presentation muscles of mastication
TRANSCRIPT
![Page 1: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/1.jpg)
MUSCLES OF MASTICATION
![Page 2: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/2.jpg)
Muscles of masticationMastication is a harmonious and skillful activity which requires the presence and co ordination of not only the muscles of mastication but also the supra infrahyoid muscles, and the facial muscles
![Page 3: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/3.jpg)
MUSCLES OF MASTICATION
• INTRODUCTION• GROWTH AND DEVELOPMENT• ANATOMIC DESCRIPTION• INNERVATION AND VASCULAR SUPPLY• PHYSIOLOGY OF MUSCLE ACTION• APPLIED ASPECTS
![Page 4: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/4.jpg)
MUSCLES OF MASTICATION
• INTRODUCTION
A muscle is defined as an organ that by contraction produces movements of an animal; A tissue composed of contractile cells or fibers that effect movements of an organ or part of the body
Originates from skull &attaches to mandible
functions as A group
mastication, deglutition, speech & respiration
![Page 5: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/5.jpg)
•
GROWTH AND DEVELOPMENTEMBRYOLOGY
• First Pharngeal Arch
![Page 6: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/6.jpg)
Deep portion
Superficial portion
ANATOMIC DESCRIPTION OF MUSCLES OF MASTICATIONANATOMIC DESCRIPTION OF MUSCLES OF MASTICATION
MASSETERMASSETER
ORIGINORIGIN
INSERTIONINSERTION
VASCULAR SUPPLYVASCULAR SUPPLY
INNERVATIONINNERVATION
ACTIONSACTIONS
![Page 7: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/7.jpg)
Powerful elevator muscle
Superficial muscle helps in protruding the mandible
Deep portion helps in stabilizing the condyle against the articular eminence when biting in a protruded position.
Unilateral movement helps in lateral movement of the mandible
ACTIONS OF MASSETERACTIONS OF MASSETER
![Page 8: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/8.jpg)
TEMPORALIS
ORIGINORIGIN
FIBRES ORIENTATION FIBRES ORIENTATION
INSERTIONINSERTION
VASCULAR SUPPLYVASCULAR SUPPLY
INNERVATIONINNERVATION
ACTIONACTION
![Page 9: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/9.jpg)
The strongest of the masticatory musclesDivided into three partsWell developed in carnivores and animals requiring a strong bite forceIt elevates the mandible when it contracts.Contraction of the anterior part raises the mandibleContraction of the middle part elevates and retrudes the mandible
ACTIONS OF TEMPORALISACTIONS OF TEMPORALIS
![Page 10: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/10.jpg)
LATERAL PTERYGOIDLATERAL PTERYGOID
ORIGINORIGIN
FIBRES ORIENTATION FIBRES ORIENTATION
INSERTIONINSERTION
VASCULAR SUPPLYVASCULAR SUPPLY
INNERVATIONINNERVATION
ACTIONSACTIONS
![Page 11: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/11.jpg)
LATERAL PTERYGOID Arises: 2 heads
Upper: Infratemporal surface &crest of greater wing of sphenoid
Lower: Lat surface of the lat pterygoid plate
Inserts: Upper : Anterior & medial surface of
articular disc & Lower : pterygoid fovea below the head of
mandible
Lower head
Upper head
![Page 12: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/12.jpg)
Originates at the outer surface of the lateral pterygoid plate and extends backward upward and outward to insert into the neck of the condyle.When there is bilateral contraction the condyles are pulled down the articular eminences and the mandible is protruded.
Unilateral contraction causes a mediotrusive movement of that condyle and lateral movement of the mandible to the other side
. The inferior lateral pterygoid is active during opening in contrast to the superior part.
INFERIOR
HEAD
![Page 13: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/13.jpg)
MEDIAL PTERYGOIDMEDIAL PTERYGOID
ORIGINORIGIN
FIBRES ORIENTATION FIBRES ORIENTATION
INSERTIONINSERTION
VASCULAR SUPPLYVASCULAR SUPPLY
INNERVATIONINNERVATION
ACTIONSACTIONS
![Page 14: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/14.jpg)
MEDIAL PTERYGOIDArises :2 heads
Superficial:Tuberosity of Maxilla & Pyramidal process of palatine bone
Deep: Medial surface of lateral pterygoid plate
Inserts: Medial surface of ramus and angle of the mandible
Deep head
Superficial head
![Page 15: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/15.jpg)
The medial pterygoid muscle
Originates from the pterygoid fossa and extends downwards backwards and outwards to insert in the medial side of the ramus of the mandible forming a sling along with the masseter at the angle of the mandible.
It assists in closing of the jaw and contraction of the muscle also causes protrusion. Unilateral contraction-mediotrusive movement
![Page 16: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/16.jpg)
VASCULAR SUPPLY
TEMPORALISTEMPORALIS
MASSETERMASSETER
LATERAL PTERYGOIDLATERAL PTERYGOID
MEDIAL PTERYGOIDMEDIAL PTERYGOID
![Page 17: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/17.jpg)
ACCESSORY MUSCLES OF MASTICATION
• Suprahyoid Muscles
Digastric Stylohyoid Mylohyoid Geniohyoid
![Page 18: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/18.jpg)
• Digastric
Two bellies
Origin
Insertion
Innervation
Suprahyoid Muscles
![Page 19: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/19.jpg)
Suprahyoid Muscles
• DigastricVascular Supply
Posterior Belly - Posterior Auricular and occipital Arteries
Anterior Belly – Submental branch of Facial Artery
![Page 20: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/20.jpg)
• Stylohyoid
Origin
Insertion
Vascular Supply – branches of Facial, Posterior Auricular and occipital arteries
Innervation – Stylohyoid branch of Facial Nerve
Action – elevates the hyoid bone and draws it backwards, elongating the floor of mouth
![Page 21: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/21.jpg)
• Mylohyoid Floor of the mouth
Origin
Insertion
Vascular Supply – sub lingual branch of Lingual artery
Maxillary Artery
Submental branch of Facial artery
Innervation – Mylohyoid branch of inferior alveolar nerve
![Page 22: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/22.jpg)
• GeniohyoidOrigin
Insertion
Vascular Supply – lingual artery ( sublingual branch)
Innervation – First cervical spinal nerve through the hypoglossal nerve.
![Page 23: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/23.jpg)
INFRAHYOID MUSCLES
• Sternohyoid Origin – posterior surface of medial part of clavicle
upper posterior aspect of the manubrium sterni
Insertion – inferior border of body of hyoid bone
Vascular Supply – superior thyroid artery
Innervation – Ansa cervicalis
Action – depresses hyoid bone
![Page 24: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/24.jpg)
• Omohyoid Two bellies
Origin Inferior belly– upper border of scapula near the scapular notch and superior transverse scapular ligamentsInsertion – intermediate tendonSuperior belly – intermediate tendonInsertion – lower part of body of hyoidVascular Supply – superior thyroid and lingual arteriesInnervation – Ansa cervicalis
![Page 25: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/25.jpg)
• Sternothyroid Origin – posterior surface of manubrium sterni
posterior edge of cartilage of first rib
Insertion – oblique line on the lamina of thyroid cartilage
Vascular Supply – superior thyroid and lingual arteries
Innervations – Ansa cervicalis
![Page 26: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/26.jpg)
• ThyrohyoidOrigin - oblique line on the lamina of thyroid cartilage
Insertion – lower border of greater cornua and body of hyoid bone
Vascular Supply - superior thyroid and lingual arteries
Innervations – First spinal cervical nerve (hypoglossal nerve)
Action – depresses hyoid bone
![Page 27: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/27.jpg)
PHYSIOLOGY OF MUSCLES OF MASTICATIONPHYSIOLOGY OF MUSCLES OF MASTICATION
![Page 28: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/28.jpg)
General Mechanism of Muscle ContractionGeneral Mechanism of Muscle Contraction
![Page 29: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/29.jpg)
MANDIBULAR MOVEMENTS AND MUSCLE ACTIVITY
COMPLEX NEUROMUSCULAR ACTIVITY
ELECTROMYOGRAPHY OF :-
• MANDIBULAR OPENING• -Lat,med
Pterygoid,digastric,mylohyoid & Geniohyoid
-No Activity In Temporalis & Masseter Muscle
![Page 30: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/30.jpg)
• MANDIBULAR CLOSING - With Out Resistance; masseter & Med Pterygoid
- With Resistance Temporalis, masseter, Med Pterygoid
![Page 31: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/31.jpg)
MANDIBULAR MOVEMENTS AND MUSCLE ACTIVITY
• RETRUSION
-Post Fibers Of Temporalis,Deep fibres of Masseter
![Page 32: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/32.jpg)
• PROTRUSION
-Without Occl Contact Lat &Med Pterygoid And Masseter
-With Occl Contact Pterygoids,masseter
![Page 33: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/33.jpg)
MANDIBULAR MOVEMENTS AND MUSCLE ACTIVITY
LATERAL MOVEMENTS
• Ipsilateral Contraction Of The Posterior & Middle Fibers Of Temporalis Ms,Masseter Ms
• Contralateral Contraction Of Lat & Med Pterygoid Ms & Ant Fibers Of TheTemporalis
![Page 34: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/34.jpg)
![Page 35: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/35.jpg)
MUSCLE HYPERTROPHY
• Results from increase no of actin & Myosin filaments• Significant hypertrophy in 6-10 weeks
Causes:• Developmental defects• Functional disturbances• Inflammations & Infections• Metabolic changes• Neoplasm• Over loading the muscle
![Page 36: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/36.jpg)
MUSCLE HYPERTROPHY
• Massetric Hypertrophy
Congenital facial hemi hypertrophy
Functional hypertrophy
![Page 37: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/37.jpg)
TRISMUS
A Motor Disturbance Of The Trigeminal Nerve, Especially Spasm Of The Muscles Of Mastication With Difficulty In Opening The Mouth
Causes :• Trauma To Muscle / Blood Vessels• Hemorrhages• Infections• Excessive Volume Of LA .• Contaminated LA• Trauma• Profound Muscle Spasm, Tenderness & Trismus
![Page 38: Presentation Muscles of Mastication](https://reader033.vdocuments.net/reader033/viewer/2022050620/5476992cb4af9f0a5a8b45cd/html5/thumbnails/38.jpg)