Volume and Shape of Masticatory Muscles in Patients with Hemifacial Microsomia

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.

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

Journal of Dental Research ◽

10.1177/0810752 ◽

2002 ◽

Vol 81 (11) ◽

pp. 752-756 ◽

Cited By ~ 21

Author(s):

N. Kitai ◽

Y. Fujii ◽

S. Murakami ◽

S. Furukawa ◽

S. Kreiborg ◽

...

Keyword(s):

Masticatory Muscles ◽

Muscle Volume ◽

Zygomatic Arch ◽

Masticatory Muscle ◽

Mandibular Ramus ◽

Cross Sectional ◽

Temporal Fossa ◽

Mandibular Prognathism ◽

Masseter Muscles ◽

Area And Volume

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.

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Overall Activity of All Masticatory Muscles during Lateral Excursion

Journal of Dental Research ◽

10.1177/154405910608500112 ◽

2006 ◽

Vol 85 (1) ◽

pp. 69-73 ◽

Cited By ~ 12

Author(s):

S. Yamaguchi ◽

H. Rikimaru ◽

K. Yamaguchi ◽

M. Itoh ◽

M. Watanabe

Keyword(s):

Positron Emission Tomography ◽

Masticatory Muscles ◽

Emission Tomography ◽

Masticatory Muscle ◽

Lateral Pterygoid Muscle ◽

Relative Contribution ◽

Medial Pterygoid Muscle ◽

Positron Emission ◽

Medial Pterygoid ◽

Pterygoid Muscles

Quantification of the overall activity of every masticatory muscle is requisite for the analysis of stomatognathic function, which has not been accomplished by conventional electromyography. We used positron emission tomography and 18F-fluoro-deoxy-glucose to quantify the overall activity of every masticatory muscle during lateral excursion, and to evaluate the relative contribution of each masticatory muscle to lateral excursion. The present study suggested that lateral and medial pterygoid muscles are more responsible for lateral excursion than are masseter and temporal muscles. In particular, the contralateral lateral pterygoid muscle plays a major role, followed by the contralateral medial pterygoid muscle.

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Jaw Clenching: Muscle and Joint Forces, Optimization Strategies

Journal of Dental Research ◽

10.1177/154405910708600907 ◽

2007 ◽

Vol 86 (9) ◽

pp. 843-847 ◽

Cited By ~ 19

Author(s):

H.J. Schindler ◽

S. Rues ◽

J.C. Türp ◽

K. Schweizerhof ◽

J. Lenz

Keyword(s):

Control Strategies ◽

Masticatory Muscles ◽

Objective Functions ◽

Cross Sectional ◽

Temporomandibular Joints ◽

Joint Forces ◽

Medial Pterygoid ◽

Geometrical Data ◽

Force Components ◽

Best Fit

Realistic masticatory muscle and temporomandibular joint forces generated during bilateral jaw clenching are largely unknown. To determine which clenching directions load masticatory muscles and temporomandibular joints most heavily, we investigated muscle and joint forces based on feedback-controlled electromyograms of all jaw muscles, lines of action, geometrical data from the skull, and physiological cross-sectional areas acquired from the same individuals. To identify possible motor control strategies, we applied objective functions. The medial pterygoid turned out to be the most heavily loaded muscle for all bite directions. Biting with accentuated horizontal force components provoked the highest loading within the medial and lateral pterygoids. The largest joint forces were also found for these bite directions. Conversely, the lowest joint forces were detected during vertical biting. Additionally, joint forces with a clear posterior orientation were found. Optimization strategies with the elastic energy as objective function revealed the best fit with the calculated results.

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PEMBELAJARAN SIMULASI PENCITRAAN CT DENGAN MENGGUNAKAN PRINSIP REKONSTRUKSI CITRA DALAM SOFTWARE MATLAB

Jurnal Dinamika Pendidikan ◽

10.33541/jdp.v8i3.127 ◽

2015 ◽

Vol 8 (3) ◽

pp. 161

Author(s):

Samuel Gideon

Keyword(s):

Image Reconstruction ◽

Ct Imaging ◽

The Body ◽

Reconstruction Technique ◽

Imaging Features ◽

Back Projection ◽

Cross Sectional ◽

Low Contrast ◽

Image Reconstruction Technique ◽

Imaging Algorithms

This research was conducted as a learning alternatives for study of CT (computed tomograpghy) imaging using image reconstruction technique which are inversion matrix, back projection and filtered back projection. CT imaging can produce images of objects that do not overlap. Objects more easily distinguishable although given the relatively low contrast. The image is generated on CT imaging is the result of reconstruction of the original object. Matlab allows us to create and write imaging algorithms easily, easy to undersand and gives applied and exciting other imaging features. In this study, an example cross-sectional image recon-struction performed on the body of prostate tumors using. With these methods, medical prac-titioner (such as oncology clinician, radiographer and medical physicist) allows to simulate the reconstruction of CT images which almost resembles the actual CT visualization techniques.Keywords : computed tomography (CT), image reconstruction, Matlab

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(Preprint)

10.2196/preprints.12282 ◽

2018 ◽

Author(s):

Dr Malathi Dayalan ◽

Dr Sudeshna Sharma ◽

Dr Shweta Poovani ◽

Dr Saher Altaf

Keyword(s):

Myofascial Pain ◽

Mouth Opening ◽

Masticatory Muscles ◽

Matched Pair ◽

Masticatory Muscle ◽

Muscle Disorders ◽

Occlusal Contact ◽

Group I ◽

Group Ii

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).

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The prevalence and management of patients with hypodontia: A cross -sectional study

Journal of Orthodontics ◽

10.1177/14653125211065457 ◽

2021 ◽

pp. 146531252110654

Author(s):

Nusaybah Elsherif ◽

Jose Rodriguez ◽

Farooq Ahmed

Keyword(s):

Orthodontic Treatment ◽

Negative Impact ◽

Cross Sectional Study ◽

Class I ◽

Class Iii ◽

Dental Anomalies ◽

Missing Teeth ◽

Cross Sectional ◽

Related Quality ◽

Pre Treatment

Background: Hypodontia is one of the most common anomalies in dentistry. Hypodontia has a negative impact on oral health-related quality of life with patients best seen in a multidisciplinary clinic to improve treatment outcomes. Aim: To investigate the prevalence of hypodontia and its association with other dental anomalies, as well as malocclusion, and to investigate the treatment planned for patients attending the clinic and whether the type of missing teeth affected the proposed treatment. Materials and Methods: Analysis of consecutive patients attending the hypodontia clinic at a dental hospital between February and November 2020. A total of 100 patients who met the inclusion criteria were identified. Data collected included the following: age/sex; number and type of missing teeth; pre-treatment occlusion; presence of other dental anomalies; and planned treatment. Results: A total of 100 patients (55% female; age range = 7–41 years; mean age = 18 years) were included. Of the cohort, 47% had a class I skeletal relationship and participants were significantly less likely to have a class III skeletal or incisor relationship; 45% had another dental anomaly with the most common being microdontia. Space opening was the preferred treatment option for those managed by orthodontic treatment with resin-bonded bridges most likely to be used for restoration of spaces, 86%. Conclusion: Lower second premolars were the most commonly missing teeth. Participants were significantly less likely to have a class III incisor or skeletal relationship than class I or II. Space opening was the favoured approach for orthodontic treatment, particularly for maxillary lateral incisors.

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The Prevalence of Nephrolithiasis in Patients with Primary Gout: A Cross-sectional Study Using Helical Computed Tomography

The Journal of Rheumatology ◽

10.3899/jrheum.081128 ◽

2009 ◽

Vol 36 (9) ◽

pp. 1958-1962 ◽

Cited By ~ 14

Author(s):

TORU SHIMIZU ◽

HIROSHI HORI

Keyword(s):

Computed Tomography ◽

Confidence Interval ◽

Laboratory Data ◽

Helical Computed Tomography ◽

Cross Sectional ◽

Patients Âgés ◽

Primary Gout ◽

Stone Formers ◽

Significant Difference ◽

History Of

Objective.To investigate the prevalence of nephrolithiasis in gouty patients by computed tomography (CT) imaging and to compare it with the “prevalence” of urolithiasis calculated from histories of urinary tract calculus.Methods.The kidneys of 383 male patients with primary gout were examined using an unenhanced 2-row helical CT detector, imaging at 2 mm collimation and a helical pitch of 3. The urolithiasis history of the 383 patients was investigated by inquiry. Patients’ ages, body mass index, and laboratory data from a 1-hour clearance test were determined.Results.CT scans confirmed nephrolithiasis in 103 (26.9%, 95% confidence interval 22.5%–31.6%) of the 383 gouty patients, and history of urinary calculus was positive in 65 (17.0%, 95% confidence interval 13.4%–21.1%) of the 383. However, 64 (62%) of the 103 stone-formers identified by CT had no history of urolithiasis. There was a significant difference between the ages of the 103 stone-formers identified by CT and the 65 stone-formers identified from the history.Conclusion.The prevalence of nephrolithiasis obtained using CT was 26.9% in the 383 patients with primary gout. Our results imply that we cannot determine an accurate prevalence of urolithiasis from a patient’s history. Most of the “prevalence” reported in the past may not correspond to a statistically justifiable one, but instead to the “cumulative incidence” during the contraction period of gout. Thus, the prevalence of nephrolithiasis confirmed by a cross-sectional method and the “prevalence” of urolithiasis calculated from patients’ calculus histories should be clearly distinguished.

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Dental Anomalies among Patients with Malocclusion- A Cross Sectional Study

IOSR Journal of Dental and Medical Sciences ◽

10.9790/0853-1508043337 ◽

2016 ◽

Vol 15 (08) ◽

pp. 33-37

Author(s):

Sheloni M ◽

Nadeem Nadeem ◽

Adil Ahmed ◽

Anu V

Keyword(s):

Cross Sectional Study ◽

Sectional Study ◽

Dental Anomalies ◽

Cross Sectional

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FEATURES OF MANUFACTURE OF ADVANCED PROVISIONAL BRIDGE-BASED PROSTHESES

Art of Medicine ◽

10.21802/artm.2021.1.17.33. ◽

2021 ◽

pp. 33-37

Author(s):

А. В. Kostyshyn

Keyword(s):

High Efficiency ◽

Age Groups ◽

Masticatory Muscles ◽

Pathological Process ◽

Muscle Group ◽

Control Group ◽

Masticatory Muscle ◽

Orthopedic Treatment ◽

Group 2 ◽

Reinforcement Model

Abstract. The relevance of the topic is related to the need to improve methods of preparation of dentitions for orthopedic treatment, taking into account the defects of dentitions in patients with reduced occlusion height, taking into account the condition of the masticatory muscles and temporary use of plastic dentures, which provide gradual lifting of occlusion to normalize the masticatory group muscles and reorganization of myostatic reflexes. The aim of the research. Improving the effectiveness of preparation for orthopedic treatment of patients with partial tooth loss, with reduced occlusion height, by improving the design of a temporary bridge-based prosthesis. Materials and methods of research. We examined, treated and conducted clinical observation of 93 patients, who were divided into three groups according to the height of the reduction in occlusion, to achieve this goal and solve problems during the dissertation. Group 1 consisted of 32 patients with included dentition defects with reduced occlusion height up to 2 mm (n=32), group 2 - patients with included dentition defects with reduced occlusion height up to 2-4 mm (n=31), group 3 - these are patients with included dentition defects with reduced occlusion height up to 4-6 mm (n=30). All patients of the main groups belonged to the second and third age groups according to the WHO, aged 35-55 years. The control group (n=30) are young people who belonged to the 1st age group according to the WHO with intact dentition, without concomitant somatic and dental pathology, were admitted in one visit. Also, 123 fiberglass-reinforced plastic prostheses were made. Research results. When drawing up a plan for orthopedic treatment of patients with reduced occlusion height, we took into account possible complications, which are characterized by chipping of the facing material, pathological changes in the temporomandibular joint and masticatory muscle group. We have improved the method of manufacturing non-removable temporary plastic orthopedic constructions by reinforcing with fiberglass tapes and beams, to prevent them and gradually raise the bite. Expanded data on the dynamics of changes in myostatic reflexes and the effectiveness of the use of fixed orthopedic constructions, depending on the pathological process, the timing of adaptation of the masticatory muscle group to orthopedic constructions, according to the degree of reduction in occlusion height. The absence of complaints of breakage and other technical defects of the proposed temporary orthopedic constructions in 100% of cases, successfully allows to use it in the clinic of orthopedic dentistry. A new method of preparing patients for permanent orthopedic treatment by combined reinforcement of temporary non-removable bridge constructions with fiberglass tapes and beams is proposed, which differ in that after preliminary modeling of the frame of the bridge constructions, the technology of double reinforcement, model two support platforms with a step-like transition between them, in which fiberglass tapes and beams are fitted with dental tweezers, after which they are polymerized by the generally accepted method with a photopolymer lamp. Complete the modeling of the constructions and polymerize the prosthesis in the pneumopolymerizer with subsequent grinding and polymerize the prosthesis. Conclusion. The results of the research revealed the high efficiency of the improved method of manufacturing non-removable makeshift plastic of orthopedic constructions.

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