Human Masticatory Muscle Volume and Zygomatico-mandibular Form in Adults with Mandibular Prognathism

2002 ◽  
Vol 81 (11) ◽  
pp. 752-756 ◽  
Author(s):  
N. Kitai ◽  
Y. Fujii ◽  
S. Murakami ◽  
S. Furukawa ◽  
S. Kreiborg ◽  
...  

Although several investigators have reported associations between masticatory muscles and skeletal craniofacial form, there is no agreement on the association. We tested the hypothesis that masticatory muscle volume correlates with the size and form of the adjacent local skeletal sites. For this purpose, we investigated the morphological association of the cross-sectional area and volume of temporal and masseter muscles with zygomatico-mandibular skeletal structures using computerized tomography (CT) in 25 male adults with mandibular prognathism. Muscle variables significantly correlated with widths of the bizygomatic arch and temporal fossa but not with the cranium width. Masseter volume significantly correlated with cross-sectional areas of the zygomatic arch and mandibular ramus. Masseter orientation was almost perpendicular to the zygomatic arch and mandibular antegonial region. The zygomatic arch angle significantly correlated with the antegonial angle. The results of the study suggest that the masticatory muscles exert influence on the adjacent local skeletal sites.

2003 ◽  
Vol 40 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Mariko Takashima ◽  
Noriyuki Kitai ◽  
Shumei Murakami ◽  
Souhei Furukawa ◽  
Sven Kreiborg ◽  
...  

Objective To test the following hypotheses in hemifacial microsomia (HFM): (1) the volumes of the masseter, lateral and medial pterygoid, and temporal muscles are reduced on the affected versus unaffected side; (2) significant differences exist between the degrees of right-left disproportion in these four masticatory muscles; (3) circumferential shapes of the masticatory muscles are more irregular on the affected versus unaffected side; and (4) the degree of masticatory muscle right-left disproportion can be judged by the degree of ear, mandibular, or dental anomalies. Subjects and Methods Ten preadolescent patients with HFM were studied using facial photographs, dental casts, cephalometric and panoramic radiographs, and helical computed tomography scanning and three-dimensional reconstruction technique. Volumes of masseter, lateral and medial pterygoid, and temporal muscles on both sides were measured. Muscle volume disproportion was expressed as the affected/unaffected ratio. Muscle circumferential irregularity was expressed as the ratio between the total circumferential length and correspponding cross-sectional area. Results Masticatory muscle volumes were significantly smaller on the affected versus unaffected side. No significant differences were observed between the degrees of disproportion of the four masticatory muscles examined. Circumferential shapes of masticatory muscles were significantly more irregular on the affected versus unaffected side. There were no significant relationships of the degree of ear, mandibular, or dental anomalies in relation to masticatory muscle disproportion. Conclusions In HFM the masseter, lateral and medial pterygoid, and temporal muscles all have a significantly smaller volume on the affected versus unaffected side, and specific muscles were not severely affected in the present subjects. Furthermore, all four muscles showed a significantly more irregular shape on the affected versus unaffected side. Finally, the severity of masticatory muscle disproportion can probably not be judged by the degree of ear, mandibular, and dental anomalies in preadolescent patients with HFM.


2008 ◽  
Vol 65 (7) ◽  
pp. 513-519
Author(s):  
Tatjana Cutovic ◽  
Jasna Pavlovic ◽  
Ruzica Kozomara

Introduction/Aim. There are numerous factors that influence the formation of condylar processus: the growth and development of cranial base, growth and development of the jaws and alveolar extensions, teething, the way of intercuspidation, the overlap of incisors, functions of masticatory muscles, etc. Considering the fact that the above-mentioned factors significantly differ in persons with different morphological set of the face, we set a hypothesis that dimensions of condylar processus and the mandibular ramus considerably differ in persons with mandibular prognathism compared to eugnatic persons. The aim of this study was to establish the differences in dimensions of condylar processus between the above-mentioned groups. Methods. Six parameters representing the dimensions of the condylar processus were measured on profile teleradiographs of 30 eugnatic persons and 30 paersons with mandibular prognathism: the height of condylar processus, the height of head of the mandible, width of the head, width of the neck, height of the ramus without the condylar processus and the overall height of the ramus. Results. A considerable difference in the values of the parameters was found, as well as the distribution toward the values of reference. It was found that the height of the condylar processus was significantly greater in persons with mandibular prognathism, whereas the width of the head of the mandible, the width of the neck and the height of the ramus without the condylar processus was considerably decreased within the same group. The height of the head of the mandible and the overall height of the ramus was not significantly changed. Conclusion. In persons with mandibular prognathism, morphological features of the condylar processus are changed. The condylar processus lengthens on account of shortening of the lower part of the ramus, and the mentioned lengthening is the most prominent in its condylar neck area which is also the centre of its most intense growth.


2018 ◽  
Vol 40 (335) ◽  
pp. 28-31
Author(s):  
Armands Vekšins ◽  
Oskars Kozinda

Abstract The biceps brachii - brachialis muscles has attachment on the medial coronoid process (MCP) and proximal radius. It is considered that medial coronoid disease (MCD) can be caused by biceps brachii – brachialis muscle generated force to MCP. Computed tomography data from 31 dogs were analysed. The aim of this study was to compare biceps brachii – brachialis muscle volume and maximum cross-sectional area (mCSA) between clinically normal dogs to dogs with a MCD. Results showed that in dogs with MCD, biceps brachii - brachialis muscle volume and mCSA is smaller than in clinically normal dogs and therefore the generated muscle force cannot be considered as the main or accompanying cause of a MCD.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Yong-Jin Chen ◽  
Fei Huang ◽  
Min Zhang ◽  
Hai-Yan Shang

To investigate the effects of psychological stress on the masticatory muscles of rats, a communication box was applied to induce the psychological stress (PS) in rats. The successful establishment of psychological stimulation was confirmed by elevated serum levels of adrenocorticotropic hormone (ACTH) and changed behaviors in the elevated plusmaze apparatus. The energy metabolism of the bilateral masseter muscles was tested via chemocolorimetric analysis, whereas muscle ultrastructure was assessed by electron microscopy. In comparison to the control group, the PS group showed evidence of swollen mitochondria with cristae loss and reduced matrix density in the masticatory muscles after three weeks of stimulation; after five weeks of stimulation, severe vacuolar changes to the mitochondria were observed. Increased vascular permeability of the masticatory muscle capillaries was found in the five-week PS rats. In addition, there was decreased activity ofNa+-K+ATPase andCa2+-ATPase and a simultaneous increase in the activity of lactate dehydrogenase and lactic acid in the masticatory muscles of PS rats. Together, these results indicate that psychological stress induces alterations in the ultrastructure and energy metabolism of masticatory muscles in rats.


2002 ◽  
Vol 81 (11) ◽  
pp. 752-756 ◽  
Author(s):  
N. Kitai ◽  
Y. Fujii ◽  
S. Murakami ◽  
S. Furukawa ◽  
S. Kreiborg ◽  
...  

2014 ◽  
Vol 25 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Marcelo Oliveira Mazzetto ◽  
Carolina Almeida Rodrigues ◽  
Laís Valencise Magri ◽  
Melissa Oliveira Melchior ◽  
Guiovaldo Paiva

Temporomandibular disorders (TMD) are manifested as a group of signs and symptoms that affect a particular population profile. Some variables such as sex and age influence the clinical expression of this condition. This observational descriptive cross-sectional study aimed to correlate the severity of TMD established by the craniomandibular index (CMI) with the variables: age, sex and electromyographic activity of the masseter and anterior temporal muscles. Fifty-four subjects (15 males/39 females) aged between 16 to 65 years (mean age = 41 years) and diagnosed with TMD were evaluated. Severity was determined by the CMI. These subjects also underwent examination by surface electromyography of the masseter and anterior temporal muscles. No correlation was found between age and severity of TMD (p=0.19/r=0.16), however there was a trend of greater severity in young adults (25-50 years). The sex variable in the correlation was positive with the CMI (p=0.03/r=-0.96) and superior to women. A greater EMG activity of the anterior temporal in relation to masseter (p=0.01) was found and the left temporal activity had the highest average (161.5 ± 44.6 Hz). The electromyographic activity of the anterior temporal and right masseter muscles was positively correlated with the Dysfunction Index CMI (p=0.01). The use of CMI to quantify the severity of TMD and of EMG to assess the functionality of the masticatory muscles can be important allies to direct the treatment.


2018 ◽  
Author(s):  
Dr Malathi Dayalan ◽  
Dr Sudeshna Sharma ◽  
Dr Shweta Poovani ◽  
Dr Saher Altaf

BACKGROUND Masticatory system is a complex functional unit, primarily engaged in chewing, swallowing and breathing functions, and some parts are involved in taste recognition and determination of food consistency. Sophisticated functional performances of speech and emotional expressions are specifically human qualities. Irregularities in occlusion appears to be the precipitating factor in the pathogenesis of myofascial pain dysfunction syndrome. Tek- Scan III records the bite length, number, distribution, timing, duration and the relative force of each tooth contact. It also records the sequence of occlusal contacts in terms of time and the associated force with each occlusal contact. The aim of this study was to treat masticatory muscle disorders with occlusal equilibration, and compare the efficacy of treatment outcomes between selective grinding and stabilization splints using Tek-Scan III. OBJECTIVE Objective of this study was to compare the efficacy of occlusal equilibration achieved through selective griding and stabilization splints using Tek-Scan III. METHODS In this in vivo study, 40 patients with masticatory muscle disorders were selected based on the inclusion and exclusion criteria. The occlusal discrepancies were analyzed using Tek-Scan III. The selected 40 subjects were then randomly divided into 2 groups based on the treatment they recieved; Group I – Selective grinding group (20) and Group II – Stabilization splint group (20). Comparison of pre-treatment and post treatment results were evaluated in terms of pain, mouth opening, left and right side force percentage as recorded through Tek-Scan III and reduction of disclusion time. Statistical analysis was carried out with Kolmogorov Smirnov test, Wilcoxon matched pair test and Mann-Whitney U test. RESULTS Wilcoxon matched pairs test demonstrated that there was statistically significant results ( p = 0.0007) in both the groups for reduction of disclusion time, elimination of pain and improved mouth opening. Patients in Group I showed better results as compared to Group II in terms of disclusion time, pain and mouth opening. CONCLUSIONS Occlusal equilibration brought about by reducing the disclusion time using the Tek- Scan III reduced the symptoms of pain in masticatory muscles. Patients in group I (Selective grinding) however showed better results when compared to patients in group II (Stabilization splints).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adrien J. Létocart ◽  
Franck Mabesoone ◽  
Fabrice Charleux ◽  
Christian Couppé ◽  
René B. Svensson ◽  
...  

Abstract Background To investigate how anatomical cross-sectional area and volume of quadriceps and triceps surae muscles were affected by ageing, and by resistance training in older and younger men, in vivo. Methods The old participants were randomly assigned to moderate (O55, n = 13) or high-load (O80, n = 14) resistance training intervention (12 weeks; 3 times/week) corresponding to 55% or 80% of one repetition maximum, respectively. Young men (Y55, n = 11) were assigned to the moderate-intensity strengthening exercise program. Each group received the exact same training volume on triceps surae and quadriceps group (Reps x Sets x Intensity). The fitting polynomial regression equations for each of anatomical cross-sectional area-muscle length curves were used to calculate muscle volume (contractile content) before and after 12 weeks using magnetic resonance imaging scans. Results Only Rectus femoris and medial gastrocnemius muscle showed a higher relative anatomical cross-sectional area in the young than the elderly on the proximal end. The old group displayed a higher absolute volume of non-contractile material than young men in triceps surae (+ 96%). After training, Y55, O55 and O80 showed an increase in total quadriceps (+ 4.3%; + 6.7%; 4.2% respectively) and triceps surae (+ 2.8%; + 7.5%; 4.3% respectively) volume. O55 demonstrated a greater increase on average gains compared to Y55, while no difference between O55 and O80 was observed. Conclusions Muscle loss with aging is region-specific for some muscles and uniform for others. Equivalent strength training volume at moderate or high intensities increased muscle volume with no differences in muscle volume gains for old men. These data suggest that physical exercise at moderate intensity (55 to 60% of one repetition maximum) can reverse the aging related loss of muscle mass. Trial registration NCT03079180 in ClinicalTrials.gov. Registration date: March 14, 2017.


2022 ◽  
pp. 110956
Author(s):  
Marcel B. Lanza ◽  
Hugo C. Martins-Costa ◽  
Carolina C. De Souza ◽  
Fernando V. Lima ◽  
Rodrigo C. Diniz ◽  
...  

2022 ◽  
pp. 98-100
Author(s):  
A. A. Sultanov ◽  
Y. Y. Pervov ◽  
A. K. Yatsenko ◽  
M. A. Sultanova ◽  
D. O. Drozdova

The article presents a clinical case of the diagnostics and treatment of the temporomandibular joint dysfunction (TMJ) in patient after orthodontic treatment. The hypertonia of masticatory muscles, limit of mouth opening and deviation of the jawbone to the right were observed during physical examination. Adhesion of the disk to the articular tubercle of the right temporal bone was detected on MRI. Hyperrotation of the articular head and the deviation of the jawbone to the right were observed on the charts during axiography. Disappearing of the feeling of heaviness in the right TMJ, free mouth opening, absence of deviation symptom, and the reduction of the rigidity of the masseter muscles were observed on the basis of diagnostic examinations after treatment. Presented clinical experience lets us make a conclusion that it is necessary to prescribe taking axiography and MRI during diagnosing and treating temporomandibular joint dysfunction.


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