heel heights. Conclusion: The findings of this study indicate that increased heel height would enhance the immediate effects on muscle morphology as well as plantar pressure redistribution potentially causing lower limb muscle fatigue and injuries.

Why do Zenker's diverticulae occur more often on the left than the right side?

Zenker's diverticulum is a pharyngoesophageal outpouching of mucosa and submucosa through Killian's dehiscence. To investigate the propensity for Zenker's diverticulum to occur on the left side by examining muscle thickness in Killian's dehiscence, and to explore correlations between muscle thickness, sex, height and age. The study included 109 Caucasian cadavers, 52 male and 57 female. The mean thickest and thinnest measurements of left medial, left lateral, right medial and right lateral aspects of Killian's dehiscence were calculated. The paired student's t-test was used to determine significance. The average left muscle layer was significantly thinner than the right muscle layer, in both medial and lateral aspects. Furthermore, medial muscle thickness was significantly thinner than its respective lateral aspect for both the left and right sides. No correlations were found between muscle thickness and cadavers' sex, length or stature, or age. There was a significant difference in muscle thickness between the left and right sides of Killian's dehiscence. The findings suggest there is a reason why Zenker's diverticulum occurs predominantly on the left side. The study also showed a significant difference in muscle thickness between the medial and lateral aspects of Killian's triangle.

Comparison of lumbar multifidus thickness and perceived exertion during graded superman exercises with or without an abdominal drawing-in maneuver in young adults.

The present study aimed to investigate lumbar multifidus (LM) thickness and perceived exertion during graded superman exercises (GSE) or GSE with an abdominal drawing-in maneuver (GSE-AD) in young adults. Twelve young adult males and females, who were informed of the purpose and procedures of this study and then gave their voluntary consent to participate, were included in this study. All subjects randomly performed three GSE and GSE-AD over 3 days. Ultrasonography was used to measure the LM thickness to the left and right of the L5 region. Additionally, the issue of whole-body fatigue felt by the subject while performing the GSE or GSE-AD was measured using the Borg scale. The intrarater reliability of the LM measurement was found to be intraclass correlation coefficient (ICC[3,1])=0.97 (0.87–0.99) at resting and ICC(3,1)=0.94 (0.78–0.99) at contraction. Both the left and right LM showed significantly higher contraction during the grade 3 GSE (P< 0.05). The whole-body fatigue was significantly greater following GSE 2 and 3 than following GSE-AD 2 and 3 (P<0.05). In particular, GSE-AD had a significantly lower Borg score compared to GSE (P<0.05) and did not show any significant difference in muscle thickness (P>0.05). It is recommended that the abdominal drawing-in maneuver be applied with grade 3 GSE to enhance stability and reduce spinal fatigue.

Epidemiological and clinical characteristics of 304 patients with infantile hypertrophic pyloric stenosis in Anhui Province of East China, 2012–2015

Objective: To analyze the clinical and epidemiological features of patients with infantile hypertrophic pyloric stenosis (IHPS) so as to provide scientific evidence for diagnosis and prevention of IHPS.Methods: We performed a retrospective study of infants with IHPS diagnosed from 2012 to 2015 at Anhui Provincial Children’s Hospital. Demographic characteristics and clinical data were collected.Results: Three hundred four patients (264 males and 40 females) were studied, of which 94.7% were full term and 75.7% were bottle fed or mixed fed; 16.8% of the patients had other congenital malformations in combination with IHPS. The proportion of IHPS cases with hyponatremia, hypokalemia, and hypochloremia was 18.4%, 12.5%, and 53.9%. A negative correlation was found between duration of disease and serum electrolytes. The mean pyloric muscle thickness, pyloric length, and diameter were 4.8 ± 0.7 mm, 19.4 ± 2.5 mm, and 13.3 ± 1.8 mm, respectively. There were significant differences in muscle thickness, pyloric length, and diameter between short (≤14 d) and long (>14 d) durations of disease. All patients underwent pyloromyotomy, and postoperative recovery was good.Conclusions: IHPS occurs mainly in male, full-term, bottle-fed or mixed-fed infants. Patients with long duration of disease were more likely to develop electrolyte disorder and thicker muscle layer. More attention should be paid to early discovery and diagnosis, which will help to improve the curative effect and prognosis of IHPS.

Measurement of muscle thickness of the serratus anterior and lower trapezius using ultrasound imaging in competitive recreational adult swimmers, with and without current shoulder pain

ObjectivesTo compare serratus anterior and lower trapezius muscle thickness between swimmers with and without current shoulder pain, and between sides when measured by real-time ultrasound imaging. DesignA single blinded age and gender-matched case-control study with 26 symptomatic and 26 asymptomatic recreational swimmers. MethodsMuscle thickness of serratus anterior and lower trapezius were measured using previously validated real-time ultrasound imaging protocols. Serratus anterior thickness was measured in side lying with 90° of glenohumeral flexion at rest and during a scapular protraction contraction. Lower trapezius thickness was measured in prone with 145° of glenohumeral abduction whilst at rest and when holding the weight of the arm. ResultsThere was no statistically significant difference between the muscle thickness of serratus anterior and lower trapezius between the symptomatic shoulder and the dominance-matched shoulder in the asymptomatic group of swimmers. There was also no significant difference in muscle thickness between the symptomatic side and asymptomatic side within the symptomatic group. ConclusionsThere appears to be no difference in serratus anterior and lower trapezius thickness between swimmers who have mild to moderate shoulder pain, who continue to swim and those who do not have shoulder pain. When imaging the serratus anterior and lower trapezius in swimmers with mild shoulder pain, clinicians should expect no differences between sides. If muscle thickness differences between sides are detected in recreational swimmers, this may indicate that the swimmer is participating in other asymmetrical activities or has a higher level of shoulder pain.

The Study of Asymmetrical of the Serratus Anterior and Lower Trapezius Muscles in Chronic Stroke Patients

PURPOSE: The purpose of this study was to compare the muscle architecture of serratus anterior and lower trapezius using rehabilitative ultrasound imaging (RUSI) in affected and unaffected side of chronic stroke patients. METHODS: The participants were thirty five patients with stroke hemiplegia in this study. RUSI was used to measure the muscle thickness of the serratus anterior and lower trapezius muscles. We compared the muscle thickness according to affected side and sex, determined the reliability of the measurement image. Independent t-test, intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were used for statistical analysis. RESULTS: Significant difference in muscle thickness of serratus anterior was observed between affected and unaffected side (p

성별에 따른 몸통근육의 초음파 영상 구조 비교

PURPOSE:The purpose of this study is to compare ultrasound images of trunk muscles according to gender in healthy subjects.METHODS:Twenty six subjects(13 males and 13 females) were enrolled in this study. The thickness of trunk muscles was measured for transverse abdominis (TrA), external oblique abdominis (EOA), internal oblique abdominis(IOA), and multifidus (MF) using ultrasound. The thickness of the muscles was measured for the length of cross-section except for fascia. The muscle thickness wasmeasured at the both side, then the mean value was calculated. Also, each of trunk muscle wasanalysed by echodensity, white area index. RESULTS:As a results, there was significant difference in muscle thickness of EOA, IOA according to gender (p<0.05).

The effects of kinesio taping on architecture, strength and pain of muscles in delayed onset muscle soreness of biceps brachii.

[Purpose] This study aimed to confirm the effects of kinesio taping (KT) on muscle function and pain due to delayed onset muscle soreness (DOMS) of the biceps brachii. [Subjects and Methods] Thirty-seven subjects with induced DOMS were randomized into either Group I (control, n=19) or Group II (KT, n=18). Outcome measures were recorded before the intervention (application of KT) and at 24, 48, and 72 hours after the intervention. DOMS was induced, and muscle thickness was measured using ultrasonic radiography. Maximal voluntary isometric contraction (%MVIC) was measured via electromyography (EMG). Subjective pain was measured using a visual analogue scale (VAS). [Results] Group I exhibited a positive correlation between muscle thickness and elapsed time from intervention (24, 48, and 72 hours post induction of DOMS); they also showed a significant decrease in MVIC(%). Group II showed significant increases in muscle thickness up to the 48-hour interval post induction of DOMS, along with a significant decrease in MVIC (%). However, in contrast to Group I, Group II did not show a significant difference in muscle thickness or MVIC (%) at the 72-hour interval in comparison with the values prior to DOMS induction. [Conclusion] In adults with DOMS, activation of muscles by applying KT was found to be an effective and faster method of recovering muscle strength than rest alone.

안정화 운동과 근력운동이 비특이성 요통환자의 통증, 관절가동범위, 근력, 근 두께에 미치는 영향

Purpose : The purpose of this study was to find the effects of the lumbar stabilization exercise and strength exercise on pain, ROM, strength, muscle thickness of low back pain(LBP) patients. Method : The subjects were consisted of twelve patients who had nonspecific LBP. All subjects randomly assigned to lumbar stabilization exercise group(N=6) and strength exercise group(N=6). We measured muscular strength, ROM by using Tergumed-extension, rotation and muscle thickness by using ultrasonography and pain score by using Visual analog scale(VAS). The lumbar stabilization exercise group received TOGU exercise, strength exercise group received Tergumed exercise. The data analyzed by repeated measure of Independent t-test, paired t-test, reliability test. Result : The results were as follows. The result which measured of the change of pain score was a significant decrease. The result which measured of the change of ROM and strength was a significant increase. The result which measured of the change of the Internal abdominal oblique, External abdominal oblique on muscle thickness was a significant increase. Stabilization exercise group and Strength exercise group showed the significant difference in muscle thickness on Transversus abdominis, Multifidus. Stabilization exercise group was more increased in muscle thickness. Conclusion : Therefore, we suggest that stabilization exercise is effective for non-specific low back pain.

Changes in neck muscle thickness due to differences in intermittent cervical traction force measured by ultrasonography.

[Purpose] Many patients receive intermittent cervical traction in a daily treatment setting. However, unified settings for traction force, duration, and direction have yet to be determined. Therefore, an objective index is required to determine changes in traction conditions or to indicate its effectiveness. [Subjects] Fifteen healthy males volunteers participated in this study. [Methods] The thickness of the trapezius and splenius capitis muscles before and during traction were measured using ultrasonography at three traction forces: 5, 8 and 11 kg. [Results] Significant differences in muscle thickness were observed at 11 kg in the trapezius, and at 8 kg and 11 kg in the splenius capitis muscles. The muscle thickness ratio of the trapezius muscle showed a significant difference between 11 kg and 5 and 8 kg, and between 5 kg and 8 and 11 kg, as well as between 8 kg and 11 kg for the splenius capitis muscles. [Conclusion] Differences in muscle direction between the trapezius and splenius capitis muscles may account for the contrasting results obtained at the 8 kg traction force. This finding suggests that cervical traction must be performed considering the effects on different neck regions.

Masseter muscle thickness in different skeletal morphology: An ultrasonographic study

The thickness of the masseter muscle during relaxation and contraction states was measured by ultrasonography. Subjects were classified according to their sagittal skeletal relationships. The association between muscle thickness and facial morphology was studied. Masseter muscle thickness influences the skeletal patterns. To measure and compare the thickness of the masseter muscle in individuals with skeletal class I occlusion and skeletal class II malocclusions and to correlate its relationship with craniofacial morphology. The study was conducted in a hospital setup and was designed to study the thickness of the masseter muscle in different skeletal morphologies. Seventy two individuals between the ages of 18 and 25 years were divided into Group I, Group IIA and Group IIB according to their skeletal relationships. Masseter muscle thickness was measured by ultrasonography. Eight linear and six angular cephalometric measurements were assessed. Analysis of variance and Pearson's correlation analysis. There was a statistically significant difference in muscle thickness between subjects of different skeletal patterns. Significant positive correlation between masseter muscle thickness and posterior total face height, jarabak ratio, ramus height, mandibular length and significant negative correlations with mandibular plane angle, gonial angle and PP-MP angle were observed. This study indicates the strong association between the masseter muscle and skeletal morphology.