Muscles of Mastication

2007 ◽  
pp. 201-201
Author(s):  
Byas Ghosh
2019 ◽  
pp. 1-8 ◽  
Author(s):  
Nasser Mohammed ◽  
Yi-Chieh Hung ◽  
Thomas J. Eluvathingal Muttikkal ◽  
Roy C. Bliley ◽  
Zhiyuan Xu ◽  
...  

OBJECTIVEThe motor root of the trigeminal nerve runs close to the sensory root and receives considerable radiation during Gamma Knife radiosurgery (GKRS) for trigeminal neuralgia (TN). The object of this study was to evaluate via MRI the changes in the muscles of mastication before and after upfront GKRS in patients with idiopathic TN.METHODSIn this single-institution retrospective cohort study, all patients with idiopathic unilateral TN treated with primary GKRS at the University of Virginia in the period from 2007 to 2017 were included provided that they had pre- and post-GKRS MRI data. The thicknesses of the temporalis, pterygoid, and masseter muscles were measured on both pre- and post-GKRS MRI in a blinded fashion. Changes in the muscles like fatty infiltration, MRI signal, or atrophy were noted.RESULTSAmong the 68 patients eligible for inclusion in the study, 136 temporalis muscles, 136 medial pterygoid muscles, 136 lateral pterygoid muscles, and 136 masseter muscles were assessed. A subset of patients was found to have muscle atrophy even prior to GKRS. Pre-GKRS atrophy of the masseter, medial pterygoid, lateral pterygoid, and temporalis muscles was seen in 18 (26%), 16 (24%), 9 (13%), and 16 (24%) patients, respectively. Logistic regression analysis showed that distribution of pain in the V3 territory (p = 0.01, OR 5.43, 95% CI 1.46–20.12) and significant pain on chewing (p = 0.02, OR 5.32, 95% CI 1.25–22.48) were predictive of pre-GKRS atrophy. Reversal of atrophy of these muscles occurred after GKRS in a majority of the patients. The incidence of new-onset permanent post-GKRS muscle atrophy was 1.5%. The median follow-up was 39 months (range 6–108 months).CONCLUSIONSA subset of patients with TN with significant pain on chewing have pre-GKRS disuse atrophy of the muscles of mastication. A reversal of the atrophy occurs in a majority of the patients following GKRS. New-onset motor neuropathy post-GKRS was rare.


2014 ◽  
Vol 48 (3) ◽  
pp. 255-268 ◽  
Author(s):  
I.A. Koretsky ◽  
S.J. Rahmat ◽  
N. Peters

Abstract Remarks on Correlations and Implications of the Mandibular Structure and Diet in Some Seals (Mammalia, Phocidae). Koretsky, I. A., Rahmat, S. J., Peters, N. — The diverse representatives of Recent seals within the three extant subfamilies (Cystophorinae, Phocinae, Monachinae) of the family Phocidae exhibit dietary variations among species, feeding on invertebrates and a diversity of prey depending on the season and availability. To explain this variability, an introductory morphological examination of the mandibular structure of Recent seals from each subfamily was performed, focusing on: heights of the mandibular ramus and condyloid process; measurements of the masseteric fossa; and attachments of muscles of mastication. After measuring the condyloid angles (the inclination of the condyloid process in relation to the axis of the alveolar row) among the examined species, a correlation between the size ofthe angle, function, and diet was recognized. Seals with a tall mandibular ramus and greater condyloid angle (Cystophorinae) feed on larger-sized prey, while seals with a shorter ramus and lesser condyloid angle feed on small (Monachinae) to medium-sized (Phocinae) prey, regardless of the overall size of the seal. This study focused on the mandibular morphology of some living and fossil representatives of Phocidae, providing an association between functional and ecological interpretations of modern seals in general and extrapolating this knowledge for fossil dietary preference.


2015 ◽  
Vol 9 (1) ◽  
pp. 187-189 ◽  
Author(s):  
Khaja Amjad Hussain ◽  
Saleh Nasser Azzeghaibi ◽  
Bassel Tarakji ◽  
SenthilRajan R. S ◽  
Syed Sirajuddin ◽  
...  

As the number of aged people in the world is growing, the need to provide patients with tooth alternate through removable partial dentures is equally growing. There are adversarial effects that should be kept in mind which might disturb the remaining teeth; specially, the abutments and the supporting tissues. These effects might spread to the muscles of mastication and also to the supporting periodontal tissues. Thus, we should plan removable partial dentures (RPDs) without mutilation to the adjacent teeth or the underlying tissues.


2010 ◽  
pp. 57-60
Author(s):  
Victor Cox ◽  
David Klugh

Author(s):  
Martin E. Atkinson

It is essential that dental students and practitioners understand the structure and function of the temporomandibular joints and the muscles of mastication and other muscle groups that move them. The infratemporal fossa and pterygopalatine fossa are deep to the mandible and its related muscles; many of the nerves and blood vessels supplying the structures of the mouth run through or close to these areas, therefore, knowledge of the anatomy of these regions and their contents is essential for understanding the dental region. The temporomandibular joints (TMJ) are the only freely movable articulations in the skull together with the joints between the ossicles of the middle ear; they are all synovial joints. The muscles of mastication move the TMJ and the suprahyoid and infrahyoid muscles also play a significant role in jaw movements. The articular surfaces of the squamous temporal bone and of the condylar head (condyle) of the mandible form each temporomandibular joint. These surfaces have been briefly described in Chapter 22 on the skull and Figure 24.1A indicates their shape. The concave mandibular fossa is the posterior articulating surface of each squamous temporal bone and houses the mandibular condyle at rest. The condyle is translated forwards on to the convex articular eminence anterior to the mandibular fossa during jaw movements. The articular surfaces of temporomandibular joints are atypical; they covered by fibrocartilage (mostly collagen with some chondrocytes) instead of hyaline cartilage found in most other synovial joints. Figures 24.1B and 24.1C show the capsule and ligaments associated with the TMJ. The tough, fibrous capsule is attached above to the anterior lip of the squamotympanic fissure and to the squamous bone around the margin of the upper articular surface and below to the neck of the mandible a short distance below the limit of the lower articular surface. The capsule is slack between the articular disc and the squamous bone, but much tighter between the disc and the neck of the mandible. Part of the lateral pterygoid muscle is inserted into the anterior surface of the capsule. As in other synovial joints, the non-load-bearing internal surfaces of the joint are covered with synovial membrane.


2021 ◽  
pp. 63-92
Author(s):  
Daniel R. van Gijn ◽  
Jonathan Dunne

The mandible is the largest of the facial bones, occupying a prominent position upon and providing the foundation for the lower third of the face. Despite holding the honour of being the strongest bone in the face, its protrusive location makes it vulnerable to injury – particularly in relation to aggressively placed fists, steering wheels and concrete. Anatomically, the mandible consists of a symmetrical, horseshoe shaped body continuous with paired broad rami posteriorly. The former houses the lower teeth within the alveolus whilst the latter provides attachment for the four principle muscles of mastication from the its medial and lateral surfaces and coronoid and condylar processes. In addition to the aforementioned muscles of mastication, the mandible provides origin to the muscles of the tongue, the floor of mouth and some muscles of facial expression.


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