JuniorDentist.com

Oral Care Tips by a Dentist

You are here: Home / I year / Dental anatomy / Muscles of mastication – Origin, Insertion, Function, Nerve and Blood supply

Muscles of mastication – Origin, Insertion, Function, Nerve and Blood supply

August 21, 2008 by Dr. Varun Pandula 67 Comments

The muscles which are required for mastication or chewing are known as the muscles of mastication. These muscles help mainly in the movement of the mandible and not the maxilla as maxilla is an integral part of the skull and the mandible being the only movable bone in the skull.

There are many muscles which help in the process of mastication but the main muscles which take part in the process are

Primary Muscles Of Mastication:

  • Masseter muscle
  • Temporalis
  • Lateral Pterygoid
  • Medial Pterygoid

Accessory Muscles Of Mastication:

Suprahyoid Muscles  

  •  Digastric
  •  Stylohyoid
  •  Mylohyoid
  •  Geniohyoid

Infrahyoid muscles

  • Sternohyoid
  • Thyrohyoid
  • Omohyoid
Muscles of mastication lateral view

Courtesy Netter’s Atlas

Now let us discuss in detail about each of these muscles:

Masseter Muscle:

It is one of the main muscle which helps in the process of mastication

In humans, the masseter is the second most efficient masticatory muscle. Its origin and insertion make it very useful for the movement of the jaw and for applying good bite force for mastication.

Masseter muscle is a powerful muscle because of its Multipennate arrangement of fibers

The masseter muscle extends from the zygomatic arch to the ramus and body of the mandible. The fibers of this muscle are broad, extending from the region of the second molar on the surface of the mandible to the surface of the ramus.The muscle is divided into 2 parts

  • Superficial
  • Deep

Origin of masseter muscle:

  • Superficial layer – anterior 2/3rd of lower border of zygomatic arch & zygomatic processof maxilla
  • Middle layer – anterior 2/3rd of deep surface & posterior 1/3rd of lower border of zygomatic arch
  • Deep layer – deep surface of zygomatic arch

Insertion of masseter muscle:

  •  Superficial layer –lower part of lateral surface of ramus of mandible
  •  Middle layer –middle part of ramus
  •  Deep layer – upper part of the ramus & coronoid process

The main function of masseter muscle is

  • Elevation of the mandible
  • lateral movements of the mandible for efficient chewing and grinding of the food
  • unilateral chewing
  • Retraction of the mandible

Blood supply of masseter muscle:

  • Masseteric artery .

Nerve supply of masseter muscle:

  • Massetric nerve.

Clinical Importance of Masseter Muscle of Mastication:

  • Masseter muscle can be palpated both intraorally and extraorally
  • Most common muscle involved in Myositis Ossificans
  • Masseter Muscle shows Dual action in Complete Denture
  • The muscle that commonly undergoes Hypertrophy in Bruxism is Masseter
  • Because of the Multipennate arrangement of fibers masseter is a very powerful muscle

Masseter Muscle Function – Elevation of Mandible

Temporalis Muscle:

This is the muscle which helps in elevation of the mandible, It is one of the muscles of mastication. It is large shaped in appearance and covers the Temporal area of the skull.

Origin and Insertion of Temporalis Muscle:

  • From the Parietal bone of the skull and is inserted on the coronoid process of the mandible.

Arterial supply of Temporalis Muscle:

  • The Deep Temporal artery supplies the large muscle.

Nerve Supply of Temporalis Muscle:

  • Trigeminal nerve( this nerve has been associated with being the cause of Headache and migrane.

Functions of Temporalis Muscle:

  • Elevation of the mandible
  • Retraction of the mandible.
  • Crushing of food between the molars.
  • Posterior fibers draw the mandible backwards after it has been protruded.
  • It is also a contributor to side to side grinding movement.

Clinical Importance of Temporalis Muscle:

  • Sudden contraction of temporalis muscle will result in coronoid fracture, which is rare.

Temporalis muscle

 

Lateral Pterygoid Muscle:

This is a small muscle which also helps in the mastication process. It is divided into 2 heads

Origin of Lateral Pterygoid Muscle:

  • Upper head – infratemporal surface & crest of greater wing of sphenoid bone
  • Lower head – lateral pterygoid plate

Insertion of Lateral Pterygoid Muscle:

  • Pterygoid fovea on the anterior surface of neck of mandible
  • Anterior margin of articular disc & capsule of TMJ

Nerve Supply of Lateral Pterygoid Muscle:

  • Pterygoid branch of Trigeminal nerve.

Arterial supply of Lateral Pterygoid Muscle:

  • Pterygoid branch of Maxillary artery.

Functions of Lateral Pterygoid Muscle:

  • Depresses the mandible
  • Protrudes it forward for opening of the jaw
  • Side Movements

Clinical Importance of Lateral Pterygoid Muscle:

  • Most commonly involved muscle in MPDS
  • Only muscle of mastication which has its attachment to the TMJ
  • Lateral Pterygoid forms the roof of the Pterygomandibular space.

 

The combined efforts of the Digastric and Lateral Pterygoid provide for natural jaw opening.

 

Medial Pterygoid muscle:

It is a thick muscle of mastication.

Origin and Insertion of Medial Pterygoid Muscle:

  • It Arises from the deep head the lateral pterygoid plate, and from the maxillary tuberosity.
  • Insertion is seen on the Medial angle of the Mandible.

Arterial supplyof Medial Pterygoid Muscle:

  • Pterygoid branch of Maxillary artery.

Nerve Supply of Medial Pterygoid Muscle:

  • Mandibular nerve through the medial pterygoid.

Functions of Medial Pterygoid Muscle:

  • Elevates the mandible,
  • Closes the jaw,
  • Helps in side to side movement.

Lateral Pterygoid and medial pterygoid muscle.

Clinical Importance of Medial Pterygoid Muscle:

  • Medial Pterygoid muscle can be palpated only intraorally
  • Most commonly involved in MPDS
  • Trismus following inferior alveolar nerve block is mostly due to involvement of medial pterygoid muscle

Unique features of Masticatory Muscles:

  • 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
  • Elevators predominantly white fibrous which perform fast twitching
  • 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

 

Comments

  1. varun says

    August 31, 2014 at 3:53 pm

    I am really glad that it was helpful to everyone, do let me know if you want any other topics to be explained in a similar way …

  2. Elizabeth Palmer says

    September 26, 2014 at 9:42 pm

    What is MPDS? Also, is there anything else unique about the pterygoid muscles?

    THanks! PLease also try to email your response, not sure if I can find this site again!

  3. Elizabeth Palmer says

    September 26, 2014 at 9:42 pm

    What is MPDS? Also, is there anything else unique about the pterygoid muscles?

    THanks! PLease also try to email your response, not sure if I can find this site again!

  4. Sana Khan says

    February 3, 2015 at 5:54 am

    Thanks a ton!!
    My lecturer was very impressed seeing my answer in the exam.

  5. Bhavna says

    February 19, 2016 at 10:13 am

    Thanks it’s really helpful
    Very clear & precised description

  6. Very gud especially diagrams along helps a lot says

    March 31, 2016 at 10:54 pm

    Plzz send me a link so that I can constantly look here for my problematic topics

    Nicely explained

    Once again thank u so much

  7. debasmita ray says

    November 26, 2016 at 7:34 pm

    Clinical importance part is so helpfull

  8. Anna says

    April 12, 2017 at 5:37 pm

    What sensor nerve innervites the masticator muscules?

  9. mydentalcareguide.com says

    May 8, 2017 at 1:17 pm

    Each of these primary muscles of mastication is paired, with each side of the mandible possessing one of the four.

  10. Hamna says

    May 25, 2017 at 5:30 am

    What is MPSD
    Please

  11. Varun says

    May 28, 2017 at 5:10 am

    It is expanded to Myofunctional Pain Dysfunction Syndrome. As the name suggests it is a pain disorder, where certain points on the muscles of the head and neck when triggered lead to excruciating pain. It is mainly Unilateral (on one side of the face only).

  12. Ashely says

    August 10, 2017 at 8:59 am

    THANK YOU SOOOOOOOOOOOO MUCH
    THIS POST WAS OF GREAT HELP…..

  13. Ritu Maiti says

    November 15, 2017 at 2:10 am

    Very nicely explained.

  14. Aditya says

    November 23, 2017 at 8:21 am

    could u explain why masseter muscle is more sensitive than temporal muscle, when u palpate the muscle especially after long duration mastication activity..? thx

  15. Varun says

    November 27, 2017 at 5:55 am

    Hi Aditya,

    The answer lies in the function of both the muscles, Masseter muscle as the name suggests plays a major role in Chewing food with your Molars of posterior teeth which requires more force and tension. The Temporalis muscle on the other hand, being larger in size and also having more surface area of attachment is only used to elevate or lift the mandible and does not put any force for chewing.

    So after a long duration of mastication, the masseter muscle which is smaller and applies more force on the mandible helping to chew any hard substances is more fatigued as compared to Temporalis muscle which only lifts the mandible.

  16. Kivera Wanjiku says

    March 14, 2018 at 12:52 pm

    Your notes are incredible ?

  17. Harsh Gandhi says

    April 19, 2018 at 8:37 am

    Which dual function is performed by massetar in CD

« Older Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts

  • Gum infection can lead to Hearth Arrhythmia – Research by Hiroshima University
  • Classification of Fluorosis Stains on Teeth
  • Indian Orthodontic Society complain against at-home Aligner providers to DCI
  • Triple Antibiotic Paste Composition and use in Root Canal Treatment
  • Frequently asked Questions regarding Dental Braces and Water Sports

Search Juniordentist.com

Popular P Topics

  • Dry Socket Pictures | Pictures of Alveolar Osteitis
  • How many days does it take for Antibiotics to get rid of tooth infection or abscess
  • Protocol for Management and handling of Dental Hospital Waste - Color coding for waste disposal
  • Sequence of Extraction for Complete Maxillary and Mandibular teeth extraction
  • List of Papillae of Tongue – Location and Histology
  • Kennedy’s Classification of Edentulous Space and Applegate’s Rules
  • Differences between male skull and female skull
  • Types of Bevels and their Uses in Tooth or Cavity Preperation
  • Faulty Radiographs due to Faulty Processing Techniques
  • Arrested Caries - Causes, Color, Stages of Development and Treatment

Categories

Disclaimer

Juniordentist.com is intended for educational, informative and entertainment purposes only. It is not intended to replace your Dental Visit. Only a proper dental Checkup by a professional in person can help diagnose the problem you are suffering from and help give you the required treatment. You should always understand that a Patient to Doctor interaction is the only way to properly diagnose the problem and decide its cure.

Varun Pandula

Varun Pandula

A Dentist by profession but a tech enthusiast by heart, trying to learn and enjoy both the professions.

View Full Profile →

About Me

Hi I'm Varun, I'm currently a Dental Surgeon from India practicing from the past few years. I Started this Blog to help dental students as you can see from the name and also constantly try to keep updating information which can be useful for patients and Dental Practitioners as well. You can contact me here to for any Questions. Read More…

Recent Posts

  • Gum infection can lead to Hearth Arrhythmia – Research by Hiroshima University
  • Classification of Fluorosis Stains on Teeth
  • Indian Orthodontic Society complain against at-home Aligner providers to DCI
  • Triple Antibiotic Paste Composition and use in Root Canal Treatment
  • Frequently asked Questions regarding Dental Braces and Water Sports

Recent Comments

  • Dr. Varun Pandula on Contraindications of Root Canal Treatment
  • Nola on Contraindications of Root Canal Treatment
  • Dr. Varun Pandula on Arrested Caries – Causes, Color, Stages of Development and Treatment
  • Dr. Varun Pandula on Sequence of Extraction for Complete Maxillary and Mandibular teeth extraction
  • Dr. Varun Pandula on Enlargement of Lymph Nodes and their related Dental Conditions