Muscles of mastication are the group of muscles that help in movement of the mandible as during chewing and speech. We need to study these muscles as they control the opening & closing the mouth & their role in the equilibrium created within the mouth. They also play a role in the configuration of face.
this presentation describes the detail anatomy of Temporo-mandibular joint with respect to its articulating surfaces, ligaments, muscles and blood and nerve supply.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
this presentation describes the detail anatomy of Temporo-mandibular joint with respect to its articulating surfaces, ligaments, muscles and blood and nerve supply.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Mastication is a harmonious and skillful activity which requires the presence and co ordination of not only the muscles of mastication but also the supra infra-hyoid muscles, and the facial muscles
BASIC MUSCLES:
Temporalis
Masseter
Medial Pterygoid
Lateral Pterygoid
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
Space infection. by Dr. Amit T. Suryawanshi, Oral Surgeon, Pune All Good Things
Hi. This is Dr. Amit T. Suryawanshi. Oral & Maxillofacial surgeon from Pune, India. I am here on slideshare.com to share some of my own presentations presented at various levels in the field of OMFS. Hope this would somehow be helpful to you making your presentations. All the best.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Chronic inflammation /orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This ppt contains an elaborate description of muscles, focussing on muscles of mastication. both main muscles and accessory muscles have been described along with palpation of each. A brief is given about disorders.
A brief ppt on stomatognathic system and its working.Function can influence the overall pattern and the relationship of parts, the very foundations of stomatognathic system.
We should do more than just analyze teeth in occlusion.
It is equally important to appreciate respiration, mastication, deglutition, speech and even maintenance of head in constant postural position.
Muscles of mastication
Introduction
Definitions
Development
Classification
Description of individual muscles
Muscles of facial expression
Introduction
Development
Classification
Description of individual muscles
Applied aspects
Muscles of mastication /orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
A teamwork of specialized dentists, general dentists, dental assistants, dental hygienists, and dental technicians is needed in providing good oral health services. A bad workman always blames his tools. It is mandatory that the associated dental personnel have adequate knowledge of the material science. This not only enables them to select and handle the appropriate materials for the given clinical situation, but also ensures optimal properties of the material.
Currently, complete dentures are mainly designed and fabricated using conventional methods, which involve a broad series of clinical and laboratory procedures.
Dentists may want to consider using an update of a unique complete denture technique that saves total chair time and, therefore, decreases cost.
It is possible to fabricate a complete denture with different techniques in minimal visit. These techniques has positive benefits saving a lot of time and materials for both the patient and the clinician.
The patient who requires a single denture opposing a natural or restored dentition challenges the clinician even more than the completely edentulous patient does. This is due to the biomechanical differences in the supporting tissues of the opposing arches. So a proper evaluation, correction of the existing factors and proper sequence of denture construction is necessary to give a more stable prosthesis.
Fixed partial dentures transmit forces through the abutments to the periodontium. Failures are due to poor engineering, the use of improper materials, inadequate tooth preparation, and faulty fabrication. Of particular concern to prosthodontist is the selection of teeth for abutments. They must recognize the forces developed by the oral mechanism, and resistance.
Successful selection of abutments for fixed partial dentures requires sensitive diagnostic ability. Thorough knowledge of anatomy, ceramics, the chemistry and physics of dental materials, metallurgy, Periodontics, phonetics, physiology, radiology and the mechanics of oral function is fundamental.
Fixed prosthodontic treatment can offer exceptional satisfaction for both patient and the dentist. Fixed Prosthodontics can transform an unhealthy, unattractive dentition with poor function into a comfortable, healthy occlusion capable of giving years of further service while greatly enhancing esthetics.
Nothing is more important in the construction of fixed partial dentures than an adequate diagnosis and a well-devised treatment plan. Although these two subjects are usually considered together. Astute dentists must recognize their subtle differences. Diagnosis is an evaluation of the condition of the patient when he presents for treatment. Treatment planning concerns the treatment procedures by which the dentist will restore the patient to an optimum state of dental health.
The human mandible can be related to the maxilla in several positions in the horizontal plane. Among these centric relation is a significant position, because of its usefulness in relating the dentulous and edentulous mandible to maxilla, where the teeth , muscles and temporomandibular joint function in harmony. It is a position of occluso-articular harmony.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
2. CONTENTS:
Introduction
Definitions
Development
Important facts about mastication
Features of Masticatory muscle
Classification
Primary muscles
Accessory muscles
Mandibular movements and role played by muscles
Masticatory muscle disorders
Conclusion
Reference
3. INTRODUCTION:
To propel the skeleton, man has 639 muscles, composed of 6
billion muscle fibers. Each fiber has 1000 fibrils, which means
there are 6000 billion fibrils at work at one time or another.
Food is the main source of energy this energy is derived through
the complicated process of digestion. 1st step of digestion is
mastication.
Teeth, jaws, muscles of the jaws, tongue and the salivary glands
aid in mastication.
Rhythmic opposition and separation of jaws with the involvement
of teeth, lips ,cheeks and tongue for chewing of food in order to
prepare it for swallowing and digestion.
Main purpose of mastication is to reduce the size of food particles
to a size that is convenient for swallowing (bolus formation) with
the help of saliva.
4. Muscles of mastication are the group of muscles that help in
movement of the mandible as during chewing and speech. We need
to study these muscles as they control the opening & closing the
mouth & their role in the equilibrium created within the mouth. They
also play a role in the configuration of face.
Four pairs of the muscles in the mandible make chewing movement
possible.
These muscles along with accessory ones together are termed as
“MUSCLES OF MASTICATION”
Influence of these muscles in prosthetic dentistry, defines the borders
& peripheral extensions.
A good knowledge of masticatory system and functional efficiency is
basic requirement for good prosthodontist.
5. DEFINITIONS:
GPT 8
MUSCLE:
An organ that by contraction produces movements of an animal; a
tissue composed of contractile cells or fibers that effect movement of an organ
or part of the body.
MASTICATION
Is defined as the process of chewing food in preparation for swallowing and
digestion.
6. DEVELOPMENT:
The muscular system develops from intra embryonic mesoderm
from embryonic cells called myoblast.
Muscles of mastication are derived from first brachial arch that is
mandibular arch.
5th- 6th week
Primitive cells form and differentiate
Get oriented to site of origin and insertion
7th week
Mandibular arch mass enlarges
Cell migrate to areas of formation of 4 major muscles
of mastication
Cell differentiation occurs before formation of
facial arch.
10th week
Muscle mass well organized
Nerve masses get incorporated
7. IMPORTANT FACTS ABOUT MASTICATION:
There are about 15 chews in a series from the time of food entry
until swallowing
Average jaw opening during chewing is between 16-20mm
Average lateral displacement on chewing is between 3 and 5mm
Duration of masticatory cycle varies between 0.6 and 1 sec
Men chew faster and have a shorter occlusal phase than women, it
also depends on the type of food
Masticatory forces: The aver maximum sustainable biting force is
756N{170 pounds}.
Molar region: Biting force range 400-890N
Premolar region: Biting force range 222-445N
Canine region: Biting force range 133-334N
Incisor region: Biting force range 89-111N
8. FEATURES OF MASTICATORY MUSCLE:
Have shorter contraction times than most other body muscles
Incorporate more of muscle spindles to monitor their activity
Do not have Golgi tendon organs to monitor tension
Do not get fatigued easily
Psychological stress increases the activity of jaw closing muscles
Occlusal interferences cause a hypertonic synchronous muscle activity
Closing movement also determined by the height of the teeth
13. Greek word “maseter”- a chewer
It is one of the most powerful muscles involved in the power
stroke closure of the mandible
This is a quadrilateral muscle, partly tendinous, partly fleshy
which covers the lateral part of ramus of mandible.
It consists of 3 layers which blend anteriorly.
Multiple arrangement of fibers:
Superficial
Middle
Deep
Deep Superficial
14. ORIGIN:
SUPERFICIAL LAYER (LARGEST)
Maxillary process of zygomatic bone
Anterior 2/3rd of inferior border of zygomatic arch
MIDDLE LAYER:
Medial aspect of anterior 2/3rd of zygomatic arch
Lower border of posterior third of zygomatic arch
DEEP LAYER:
Deep surface of zygomatic arch
15. INSERTION:
SUPERFICIAL LAYER (LARGEST)
Angle of mandible
Lower posterior half of lateral surface of mandibular
ramus
MIDDLE LAYER:
Middle part of the ramus of mandible
DEEP LAYER:
Upper part of mandibular ramus
Coronoid process
16. NERVE SUPPLY:
Supplied by masseteric nerve a branch of anterior division of
mandibular nerve
BLOOD SUPPLY:
Supplied by masseteric artery branch of maxillary artery
Venous drainage through masseteric vein
17. FUNCTION:
Elevates the mandible to close the mouth and to occlude the
teeth in mastication.
Its activity in the resting position is minimal.
It has a small effect in side-to-side movement, protraction
and retraction.
18. PALPATION:
The patient is asked to clench their teeth and, using both hands, the
practitioner palpates the masseter muscles on both sides extra orally,
making sure that the patient continues to clench during the procedure.
Palpate the origin of the masseter bilaterally along the zygomatic arch
and continue to palpate down the body of the mandible where the
masseter is attached.
Anterior Superior Position Posterior Inferior Position
19. CLINICAL IMPORTANCE OF MASSETER:
On Denture Border
An active masseter muscle will create a concavity in the
outline of the distobuccal border and a less active muscle
may result in a convex border.
In this area the buccal flange must converge medially to
avoid displacement due to contraction of the masseter
muscle because the muscle fibers in that area are vertical
and oblique
20. EFFECT OF MASSETER MUSCLE ON THE
DISTOBUCCAL BORDER:
A. Moderate activity will create a straight line
B. An active muscle will create a concavity.
C. An inactive muscle will create a convexity.
22. Extensive fan-shaped muscle that covers the temporal
region. It is powerful masticatory muscle that can easily be
seen & felt during closure of mandible.
Bulk and length of the fibers are larger than that of medial
pterygoid and masseter.
It is the largest masticatory muscle but not considered to be
the most powerful muscle.
23. ORIGIN:
Origin is from inferior temporal line, floor of the temporal
fossa and from the overlying temporal fascia
Divided into 3 areas:
Anterior temporal
Middle temporal
Posterior temporal
Anterior Middle
Posterior
24. INSERTION:
Margins & deep surface of the coronoid
process
Anterior border of ramus of mandible
NERVE SUPPLY:
Deep temporal branches from anterior
division of mandibular nerve
BLOOD SUPPLY:
Superficial temporal artery branch of maxillary artery
superficial temporal vein & middle temporal vein
25. FUNCTION:
Anterior fibers elevate the mandible
Posterior fibers retract the mandible
Crushing of food between the molars
Posterior fibers draw the mandible backwards after it has
been protruded
It is also a contribute side to side grinding movement
26. PALPATION:
The muscle is divided into three functional areas and therefore each
area is independently palpated.
To locate the muscle, have the patient clench.
The anterior region is palpated above the zygomatic arch and anterior
to the TMJ.
The middle region is palpated directly above the TMJ and superior to
the zygomatic arch.
The posterior region is palpated above and behind the ear.
Anterior Middle Posterior
27. CLINICAL IMPORTANCE OF TEMPORALIS MUSCLE:
Sudden contraction of temporalis muscle will result in coronoid
fracture, which is rare.
The patient is instructed to close and move his mandible from side
to side and then immediately asked to open wide.
The side to side motion records the activity of the coronoid process
in a closed position whereas opening causes the coronoid to sweep
past the denture periphery.
29. Also called as external pterygoid muscle.
It is the muscle of mastication that occupy primarily a
horizontal position.
It is a thick, short, conical and triangular muscle with two
heads:
Superior head
Inferior head
Inferior head
Superior headInfratemporal creast
30. ORIGIN:
Superior head: Infratemporal surface &
infratemporal crest of the greater wing of the
sphenoid bone.
Inferior head: Lateral surface of the lateral
pterygoid plate.
INSERTION:
Fibers run backwards and laterally and
converge into the pterygoid fovea on anterior
surface of neck of mandible
Into anterior margin of articular disc and capsule
of TMJ
Superior
Inferior
31. NERVE SUPPLY:
Mandibular nerve via lateral pterygoid nerve from anterior
trunk
BLOOD SUPPLY:
Maxillary artery
Ascending palatine artery
FUNCTION:
Acting together, these muscles protrude the mandible and
depress the chin.
Acting alone & alternately, they produce side –to –side
movements of mandible
32. PALPATION:
Placing the forefinger, or the little finger, over the buccal area
of the maxillary third molar region and exerting pressure in a
posterior, superior, and medial direction behind the maxillary
tuberosity.
33. CLINICAL IMPORTANCE OF LATERAL PTERYGOID
MUSCLE:
Most commonly involved muscle in MPDS
Unilateral failure of lateral pterygoid muscle to contract results in
deviation of the mandible toward the affected side on opening
Bilateral failure results in limited opening, loss of protrusion and loss
of full lateral deviation
In patients with nonworking side interferences, the lateral pterygoid
muscle on the opposite of the interference is sometimes painful
35. It is also called as the internal pterygoid muscle.
It is almost a mirror-like image of the masseter muscle.
It is rhomboidal and runs practically in the same direction on
the inner surface of the mandible
It consist of two heads which differ in origin:
Superficial
Deep
36. ORIGIN:
Superficial head from maxillary tuberosity
Deep head from medial surface of lateral
pterygoid plate and part of palatine bone
INSERTION:
Fibers run backwards, downwards and
Laterally into the roughened area of medial
surface of the angle mandible
Origin
Insertion
37. NERVE SUPPLY:
Branch of the main trunk of mandibular nerve
BLOOD SUPPLY:
Pterygoid branch of 2nd part of maxillary artery
FUNCTION:
It helps to elevate the mandible and closes the jaws .
Acting together, they help to protrude the mandible.
Acting alone, it protrudes the side of the jaw.
Acting alternately, they produce a grinding motion
38. PALPATION:
It can be palpated by placing the finger on the lateral aspect
of the pharyngeal wall of the throat, this palpation is difficult
and sometimes uncomfortable for the patient.
Functional manipulation is done when the muscle becomes
fatigued and symptomatic.
The muscle contracts as the teeth are coming in contact.
Also stretches when the mouth is open wide.
39. CLINICAL IMPORTANCE OF MEDIAL PTERYGOID
MUSCLE:
Most commonly involved in MPDS
Trismus following inferior alveolar nerve block is mostly due to
involvement of medial pterygoid muscle
The medial pterygoid muscle is not usually involved in gnathic
dysfunctions but when they are hypertonic, the patient is usually
conscious of a feeling of fullness in the throat and an occasionally
pain on swallowing
41. DIGASTRIC MUSCLE
Formed by 2 belly like masses of muscle tissue joined by an
intermediate tendon.
ORIGIN:
Anterior belly from diagastric fossa of mandible, lateral to
mental symphysis.
Posterior belly from mastoid notch of temporal bone.
INSERTION:
Both meet at the intermediate tendon and held by the
fibrous pulley to the hyoid bone.
42. NERVE SUPPLY:
Anterior belly by nerve to Mylohyoid
Posterior belly by –facial nerve
FUNCTION:
Depression of jaw, both sides contract simultaneously
Provide antagonism to elevation of mandible
Elevation of hyoid during swallowing
43. MYLOHYOID MUSCLE
Flat, triangular muscle lying deep to the anterior
belly of digastric
It forms the floor of the mouth.
Flat triangular
ORIGIN:
Mylohyoid line of mandible.
INSERTION:
Middle and anterior fibers into median raphae.
Posterior fibers body of hyoid bone.
44. NERVE SUPPLY:
Nerve to Mylohyoid
FUNCTION:
Helps in depression of mandible, elevation of hyoid bone
It elevates the floor of mouth to help in deglutition.
45. CLINICAL IMPORTANCE OF MYLOHYOID
MUSCLE:
ON DENTURE BORDERS:
Mylohyoid area
Instruct the patient to place the tip of his tongue into the
upper and lower vestibules on the right and left side.
The area to be molded is reheated and the patient and is
instructed to swallow two or three times in rapid succession.
The tongue movements raise the level of the floor of the
mouth through contraction of the mylohyoid muscle.
46. GENIOHYOID MUSCLE
Short and narrow muscle lies above Mylohyoid
ORIGIN:
Inferior mental spine (genial tubercle)
INSERTION:
Fibers run backwards, downwards to be inserted into the
anterior surface of the body of hyoid bone.
47. NERVE SUPPLY:
1st Cranial nerve, the fibers pass through hypoglossal
nerve.
FUNCTION:
Carry hyoid bone and the tongue upward
during deglutition.
48. CLINICAL IMPORTANCE OF GENIOHYOID
MUSCLE:
For mandibular impressions:
On recording labial flange and labial frenum
The lip is massaged from side to side to mold the compound to
desired functional extension.
In order to activate the mentalis muscle the patient is asked to
pout or lick his lower lip.
For maxillary impressions in labial flange and labial frenum area:
Manually mold the compound by externally moving the lip side
to side, simultaneously applying finger pressure to control the
width of the border
Lift the patients upper lip and vertically place the frenum into the
softened compound and mold with your fingers using a side to
side external motion
49. STYLOHYOID MUSCLE
Small muscle that lies along the upper border of
the posterior belly of digastric muscle.
ORIGIN:
From the lateral & inferior surface of the styloid
process of temporal bone.
INSERTION:
Is inserted into the body of the hyoid bone, at its
junction with the greater cornu.
NERVE SUPPLY:
Branch from facial nerve
FUNCTION:
Pulls hyoid bone upwards and backwards
50. BUCCINATOR MUSCLE
It is an accessory muscle of mastication, occupying the gap
between mandible and maxilla forming important part of the
cheek.
Also known as muscle of cheek.
ORIGIN:
Upper fibers: From maxilla opposite molar teeth
Middle fibers: From pterygomandibular raphe
Lower fibers: From mandible opposite molar
INSERTION:
Upper fibers: Straight to the upper lip
Middle fibers: Decussate before passing to the lips
Lower fibers: Straight to the lower lip
51. NERVE SUPPLY:
Buccal branch of facial nerve
FUNCTION:
Flatten cheek against gums and teeth, prevent
accumulation of food in the vestibule of mouth and to bring
the food on to the occlusal table during mastication.
52. CLINICAL IMPORTANCE OF BUCCINATOR
MUSCLE:
ON DENTURE BORDER
For buccal flange area in mandibular impressions:
The area is moulded by massaging the cheek in an anterior-
posterior direction using moderate manual pressure against the
compound.
This moves the fibers of the buccinators muscle and the tissues
of the cheek in the direction of functional action of the
buccinators muscle.
In maxillary impressions:
The cheek is manually molded in anterior-posterior direction
using slight finger pressure against the compound or the patient
is instructed to control the amount of movement by sucking
action.
53. MANDIBULAR MOVEMENTS AND ROLE
PLAYED BY MUSCLES:
1. ELEVATION:
Prime Movers: (a) Masseter
(b) Medial Pterygoid
(c) Temporalis
Antagonist: (a) Superior Lateral Pterygoid
2. DEPRESSION:
Prime movers: (a) Inferior lateral pterygoid
(b) Digastric
Antagonist: (a) Elevator group muscles
54. 3. PROTRUSION:
Prime Movers: (a) Inferior Lateral Pterygoid
(b) Masseter
(c) Medial Pterygoid
Antagonist: (a) Digastric
(b) Posterior Temporal
4. RETRUSION:
Prime movers: (a) Posterior & Middle Temporal
(b) Digastric
Antagonist: (a) Inferior Lateral Pterygoid
5. LATERAL:
Prime movers: (a) Working side of temporal muscle
Antagonist: (a) Non working side of Pterygoid muscle
55.
56. MASTICATORY MUSCLE DISORDERS:
SOME OF THE COMMON MASTICATORY MUSCLE
DISORDERS INVOLVE:
Trismus
Bruxism
Tetanus
Congenital hyperplasia/ hypoplasia
Hypermobility/ hypo mobility of the muscle
Muscle pains
MPDS
Myositis ossificans etc.
Temporal tendonitis
57. TRISMUS
Due to prolonged tetanic spasm of the jaw muscles by which
normal opening of the mouth is restricted.
Restricted jaw movements regardless of the etiology.
CAUSES:
Intracapsular: Arthritis
Condylar fracture
Pericapsular: Irradiation
Dislocation
Infection & inflammation
Muscular: TMJ dysfunction syndrome
Tetanus
Other: Oral sub mucous fibrosis
Systemic sclerosis
Fractures
59. BRUXISM
Bruxism is the clenching or grinding of the teeth when
the individual is not chewing or swallowing
It can occur as a brief rhythmic strong contractions of the
jaw muscles during eccentric lateral jaw movements, or
in maximum intercuspation, which is called clenching.
CAUSES: Associated with stressful events
Non stress related or hereditary
Bruxism may lead to: Tooth wear
Fracture of the teeth or restoration
Muscle hypertrophy
60. Increased muscle tension is directly related to stress activity
during the day.
TREATMENT:
Coronoplasty
Maxillary stabilization appliance
61. TETANUS (LOCK JAW)
Tetanus is a disease of the nervous system characterized by
intense activity of motor neuron and resulting in severe muscle
spasm
Caused by exotoxins of gram positive bacillus, clostridium
tetani.
CLINICAL FEATURES:
Pain and stiffness in the jaws and neck muscles ,with muscle
rigidity producing trismus and dysphagia
Rigidity of facial muscles
Sometimes whole body becomes affected.
TREATMENT:
All patients should receive antimicrobial drugs
Active and passive immunization.
Surgical wound care
Anticonvulsant if indicated
62. MYOFACIAL PAIN DYSFUNCTION SYNDROME
(MPDS)
Muscular disorders (myofacial pain disorders) are the most
common cause of TMJ pain associated with masticatory muscles.
Common etiologies include:
1. Many patient with “high stress level”
2. Poor habits including gum chewing, bruxism, hard candy
chewing
3. Poor dentition
TREATMENT:
Its treatment includes 4 phases of therapy which includes muscle
exercises and drugs involving NSAIDs and muscle relaxants.
A bite appliance is also worn by the patient in the furthur stages
to ‘splint’ the muscle movement.
63. CONGENITAL HYPOPLASIA/ HYPERPLASIA
It occurs very rarely, and is more common in masseter and
orbicularis oris.
Its oral symptoms include enlargement or decreased size of
the affected muscle, which may show an asymmetric facial
pattern and stiffness in the temporo-mandibular joint.
It may or may not be associated with hypermobility/ hypo
mobility of the muscles.
64. MUSCLE HYPERMOBILITY/ HYPOMOBILITY
This disorder involves extreme or diminished activity of the
masticatory muscles.
Its etiology includes various factors such as:
Decreased/ increased threshold potential of neural activity.
Parkinsonism
Facial paralysis
Nerve decompression
Secondary involvement of systemic diseases.
65. CONCLUSION:
The masticatory muscles include a vital part of the
orofacial structure and are important both functionally and
structurally
It can be influenced by a variety of factors many of which
are controlled by the practicing prosthodontist
During functional impression making
Accurate recording of various clinical parameters like
vertical dimension, centric relation
Morphology of artificial tooth
Maintenance of arch form
The proper management and periodical self -examination
of the muscles may provide a greater chance of catching
the disease process at an early stage which may be
useful for its better prognosis.
66. REFERENCES:
Human anatomy by B.D. Chaurasia, 3rd ed.
Human anatomy by dental students by M.K. Anand,
1st ed.
Burkits oral medicine diagnosis & treatment 10th
edition
Textbook of complete dentures by Charles M heartwell
Complete denture prosthodontics by John J Sharry.