[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (8)

Search Parameters:
Keywords = superficial part of masseter muscle

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
15 pages, 15373 KiB  
Article
The Difference in Electromyographic Activity While Wearing a Medical Mask in Women with and without Temporomandibular Disorders
by Michał Ginszt, Grzegorz Zieliński, Jacek Szkutnik, Marcin Wójcicki, Michał Baszczowski, Monika Litko-Rola, Diana Zielińska and Ingrid Różyło-Kalinowska
Int. J. Environ. Res. Public Health 2022, 19(23), 15559; https://doi.org/10.3390/ijerph192315559 - 23 Nov 2022
Cited by 9 | Viewed by 1794
Abstract
Wearing a medical mask influences resting activity of the temporalis anterior and masseter muscles in healthy young women. However, no studies link medical mask-wearing with masticatory muscle activity in patients with temporomandibular disorders (TMDs). Therefore, this study aims to compare electromyographic patterns while [...] Read more.
Wearing a medical mask influences resting activity of the temporalis anterior and masseter muscles in healthy young women. However, no studies link medical mask-wearing with masticatory muscle activity in patients with temporomandibular disorders (TMDs). Therefore, this study aims to compare electromyographic patterns while wearing a medical mask between women with and without temporomandibular disorders. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 115 adult women qualified for the study. Participants were divided into the following two groups: diagnosed TMDs (n = 55; mean age: 23.5 ± 2.3 years) and healthy women (n = 60; mean age: 23.7 ± 2.6 years). Examinations of the resting and functional electromyographic activity of the temporalis anterior (TA), superficial masseter (MM), anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) were carried out using the BioEMG III™. Both groups showed statistically significant decreases in resting masticatory muscle activity during medical mask examination compared to no mask measurement. The significant differences in no mask measurement between both groups were noted regarding resting masticatory activity, clenching in the intercuspal position, and clenching on dental cotton rollers. During medical mask examination, women with TMDs showed differences in resting masticatory activity and clenching on dental cotton rollers compared to the healthy group. In all analyzed variables, both groups showed similar electromyographic patterns in the maximum mouth opening measurement during medical mask and no mask examination. A medical mask influences the resting bioelectric activity of the masticatory muscles in women with temporomandibular disorders and healthy women. We observed differences and some similarities in resting and functional electromyographic patterns within masticatory and neck muscles in both groups during medical mask and no mask examination. Full article
Show Figures

Figure 1

Figure 1
<p>Electrode placement during two measurements: without (<bold>a</bold>) and with face mask (<bold>b</bold>).</p>
Full article ">Figure 2
<p>Example of the surface electromyography traces during resting activity (<bold>a</bold>), maximum voluntary clenching (<bold>b</bold>), and maximum mouth opening (<bold>c</bold>).</p>
Full article ">
15 pages, 1553 KiB  
Article
Masticatory Muscle Thickness and Activity Correlates to Eyeball Length, Intraocular Pressure, Retinal and Choroidal Thickness in Healthy Women versus Women with Myopia
by Grzegorz Zieliński, Marcin Wójcicki, Maria Rapa, Anna Matysik-Woźniak, Michał Baszczowski, Michał Ginszt, Monika Litko-Rola, Jacek Szkutnik, Ingrid Różyło-Kalinowska, Robert Rejdak and Piotr Gawda
J. Pers. Med. 2022, 12(4), 626; https://doi.org/10.3390/jpm12040626 - 13 Apr 2022
Cited by 14 | Viewed by 3794
Abstract
This study aims to examine the correlations between masticatory and neck muscle thickness and activity versus eyeball length, retinal thickness, choroidal thickness, and intraocular pressure in healthy women versus women with myopia. The study group consisted of 21 women aged 24 years and [...] Read more.
This study aims to examine the correlations between masticatory and neck muscle thickness and activity versus eyeball length, retinal thickness, choroidal thickness, and intraocular pressure in healthy women versus women with myopia. The study group consisted of 21 women aged 24 years and a control group of 19 women (mean age 23 years). For bioelectrical activity analysis within the temporalis anterior, the superficial part of the masseter muscle, the middle part of the sternocleidomastoid muscle, and the anterior belly of the digastric muscle, an eight-channel BioEMG III electromyograph were used. An M-Turbo ultrasound machine was used to analyze masticatory and neck muscle thickness. The eyeball length was examined by IOL Master 500; choroidal and retinal thickness by Optovue Angiovue; and intraocular pressure by Tono-Pen XL. Refractive errors are related to differences in muscle thickness and electromyographic activity. Bioelectrical activity within the temporalis anterior seems to be associated with ocular length, retinal thickness, and choroidal thickness in women with myopia. Full article
(This article belongs to the Special Issue The Challenges and Therapeutic Prospects in Eye Disease)
Show Figures

Figure 1

Figure 1
<p>Example of an ultrasound examination of muscle thickness. (<b>a</b>) The temporalis muscle in the relaxed mandible position with slight contact between opposing teeth; (<b>b</b>) the temporalis muscle in the maximum voluntary clenching; (<b>c</b>) the masseter muscle in the relaxed mandible position with slight contact between opposing teeth; (<b>d</b>) the masseter muscle in the maximum voluntary clenching; line A-A—measuring line of the thickness of the muscle in the relaxed mandible position with slight contact between opposing teeth; line B-B—measuring line of the thickness of the maximum voluntary clenching.</p>
Full article ">Figure 2
<p>Example of the surface electromyography traces during resting activity.</p>
Full article ">Figure 3
<p>Example of a study of retinal thickness (<b>A</b>) and choroidal thickness (<b>B</b>).</p>
Full article ">Figure 4
<p>Scheme of anatomical compounds.</p>
Full article ">
11 pages, 603 KiB  
Article
Cervical Myofascial Pain Is Associated with an Imbalance of Masticatory Muscle Activity
by Michał Ginszt, Jacek Szkutnik, Grzegorz Zieliński, Magdalena Bakalczuk, Małgorzata Stodółkiewicz, Monika Litko-Rola, Apolinary Ginszt, Mansur Rahnama and Piotr Majcher
Int. J. Environ. Res. Public Health 2022, 19(3), 1577; https://doi.org/10.3390/ijerph19031577 - 29 Jan 2022
Cited by 15 | Viewed by 4291
Abstract
This study aimed to assess the relationship between the occurrence of cervical myofascial pain with active myofascial trigger points (MTrPs) within the upper trapezius muscle and the electromyographic asymmetry index (AsI) of masticatory muscles: temporalis anterior (TA), superficial part of the masseter muscle [...] Read more.
This study aimed to assess the relationship between the occurrence of cervical myofascial pain with active myofascial trigger points (MTrPs) within the upper trapezius muscle and the electromyographic asymmetry index (AsI) of masticatory muscles: temporalis anterior (TA), superficial part of the masseter muscle (MM), and anterior belly of the digastric muscle (DA). The study group comprised 100 subjects (80 women and 20 men) aged 18 to 30 years (mean 23 ± 2.6 years) reporting pain in the neck muscles, diagnosed with myofascial pain with active MTrPs only within the upper trapezius muscle. The control group comprised 60 healthy, pain-free subjects (42 women and 18 men) aged 20 to 30 years (mean 22.8 ± 2.6 years) without MTrPs in the upper trapezius muscle. The palpation measurement, based on the diagnostic criteria of Travell and Simons, was used to diagnose active MTrPs. The masticatory muscle activity was recorded using an 8-channel device for surface electromyography—BioEMG IIITM. Significant differences in electromyographic patterns between the group with MTrPs in the right side of upper trapezius muscle and the control group were observed within resting activity for the AsI TA (MTrPs: 8.64 vs. controls: −3.22; p = 0.001) and AsI MM (MTrPs: 7.05 vs. controls: −2.09; p = 0.018). Controls presented different electromyographic patterns during maximum voluntary clenching with cotton rolls between teeth within masseter muscle compared to the MTrPs group (MTrPs: 9.27 vs. controls: −0.43 vs. p = 0.041). Participants with MTrPs in the left side of upper trapezius muscle presented predomination of left-sided electromyographic patterns at rest within temporalis anterior in comparison to controls (MTrPs: −19.22 vs. controls: −3.22; p = 0.001). MTrPs within the trapezius muscle may be related to asymmetry within the masticatory muscle activity, suggesting that the presence of myofascial pain within the cervical muscles plays a role in the imbalance of the stomatognathic system. A unilateral active MTrPs within the trapezius muscle may increase the sEMG activity on the same side of the temporalis anterior and masseter muscles. Full article
(This article belongs to the Collection Relationships between Oral Health Management and Systemic Health)
Show Figures

Figure 1

Figure 1
<p>sEMG electrodes placement during the electromyographic examination.</p>
Full article ">
10 pages, 1050 KiB  
Article
The Effects of Wearing a Medical Mask on the Masticatory and Neck Muscle Activity in Healthy Young Women
by Michał Ginszt, Grzegorz Zieliński, Jacek Szkutnik, Marcin Wójcicki, Michał Baszczowski, Monika Litko-Rola, Ingrid Rózyło-Kalinowska and Piotr Majcher
J. Clin. Med. 2022, 11(2), 303; https://doi.org/10.3390/jcm11020303 - 7 Jan 2022
Cited by 12 | Viewed by 2271
Abstract
The objective of this study was to analyze the influence of wearing a medical mask on masticatory and neck muscle activity in healthy young women. We recruited 66 healthy women aged from 18 to 30 years (mean 23.6 ± 2.3 years). The temporalis [...] Read more.
The objective of this study was to analyze the influence of wearing a medical mask on masticatory and neck muscle activity in healthy young women. We recruited 66 healthy women aged from 18 to 30 years (mean 23.6 ± 2.3 years). The temporalis anterior (TA), the superficial part of the masseter muscle (MM), the anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) potentials were recorded at rest and during functional activity using an eight-channel device for surface electromyography—BioEMG IIITM. There was a statistically significant decrease in mean TA activity during medical mask measurement compared to no mask examination at rest (2.16 µV vs. 2.58 µV; p = 0.05; ES = 0.2). Significant decreases in resting RMS values were also observed during the medical mask phase in comparison to no mask examination concerning the left MM (1.75 µV vs. 2.17 µV; p = 0.01; ES = 0.3), and mean bioelectrical activity of the MM (1.81 µV vs. 2.15 µV; p = 0.02; ES = 0.2). The differences between the two conditions did not reach the assumed significance level (p > 0.05) in terms of other indices. Wearing a medical mask has a small effect on decreasing the resting potentials of the temporalis anterior and masseter muscles without changing the parameters of activity and asymmetry within the stomatognathic system. Full article
(This article belongs to the Special Issue Clinical Features of COVID-19 in Elderly Patients)
Show Figures

Figure 1

Figure 1
<p>Electromyographic examination during two conditions: without (<b>a</b>) and with medical mask (<b>b</b>).</p>
Full article ">Figure 2
<p>Example of the surface electromyography traces during resting activity (<b>a</b>) and maximum voluntary clenching in the intercuspal position (<b>b</b>).</p>
Full article ">
13 pages, 566 KiB  
Article
The Influence of Visual Input on Electromyographic Patterns of Masticatory and Cervical Spine Muscles in Subjects with Myopia
by Grzegorz Zieliński, Anna Matysik-Woźniak, Maria Rapa, Michał Baszczowski, Michał Ginszt, Magdalena Zawadka, Jacek Szkutnik, Robert Rejdak and Piotr Gawda
J. Clin. Med. 2021, 10(22), 5376; https://doi.org/10.3390/jcm10225376 - 18 Nov 2021
Cited by 14 | Viewed by 2358
Abstract
This study aimed to analyze the change of visual input on electromyographic patterns of masticatory and cervical spine muscles in subjects with myopia. After applying the inclusion criteria, 50 subjects (18 males and 32 females) with myopia ranging from −0.5 to −5.75 Diopters [...] Read more.
This study aimed to analyze the change of visual input on electromyographic patterns of masticatory and cervical spine muscles in subjects with myopia. After applying the inclusion criteria, 50 subjects (18 males and 32 females) with myopia ranging from −0.5 to −5.75 Diopters (D), were included in the study. Four muscle pairs were analyzed: the anterior part of the temporalis muscle (TA), the superficial part of the masseter muscle (MM), the anterior belly of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle belly (SCM) during resting and functional activity. Statistical analysis showed a significant decrease within functional indices (FCI) for the sternocleidomastoid muscle (FCI SCM R, FCI SCM L, FCI SCM total) during clenching in the intercuspal position with eyes closed compared to eyes open. During maximum mouth opening, a statistically significant increase of functional opening index for the left temporalis muscle (FOI TA L) was observed. Within the activity index (AcI), there was a statistically significant decrease during clenching on dental cotton rollers with eyes closed compared to eyes open. Full article
(This article belongs to the Special Issue New Frontiers in Masticatory Function)
Show Figures

Figure 1

Figure 1
<p>Electrode placement during the electromyographic examination. TA—the temporalis anterior; MM—the superficial part of the masseter muscle; DA—the anterior belly of the digastric muscle; SCM—the middle part of the sternocleidomastoid muscle belly.</p>
Full article ">
15 pages, 4383 KiB  
Article
A Rare Case of Facial Artery Branching—A Review of the Literature and a Case Report with Clinical Implications
by Martin Siwetz, Nicol Turnowsky, Niels Hammer, Michael Pretterklieber, Andreas Wree and Veronica Antipova
Medicina 2021, 57(11), 1172; https://doi.org/10.3390/medicina57111172 - 28 Oct 2021
Cited by 9 | Viewed by 4538
Abstract
Background and Objectives: Vascular variations appear as morphologically distinct patterns of blood diverging from the most commonly observed vessel patterns. The facial artery is considered to be the main vessel for supplying blood to the anterior part of the face. An anatomical understanding [...] Read more.
Background and Objectives: Vascular variations appear as morphologically distinct patterns of blood diverging from the most commonly observed vessel patterns. The facial artery is considered to be the main vessel for supplying blood to the anterior part of the face. An anatomical understanding of the facial artery, its course, its topography, and its branches is important in medical and dental practice (especially in neck and face surgery), and is also essential for radiologists to be able to interpret vascular imaging in the face following angiography of the region. A profound knowledge of the arteries in the region will aid in minimizing the risks to the patient. Materials and Methods: In our publication a narrative literature review and a case report are presented. Results: A rare case of a facial artery pattern has been described anatomically for the first time with respect to its course and branching. This variation was found on the left side of a 60-year-old male corpse during anatomical dissection. The anterior branch of the facial artery arched in the direction of the labial angle, and there divided into the inferior and superior labial arteries. At the same time, the posterior branch coursed vertically and superficially to the masseter muscle. It here gave off the premasseteric branch, and continued towards the nose, where it ran below the levator labii superioris and the levator labii superioris alaeque nasi muscles and terminated at the dorsum nasi. Conclusions: Our review of the literature and the case report add to knowledge on the facial artery with respect to its topographical anatomy and its branching and termination patterns, as well as the areas of supply. An exact knowledge of individual facial artery anatomy may play an important role in the planning of flaps or tumor excisions due to the differing vascularization and can also help to prevent artery injuries during aesthetic procedures such as filler and botulinum toxin injections. Full article
(This article belongs to the Special Issue Topographic Anatomy of the Human Body)
Show Figures

Figure 1

Figure 1
<p>(<b>A</b>) The dissection situs of the left side of a male face with a rare variation in the branching pattern of the facial artery. (<b>B</b>) A schematic depiction of the dissection situs and branching pattern of the facial artery on the left side of the face in the same orientation. The common trunk (CT) of the facial artery splits at the level of the base of the mandible into an anterior branch (AB) and a posterior branch (PB) that gives off the premasseteric branch (<b>*</b>).</p>
Full article ">Figure 2
<p>Types of facial artery according to prior literature. Lateral views according to the original depiction.</p>
Full article ">Figure 2 Cont.
<p>Types of facial artery according to prior literature. Lateral views according to the original depiction.</p>
Full article ">Figure 2 Cont.
<p>Types of facial artery according to prior literature. Lateral views according to the original depiction.</p>
Full article ">Figure 2 Cont.
<p>Types of facial artery according to prior literature. Lateral views according to the original depiction.</p>
Full article ">Figure 2 Cont.
<p>Types of facial artery according to prior literature. Lateral views according to the original depiction.</p>
Full article ">Figure 3
<p>Types of facial artery branching patterns. Frontal views according to the original depiction.</p>
Full article ">
10 pages, 3349 KiB  
Article
Anatomical Considerations When Treating Compensatory Hypertrophy of the Upper Part of the Masseter after Long-Term Botulinum Neurotoxin Type A Injections
by Kyu-Lim Lee, Hyun Jin Cho, Hyungkyu Bae, Hyun Jin Park, Min Sun Park and Hee-Jin Kim
Toxins 2020, 12(3), 202; https://doi.org/10.3390/toxins12030202 - 22 Mar 2020
Cited by 8 | Viewed by 5450
Abstract
The masseter is the most targeted muscle when treating hypertrophy to produce a smooth face shape. Compensatory hypertrophy is a well known clinical sequela that occurs in botulinum neurotoxin (BoNT) treatments and is limited to the lower part of the masseter. Based on [...] Read more.
The masseter is the most targeted muscle when treating hypertrophy to produce a smooth face shape. Compensatory hypertrophy is a well known clinical sequela that occurs in botulinum neurotoxin (BoNT) treatments and is limited to the lower part of the masseter. Based on the masseteric hypertrophy procedure, which targets a confined area, we predicted the possibility of compensatory hypertrophy occurring in the upper part of the masseter. If the patient complains about an unexpected result, additional injections must be performed, but the involved anatomical structures have not been revealed yet. The aim of this study was to identify the morphological patterns of the masseter. Deep tendons were observed in most specimens of the upper part of the masseter and mostly appeared in a continuous pattern (69.7%). The superficial and deep tendons could be classified into a simply connected form and forms surrounding part of the muscle. In 45.5% of cases there were tendon capsules that completely enclosed the muscle, which can interfere with how the injected toxin spreads. Interdigitation patterns in which the tendons could be identified independently between the muscles were present in 9.1% of cases. The present findings provide anatomical knowledge for use when injecting BoNT into the masseter. Full article
(This article belongs to the Special Issue Botulinum Neurotoxin Injection)
Show Figures

Figure 1

Figure 1
<p>Photography of compensatory hypertrophy of the upper part of the masseter. (Reproduced with the permission of courtesy from Cho HJ, Labella clinic).</p>
Full article ">Figure 2
<p>Type 1a, simply continuous pattern. (<b>A</b>) The superficial tendon of the surface of the masseter was anteriorly retracted. (<b>B</b>) Demonstrating the muscle belly, that is connected and surrounded by the tendons. These tendons are the deep tendon and the superficial tendon of the masseter muscle. ZA, Zygomatic arch.</p>
Full article ">Figure 3
<p>Type 1b and 1c, one-unit and two-unit capsule patterns, respectively. The capsule pattern was subdivided according to the number of capsules. (<b>A</b>) One-unit pattern, the superficial tendon was retracted and exposed the muscle belly located inside (muscle belly; white asterisk) (Left); the muscle belly that was surrounded by tendons was separated and indicated (Right). (<b>B</b>) Two-unit pattern, the superficial tendon was preserved in between two capsules and retracted apart from both sides of the preserved tendon (Left); The muscle belly was separated and indicated (Right). ZA, Zygomatic arch.</p>
Full article ">Figure 4
<p>Type 2, interdigitation pattern. The superficial tendon and part of the muscle belly of the masseter were retracted from a lateral to a medial direction. The deep tendons were located sporadically in the muscle belly. ZA, Zygomatic arch.</p>
Full article ">Figure 5
<p>Classification of the deep tendon structure in the superficial part of the masseter muscle. Top left, Type 1a, a simply continuous pattern, in which the deep and the superficial tendons of the masseter are connected and surround the muscle belly; top right, Type 1b. One-unit capsule pattern, in which the deep tendons completely enclose the part of the muscle belly to be a single capsule; bottom left, Type 1c. Two-unit capsules pattern, in which the deep tendons are completely enclosing the parts of the muscle belly to be two capsules; bottom right, Type 2. Interdigitation pattern, in which the deep tendons are located sporadically in the muscle belly.</p>
Full article ">Figure 6
<p>Redrawn illustration on the previous results (Kim et al., Intramuscular Nerve Distribution of the Masseter Muscle as a Basis for Botulinum Toxin Injection. J Craniofac Surg. 2010, 21(2), 588–91) [<a href="#B19-toxins-12-00202" class="html-bibr">19</a>].</p>
Full article ">Figure 7
<p>Compensatory hypertrophy due to long-term treatment. The red color points represent the area where excessive symptoms of compensatory hypertrophy appear during clenching; Blue color points represent the injection points where BoNT injections are administered periodically over a long period of time. (Reproduced with the permission of courtesy from Cho HJ, Labella clinic).</p>
Full article ">
5182 KiB  
Article
The Anatomical Basis of Paradoxical Masseteric Bulging after Botulinum Neurotoxin Type A Injection
by Hyung-Jin Lee, In-Won Kang, Kyle K. Seo, You-Jin Choi, Seong-Taek Kim, Kyung-Seok Hu and Hee-Jin Kim
Toxins 2017, 9(1), 14; https://doi.org/10.3390/toxins9010014 - 30 Dec 2016
Cited by 39 | Viewed by 18184
Abstract
The aim of this study was to determine the detailed anatomical structures of the superficial part of the masseter and to elucidate the boundaries and locations of the deep tendon structure within the superficial part of the masseter. Forty-four hemifaces from Korean and [...] Read more.
The aim of this study was to determine the detailed anatomical structures of the superficial part of the masseter and to elucidate the boundaries and locations of the deep tendon structure within the superficial part of the masseter. Forty-four hemifaces from Korean and Thai embalmed cadavers were used in this study. The deep tendon structure was located deep in the lower third of the superficial part of the masseter. It was observed in all specimens and was designated as a deep inferior tendon (DIT). The relationship between the masseter and DIT could be classified into three types according to the coverage pattern: Type A, in which areas IV and V were covered by the DIT (27%, 12/44); Type B, in which areas V and VI were covered by the DIT (23%, 10/44); and Type C, in which areas IV, V, and VI were covered by the DIT (50%, 22/44). The superficial part of the masseter consists of not only the muscle belly but also the deep tendon structure. Based on the results obtained in this morphological study, we recommend performing layer-by-layer retrograde injections into the superficial and deep muscle bellies of the masseter. Full article
(This article belongs to the Collection Botulinum Toxins on Human Pain)
Show Figures

Figure 1

Figure 1
<p>Photograph of paradoxical masseteric bulging. (Reproduced with permission from Seo K, Botulinum Toxin for Asians; Seoul Medical Publishing.)</p>
Full article ">Figure 2
<p>Detailed characteristics of the deep inferior tendon (DIT). (<b>A</b>) The DIT was located deep to the superficial muscle belly of the superficial part of the masseter. (<b>B</b>) The muscle fibers originated from the superficial aponeurosis of the masseter muscle, descended, and then changed into the tendon structure attaching to the inferior mandibular border. White arrowheads indicate the muscle fibers that originate from the deep to the superficial aponeurosis of the masseter muscle. A: anterior; S: superior; OOr: orbicularis oculi muscle.</p>
Full article ">Figure 3
<p>Classification of the DIT. The DIT can be found easily after removing the superficial muscle belly of the superficial part of the masseter. (<b>A</b>) Type A in which the DIT covers areas IV and V. (<b>B</b>) Type B in which the DIT covers areas V and VI. (<b>C</b>) Type C in which the DIT covers areas IV, V, and VI.</p>
Full article ">Figure 4
<p>Proportions of the DIT in the superficial part of the masseter. The surface area of the superficial part of the masseter muscle was 22.22 ± 4.2 cm<sup>2</sup> (<b>A</b>), and the DIT area within the masseter muscle was 4.48 ± 2.2 cm<sup>2</sup> (<b>B</b>), hence constituting 22% of the superficial part of the masseter.</p>
Full article ">Figure 4 Cont.
<p>Proportions of the DIT in the superficial part of the masseter. The surface area of the superficial part of the masseter muscle was 22.22 ± 4.2 cm<sup>2</sup> (<b>A</b>), and the DIT area within the masseter muscle was 4.48 ± 2.2 cm<sup>2</sup> (<b>B</b>), hence constituting 22% of the superficial part of the masseter.</p>
Full article ">Figure 5
<p>Serial dissections of the layered structures of the masseter muscle from superficial to deep. (<b>A</b>) Surfaces of the superficial part of the masseter. (<b>B</b>) The DIT was exposed after removing the superficial muscle belly and the aponeurosis of the superficial part of the masseter. (<b>C</b>) Another muscle belly was revealed after removing the DIT. (<b>D</b>) The middle and deep parts of the masseter muscle were attached at the lateral surface of the mandible and the periosteum.</p>
Full article ">Figure 6
<p>The illustration of the coronal section of the masseter from superficial to deep (<b>A</b>) and the expected muscle feature showing the masseteric bulging after the BTX-A injection into the masseter muscle during clenching (<b>B</b>). When masseter contracts, paradoxical masseteric bulging may occur at the superficial belly of the superficial part of the masseter because the DIT blocks the toxin’s diffusion. (SB: superficial muscle belly of superficial part of the masseter; DB: deep muscle belly of superficial part of the masseter; DP: deep part of the masseter; DIT: deep inferior tendon; SaM: superficial aponeurosis of the masseter).</p>
Full article ">
Back to TopTop