Ultrasound Measurements of the Masseter Muscle as Predictors of Cephalometric Indices in Orthodontics: A Pilot Study (original) (raw)
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International Orthodontics, 2018
This study investigated the relationship between masseter muscle thickness and cephalometric facial parameters in pre-orthodontic treatment patients. Participants were grouped according to their vertical facial patterns into low, normal, and high angle facial patterns using standardised lateral cephalometric radiograph. Associations between the masseter muscle thickness (measured using ultrasonography) and different vertical facial patterns were analysed. Masseter muscle thickness in low angle subjects were significantly higher than the normal and high angle cases during both relaxation and contraction phases (P < 0.001). Masseter muscle thickness correlated positively with Jarabak ratio and ramus thickness (R1/R2) during both phases, and negatively with LAFH, FMA, MMPA and gonial angle.
Masseter Muscle Thickness Measured by Ultrasonography and its Relation to Facial Morphology
Journal of Dental Research, 1991
The aims of this study were to evaluate ultrasonography as a method for measuring masseter muscle thickness, to quantitate the normal range of the ultrasonically measured thickness of the masseter in adults, and to test whether the variation in the thickness of the muscle is related to the variation in the facial morphology in different individuals. In 40 healthy, fully-dentate young adults, 20 men and 20 women, the masseter thickness was measured bilaterally by a real-time ultrasound imaging technique. The measurements were performed under both relaxed conditions and with maximal clenching. Standardized facial photos of the subjects were taken so that their facial morphology could be determined. The measurement error of the thickness of the masseter was found to be small, not exceeding 0.49 mm. Under relaxed conditions, the mean thickness (± S.D.) of the muscle in men was 9.7 (± 1.5) mm, and under contracted conditions, 15.1 ( ± 1.9) mm. In women, the respective measurements were 8...
The Journal of Nihon University School of Dentistry, 1997
A study was done to clarify the attachment position of the superficial masseter muscle and its relationship with craniofacial morphology in dentate and edentulous subjects. Data were obtained from lateral cephalometric radiographs of a total of 39 cadavers in which the superficial masseter muscle had been defined with colloidal barium. Principal component analysis provided evidence that the lower masseter muscle width was associated with the size of the ramus, and related to the position of the anterior margin of the muscle. Linear discriminant function data suggested that ramus width, coronoid height and the distance between the anterior margin of the masseter muscle and the mandibular notch contributed most to the observed difference between dentate and edentulous subjects. The derived function correctly assigned 100% of dentate and 95 % of edentulous subjects. The results of this study indicated that a reduction of masticatory function was associated with the position of the anterior border of the masseter muscle insertion and also with differences in ramus dimension, the most significant of which were differences in the coronoid process and gonial angle. In general, age was not a significant determinant of variation in superficial masseter muscle dimensions or orientation.
Journal of Indian Orthodontic Society
Objective: Aims of the study were to measure the thickness of masseter muscle in both males and females of different growth pattern and then to evaluate the relation of thickness of masseter muscle with different growth pattern in both genders. Materials and methods: This was a double-blind study conducted on 40 subjects in the age range of 15 to 24 years consisting of twenty females and twenty males selected for the study based on clinical examination. However four subjects which included four male subjects refused to undergo ultrasonography. Therefore, only thirty-six subjects were undergone ultrasonography. Their ultrasonography was done to measure the masseter muscle thickness. Lateral cephalograms taken to assess their growth pattern. Based on the growth pattern, the subjects were divided into three groups hypodivergents, normodivergents and hyperdivergents and their relation to muscle thickness was evaluated. A null hypothesis was formulated after beginning of study and it was assumed that masseter muscle thickness have no correlation with growth pattern. Results: The results showed significantly (<0.05) thicker muscle mass in hypodivergent subjects as compared to normodivergents (<0.01) and hyperdivergents (<0.001) but not between normodivergents and hyperdivergents (>0.05) in both normal and clenched position. Thicker muscle mass was found on the right side as compared to the left side in both males and females whereas gender wise thicker muscle mass was found in males as compared to females. Females showed more variation in muscle thickness values. Conclusion: It can be concluded that hypodivergent subjects have thickest masseter muscle thickness whereas hyperdivergents have thinnest muscle mass. Males have thicker muscle mass as compared to females. Hence, masseter muscle
Masseter muscle thickness in growing individuals and its relation to facial morphology
Archives of Oral Biology, 1996
It is widely accepted that an interaction exists between masticatory muscle function and craniofacial growth. In adults, correlations have been found between facial dimensions and jaw-muscle cross-sectional area, and between facial dimensions and masseter muscle thickness. Little is known about growth of the human masticatory muscles and its relation with facial dimensions at different ages. In 329 Greek individuals, aged 7-22 yr, masseter muscle thickness was measured by ultrasonography. Muscle thickness was related to age, stature and weight, and to facial dimensions, measured by means of anthropological calipers. Muscle thickness was statistically assessed by univariate analysis of variance, after the males and females had been divided into three age groups. Facial dimensions were assessed by multivariate analysis of variance, age being considered as a covariate. The relation between muscle thickness and facial dimensions was subjected to stepwise multiple regression analysis. Masseter muscle thickness increased with age in both sexes. No differences were found between the left-and right-hand side. For each age group (and corrected for stature and weight), males had significantly thicker masseters than females (p < 0.01). Variation in muscle size and facial dimensions mainly coincided with variation in age, stature and weight. Apart from these, muscle thickness showed a significantly negative relation with anterior facial height and mandibular length, and a significantly positive relation with intergonial width and bizygomatic facial width.
Medicina
Objectives: This review investigated the effects of orthodontic or functional orthopedic therapy on masseter muscle thickness through the use of ultrasonography (US) in growing subjects when compared with untreated subjects. Materials and Methods: This review systematically assessed studies that investigated growing subjects undergoing orthopedic therapy for the correction of malocclusion of vertical, sagittal and transversal plane. Electronic databases (CENTRAL, MEDLINE-PubMed, Scopus and Web of Science) were searched up to February 2019, including available RCTs and CCTs, without language restrictions. The primary outcome was the effect of orthopedic or functional treatment on masseter muscle thickness. The risk of bias of included studies was assessed through the Newcastle-Ottawa quality assessment scale with the aim of defining their methodological quality. A random-effects meta-analysis analyzing mean differences with 95% confidence intervals was used for quantitative analysis....
Accuracy and reliability of 2D cephalometric analysis in orthodontics
Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial, 2014
Lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. The aim of this study was to evaluate the available scientific literature and existing evidence for the validation of using lateral cephalometric imaging for orthodontic treatment planning. The secondary objective was to determine the accuracy and reliability of this technique. We did not attempt to evaluate the value of this radiographic technique for other purposes. A literature search was performed using specific keywords on electronic databases: Ovid MEDLINE, Scopus and Web of Science. Two reviewers selected relevant articles, corresponding to predetermined inclusion criteria. The electronic search was followed by a hand search of the reference lists of relevant papers. Two reviewers assessed the level of evidence of relevant publications as high, moderate or low. Based on this, the evidence grade for diagnostic efficacy was rated as strong, moderately strong, limited or insufficient. The initial search revealed 784 articles listed in MEDLINE (Ovid), 1,034 in Scopus and 264 articles in the Web of Science. Only 17 articles met the inclusion criteria and were selected for qualitative synthesis. Results showed seven studies on the role of cephalometry in orthodontic treatment planning, eight concerning cephalometric measurements and landmark identification and two on cephalometric analysis. It is surprising that, notwithstanding the 968 articles published in peer-reviewed journals, scientific evidence on the usefulness of this radiographic technique in orthodontics is still lacking, with contradictory results. More rigorous research on a larger study population should be performed to achieve full evidence on this topic.
Longitudinal study of cephalometric soft tissue profile traits between the ages of 6 and 18 years.
Objective: To study the longitudinal changes in 19 soft tissue cephalometric traits (according to the Bergman cephalometric soft tissue facial analysis). Materials and Methods: Cephalograms and photographs of 40 subjects (20 male, 20 female, from the Burlington Growth Centre) that were obtained at ages 6, 9, 12, 14, 16, and 18 years were used. Subjects were orthodontically untreated whites and had Class I dentoskeletal relationships (ideal overjet and overbite). Images were obtained with the lips in a relaxed position or lightly touching. Results: Three groups of soft tissue traits were identified: (1) traits that increased in size with growth (nasal projection, lower face height, chin projection, chin-throat length, upper and lower lip thickness, upper lip length, and lower lip-chin length); (2) traits that decreased in size with growth (interlabial gap and mandibular sulcus contour [only in females]); and (3) traits that remained relatively constant during growth (facial profile angle, nasolabial angle, lower face percentage, chin-throat/lower face height percentage, lower face-throat angle, upper incisor exposure, maxillary sulcus contour, and upper and lower lip protrusion). Conclusion: Current findings identify areas of growth and change in individuals with Class I skeletal and dental relationships with ideal overjet and overbite and should be considered during treatment planning of orthodontic and orthognathic patients. (Angle Orthod. 2014;84:48-55.)
Soft Tissue Cephalometric Standards for a Moroccan Teenage Population
Objectives: The goal of this study was to assess the soft tissue measurements of Moroccan adolescents with balanced facial profile and correct occlusion and to compare them with other ethnicities norms. Methods: The material included the lateral cephalometric radiographs of 64 patients, 30 boys and 34 girls, aged between 14 and 18, with correct occlusion, balanced facial profile, and no subsequent orthodontic treatment. Seven reference lines were identified and traced, on each radiograph, according to Ricketts and Holdaway norms. Twelve linear and 2 angular measurements were analyzed. Results: Only the H angle shows a significant difference between boys and girls in our sample. The standards set on the American population and the jordanian one showed several statistically significant differences in comparison with ours. Conclusion: The results of this study show several differences between the Moroccan soft tissue profile norms and those of their American and jordanian counterparts and strength the idea that the norms of a specific population should be used as a reference for a successful orthodontic treatment.