This document provides an overview of the oro-facial musculature. It begins with an introduction and classification of muscles, followed by the embryology of muscle development. It then describes the anatomy, innervation and actions of specific muscle groups including the scalp, ear, eyelid, extraocular, nose, mouth, neck and tongue muscles. It discusses the origins of cranio-facial muscles and compares muscle fiber types. Finally, it provides brief descriptions of some clinical considerations related to injuries of the scalp and face.

2. ORO-FACIAL MUSCULATURE
DR. CHAITHRASHREE.S.RAO
IST MDS

3. CONTENTS:
• Introduction
• Classification
• Embryology of muscle
• Anatomy of muscle
• Muscles of –
• Scalp
• Ear
• Eyelid
• Extraocular
• Nose

4. • Mouth
• Mastication
• Suprahyoid
• Infrahyoid
• Lateral Cervical muscles
• Lateral Vertebral muscles
• Tongue
• Palate
• Pharynx
• Triangles of the neck
• Conclusion

5. INTRODUCTION
• Muscles are formed from Myoblasts of the Mesenchyme which
forms the bulk of the mesoderm.
• There are more than 600 muscles in our body .
• Muscle cells can be excited chemically, electrically and
mechanically to produce an action potential that is transmitted along
their cell membranes.
• In man, muscle tissue constitutes 40–50% of the body mass.
• These muscles have their full complement of cells during development
and increase in size only by increasing the volume of individual
myocytes, rather than by increasing the number of cells.

7. • Both striated and smooth muscles arise from Mesoderm with an
exception for a few which originate from the Ectoderm.
• The intrinsic muscles of the trunk are derived from the myotomes
while the muscles of head and limbs differentiate directly from the
mesoderm.
• A myotome is a group of muscles innervated by the ventral root a
single spinal nerve. This term is based on the combination of two
Ancient Greek roots; “myo-” meaning “muscle”, and “tome”, a
“cutting” or “thin segment”.
• Like spinal nerves, myotomes are organised into segments because
they share a common origin

8. • During the third week of gestation,
the notochord has developed and the mesoderm
lateral to it has differentiated into three
columns.
• The column running directly next to the
notochord is the paraxial mesoderm.
• The paraxial mesoderm will then start to divide
into cube-shapebilaterally paired segments
called somites.
• Each of these segments corresponds to a
division of the vertebral column and spinal
cord in an adult.
EMBRYOLOGY

9. • Each somite will differentiate into three
different regions.
• The ventral portion will form the sclerotome
while the dorsal portion forms
the dermomyotome which later splits into the
dermatome and myotome.
• sclerotome – forms the ribs and vertebrae
• dermatome – forms connective tissue and
dermis of the skin
• myotome – forms the skeletal muscle of
the neck, trunk, and limbs

10. MESODERMAL ORIGIN MUSCLES INNERVATION
SOMITOMERE 1,2 SUPERIOR, INFERIOR,
MEDIAL RECTI;
INFERIOR OBLIQUE
C-3
SOMITOMERE 3 SUPERIOR OBLIQUE C-4
SOMITOMERE 4 MUSCLES OF
MASTICATION
C-5
SOMITOMERE 5 LATERAL OCULAR C-6
SOMITOMERE 6 FACIAL MUSCLES C-7
SOMITOMERE 7 STYLOPHARYNGEUS C-9
SOMITES 1,2 LARYNGEAL MUSCLES C-10
SOMITES 1-4 TONGUE C-12
SOMITES 3-7 STERNOMASTOID
TRAPEZIUS
C-11
CRANIO-FACIAL MUSCLE ORIGINS:

11. •General principles of muscle differentiation
• MYOBLASTS, the precursors of muscle cells develop from
mesenchymal cells.
• They have a prominent nucleus and an enlarged nucleolus, many free
ribosomes and polysomes in their cytoplasm, a few uniformly
distributed globular mitochondria and sparse endoplasmic reticulum.

13. Structure of muscle fibres:

15. TYPE 1 V/S TYPE 2 MUSCLES
TYPE 1
• Small
• Slow-firing
• Relatively fatigue resistant
• Oxidative fibres
TYPE 2
• Large
• Fast-firing
• Fatigable fibres
• Type 2a – fast, oxidative,
glycolytic fibres
• Type 2b – fast, glycolytic, fibres

16. CRANIO-FACIAL MUSCLES:

17. VARIOUS CLASSIFICATION HAVE BEEN
SUGGESTED TILL NOW
1. TOPOGRAPHICALLY & FUNCTIONALLY
2. ACC. TO LOCATION ALONE
3. COSMETICALLY

18. ACC. TO LOCATION
THESE INCLUDES MUSCLES OF
• SCALP OR EPICRANIUM
• EYELID
• NOSE
• EAR &
• MOUTH
• NECK

19. TOPOGRAPHICALLY & FUNCTIONALLY
• EPICRANIAL
• CIRCUMORBITAL AND PALPEBRAL
• NASAL
• BUCCOLABIAL

20. COSMETICALLY
THEY ARE DIVIDED INTO TWO MAJOR CATEGORIES
1. FACIAL ELEVATORS: levator labii superioris aleque nasi , levator
labii superioris , zygomaticus major, levator anguli oris,
zygomaticus minor, risorius
2. FACIAL DEPRESSOR : depressor labii inferioris, depressor anguli
oris, mentalis

21. OCCIPITOFRONTALIS
• Origin & Insertion:
• Has 4 bellies- 2 occipital and 2 frontal
which are connected by an aponeurosis
(galea aponeurotica)
• Occipital bellies arise from the highest
nuchal line and passes forward to attach to
the aponeurosis. The 2 muscle bellies are
separated in the midline.
• Frontal belly arises from the aponeurosis
and passes forwards to become attached to
the upper part of orbicularis oculi and the
skin of the eyebrow.

22. • NERVE SUPPLY:
• Facial nerve
• Post auricular branch to occipitalis
• Temporal branches to frontalis
• BLOOD SUPPLY:
• Branches of the superficial temporal, ophthalmic, posterior auricular
and occipital arteries.

23. • ACTION:
• Frontalis:
• Raise the eyebrows and the skin over the root of the nose, and at the
same time draw the scalp forward forming transverse wrinkles of the
forehead.
• Occipitalis:
• in some individuals occipitalis can pull the scalp backwards, but
otherwise it merely anchors the aponeurosis when frontalis elevates
the eyebrows.

24. TEMPOROPARIETALIS
• Variably developed sheet of muscle that lies on either sides of the
frontal parts of occipito frontalis and anterior and superior auricular
muscles
• ACTIONS:
• Elevates the ear.
• Tightens the scalp.

25. • NERVE SUPPLY:
• Facial nerve
• Post auricular branch
• Temporal branches
• BLOOD SUPPLY:
• Branches of the superficial temporal, ophthalmic, posterior auricular and occipital
arteries.

26. EPICRANIAL APONEUROSIS
• Fibro muscular sheet that extends from occipital to the
eyebrows,
• Thin and continious over the temporal facia to the
zygomatic arch.
• Ant: splits to enclose the frontal parts
• Post: btw the occipitalis muscle attached to external
occipital protruberance and highest nucal lines
• On either sides: anterior and superior circular muscles
• Over the cranial vault: united to skin by fibrous
superficial fascia

27. • Nerve supply:
• Occipital part: posterior auricular branch
• Frontal part: temporal branches of facial nerve
• Actions:
• From above: raises eyebrows and skin over the nose as in surprise horror or
fright
• From below: draws scalp forwards , forms transverse wrinkles
• Occipital part: draws scalp backwards
• Together moves the scalp backwards and forwards

28. • Frontalis muscle is one among the many muscles examined to check
the functioning of facial nerve.
• Transverse wrinkles on the forehead are absent when the patient is
asked to look upwards without moving his head in cases of
infranuclear lesions of the facial nerves
APPLIED ASPECTS

29. • Lacerations of the Scalp:
• The scalp has a profuse blood supply to
nourish the hair follicles.
• Even a small laceration of the scalp can
cause severe blood loss.
• It is often difficult to stop the bleeding of a
scalp wound because the arterial walls are
attached to fibrous septa in the
subcutaneous tissue and are unable to
contract or retract to allow blood clotting to
take place.
• Local pressure applied to the scalp is the
only satisfactory method of stopping the
bleeding

30. • Sebaceous gland cysts:
• The skin of the scalp possesses numerous sebaceous glands, the ducts
of which are prone to infection and damage by combs. For this reason,
sebaceous cysts of the scalp are common.
• Scalp Infections:
• Infections of the scalp tend to remain localized and are usually painful
because of the abundant fibrous tissue in the subcutaneous layer.
• Occasionally, an infection of the scalp spreads by the emissary veins,
which are valveless, to the skull bones, causing osteomyelitis.
• Infected blood in the diploic veins may travel by the emissary veins
farther into the venous sinuses and produce venous sinus thrombosis.

31. Black Eye
• The blood and fluid gathering in the layer of loose
areolar tissue following a strike on head tracks freely
under the scalp creates generalized swelling over the
dome of the skull.
• This cannot enter either occipital or temple regions
due to the bony attachments of the occipitofrontalis.
• The blood and fluid track forwards into the eyelids as
occipitofrontalis has no bony connection anteriorly.
• This result in creation of hematoma few hours after a
head injury or cranial surgery causing black
discoloration of skin around the eyes, a condition
named black eye.

32. MUSCLES OF THE FACE
• Also known as muscles of facial expression are subcutaneous muscles.
• These muscles are regulators (sphincter or dilators) of the three
opening on the face namely; the palpebral fissures, nostrils and oral
fissure.
• Facial expressions produced are secondary functions of these muscles.
• Some anatomists think that facial expressions are merely side effects
of the action of the muscles of face.

33. FUNCTIONAL GROUP OF FACIAL MUSCLES:

34. MUSCLES OF EYELID
Levator palpebrae
superioris
Corrugator supercilli
Orbicularis oculi

35. ORBICULARIS OCULI
• Origin and Insertion:
• From nasal part of the frontal bone
and from the frontal process of the
maxilla in front of the lacrimal
groove.
• the muscle has three parts:- the
palpebral portion, the orbital portion
and the lacrimal portion.

37. • Palpebral portion:
• Thin and pale muscle which arises from the bifurcation of the medial
palpebral ligament
• Forms a series of concentric curves and gets inserted into the lateral
palpebral raphe.
• Orbital portion:
• Reddish colour
• form complete ellipse without interruption at the lateral palpebral
commisure.
• The upper portion of the muscle blends with Frontalis and Corrugator
• Lacrimal portion:
• Situated behind the medial palpebral ligament and lacrimal sac.
• Divides into two; upper and lower parts which are inserted into the
superior and inferior tarsi medial to puncta lacrimalia.

38. CORRUGATOR SUPERCILI
• Origin and Insertion:
• Arises from medial end of the
super-cilliary arch and its fibres
pass upwards and lateral
between the palpebral and orbital
portions of the Orbicularis oculi.
• Inserted into deep surface of
skin, above the middle of the
orbital arch.

39. LEVATOR PALAPEBRAE SUPERIORIS
• Origin:
• Arises from the under surface of the small wing of the
sphenoid anterosuperior to the optic foramen.
• The narrow tendinous muscle becomes broad and fleshy and
end in the wide aponeurosis which splits into three lamellae.
• Insertion:
• Superficial lamella: blends with the orbital septum and
inserts into the anterior surface of the superior tarsus.
• Middle lamellae: inserted into the upper margin of the
superior tarsus.
• Deep lamellae: blends with the sheath of rectus superior and
attached to the superior fornix of the conjunctiva.

40. • NERVE SUPPLY:
• Both Orbicularis oculi and Corrugator supercilli are supplied by the
facial nerve.
• BLOOD SUPPLY:
• ORBICULARIS OCULI: Branches of the facial, superficial temporal,
maxillary and ophthalmic arteries
• CORRUGATOR: Branches from adjacent arteries, mainly from the
superficial temporal and ophthalmic arteries.

41. FUNCTIONS:
• Orbicularis oculi:
• It acts a sphincter muscle.
• Palpebral portion is involuntary - closes the lid during
sleeping/blinking.
• Orbital portion is voluntary – firm closure of the eyelids. During
closure the medial palpebral ligament is tightened and the wall of the
lacrimal sac is drawn lateral and forwards forming a vacuum and tears
are sucked through the lacrimal canals.

42. ACTIONS:
• Levator palpebrae superioris –
• direct antagonist of orbicularis oculi. It raises
the upper eyelid and exposes the bulb of the
eye.
• Corrugator supercilli-
• Draws the eyebrow downwards and medially
producing vertical wrinkles of the forehead.
• Drags the eye brows medially and downward
and protects eye from bright sunlight.

43. APPLIED ASPECTS
• Paralysis from of orbicularis oculi prevents eye from being closed and
exposes cornea leaving it to become dry.
• Lower eyelid falls away from the eyeball forming a pond in which the
tears pool and spill over the face.
• It also causes conjunctival sac to get accumulated with grit causing
infections.

44. EXTRA-OCCULAR MUSCLES:
• Rectus superior
• Rectus inferior
• Rectus medialis
• Rectus lateralis
• Obliquus superior
• Obliquus inferior

45. RECTI MUSCLES:
• Origin and insertion:
• Arises from a fibrous ring (common annular tendon or
tendinous ring) which surrounds the upper, medial, and lower
margins of the optic foramen and encircles the optic nerve.
• It also encloses the lower and medial part of the superior
orbital fissure.
• Two specialised parts of the fibrous ring :
• A lower, LIGAMENT/TENDON OF ZINN: gives origin to inferior
rectus and lower head of lateral rectus.
• An upper, SUPERIOR TENDON OF LOCKWOOD: gives origin to
superior rectus, medial rectus and upper head of lateral rectus.
• Each muscle passes forward and is inserted into the sclera by a
tendinous expansion.

47. SUPERIOR OBLIQUE MUSCLES:
• Origin and insertion:
• Arises: above the margin of the optic foramen, above and medial to the origin
of superior rectus.
• The fibres become a rounded tendon and pass through fibrocartilaginous ring
or pulley attached to the trochlear fovea of frontal bone.
• The tendon passes backwards laterally and downwards below the superior
rectus
• Insertion: sclera of the lateral part of the bulb of the eye between insertions
of superior rectus and lateral rectus.

49. INFERIOR OBLIQUE MUSCLE:
• Origin and insertion:
• Arises from the orbital surface of the maxilla, lateral to the lacrimal
groove. The fibres pass laterally backward and upwards between
inferior rectus and the floor of the orbit
• Insertion: sclera of the lateral part of the eye between superior rectus
and lateral rectus behind the insertion of superior oblique

50. • NERVE SUPPLY:
• Lateral Rectus: abducent nerve (VI)
• Superior Oblique: trochlear nerve (IV)
• Rest of the muscles: occulomotor nerve (III)
• BLOOD SUPPLY :
• All extraocular muscles are supplied by Ophthalmic artery.

51. ACTIONS
• Two extraocular muscles, the medial rectus and lateral rectus, work together to
control horizontal eye movements
• Contraction of the medial rectus pulls the eye towards the nose (adduction or
medial movement).
• Contraction of the lateral rectus pulls the eye away from the nose (abduction or
lateral movement).
• Contraction of the superior rectus produces eye elevation and contraction of
superior oblique produces eye depression.
• Inferior rectus produces eye depression and Inferior oblique produces eye
elevation

53. Strabismus: or the squint eye
• A squint is a condition where the eyes do not look together in the same
direction. Whilst one eye looks straight ahead, the other eye turns to
point inwards, outwards, upwards or downwards.
• Squints are common and affect about 1 in 20 children.
• By the direction of the squinting (turning) eye:
• An eye that turns inwards is called an esotropia.
• An eye that turns outwards is called an exotropia.
• An eye that turns upwards is called a hypertropia.
• An eye that turns downwards is called a hypotropia

54. Congenital squints
• Congenital squint means that the child is born with a squint, or it
develops within the first six months of life.
• Cause: In most cases, the eye muscles are not balanced but the reason
for this is not known.
• In most cases one eye turns inward. This is called congenital esotropia
(sometimes called infantile esotropia).

55. Paralysis to the Orbital Muscles
• If the facial nerve becomes damaged, the orbital muscles will cease to
function. As they are the only muscles that can close the eyelids, this
has some serious clinical consequences.
• The eye cannot shut – this can cause the cornea to dry out. This is
known as exposure keratitis.
• The lower eyelid droops, called ectropion.
• Lacrimal fluid pools in the lower eyelid, and cannot be spread across
the surface of the eye. This can result in a failure to remove debris, and
ulceration of the corneal surface.
• The test for facial nerve palsy involves raising the eyebrows and
closing the eyelids

56. MUSCLES OF NOSE:
DEPRESSOR SEPTIPROCERUS
NASALIS DILATOR NARIS POSTERIOR
DILATOR NARIS ANTERIOR
LEVATOR LABII SUPERIORIS
ALAEQUAE NASI

57. ORIGIN AND INSERTION:
• Procerus (pyramidalis nasi):
• fascia covering the lower part of the
nasal bone and upper part of the
lateral nasal cartilage.
• inserted into the skin over the lower
part of the forehead between two
eyebrows.
• Its fibres decussate with that of
frontalis.

58. • Nasalis:
• Two parts:
• Transverse and alar.
• Transverse part: from maxilla,
superior and lateral to incisive
fossa.
• Fibres expand into a thin
aponeurosis which is continuous
on the bridge of the nose.
• Alar part is attached by one end
to the greater alar cartilage, and
by the other to the integument at
the point of the nose.

59. • The Depressor septi (Depressor aloe nasi)
• Arises from the incisive fossa of the maxilla
• Inserted into the septum and back part of the ala of the
nose.
• It lies between the mucous membrane and muscular
structure of the lip.
• The Dilatator naris posterior:
• Is placed partly beneath the Quadratus labii
superioris.
• arises from the margin of the nasal notch of the
maxilla, and from the lesser alar cartilages. Inserted
into the skin near the margin of the nostril.
• The Dilatator naris anterior :
• Is a delicate fasciculus, passing from the greater alar
cartilage to the integument near the margin of the
nostril.

60. Levator labii superioris alaequae nasi:
• Arises from the upper part of the frontal process of
the maxilla and divides into medial and lateral slips.
• Insertion:
• Medial slip blends into the perichondrium of the
lateral crus of the major alar cartilage of the nose
and the skin over it.
• Lateral slip is prolonged into the lateral part of the
upper lip, where it blends with levator labii
superioris and orbicuris oris.

61. • Nerve supply
• Facial nerve
• Blood supply
• Procerus is supplied mainly by branches from the facial artery
• Nasalis is supplied by branches from the facial artery and from the
infraorbital branch of the maxillary artery
• Depressor septi is supplied by the superior labial branch of the facial
artery
• Levator labii superioris alaequae nasi is supplied by the facial artery and the
infraorbital branch of the maxillary artery

62. ACTIONS:
• Procerus:
• draws down the medial angle of the eyebrows and produces
transverse wrinkles over the bridge of the nose.
• The two Dilators (Anterior and Posterior):
• Enlarges the aperture of the nares.
• resist the collapse of the nostrils due to atmospheric pressure.
• strongly contract during the expression of some emotions such as
Anger.

63. • Depressor septi:
• Antagonist to other muscles of nose.
• Draws the ala of nose downwards and constricts the nares.
• Nasalis:
• Depresses the cartilaginous part of the nose
• Draws the ala towards the septum.

64. MUSCLES OF THE MOUTH
• Buccinator
• Orbicuaris oris
• Risorius
• Platysma
• Levator labii superioris
• Caninus
• Zygomaticus
• Mentalis
• Levator labii inferioris
• Triangularis

65. LEAVATOR LABII SUPERIORIS
• Origin and Insertion
• Has three heads
• Angular head
• Intermediate head/infraorbital head
• Zygomatic head
• Angular head:
• arises from the frontal process of the maxilla
• passes obliquely downwards and splits into two;
• one inserts into the greater alar cartilage
• the other into the lateral part of the upper lip, blending with infraorbital head
and orbicularis oris.

66. • Intermediate head/infraorbital head:
• Arises from the lower margin of the
orbit above the infra- orbital foramen.
• Inserted into the muscular substance of
the upper lip between the angular head
and the Caninus.
• Zygomatic head:
• Arises from the malar surface of the
zygomatic bone behind the
zygomaticomaxillary suture
• Inserts into medial aspect of the upper lip.

67. CANINUS/ LEVATOR ANGULI ORIS:
• Origin and insertion
• Arises from the the canine
fossa immediately below
the infraorbital foramen
• Inserted into the angle of
the mouth intermingling
with those of the
Zygomaticus, Triangularis
and Orbicularis oris.

68. ZYGOMATICUS MAJOR
• Origin and insertion:
• It arises from the anterior aspect of lateral
surface of zygomatic bone
• Inserts into the upper lip medial to the
angle of the mouth.
• Origin and insertion:
• Arises from the zygomatic bone, in front of
the zygomaticotemporal suture.
• Inserted into the angle of the mouth, where
it blends with the fibres of the Caninus,
Orbicularis oris and Triangularis.
ZYGOMATICUS MINOR

69. • NERVE SUPPLY:
• facial nerve.
• BLOOD SUPPLY:
• Levator labii superioris is supplied by the facial artery and the infraorbital
branch of the maxillary artery.
• Caninus is supplied by the superior labial branch of the facial artery and the
infraorbital branch of the maxillary artery.
• Zygomaticus is supplied by the superior labial branch of the facial artery.

70. ACTIONS:
• Levator labii superioris: elevator of upper lip.
• Angular head: dilator of naris .
• Infraorbital and zygomatic head assist in forming the nasolabial furrow.
When the whole muscle contracts it gives the expression of contempt and
disdain
• Caninus: helps in producing the nasolabial furrow.
• Zygomaticus: helps in smiling.
• Zygomaticus major: pulls the angle of the mouth upwards and lateral
• Zygomaticus minor: elevates the upper lip

71. DEPRESSOR LABII INFERIORIS
• Origin and insertion :
• Arises from the oblique line of
mandible, between symphysis
and mental foramen.
• Inserts into the integument of
the lower lip.
• Its fibres blend with that of
orbicularis oris and with those
from the opposite side.

72. MENTALIS
• ORIGIN AND INSERTION :
• Arises from the incisive fossa of the
mandible
• Inserts into the integument of the chin.
• ORIGIN AND INSERTION :
• Arises from the oblique line of the
mandible.
• Inserts into the angle of the mouth.
• At the origin its fibres are continuous with
platysma and at the insertion it is continuous
with that of orbicularis oris .
TRIANGULARIS/
DEPRESSOR ANGULI ORIS

73. • NERVE SUPPLY:
• Facial nerve
• BLOOD SUPPLY:
• Mentalis is supplied by the inferior labial branch of the facial artery and the
mental branch of the maxillary artery.
• Depressor labii inferioris is supplied by the inferior labial branch of the facial
artery and the mental branch of the maxillary artery.
• Triangularis: supplied by the inferior labial branch of the facial artery and the
mental branch of the maxillary artery

74. • ACTIONS:
• MENTALIS: Raises and protrudes the lower lip and at the same time
wrinkles the skin of the chin, expressing doubt or disdain.
• DEPRESSOR LABII INFERIORIS: draws the lower lip downwards
and laterally, as in expression of Irony
• TRIANGULARIS: depresses angle of mouth medially along with
Platysma

75. BUCCINATOR
• ORIGIN AND INSERTION :
• Arises from the outer surface of the alveolar
process of the maxilla and mandible,
corresponding to the molars anteriorly and
from the anterior border of
pterygomandibular raphe posteriorly.
• Insertion: the fibres converge towards the
angle of the mouth. The central fibres
intersect with each other, those from below
continuous with upper segment of
Orbicularis oris and those from above with
the lower segment.

76. ORBICULARIS ORIS
• ORIGIN AND INSERTION
• It arises from
• Anterior surface of maxilla
• Anterior surface of mandible
• Modiolus
• Insertion:
• Into the skin and mucous membrane of lips.
• Occupies the entire width of lips
• No direct attachment to the skeleton
• Fibers are divided in the upper & lower gp.
That can cross each other at acute angle lateral to corner of
mouth

77. • Previously considered as a sphincter muscle but recent studies have
shown that the muscle consists of 4 independent quadrants (viz. upper,
lower, left and right)
• Each quadrant contains large Pars peripheralis and small Pars
marginalis.
• Both peripheralis and marginalis originate from the modiolus.
• Pars peripheralis decussate at the midline and insert into the
contralateral philtrum edge where as pars marginalis is a continuous
band from modiolus to modiolus

78. NON-SYNDROMIC CLEFT LIPS:
• Non syndromic cleft lip is a complex genetic disorder with variable
phenotype, largely attributed to interactions of environment and
multiple genes.
• A cleft is non syndromic if there is only single malformations.
• The severity of CL, varies from minimal to complete bilateral CL.
• Minimal CL, includes superficial scarring, notching of upper lip,
notching of alveolar ridge and asymmetry in alar cartilages.
• Various literature supports that non syndromic cleft lips are caused due
to orbicularis oris sub-epithelial defects.
• In cases of cleft lip the pars peripheralis runs all the way the columella
while the pars marginalis end at the margin of the defect

79. RISORIUS
• ORIGIN AND INSERTION
• Arises in the fascia over Masseter
and passes horizontally forward
above the platysma.
• Insertion: into the skin of the angle
of the mouth.

80. • Nerve supply:
• Facial nerve
• Blood supply:
• Orbicularis oris: supplied mainly by the superior and inferior labial
branches of the facial artery, the mental and infraorbital branches of
the maxillary artery and the transverse facial branch of the superficial
temporal artery
• Buccinator is supplied by branches from the facial artery and the
buccal branch of the maxillary artery.
• Risorius is supplied mainly by the superior labial branch of the facial
artery

81. ACTIONS:
• Orbicularis oris:
• Pursing of lips and pouting.
• Buccinator:
• compresses the cheeks so that during mastication the food is kept under
immediate pressure of the teeth.
• whistling
• Risorius:
• retracts the angle of the mouth and helps in producing unpleasant grinning
expression

82. PLATYSMA
• Origin and insertion
• Origin: upper parts of pectoral and
deltoid fasciae and fibres run upwards
and medially
• Insertion:
• Anterior fibres to the base of the
mandible
• Posterior fibres to the skin of the lower
face and lip and maybe continuous with
the Risorius

83. • Nerve supply:
• Facial nerve
• Blood supply:
• By the submental branch of the facial artery and by the suprascapular artery
• Actions:
• Releases pressure of skin on the subjacent veins
• Depresses mandible
• Pulls the angle of the mouth downwards as in horror or surprise

84. MODIOLOUS
• It is defined as a lateral point to the corner of the angle of the mouth
where the muscles of facial expression converge.
• The muscles which form the modiolus are:
• Orbicularis oris
• Buccinators
• Caninus
• Triangularis
• Zygomaticus major
• Risorius
• Platysma
• Levator labii superioris

85. A few of the common facial expressions and the muscles
producing them:
EXPRESSION MUSCLES RESPONSIBLE
SMILING AND LAUGHING ZYGOMATICUS MAJOR
SADNESS LEVATOR LABII SUPERIORIS
GRIEF DEPRESSOR ANGULI ORIS
ANGER DILATOR NARIS AND DEPRESSOR SEPTI
FROWNING CORRUGATOR SUPERCILLI AND PROCERUS
HORROR PLATYSMA
SURPRISE FRONTALIS
DOUBT MENTALIS
GRINNING RISORIUS
CONTEMPT ZYGOMATICUS MINOR
CLOSING THE MOUTH ORBICULARIS ORIS
WHISTLING BUCCINATOR

87. DEVELOPMENT OF EMOTIONAL EXPRESSIONS
IN INFANTS :
EXPRESSIONS AGE
SURPRISE 5 MONTHS
SMILING 6-8 WEEKS
ENJOYMENT 16-18 WEEKS
LAUGH 7 MONTHS
CRY BIRTH
DISGUST 4 MONTHS
ANGER 3-4 MONTHS
SAD 6MONTHS
FEAR 7-11 MONTHS
Margaret Wolan Sullivan, PhD; Michael Lewis, PhD, Emotional Expressions of Young Infants and Children.
Infants and Young Children:Vol. 16, No. 2, pp. 120–142

88. The development of spontaneous facial responses to
others’ emotions in infancy: An EMG study
Jakob Kaiser, Maria Magdalena Crespo-Llado, Chiara Turati & Elena Geangu
• Viewing facial expressions often evokes facial responses in the observer.
• In the current study, 4- and 7-month old infants were presented with facial
expressions of happiness, anger, and fear.
• Electromyography (EMG) was used to measure activation in muscles relevant for
forming these expressions: zygomaticus major (smiling), corrugator supercilii
(frowning), and frontalis (forehead raising).
• The results indicated no selective activation of the facial muscles for the
expressions in 4-month-old infants.
• For 7-month-old infants, evidence for selective facial reactions was found
especially for happy (leading to increased zygomaticus major activation) and
fearful faces (leading to increased frontalis activation), while angry faces did not
show a clear differential response.
• Such mechanisms seem to undergo important developments at least until the
second half of the first year of life.

89. CLINICALLY, THE FACIAL NERVE IS EXAMINED
BY TESTING THE FOLLOWING FACIAL MUSCLE:
• FRONTALIS
• Ask the patient to look upwards without moving his head, and look for the
normal wrinkles of forehead.
• CORRUGATOR SUPERCILLI:
• Frowning and making vertical wrinkles of the forehead.
• ORBICULARI OCULI:
• Tight closure of the eyes.
• ORBICULARIS ORIS:
• Whistling and pursing the teeth.
• BUCCINATOR:
• Puffing the mouth and then blowing as in whistling
• DILATORS OF TEETH:
• Showing the teeth.

90. BELL’S PALSY
• Definition :
• The bell’s palsy is definied as a facial
paralysis of acute onset attributed to a
acute non- supportive inflammation of
facial nerve within stylomastoid
foramen.
• It may occur at any age from infancy to
old age, but appears to be most common
in young adults; males are affected more
than female.

91. • Causes:
• 1-Trauma:
• Basal skull fractures, Facial injuries, Penetrating injury to middle ear,
Altitude paralysis. (barotrauma), Scuba diving & Lightning.
• 2-Infection: External otitis, Otitis media & Mastoiditis,,etc)
• 3-Metabolic: Diabetes mellitus & Hypertension.
• 4-Neoplastic: Seventh nerve tumor & Benign lesions of parotid.
• 5-Idiopathic: Familial Bell palsy, Autoimmune syndrome & Multiple
sclerosis.

92. • clinical features:
• 1-Pain behind ear (mastoid foramen).
• 2- affection of taste and hearing.
• 3-Inability to raise eye brow.
• 4-Inability to close eye on affected side.
• 5-Flattening of nosolabial fold.
• 6-Accumulation of food inside the cheek(affected side).
• 7-Dropping corner of mouth.
• 8-Dripping of saliva.

93. • Assessment Tests for bell's palsy include the following: Muscle test :
• 1. Forehead wrinkling (frontalis muscle)
• 2. Eye closure (orbicularis oculi muscle)
• 3. Wide smile
• 4. Whistling
• 5. Blowing (eg, buccinator muscle, orbicularis oris muscle, zygomatic
muscle).

95. TETANUS
• Tetanus is a clinical diagnosis
characterized by a triad of muscle
rigidity, muscle spasms and
autonomic instability.
• Clostridium tetani spores enter into
the body through any abrasions on
the skin.
• Release tetanospasmin (potent
neurotoxin)

96. • C/F:
• Early symptoms of tetanus include
• neck stiffness,
• sore throat
• dysphagia
• trismus.
• Spasm extending to the facial muscles causes the typical facial
expression, ‘risus sardonicus’.
• Truncal spasm causes opisthotonus.

97. MOBIUS SYNDROME :
• It is an extremely rare congenital neurological
disorder
• Characterized by facial paralysis and the inability
to move the eyes from side to side.
• Born with complete facial paralysis and cannot
close their eyes or form facial expressions.
• Limb and chest wall abnormalities sometimes
occur with the syndrome.

98. MELKERSONS-ROSENTHAL
SYNDROME :
• It is a rare
neurological
characterized by
recurring facial
paralysis, swelling of
the face and lips
(usually the upper
lip), and the
development of folds
and furrows

99. Ramsay Hunt Syndrome:
• Ramsay Hunt Syndrome:
• Peripheral facial nerve palsy May be
unilateral or bilateral Vesicular rash on ear
Ear pain, tingling, tearing, loss of sensation
and nystagmus.
• Ramsay Hunt Syndrome Type II:
• Reactivation of latent Herpes zoster virus
within the dorsal root ganglion of facial
nerve is associated with vesicles affecting
ear canal

100. Effects of a myofunctional appliance on orofacial muscle activity
and structuresAntje Tallgren, LDS, Odont Dr; Richard L. Christiansen, DDS, MSD,PhD; Major M. Ash Jr., DDS, MS,
• The aim of the study was to examine the effect of an oral shield treatment on orofacial muscle
activity and facial morphology in children with lip and/or tongue dysfunction.
• The sample consisted of 7 girls and 2 boys, 7 to 1 2 years old. EMG recordings with and
without the shield in situ were obtained when the shield was placed, and 3, 6, and 12 months
later.
• Lateral cephalograms were obtained at the initial and 1 -year stages. The lip muscles showed
dominant activity when the subjects were sucking on an empty straw and during swallowing;
this was strongest during the first 3 months.
• The mentalis, buccinator, and digastric muscles generally showed weaker activity. The anterior
temporal muscle showed dominant activity during maximal clench, but after the 3-month stage a
significant decrease was noted.
• After 1 year of treatment, no significant changes in overjet or overbite were observed. Most of
the craniofacial growth changes were normal for the age group.
• The results indicate that treatment with an oral shield caused a decrease in orofacial muscle
activity during oral functions.

101. MUSCLES OF THE EAR:
• AURICULARIS
SUPERIOR
• AURICULARIS
ANTERIOR
• AURIULARIS
POSTERIOR

102. ANTERIOR AURICULARIS
• Smallest & weak muscle
• Protector of outer ear
Origin
• From aponeuratic tendon of scalp in the temporal region
Course & insertion
• Runs horizontally & backwards & insert into cartilage of
outer ear at the ant. Border
Nerve supply
• Temporal branch
Action
• Draws the ear upwards & forwards

103. AURICULARIS SUPERIORIS
• Largest
• Just behind the anterior
Origin
• Above the ear from aponeuratic tendon of scalp
Course & insertion
• Descends & converge & insert to medial surface
• of cartilage
Nerve supply
• Both temporal & post auricular branch
Action
• Elevate the ear

104. AURICULARIS POSTERIORIS
• Small but strong muscle
• Retractor of the ear
Origin
• From the base of mastoid process of temporal
bone & lateral part of sup. Nuchal line
Course & insertion
• Run horizontally over the insertion of
sternocledomastoid muscle to insert on the
convexity of cranial surface of conche
Nerve supply
• Post auricular of facial nerve
Actions
• Draw the ear backwards

105. MUSCLES OF THE TONGUE:
• The tongue muscles are developed from occipital myotome, which is
formed by the fusion of four pre-cervical somites.
• The myotome migrates forward to invade the tongue along the epi-
pericardial ridge, carrying its own nerve supply.
Development of tongue muscles:

106. • MUSCLES OF THE TONGUE –
• Middle fibrous septum divides the tongue into right and left halves.
• Intrinsic muscles
• Superior longitudinal
• Inferior longitudinal
• Transverse
• Vertical
• Extrinsic muscles
• Genioglossus
• Hyoglossus
• Styloglossus
• Palatoglossus

107. INTRINSIC MUSCLES -
• Occupy the upper part of the tongue –
• Are attached to the submucous fibrous layer and to the median fibrous
septum.
• They alter the shape of the tongue
• Superior longitudinal muscle –
• Lies beneath the mucous membrane.
• It shortens the tongue and makes its dorsum concave
• Inferior longitudinal muscle –
• Is a narrow band lying close to the inferior surface of the tongue between the
styloglossus and the hyoglossus
• It shortens the tongue and makes the dorsum convex.

108. • Transverse / horizontal muscle –
• Extends from the median septum to the margins.
• It makes the tongue narrow and elongated.
• Vertical muscle –
• Is found at the borders of the anterior part of the tongue.
• It makes the tongue broad and flattened.

109. EXTRINSIC MUSCLES -
• Connect the tongue to the :
• Mandible via genioglossus
• Hyoid bone through hyoglossus
• Styloid process via styloglossus
• Palate via palatoglossus

110. GENIOGLOSSUS -
• Fan shaped muscle
• Which forms the main bulk of the tongue
• It arises from the upper genial tubercle of the mandible
• From here the fibers fan out and run backwards
• Upper fibers are inserted into the tip
• Middle fibers are inserted into dorsum
• Lower fibers into hyoid bone.
• ACTIONS:
• Upper fibers - retract the tip
• Middle fibers - depress the tongue
• Lower fibers - pull the posterior part of the tongue forwards and thus protrude
the tongue from the mouth.

111. HYOGLOSSUS
• Is an important landmark in the submandibular region
• Origin
• whole length of greater cornua and lateral part of body of
hyoid bone.
• Fibers run upwards and forwards
• Insertion
• side of tongue between styloglossus and inferior
longitudinal muscle of tongue
• Nerve supply
• hypoglossal nerve
• Action –
• depresses tongue, makes dorsum convex and retracts the
protruded tongue.

112. STYLOGLOSSUS
• Origin –
• tip and adjacent part of the anterior surface of the styloid
process as well as from the upper end of the stylohyoid
ligament.
• Fibers –
• pass downwards and forwards
• Insertion
• into the side of the tongue, intermingling with the fibers of the
hyoglossus
• Nerve supply –
• hypoglossal nerve
• Action –
• during swallowing it pulls the tongue upwards and backwards.

113. PALATOGLOSSUS -
• Origin –
• oral surface of palatine aponeurosis
• Fibers –
• descends in the palatoglossal arch
• Insertion-
• Side of the tongue (at the junction of oral and pharyngeal parts)
• Nerve supply –
• cervical part of accessory nerve
• Action –
• pulls up the root of the tongue, approximates the palatoglossal arches and thus
closes the oropharyngeal isthmus

115. • ARTERIAL SUPPLY –
• Chiefly derived from lingual artery
• Root of the tongue is also supplied by the tonsillar and ascending pharyngeal arteries.
• VENOUS DRAINAGE –
• The deep lingual vein is the largest and the principal vein of the tongue.
• It is visible on the inferior surface of the tongue.
• It runs backwards and crosses the genioglossus and the hyoglossus below the
hypoglossal nerve.
• LYMPHATIC DRAINAGE –
• Tip of the tongue drains bilaterally to the submental nodes
• Right and left halves of the remaining part of the anterior 2/3rd of the tongue drains
unilaterally to the submandibular nodes.
• Posterior 1/3rd of the tongue drains bilaterally to the jugulo-omohyoid nodes.

117. APPLIED ANATOMY:
• Orofacial Myofunctional Disorders (OMD):
• With OMD, the tongue moves forward in an exaggerated way during
speech and/or swallowing.
• The tongue may lie too far forward during rest or may protrude
between the upper and lower teeth during speech and swallowing, and
at rest.
signs or symptoms
• Although a "tongue thrust" swallow is normal in infancy, it usually decreases
and disappears as a child grows.
• If the tongue thrust continues, a child may look, speak, and swallow differently
than other children of the same age.
• Older children may become self-conscious about their appearance.

118. Effect of OMD on speech?
• Some children produce sounds incorrectly as a result of OMD.
• OMD most often causes sounds like /s/,/z/, "sh", "zh", "ch" and "j" to
sound differently. For example, the child may say "thumb" instead of
"some“
• Both pedodontists and orthodontists may be involved when constant,
continued tongue pressure against the teeth interferes with normal
tooth eruption and alignment of the teeth and jaws
• Physicians predict the presence of a blocked airway (e.g., from
enlarged tonsils or adenoids or from allergies) that may cause forward
tongue posture.

119. TREATMENT
• A speech-language pathologist (SLP) with experience and training in
the treatment of OMD will evaluate and treat.
• Treatment techniques to help both speech and swallowing problems
caused by OMD may include the following:
• increasing awareness of mouth and facial muscles
• increasing awareness of mouth and tongue postures
• improving muscle strength and coordination
• improving speech sound productions

120. Orofacial myofunctional therapy or rest
posture therapy
• We need to teach the muscle where to rest again when normal posture
is altered.
• Teeth are moved by light, constant pressure, not by intermittent heavy
forces
• Only treating the intermittent heavy force created by tongue thrusting
is not treating the source of the problem.
• If the tongue is resting low and forward against the teeth and lips are
parted for the other 23.5 hours, then we have not addressed the actual
problem.
• The light, constant pressure of the tongue and lips have much more
influence on oral equilibrium.