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7/27/2019 Muscles of Facial Expression Condensed Grayscale Slides
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Muscles of Facial
Expression
Muscles of Facial
Expression
Alex ForrestAssoci ate Profess or of For ensic Od ontol ogyForensic Science Research & Innovation Centre, Griffith UniversityConsultant Forensic Odontologist,Queensland Health Forensic and Scientific Services,
39 Kessels Rd, Coopers Plains, Queensland, Australia 4108
Oral Biology
COMMONWEALTH OF AUSTRALIA
Copyright Regulations 1968
WARNING
This material has been reproduced and communicated to you by, or on
behalf of, Griffith University, pursuant to Part VB of The Copyright Act 1968(The Act; a copy of the Act is available at SCALEPlus, the legal
information retrieval system owned by the Australian Attorney Generals
Department, at http://scaleplus.law.gov.au).
The material in this communication may be subject to copyright under the
Act. Any further reproduction or communication of this material by you maybe the subject of Copyright Protection under the Act.
Information or excerpts from this material may be used for the purposes of
private study, research, criticism or review as permitted under the Act, and
may only be reproduced as permitted under the Act.
Do not remove this notice
Learning ObjectivesLearning Objectives
You should be able to explain the embryological origin of
the muscles of facial expression, and to explain theresulting common motor nerve and blood supply
You should be able to explain how the muscles of facial
expression are classified.
Learning ObjectivesLearning Objectives
You should be able to demonstrate knowledge of the
principal functions of the major groups of muscles offacial expression in normal function.
You should be able to relate your understanding of
muscle functions to origins and insertions.
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Facial StructureFacial Structure
The basic form of the face is determined largely by the
underlying bony structures. These are covered by the soft
tissues which comprise muscles, subcutaneous fat and
other components.
In some areas of the face, there is very little subcutaneous
soft tissue. These areas include the upper part of the nose,the margins around the orbits, the forehead, and the area
over the zygomatic arches, and around the lower border of
the mandible.
The bone can be palpated through the skin in these
areas, and as a result the skin tends to be relatively
immobile in these regions.
Try this out on your own face (or that of a friend)now
Facial StructureFacial Structure
Facial StructureFacial Structure
Other regions in the face are separated from the
underlying bone by larger amounts of subcutaneous
tissue.
As a consequence, these areas tend to be more mobile
when acted on by muscles, and are largely responsible for
the facial expressions.
These soft tissues are moved by a group of muscles
which is therefore called the subcutaneous muscles of
facial expression.
ClassificationClassification
This muscle group shares a common nerve supply; all
motor supply to them comes from the facial nerve (VII).
You will recall that the facial nerve arises from the hyoid
arch or second branchial arch, and that the muscles of
facial expression, including the platysma, are derived from
this arch as well.
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ClassificationClassification
You should note that not all the muscles supplied by VII are
classified as muscles of facial expression.
Specifically, the stylohyoid muscle and the posterior belly of
the digastric muscle are not included in this group,although they are derived from the muscle element of the
2nd arch.
ClassificationClassification
Other muscles also play a part in determining facial
expression, including the hypoglossal nerve (XII) (sticking
the tongue out) and the oculomotor nerve (III) (rolling the
eyes) but they are not classified in this group either.
ClassificationClassification
Most muscles of facial expression have a bony origin and
insert into the soft tissue of the face.
Some have variations on this theme. The buccinator
originates from the pterygomandibular raphe, for
instance, and the orbicularis oris has no bony attachment
at all.
ClassificationClassification
The muscles of facial expression can be classified into groups:
Muscles of the lips and cheeks
Muscles of the nose
Muscles of the eyelid
Muscles of the auricle of the ear
Muscles of the scalp
Platysma muscle
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Muscles of the
Lips and Cheeks
Muscles of the
Lips and Cheeks
Lips and CheeksLips and Cheeks
The muscles of the lips and cheeks are divided into two layers:
Superficial muscles
Deep mu scles
Lips and CheeksLips and Cheeks
Superficial Layer:
Levator labii superioris alaquae nasi
Levator labii superioris
Levator anguli oris
Zygomaticus major & minor
Risorius
Depressor labii inferioris
Depressor anguli oris
Mentalis
Lips and CheeksLips and Cheeks
Deep Layer:
Buccinator
Orbicularis oris
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Lips and CheeksLips and Cheeks
Levator labii superioris alaquae nasi
Levator labii superioris
Levator anguli oris
Zygomaticus major & minor
Risorius
Depressor labii inferioris
Depressor anguli oris
Mentalis
Superficial Layer:
Grays Anatomy, Longman, London, 35 th Edition, 1973. p 496.Van De Graff, K. Human Anatomy, Iowa, Wm. C. Brown, 2nd Ed., 1988. p. 246
Levator labii superioris alaquae nasi
Levator labii superioris
Levator anguli oris
Zygomaticus major & minor
Risorius
Depressor labii inferioris
Depressor anguli oris
Mentalis
Superficial Layer:
Lips and CheeksLips and Cheeks
Lips and CheeksLips and Cheeks
The muscles of the
superficial layer
converge on lips and
enter them in a radialdistribution.
They originate on the
maxilla and mandible,
on the zygomatic
bones, and from the
masseteric fascia.
Grays Anatomy, Longman, London, 35th Edition, 1973. p 304. Mandible, External Surface
Grays
Anatomy,
Longman,
London, 35th
Edition, 1973.
p. 281.
Lips and CheeksLips and Cheeks
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Zygomatic Bone, Lateral Aspect
Grays
Anatomy,
Longman,
London, 35th
Edition, 1973.
p. 309.
Lips and CheeksLips and Cheeks
Many of these
superficial muscles
converge to insert on a
vertical
musculotendinous
raphe close to the
corner of the mouth.
This is known as themodiolus, and is visible
through the skin as a
surface feature on the
face.
Lockhart RD, Living Anatomy. London, Faber & Faber 7th Ed. 1974, p. 16
Lips and CheeksLips and Cheeks
Orbicularis OrisOrbicularis Oris
The fibres oforbicularis oris
form a kind of
sphincter around
and within the
lips.
Grays Anatomy, Longman, London, 35th Edition, 1973. p 496.
Orbicularis OrisOrbicularis Oris
A small number of fibres attach to the maxilla and mandible in
the area associated with the sockets of the incisors (frenula).
Some fibres insert into the modiolus, while others insert on the
deep surfaces of the skin and mucous membrane of the mouth.
University of Queensland School of Dentistry 2001
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Orbicularis OrisOrbicularis Oris
Contraction of its fibres
draws the lips together,
and tight contraction
causes pursing of the lips
as in pouting or whistling.
The lips are parted by
relaxation of the orbicularis
oris with simultaneouscontraction of the maxillary
and mandibular radiating
muscles.
Van De Graff, K. Human Anatomy, Iowa, Wm. C. Brown, 2nd Ed., 1988. p. 247
BuccinatorBuccinator
The buccinator
muscle lies deep
within the cheeks and
is closely related to
the buccal mucous
membrane.
Grays Anatomy, Longman, London, 35th Edition, 1973. p 496.
BuccinatorBuccinator
Posteriorly it attaches
to the
pterygomandibular
raphe.
Superiorly it attaches
to the alveolar process
of the maxilla, and
below to that of the
mandible.
Modified from: Grays Anatomy, Longman, London,
35th Edition, 1973. p 499.
BuccinatorBuccinator
Anteriorly its deeper fibres insert into the modiolus, andthe superficial ones insert into orbicularis oris.
Many of its fibres decussate prior to insertion to
strengthen the angle of the mouth.
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NoseNose
No detail need be known
Orbit & EyelidOrbit & Eyelid
Each eyelid is given a degree of rigidity by a dense fibrous
structure, the tarsal plate.
Grays Anatomy, Longman, London, 35th Edition, 1973. p 498.
Orbit & EyelidOrbit & Eyelid
The principal muscle of the eyelid region is the orbicularis
oculi. This comprises an orbital part, which overlies the bone
surrounding the orbital cavities, and a palpebral part which
is situated within the eyelids.
Grays Anatomy, Longman, London, 35th Edition, 1973. p 498.
Orbit & EyelidOrbit & Eyelid
Both parts are attached to the medial palpebral ligaments at
the medial corners of the orbits, and to the adjacent bones.
Clemente CD, Anatomy, A Regional Atlas of the Human
Body, Munich, Urban & Shwarzenberg, 1975, Diagram 485.
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Orbit & EyelidOrbit & Eyelid
The orbital fibres radiate
around the orbits. They
insert into the overlying
skin.
The palpebral fibres insert
into the skin of the eyelidsand into the tarsal plate
and lateral palpebral
ligament.
Grays Anatomy, Longman, London, 35th Edition,
1973. p 496.
Orbit & EyelidOrbit & Eyelid
The palpebral fibres of
the orbicularis oculi close
the eyelids gently, as in
sleeping.
The orbital fibres draw
the eyebrows down as in
frowning, and helpforcibly close the eyes,
as in an expression of
agony.
Grays Anatomy, Longman, London, 35th Edition,
1973. p 496.
AuricleAuricle
No detail need be known
ScalpScalp
The scalp consists of five layers. From superficial to deep,
these are:
S Skin
C Connective Tissue
A Aponeurosis
L Loose Connective Tissue
P Periosteum
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ScalpScalp
The epicranial
aponeurosis is a
tendinous sheet into which
the frontalis muscle
attaches anteriorly, and
the occipitalis muscle
attaches posteriorly.
At the side of the skull, theaponeurosis unites with
the underlying temporal
fascia.
Clemente CD, Anatomy, A Regional Atlas of the Human
Body, Munich, Urban & Shwarzenberg, 1975, Diagram 453.
ScalpScalp
The aponeurosis is loosely
attached to the underlying
periosteum, so some
movement is permitted.
The American Indians
used to take advantage ofthis loose connection in
the process of scalping
their victims.
Clemente CD, Anatomy, A Regional Atlas of the Human
Body, Munich, Urban & Shwarzenberg, 1975, Diagram 453.
ScalpScalp
The fibres of the frontalis
attach to bone in the
region of the root of the
nose via fibres that areknown as the procerus
muscle.
Its intermediate fibres
insert on the skin of the
eyebrows and forehead.
Clemente CD, Anatomy, A Regional Atlas of the Human
Body, Munich, Urban & Shwarzenberg, 1975, Diagram 453.
ScalpScalp
The occipitalis attaches to the superior nuchal lines of the
temporalis muscle.Together, the frontalis and occipitalis muscles can move
the aponeurosis and the overlying skin, but the amount of
movement varies between individuals.
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In the LabIn the Lab
As you study these structures, you will find that virtually all
textbooks referring to the anatomy of the head and neck
contain diagrams of these muscles to a greater or lesser
extent.
In the LabIn the Lab
You should take the opportunity to examine skulls during
your practical sessions in detail.
Feel the bones with your fingers. Can you feel
roughnesses in the bone surface in the places you expectthe muscles to attach?
The End