brief about muscles of head and neck, triangles of neck and its applied anatomy in Oral and Maxillofacial Surgery.

2. MUSCLES OF
HEAD & NECK
PRESENTED BY:
CHIRAG M A
1ST YEAR PG
Dept of ORAL & MAXILLOFACIAL SURGERY

3. CONTENTS:
• INTRODUCTION
• CLASSIFICATION OF MUSCLES
• FACIAL MUSCLES
• MASTICATORY MUSCLE
• MUSCLES OF NECK
• APPLIED ANATOMY

4. 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.
• In man, muscle tissue constitutes 40–50% of the body mass.
• Muscle cells can be excited chemically, electrically and mechanically to produce an
action potential that is transmitted along their cell membranes.

5. CLASSIFICATION
MUCLES DEPENDING ON STRIATIONS STRAITED
NON STRIATED
DEPENDING UPON THE CONTROL VOLUNTARY
INVOULUNTARY
DEPENDING ON THE SITUATION SMOOTH MUSCLE
CARDIAC MUSCLE
SKELETAL MUSCLE
MUSCLES CAN BE CLASSIFIED UNDER DIFFERENT CATEGORIES:

7. THE MUSCLES IN HEAD AND NECK CAN BE GROUPED AS:
FACIAL MUSCLES
WHICH INCLUDES THE MUSCLES OF
SCALP, EYE, LIP, NOSE AND EARS.
MASTICATORY MUSCLES
WHICH INCLUDES THE MUCLES THAT
HELP IN THE MOVEMENT OF TMJ.
ANTEROLATERAL MUSCLES
OF NECK
WHICH INCLUDES SUPRAHYOID AND
INFRAHYOID MUSCLES.

8. FACIAL MUSCLE
FACIAL MUSCLE CONSISTS OF GROUP OF MUSCLES, NAMELY:
1. MUSCLES OF SCALP
2. MUSCLES OF AURICLES
3. MUSCLES OF EYELID
4. MUSCLES OF NOSE
5. MUSCLES AROUND MOUTH

9. OCCIPITOFRONTALIS:
• IT COVERS THE DOME OF SKULL.
Origin & Insertion:
• IT IS A BROAD, MUSCULOFIBROUS LAYER
CONSISTING OF 4 bellies - 2 occipital and 2 frontal
which are connected by an EPICRANIAL aponeurosis
(galea aponeurotica).
MUSCLES OF SCALP

10. • ORBITAL PART ARISES FROM LATERAL
2/3RD OF HIGHEST NUCHAL LINE & A
PART FROM MASTOID PART OF
TEMPORAL BONE.
• FRONTALIS PART IS ADHERENT TO
SUPERFICIAL FACSIA OF EYEBROWS.
IT IS DEVIDED INTO 3 PARTS:
a. MEDIAL FIBRES – WHICH IS
CONNECTED TO PROCERUS
b. INTERMEDIATE fibers – CONNECTED
TO CORRUGATOR SUPERCILLI.
c. LATERAL FIBERS – CONNECTED TO
ORBICULARIS OCULI.

11. NERVE SUPPLY:
POST AURICULAR BRANCH OF FACIAL NERVE TO OCCIPITALIS TEMPORAL BRANCHES OF FACIAL
NERVE TO FRONTALIS
BLOOD SUPPLY:
BRANCHES OF THE SUPERFICIAL TEMPORAL, OPHTHALMIC, POSTERIOR AURICULAR AND
OCCIPITAL ARTERIES.
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.

12. APPLIED ANATOMY:
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.

13. MUSCLES OF AURICLES
THERE ARE 3 MUSCLES DEPENDING ON
THE SITE OF ATTACHMENT:
1. AURICULARIS ANTERIOR
2. AURICULARIS SUPERIOR
3. AURICULARIS POSTERIOR

14. MUSCLE ORIGIN INSERTION ACTION NERVE SUPPLY
AURICULARIS
ANTERIOR
TEMPORAL
FASCIA
MAJOR HELIX
OF EAR
PULLS EAR
FORWARDS
TEMPORAL
BRANCH
AURICULARIS
SUPERIOR
TEMPORAL
FASCIA
ABOVE EAR
PULLS EAR
UPWARDS
POSTERIOR
AURICULAR
BRANCH
AURICULARIS
POSTERIOR
MASTOID
PROCESS
BEHIND THE
EAR
PULLS EAR
BACKWARDS
POSTERIOR
AURICULAR
BRANCH
BLOOD SUPPLY IS FROM POSTERIOR AURICULAR ARTERY.

15. MUSCLES OF EYELID
MUSCLES OF EYELIDS ARE:
1. ORBICULARIS OCULLI
2. CORRUGAROR SUPERCILLI
3. LEVATOR PALPEBRAL SUPERIORIS
4. Extraocular muscles

16. ORBICULARIS OCULLI:
IT SURROUNDS THE CIRCUMFERENCE OF
ORBIT.
IT HAS 3 PARTS:
I. ORBITAL
II. PALPEBRAL
III. LACRIMAL
PART OF MUSCLE ORIGIN INSERTION
ORBITAL MAJORLY FROM NASAL PART OF
MAXILLA AND FRONTAL PROCESS
OF MAXILLA
LATERAL PALPERBRAL LIGAMENT
PALPEBRAL MEDIAL PALPEBRAL LIGAMENT BLENDS WITH CORRUGATOR
MUSCLE
LACRIMAL CREST OF LACRIMAL BONE,
BEHIND THE SAC.
TARSI OF EYELID

17. • NERVE SUPPLY:
TEMPORAL AND ZYGOMATIC BRANCH
OF FACIAL NERVE.
ACTION:
THE MAJOR ACTION OF MUSCLES
HELP IN OPENING AND CLOSING OF EYELIDS.
APPLIED ANATOMY:
PARALYSIS OF ORBICULARIS OCULLI LEADS TO DROOPING OF EYELID AND INABILITY
TO CLOSE THE EYE; HENCE EXCESSIVE TEARING WILL BE NOTED.

18. CORRUGATOR SUPERCILLI:
• SMALL PYRAMIDAL MUSCLE LOCATED AT
MEDIAL END OF EACH EYEBROW.
• ARISES FROM MEDIAL END OF THE
SUPERCILLIARY ARCH AND INSERTED INTO
DEEP SURFACE OF SKIN, ABOVE THE
MIDDLE OF THE ORBITAL ARCH.
NERVE SUPPLY:
temporal BRANCH OF FACIAL NERVE.

19. LEVATOR PALPEBRAL SUPERIORIS:
IT IS MUSCLE THAT HELPS IN ELEVATING EYELID.
ORIGIN:
ARISES FROM THE UNDER SURFACE OF
THE LESSER WING OF THE SPHENOID,
ANTEROSUPERIOR TO THE OPTIC FORAMEN.
INSERTION:
BLENDS WITH THE ORBITAL SEPTUM AND
INSERTS INTO THE ANTERIOR SURFACE OF THE
SUPERIOR TARSUS.

20. Extraocular muscles
EXTRA OCULAR MUSCLES ARE AS FOLLOWS:
4 RECTI MUSCLES:
• SUPERIOR RECTUS
• INFERIOR RECTUS
• MEDIAL RECTUS
• LATERAL RECTUS
2 OBLIQUE MUSCLES:
• SUPERIOR OBLIQUE
• INFERIOR OBLIQUE

21. RECTIC Muscle:
ALL THE RECTI MUSCLES ARISES FROM A COMMON FIBROUS RING
WHICH SURROUNDS THE UPPER, MEDIAL, AND LOWER MARGINS OF
THE OPTIC FORAMEN AND ENCIRCLES THE OPTIC NERVE.
• TWO SPECIALIZED 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.

22. EACH MUSCLE PASSES FORWARD AND IS INSERTED INTO THE SCLERA BY A
TENDINOUS EXPANSION 6MM ABOVE THE MARGIN OF THE CORNEA.

23. Oblique muscles:
• Arises: above and medial to the
origin of superior rectus. The
fibers become a rounded
tendon and pass through
fibrocartilaginous ring or pulley
attached to the trochlear fovea
of frontal bone.
• Insertion: sclera of the lateral
part of the bulb of the eye
Between insertions of superior
rectus and lateral rectus.
• 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.
SUPERIOR OBLIQUE INFERIOR OBLIQUE

25. NERVE SUPPLY:
ALL THE MUSCLES EXCEPT SUPERIOR OBLIQUE AND LATERAL RECTUS,
ARE SUPPLIED BY OCULOMOTOR NERVE. WHERE AS SUPERIOR OBLIQUE AND
LATERAL RECTUS IS SUPPLIED BY TROCHLEAR AND ABDUCENT NERVES
RESPECTIVELY.
BLOOD SUPPLY:
All extraocular muscles are supplied by Ophthalmic artery.

26. ACTION:
• Levator palpebrae superioris: antagonist of orbicular oculi as it raises the eyelid
• Other extraocular muscles
HELPS IN MOVEMENT OF EYE.

27. ASSESSMENT OF MUSCLE
ENTRAPMENT FOLLOWING
TRAUMA OF MID-FACE REGIONS.

28. MUSCLES OF NOSE
MUSCLES OF NOSE CONSISTS OF:
I. PROCERUS
II. NASALIS
III. DEPRESSOR SEPTI

29. PROCERUS:
IT IS BLENDED WITH FRONTALIS MUSCLE AND INSERTED INTO THE SKIN OVER
THE LOWER PART OF FOREHEAD BETWEEN EYEBROWS.
ACTION:
DRAWS DOWN MEDIAL ANGLE
OF EYEBROWS PRODUCING
TRANSVERSE WRINKLES OVER BRIDGE
OF NOSE.

30. NASALIS:
IT HAS 2 PARTS
I. COMPRESSOR NARIS(TRANSVERSE PART): ARISES FROM THE MAXILLA
JUST LATERAL TO NASAL NOTCH AND INSERTED INTO APONEUROSIS
ACROSS DORSUM OF NOSE WITH MUSCLE FIBERS FROM THE OTHER
SIDE.
II. DILATOR NARIS(ALAR PART): ARISES FROM MAXILLA AND INSERTED
TO ALAR CARTILAGE OF NOSE.

31. Action:
TRANSVERSE PART
HELPS IN COMPRESSION OF NASAL
APPERTURE.
ALAR PART
Draws cartilage downward and
laterally opening OF nostril, hence
helps in dilation of nostrils.

32. DEPRESSOR SEPTI:
IT ARISES FROM THE MAXILLA; ABOVE THE CENTRAL INCISOR AND
ASCENDS TO ATTACH TO THE NASAL SEPTUM.
ACTION:
PULLS NOSE
INFERIORLY

33. NREVE SUPPLY:
ALL THE MUSCLES OF NOSE ARE SUPPLIED BY BUCCAL BRANCH OF FACIAL
NERVE.
BLOOD SUPPLY
• PROCERUS IS SUPPLIED MAINLY BY BRANCHES FROM THE FACIAL
ARTERY
• NASALIS IS SUPPLIED BY THE INFRAORBITAL BRANCH OF THE
MAXILLARY ARTERY
• DEPRESSOR SEPTI IS SUPPLIED BY THE SUPERIOR LABIAL BRANCH OF
THE FACIALARTERY

34. MUSCLES AROUND THE MOUTH
• ORBICULARIS ORIS
• LEVATOR LABII SUPERIORIS
• LEVATOR LABII SUPERIORIS ALAEQUE NASI
• ZYGOMATICUS MAJOR
• ZYGOMATICUS MINOR
• LEVATOR ANGULI ORIS
• DEPRESOR ANGULI ORIS
• DEPRESOR LABII INFERIORIS
• MENTALIS
• RISORIUS
• BUCCINATOR
MUSCLES FOUND
AROUND MOUTH
ARE:

35. ORBICULARIS ORIS:
THE ORBICULARIS ORIS MUSCLE IS A COMPLEX OF MUSCLES IN THE LIPS THAT
ENCIRCLES THE MOUTH.
• IT ARISESFROM
• ANTERIOR SURFACE OFMAXILLA
• ANTERIOR SURFACE OFMANDIBLE
• MODIOLUS
• INSERTION: PERIPHERAL PART DECUSSATE
WITH OPPOSITE FIBRES CROSSING THE
MIDLINE TO INSERT INTO THE SKIN NEAR
NASOLABIAL SULCUS.

36. • IN CASES OF CLEFT LIP THE PERIPHERAL PART RUNS
ALL THE WAY TO THE COLUMELLA WHILE THE
MARGINAL PART END AT THE MARGIN OF THEDEFECT
• IN CORRECTIONOF CLEFT LIP
 ORBICULARIS MUSCLEIS EVERTED WITH
VERTICAL MATTRESS SUTURES.
 THE MUSCLE CAN BE DIVIDED INTO HORIZONTAL
STRIPS THAT ARE INTERDIGITATED AND SUTURED
TO THE UNDERSURFACE OF THEDERMIS.
APPLIED ANATOMY:

37. HAS THREE HEADS:
• ANGULAR HEAD
• INTERMEDIATE
HEAD/INFRAORBITAL
HEAD
• ZYGOMATIC HEAD
LEVATOR LABI SUPERIORIS

38. • ARISES FROM THE FRONTAL PROCESS OF THE MAXILLA.
• INSERTS INTO THE GREATER ALAR CARTILAGE.
ANGULAR HEAD:
• ARISES FROM THE LOWER MARGIN OF THE ORBIT.
• INSERTED INTO THE MUSCULAR SUBSTANCE OF THE UPPER
LIP.
INTERMEDIATE
HEAD/INFRAORBITAL
HEAD:
• ARISES FROM THE MALAR SURFACE OF THE ZYGOMATIC
BONE.
• INSERTS INTO MEDIAL ASPECT OF THE UPPER LIP.
ZYGOMATIC HEAD:

39. LEVATOR LABI SUPERIORIS ALAEQUE NASI
• IT ARISES FROM THE UPPER PART OF FRONTAL
PROCESS OF MAXILLA.
• WHILE PASSING OBLIQUELY DOWNWARDS, IT SPLITS
INTO MEDIAL AND LATERAL SLIPS.
• THE MEDIAL SLIP INSERTS INTO GREATER ALAR
CARTILAGE AND LATERAL SLIP BLENDS WITH
LEVATOR LABII SUPERIORIS.

40. 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 ORBICULARIS ORIS.
ZYGOMATICUS MAJOR:

41. 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.
ZYGOMATICUS MINOR

42. LEVATOR ANGULI ORIS / CANINUS
ORIGIN AND INSERTION:
• ARISES FROM 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.

43. NERVER SUPPLY:
BUCCAL BRANCH OF FACIAL NERVE.
BLOOD SUPPLY:
• LEVATOR LABII SUPERIORIS IS SUPPLIED BY THE FACIAL ARTERY AND THE
INFRAORBITAL BRANCH OF THE MAXILLARY ARTERY.
• LEVATOR LABII SUPERIORIS ALAEQUAE NASI IS SUPPLIED BY THE FACIAL
ARTERY AND THE INFRAORBITAL BRANCH OF THE MAXILLARY ARTERY
• ZYGOMATICUS IS SUPPLIED BY THE SUPERIOR LABIAL BRANCH OF THE FACIAL
ARTERY.
• CANINUS IS SUPPLIED BY THE SUPERIOR LABIAL BRANCH OF THE FACIAL ARTERY
AND THE INFRAORBITAL BRANCH OF THE MAXILLARY ARTERY.

44. ACTIONS:
• LEVATOR LABII SUPERIORIS: ELEVATOR OF UPPER LIP. WHEN THE WHOLE
MUSCLE CONTRACTS IT GIVES THE EXPRESSION OF CONTEMPT.
• CANINUS: HELPS IN PRODUCING THE NASOLABIAL FURROW.
• ZYGOMATICUS: HELPS IN SMILING.
o ZYGOMATICUS MAJOR: PULLS THE ANGLE OF THE MOUTH UPWARDS AND
LATERAL
o ZYGOMATICUS MINOR: ELEVATES THE UPPER LIP

45. 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.
BLOOD SUPPLY:
• INFERIOR LABIAL BRANCH OF THE FACIAL ARTERY
AND THE MENTAL BRANCH OF THE MAXILLARY
ARTERY.
ACTIONS:
• DRAWS THE LOWER LIP DOWNWARDS AND
LATERALLY, AS IN EXPRESSION OF IRONY.
DEPRESSOR LABII INFERIORIS

46. ORIGIN AND INSERTION:
• ARISES FROM THE OBLIQUE LINE OF THE
MANDIBLE.
• INSERTS INTO THE ANGLE OF THE MOUTH.
BLOOD SUPPLY:
• INFERIOR LABIAL BRANCH OF THE FACIAL
ARTERY AND THE MENTAL BRANCH OF THE
MAXILLARY ARTERY.
ACTIONS:
• DEPRESSES ANGLE OF MOUTH MEDIALLY
ALONG WITH PLATYSMA.
DEPRESSOR ANGULI ORIS /
TRIANGULARIS

47. ORIGIN AND INSERTION:
• ARISES FROM THE INCISIVE FOSSA OF THE
MANDIBLE.
• INSERTS INTO THE INTEGUMENT OF THE CHIN.
BLOOD SUPPLY:
• INFERIOR LABIAL BRANCH OF THE FACIAL ARTERY
AND THE MENTAL BRANCH OF THE MAXILLARY
ARTERY.
ACTIONS:
• RAISES AND PROTRUDES THE LOWER LIP AND AT
THE SAME TIME WRINKLES THE SKIN OF THE
CHIN, EXPRESSING DOUBT.
MENTALIS

48. 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.
BUCCINATOR

49. BLOOD SUPPLY:
• BRANCHES FROM THE FACIAL ARTERY
AND THE BUCCAL BRANCH OF THE
MAXILLARY ARTERY.
ACTION:
• COMPRESSES THE CHEEKS SO THAT
DURING MASTICATION THE FOOD IS KEPT
UNDER IMMEDIATE PRESSURE OF THE
TEETH.
• HENCE IT IS CALLED AS ACCESSORY
MUSCLE OF MASTICATION.

50. ORIGIN AND INSERTION:
• ARISES IN THE FASCIA OVER MASSETER AND
PASSES HORIZONTALLY FORWARD ABOVE THE
PLATYSMA.
• INSERTS INTO THE SKIN OF THE ANGLE OF
THE MOUTH.
BLOOD SUPPLY:
• SUPPLIED MAINLY BY THE SUPERIOR LABIAL
BRANCH OF THE FACIAL ARTERY.
ACTION:
• RETRACTS THE ANGLE OF THE MOUTH AND
HELPS IN PRODUCING UNPLEASANT GRINNING
EXPRESSION.
RISORIUS

51. IT IS DEFINED AS A LATERAL POINT TO THE CORNER OF THE ANGLE OF THE
MOUTH WHERE THE MUSCLES OF FACIAL EXPRESSION CONVERGE. (JABLONSKI
1982;MANHOLD AND BALBO 1985; HARRY AND OGSTON 1987).
THE MUSCLES WHICH FORM THE MODIOLUS ARE:
 ORBICULARIS ORIS
 BUCCINATOR
 CANINUS
 TRIANGULARIS
 ZYGOMATICUS MAJOR
 RISORIUS
 PLATYSMA
 LEVATOR LABIISUPERIORIS
MODIOLUS

52. SHIMADA AND GASSER (1989) HAVE REPORTED
VARIATIONS IN THE LOCATION OF MODIOLUS.
TYPE A: MODIOLUS
LATERALTO THE
ANGLE OF THE
MOUTH
TYPE B: MODIOLUS
ABOVETHE ANGLE
TYPE C: MODIOLUS
BELOWTHE ANGLE*CLINICAL ANATOMY 2:29-134(1989); VARIATIONS IN THE FACIAL
MUSCLES AT THE ANGLE OF THE MOUTH – KAZUYUKI
SHIMADAAND RAYMOND F. GASSER

53. COMMON FACIAL EXPRESSIONS
I. SMILING & LAUGHING: ZYGOMATICS MAJOR
II. SADNESS: LEVATOR LABII SUPERIORIS AND LEVATOR ANGULI ORIS
III. GRIEF: DEPRESSOR ANGULI ORIS
IV. ANGER: DILATOR NARIS & DEPRESSOR SEPTI
V. FROWNING: CORRUGATOR SUPERCILII & PROCERUS
VI. HORROR, TERROR & FIGHT: PLATYSMA
VII. SURPRISE: FRONTALIS
VIII. DOUBT: MENTALIS
IX. GRINNING: RISORIUS
X. CONTEMPT: ZYGOMATIC MINOR

54. FACIAL MUSCLES: ACTIONS

55. FACIAL MUSCLES: ACTIONS

56. APPLIED ANATOMY
FACIAL PARALYSIS, OFTEN UNILATERAL, MAY BE DUE TO:
(1) SUPRANUCLEAR LESIONS IN THE CORTICO NUCLEAR FIBERS FROM THE FRONTAL LOBE,
VARIABLY COMBINED WITH NUMEROUS OTHER DESCENDING FIBERS CONVERGING IN
THE FACIAL NUCLEUS.
(2) NUCLEAR OR INFRANUCLEAR LESIONS INVOLVING LOWER MOTOR NEURONS.

57. • SUPRANUCLEAR FACIAL PARALYSIS
INVOLVING “UPPER MOTOR NEURON”,
MOVEMENTS IN THE LOWER PART OF THE
FACE ARE USUALLY AFFECTED.
• INFRANUCLEAR LESIONS VARY IN THEIR
EFFECTS ACCORDING TO THE LESION’S
SITE. FACIAL MUSCLES ARE REPRESENTED
IN CELL GROUPS WITHIN THE NUCLEUS;
THEIR DEGREE OF INVOLVEMENT
GOVERNS THE EXTENT OF PARALYSIS,
WHICH IS IPSILATERAL.

58. BELL’S PALSY
IS AN ACUTE APPARENTLY ISOLATED WITH LMN FACIAL PALSY
FOR WHICH NO CAUSE CAN BE FOUND.
AETIOLOGY:
• ASSOCIATED KNOWN CLINICAL CONDITION –
DIABETES MELLITUS, SEVERE HYPERTENSION IN LAST
TRIMESTER OF PREGNANCY, DENTAL ANESTHESIA.
• CAUSES – (I) EXPOSURE TO COLD, OEDEMA AND
SUBSEQUENT COMPRESSION OF THE NERVE TRUNK
CAUSES CIRCULATORY DISTURBANCE, (II) OTHER
IMPORTANT CAUSES INCLUDE SUPPURATIVE OTITIS
MEDIA, HERPES ZOSTER, HEAD INJURY, GUILLIAN-BARRE
SYNDROME, SARCOIDOSIS AND MULTIPLE SCLEROSIS.

59. SYMPTOMS:
SUDDEN FOLLOWING EXPOSURE TO CHILL OR WITHOUT ANY APPARENT PRECIPITATING
CAUSE. POST AURICULAR PAIN IS COMMON AND MANY PRECEDE PARALYSIS BY TWO DAYS.
THERE MAY BE SPONTANEOUS LOSS OF SENSE OF TASTE AND WATERING OF EYES.
SIGNS:
I. FOREHEAD CANNOT BE WRINKLED, EYES CANNOT BE CLOSED.
II. ON ATTEMPTING CLOSURE EYE BALL TURNS UPWARDS AND OUTWARDS, KNOWN AS BELL’S
PHENOMENON.
III. ON SHOWING TEETH, THE LIPS DO NOT SEPARATE ON AFFECTED SIDE.
IV. ANGLE OF AFFECTED SIDE DROOPS WITH DRIBBLING OF SALIVA.
V. CHEEKS PUFFS OUT WITH EXPIRATION BECAUSE OF BUCCINATOR PARALYSIS.
VI. BASE OF TONGUE LOWERED.
VII.PAIN MAY PRECEDE FACIAL WEAKNESS.
VIII.DEAFNESS MAY RESULT.

60. MASTICATORY MUSCLES
• THE MUSCLES OF MASTICATION ARE MANINLY
CONCERNED IN THE MOVEMENT OF MANDIBLE
DURING MASTICATION AND SPEECH.
• THEY DEVELOP FROM THE MESODERM OF 1ST
BRANCHIAL ARCH AND IS SUPPLIED BY
MANDIBULAR NERVE, WHICH IS A NERVE OF THAT
ARCH.

61. MUSCLES OF MASTICATION INCLUDE:
1. MASSETER
2. TEMPORALIS
3. MEDIAL PTERYGOID
4. LATERAL PTERYGOID

62. IT IS A QUADRILATERAL MUSCLE THAT COVERS THE
LATERAL SURFACE OF RAMUS OF MANDIBLE.
IT IS DIVIDED INTO TWO LAYERS:
 SUPERIFICIAL PART:
 ORIGINATES FROM THE ANTERIOR 2/3RD OF
LOWER BORDER OF ZYGOMATIC ARCH AND
INSERTS INTO LOWER PART OF LATERAL SURFACE
OF RAMUS.
 DEEP LAYER:
 ORIGINATES FROM THE DEEP SURFACE OF
ZYGOMATIC ARCH AND INSERTS INTO THE REST
OF RAMUS OF THE MANDIBLE.
MASSETER

63. • NERVE SUPPLY:
 MASSETERIC NERVE WHICH IS
BRANCH OFANTERIOR DIVISION
OF MANDIBULAR NERVE.
• BLOOD SUPPLY:
 SUPPLIED BY THE MASSETERIC
BRANCH OFTHEMAXILLARY
ARTERY, THE FACIAL ARTERY AND
THE TRANSVERSE FACIAL BRANCH
OF THE SUPERFICIAL TEMPORAL
ARTERY.
• ACTION:
 ELEVATES THE MANDIBLE TO
CLOSE THE MOUTH.

64. ORIGIN AND INSERTION:
• ORIGINATES FROM TEMPORAL FOSSA
EXCLUDING THE ZYGOMATIC BONE, AND THE
TEMPORAL FASCIA.
• THE FIBRES CONVERGE AND PASSES DEEP TO
THE ZYGOMATIC ARCH AND INSERTS INTO THE
MARGINS AND DEEP PORTIONS OF THE
CORONOID PROCESS AND ANTERIOR BORDER
OF THE RAMUS.
TEMPORALIS

65. • NERVE SUPPLY:
 TWO DEEP TEMPORAL BRANCHES FROM THE
ANTERIOR DIVISION OF THE MANDIBULAR
NERVE.
• BLOOD SUPPLY:
 SUPPLIED BY THE DEEP TEMPORAL
BRANCHES FROM THE SECOND PART OF THE
MAXILLARY ARTERY.
• ACTIONS:
 ELEVATES THE MANDIBLE TO CLOSE THE
MOUTH.
 POSTERIOR FIBRES RETRACT THE PROTRUDED
MANDIBLE.
 SIDE TO SIDE GRINDING MOVEMENT

66. MEDIAL PTERYGOID
ORIGIN AND INSERTION:
IT HAS TWO HEADS:
 SUPERFICIAL HEAD: ORIGINATES FROM THE
TUBEROSITY OF THE MAXILLA AND
ADJOINING BONE.
 DEEP HEAD: ORIGINATES FORM THE
MEDIAL SURFACE OF LATERAL PTERYGOID
PLATE AND ADJOINING PROCESS OF
PALATINE BONE.
• INSERTED INTO THE ROUGHENED AREA ON
THE MEDIAL SURFACE OF ANGLE AND
ADJOINING RAMUS OF MANDIBLE, BELOW
AND BEHIND THE MANDIBULAR FORAMEN
AND MYLOHYOID GROOVE.

67. • NERVE SUPPLY:
 NERVE TO MEDIAL PTERYGOID, A BRANCH OF
THE MAIN TRUNK OF MANDIBULAR NERVE.
• BLOOD SUPPLY:
 MEDIAL PTERYGOID DERIVES ITS MAIN
ARTERIAL SUPPLY FROM THE PTERYGOID
BRANCHES OF THE MAXILLARY ARTERY.
• ACTIONS:
 ELEVATES MANDIBLE
 PROTRUSION OF MANDIBLE
 SIDE TO SIDE GRINDING MOVEMENTS

68. ORIGIN AND INSERTION:
• IT HAS TWO HEADS
 UPPER HEAD: ORIGINATES FROM THE
INFRATEMPORAL SURFACE AND CREST OF
THE GREATER WING OF SPHENOID.
 LOWER HEAD: FROM THE LATERAL
SURFACE OF THE LATERAL PTERYGOID
PLATE.
• ITS FIBRES INSERT INTO PTERYGOID FOVEA ON
THE ANTERIOR SURFACE OF THE NECK OF THE
CONDYLE MANDIBLE ANTERIOR MARGIN OF
THE ARTICULAR DISC AND CAPSULE OF TMJ.
LATERAL PTERYGOID

69. • NERVE SUPPLY:
 A BRANCH OF ANTERIOR DIVISION OF
MANDIBULAR NERVE.
• BLOOD SUPPLY:
 LATERAL PTERYGOID IS SUPPLIED BY PTERYGOID
BRANCHES FROM THE MAXILLARY ARTERY.
• ACTIONS:
 DEPRESSES MANDIBLE TO OPEN THE MOUTH
ALONG WITH SUPRAHYOID MUSCLE.
 LATERAL AND MEDIAL PTERYGOIDS PROTRUDE THE
MANDIBLE.
 LEFT LATERAL PTERYGOID AND RIGHT MEDIAL
PTERYGOID TURN THE CHIN TO THE LEFT SIDE AND
VICE VERSA.

70. APPLIED ANATOMY
• MASSETERIC HYPERTROPHY:
IT IS RECOGNIZED AS AN ENLARGEMENT
OF ONE OR BOTH MASSETER MUSCLES.
MOST PATIENTS COMPLAIN OF FACIAL
ASYMMETRY.
• SUBMASSETERIC SPACE INFECTION:
SOMETIMES INFECTION AROUND
MANDIBULAR THIRD MOLAR TOOTH
TRACKS BACKWARDS, LATERAL TO THE
MANDIBULAR RAMUS AND PUS LOCALIZES
DEEP TO THE ATTACHMENT OF MASSETER
IN THE SUBMASSETERIC TISSUE SPACE.

71. • TEMPORALIS MUSCLE FLAP:
TEMPORALIS MUSCLE IS USED TO
RECONSTRUCT DEFECTS OF THE ORAL
TISSUES LIKE TONGUE, TONGUE BASE,
BUCCAL MUCOSA, MAXILLA, SOFT
PALATE, RETROMOLAR TRIGONE AND
TONSILLAR REGION.

72. • ANTERO-MEDIAL DISPLACEMENT OF
CONDYLE DURING SUBCONDYLAR
FRACTURES DUE TO THE SPASM OF
LATERAL PTERYGOID.
• MEDIAL PTERYGOID SPASM RENDERING
TRISMUS DUE TO IMPROPER TECHNIQUE
OF IAN BLOCK.
• TRAVERSING OF FACIAL ARTERY ALONG
THE ANTERO-INFERIOR BORDER OF
MASSETER OVER THE BODY OF MANDIBLE.

73. MUSCLES OF NECK
MUSCLES OF NECK CONSISTS OF FOLLOWING GROUP OF
MUSCLES:
1. SUPERFICIAL AND LATERAL CERVICAL MUSCLES.
2. SUPRAHYOID MUSCLES.
3. INFRAHYOID MUSCLES.
4. ANTERIOR VERTEBRAL MUSCLES.
5. LATERAL VERTEBRAL MUSCLES.
6. SUBOCCIPITAL MUSCLES.
9/11/2018 73

74. SUPERFICIAL AND LATERAL CERVICAL MUSCLES
CONSISTS OF 3 MUSCLES:
I. PLATYSMA
II. TRAPEZIUS
III. STERNOCLEIDOMASTOID
9/11/2018 74

75. 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.
PLATYSMA
9/11/2018 75

76. NERVE SUPPLY:
CERVICAL BRANCH OF
FACIAL NERVE.
BLOOD SUPPLY:
BY THE SUBMENTAL BRANCH
OF THE FACIAL ARTERY AND
BY THE SUPRASCAPULAR
ARTERY.
ACTIONS:
• DEPRESSES MANDIBLE.
• PULLS THE ANGLE OF THE
MOUTH DOWNWARDS AS
IN HORROR OR SURPRISE.
9/11/2018 76

77. TRAPEZIUS
ORIGIN AND INSERTION
ORIGIN: SPINOUS PROCESS OF
VERTEBRAE C7-T12.
INSERTION: EXTERNAL OCCIPITAL
PROTRUBERANCE AND SPINE OF
SCAPULA.
NERVE SUPPLY:
ACCESSORY NERVE AND CERVICAL
NERVES C3 AND C4.
BLOOD SUPPLY:
BRANCHES OF OCCIPITAL ARTERY,
SUPERFICIAL CERVICAL ARTERY.
ACTIONS:
ROTATION, RETRACTION, ELEVATION
AND DEPRESSION OF SCAPULA.
9/11/2018 77

78. ORIGIN AND INSERTION:
ARISES FROM THE STERNUM
AND CLAVICLE BY TWO HEADS.
• MEDIAL HEAD ARISES FROM
THE UPPER PART OF THE
ANTERIOR SURFACE OF THE
MANUBRIUM STERNI.
• LATERAL HEAD ARISES
FROM THE SUPERIOR
BORDER AND ANTERIOR
SURFACE OF THE MEDIAL
THIRD OF CLAVICLE.
STERNOCLEIDOMASTOID
9/11/2018 78

79. • TWO HEAD ARE SEPARATED
FROM ONE ANOTHER AT
THEIR ORIGINS BUT
GRADUALLY BLEND TO
FORM A THICK ROUNDED
MUSCLE BELOW THE
MIDDLE OF THE NECK.
• IT INSERTS INTO THE
LATERAL SURFACE OF THE
MASTOID PROCESS
THROUGH A STRONG
TENDON AND THROUGH A
THIN APONEUROSIS INTO
THE LATERAL HALF OF THE
SUPERIOR NUCHAL LINE.
9/11/2018 79

80. NERVE SUPPLY:
SPINAL PART OF THE ACCESSORY
NERVE.
BLOOD SUPPLY:
BRANCHES OF THE OCCIPITAL AND
POSTERIOR AURICULAR AND THE
SUPRASCAPULAR ARTERY.
ACTIONS:
• ACTING ALONE, EACH
STERNOCLEIDOMASTOID MUSCLE
WILL TILT THE HEAD TOWARDS
THE OPPOSITE SIDE AND FLEXES
LATERALLY TO THE SAME SIDE.
• ACCESSORY MUSCLES OF
RESPIRATION, ALONG WITH
SCALENE MUSCLES
9/11/2018 80

81. SUPRAHYOID MUSCLES
SUPRAHYOID MUSCLES
INCLUDE:
1. DIGASTRIC
2. STYLOHYOID
3. MYLOHYOID
4. GENIOHYOID
9/11/2018 81

82. IT HAS TWO BELLIES UNITED BY AN
INTERMEDIATE TENDON.
ORIGIN:
• ANTERIOR BELLY: ORIGINATES
FROM THE DIGASTRIC FOSSA
OF MANDIBLE.
• POSTERIOR BELLY: ORIGINATES
FROM MASTOID NOTCH OF
TEMPORAL BONE.
INSERTION:
• BOTH THESE BELLIES MEET AT
THE INTERMEDIATE TENDON
WHICH PERFORATES THE
STYLOHYOID AND IS HELD BY A
FIBROUS PULLEY TO THE HYOID
BONE.
DIGASTRIC
9/11/2018 82

83. NERVE SUPPLY:
• ANTERIOR BELLY: NERVE TO
MYLOHYOID
• POSTERIOR BELLY: FACIAL
NERVE
BLOOD SUPPLY:
• THE POSTERIOR BELLY IS
SUPPLIED BY THE
POSTERIOR AURICULAR
AND OCCIPITAL ARTERIES.
• THE ANTERIOR BELLY
RECEIVES ITS BLOOD
SUPPLY FROM THE
SUBMENTAL BRANCH OF
THE FACIAL ARTERY
ACTION:
• DEPRESSES MANDIBLE
WHILE OPENING MOUTH
OR AGAINST RESISTANCE.
• ELEVATES HYOID BONE
9/11/2018 83

84. STYLOHYOID
ORIGIN AND INSERTION:
ORIGINATES FROM POSTERIOR
SURFACE OF STYLOID PROCESS.
INSERTION INTO THE JUNCTION OF
BODY AND GREATER CORNUA OF
HYOID BONE.
NERVE SUPPLY:
BRANCHES OF FACIAL NERVE.
BLOOD SUPPLY:
BRANCHES OF THE FACIAL, POSTERIOR
AURICULAR AND OCCIPITAL ARTERIES.
ACTIONS:
PULLS HYOID BONE UPWARDS AND
BACKWARDS.9/11/2018 84

85. ORIGIN AND INSERTION:
ORIGIN FROM MYLOHYOID LINE OF
THE MANDIBLE AND INSERTS ON
BODY OF HYOID BONE.
NERVE SUPPLY:
NERVE TO MYLOHYOID
BLOOD SUPPLY:
THE SUBLINGUAL BRANCH OF THE
LINGUAL ARTERY, MYLOHYOID
BRANCH OF THE INFERIOR ALVEOLAR
ARTERY AND THE SUBMENTAL BRANCH
OF THE FACIAL ARTERY.
ACTION:
HELPS IN DEPRESSION OF MANDIBLE
AND ELEVATION OF HYOID BONE.
MYLOHYOID
9/11/2018 85

86. ORIGIN AND INSERTION:
ORIGINATES FROM INFERIOR
MENTAL SPINE (GENIAL
TUBERCLES) AND INSERTS TO
ANTERIOR SURFACE OF HYOID
BONE.
NERVE SUPPLY:
HYPOGLOSSAL NERVE.
BLOOD SUPPLY:
DERIVED FROM THE LINGUAL
ARTERY.
ACTION:
ELEVATES THE HYOID BONE.
DEPRESSES THE MANDIBLE WHEN
HYOID IS FIXED.
GENIOHYOID
9/11/2018 86

87. INFRAHYOID MUSCLES
INFRAHYOID MUSCLES
INCLUDES:
1. THYROHYOID
2. OMOHYOID
3. STRENOTHYROID
4. STERNOHYOID
9/11/2018 87

88. ORIGIN AND INSERTION:
IT ARISES FROM THE OBLIQUE LINE
ON THE LAMINA OF THE THYROID
CARTILAGE, AND IS INSERTED INTO
THE LOWER BORDER OF THE GREATER
CORNI OF THE HYOID BONE.
BLOOD SUPPLY:
BRANCHES OF SUPERIOR THYROID
ARTERY.
NERVE SUPPLY:
HYPOGLOSSAL NERVE.
ACTION:
SMALL SKELETAL MUSCLE ON THE
NECK WHICH DEPRESSES THE HYOID
AND ELEVATES THE LARYNX.
9/11/2018 88
THYROHYOID

89. OMOHYOID
ORIGIN AND INSERTION:
ORIGINATES FROM UPPER BORDER OF
SCAPULA NEAR SUPRASCAPULAR NOTCH AND
GETS INSERTED INTO LOWER BORDER OF
HYOID BONE.
NERVE SUPPLY:
• BY SUPERIOR ROOT OF THE ANSA
CERVICALIS.
BLOOD SUPPLY:
• SUPPLIED BY BRANCHES FROM THE
SUPERIOR THYROID AND LINGUAL ARTERIES.
ACTIONS:
• DEPRESSION AND ELEVATION DURING
SWALLOWING OR IN VOCAL MOVEMENTS.9/11/2018 89

90. ORIGIN AND INSERTION:
ORIGINS FROM POSTERIOR
SURFACE OF MANUBRIUM STERNI
AND INSERTS INTO MEDIAL PART OF
LOWER BORDER OF HYOID BONE.
NERVE SUPPLY:
ANSA CERVICALIS
BLOOD SUPPLY:
SUPPLIED BY BRANCHES FROM THE
SUPERIOR THYROID ARTERY.
ACTIONS:
DEPRESSES THE HYOID BONE
FOLLOWING ELEVATION DURING
SWALLOWING AND VOCAL
MOVEMENTS.
STERNOHYOID
9/11/2018 90

91. ORIGIN AND INSERTION:
ORIGIN FROM POSTERIOR SURFACE OF
MANUBRIUM STERNI AND ADJOINING PART
OF FIRST COSTAL CARTILAGE AND INSERTS
INTO OBLIQUE LAMINA OF THE THYROID
CARTILAGE.
NERVE SUPPLY:
HYPOGLOSSAL NERVE.
BLOOD SUPPLY:
SUPPLIED BY BRANCHES FROM THE
SUPERIOR THYROID AND LINGUAL ARTERIES.
ACTIONS:
• DEPRESSES HYOID BONE.
• ELEVATES THE LARYNX WHEN THE HYOID
IS FIXED BY THE SUPRAHYOID MUSCLE.
STERNOTHYROID
9/11/2018 91

92. ANTERIOR VERTEBRAL MUSCLES
IT CONSISTS OF 4 MUSCLES:
1. LONGUS COLLI
2. LONGUS CAPITIS
3. RECTUS CAPITIS ANTERIOR
4. RECTUS CAPITIS LATERALIS
9/11/2018 92

93. LONGUS COLLI
IT IS SITUATED ON THE ANTERIOR SURFACE
OF THE VERTEBRAL COLUMN.
ORIGIN AND INSERTION:
ORIGIN:TRANSVERSE PROCESSES OF C-5
TO T-3
INSERTION:ANTERIOR ARCH OF THE
ATLAS.
BLOOD SUPPLY:
ASCENDING PHARYNGEAL AND
VERTEBRAL ARTERIES.
NERVE SUPPLY:
FROM C2-C6
ACTIONS:
FLEXION OF NECK.
9/11/2018 93

94. LONGUS CAPITIS
ORIGIN AND INSERTION:
ORIGIN: TRANSVERSE PROCESSES OF
THE THIRD, FOURTH, FIFTH, AND SIXTH
CERVICAL VERTEBRAE.
INSERTION: BASILAR PART OF THE
OCCIPITAL BONE.
BLOOD SUPPLY:
BRANCHES OF THE ASCENDING
CERVICAL ARTERY.
NERVE:
BARNCHES OF C1-C3/C4
ACTIONS:
FLEXION OF NECK AT ATLANTO-
OCCIPITAL JOINT.
9/11/2018 94

95. RECTUS CAPITIS ANTERIOR
IT IS A SHORT, FLAT MUSCLE, SITUATED
IMMEDIATELY BEHIND THE UPPER PART
OF THE LONGUS CAPITIS.
ORIGIN AND INSERTION:
ORIGIN: IT ARISES FROM THE
ANTERIOR SURFACE OF THE LATERAL
MASS OF THE ATLAS.
INSERTION: INSERTED INTO THE
INFERIOR SURFACE OF THE OCCIPITAL
BONE, IN FRONT OF THE FORAMEN
MAGNUM.
NERVE SUPPLY:
BRANCHES OF C1, C2.
ACTION:
AIDS IN FLEXION OF NECK.9/11/2018 95

96. RECTUS CAPITIS LATERALIS
ORIGIN AND INSERTION:
ORIGIN: UPPER SURFACE OF THE
TRANSVERSE PROCESS OF THE
ATLAS.
INSERTION: UNDER SURFACE OF
THE JUGULAR PROCESS OF THE
OCCIPITAL BONE.
NERVE:
BRANCHES OF C1, C2
ACTIONS:
LATERAL FLEXION, STABILISE
ATLANTO-OCCIPITAL JOINT
9/11/2018 96

97. LATERAL VERTEBRAL MUSCLES
IT CONSISTS OF SCALENI
MUSCLES:
1. SCALENUS ANTERIOR
2. SCALENUS MEDIUS
3. SCALENUS POSTERIOR
9/11/2018 97

98. SCALENUS ANTERIOR
IT LIES DEEPLY AT THE SIDE OF THE NECK,
BEHIND THE STERNOCLEIDOMASTOID
MUSCLE.
ORIGIN AND INSERTION:
ORIGIN: CERVICAL VERTEBRAE (C2-C7)
INSERTION: FIRST AND SECOND RIBS
BLOOD SUPPLY:
ASCENDING CERVICAL BRANCH OF
INFERIOR THYROID ARTERY
NERVE:
CERVICAL NERVES (C3-C7)
ACTIONS:
ELEVATION OF FIRST AND SECOND RIBS
9/11/2018 98

99. SCALENUS MEDIUS
ORIGIN AND INSERTION:
ORIGIN: ARISES FROM THE POSTERIOR
TUBERCLES OF THE LOWER SIX CERVICAL
VERTEBRAE.
INSERTION: UPPER SURFACE OF THE 1ST
RIB.
BLOOD SUPPLY:
SUPPLIED BY THE ASCENDING CERVICAL
BRANCH OF THE INFERIOR THYROID
ARTERY.
NERVE SUPPLY:
FROM BRANCHES OF C4-C6.
ACTIONS:
ELEVATES THE FIRST RIB AND LATERALLY
FLEX THE NECK TO THE SAME SIDE.9/11/2018 99

100. SCALENUS POSTERIOR
ORIGIN AND INSERTION:
ORIGIN: ARISES FROM POSTERIOR
TUBERCLES OF THE LOWER THREE
CERVICAL VERTEBRAE.
INSERTION: INSERTED BY TENDON
INTO THE OUTER SURFACE OF 2ND
RIB.
BLOOD SUPPLY:
ASCENDING CERVICAL A BRANCH
OF INFERIOR THYROID ARTERY
NERVE SUPPLY:
FROM BRANCHES OF C4-C6.
ACTIONS:
ELEVATES THE 2ND RIB AND TILT
THE NECK TO THE SAME SIDE.9/11/2018 100

101. SUBOCCIPITAL MUSCLES
THE SUBOCCIPITAL MUSCLES ARE A
GROUP OF MUSCLES DEFINED BY
THEIR LOCATION TO THE OCCIPUT.
THE MUSCLES ARE NAMED AS:
I. RECTUS CAPITIS POSTERIOR
MAJOR
II. RECTUS CAPITIS POSTERIOR
MINOR
III. OBLIQUUS CAPITIS SUPERIOR
IV. OBLIQUUS CAPITIS INFERIOR9/11/2018 101

102. RECTUS CAPITUS POSTERIOR MAJOR
ORIGIN AND INSERTION:
ORIGIN: SPINOUS PROCESS OF THE
AXIS (C2)
INSERTION: INFERIOR NUCHAL LINE
OF THE OCCIPITAL BONE.
BLOOD SUPPLY:
BRANCH OF OCCIPITAL ARTERY
NERVE SUPPLY:
BRANCH OF SUB-OCCIPITAL NERVE
ACTIONS:
IPSILATERAL ROTATION OF HEAD AND
EXTENSION
9/11/2018 102

103. RECTUS CAPITUS POSTERIOR MINOR
ORIGIN AND INSERTION:
ORIGIN: TUBERCLE ON THE POSTERIOR
ARCH OF THE ATLAS
INSERTION: MEDIAL PART OF THE
INFERIOR NUCHAL LINE OF THE OCCIPITAL
BONE.
BLOOD SUPPLY:
BRANCH OF OCCIPITAL ARTERY
NERVE SUPPLY:
BRANCH OF THE SUBOCCIPITAL NERVE
ACTIONS:
EXTENDS THE HEAD AT THE NECK.
9/11/2018 103

104. OBLIQUUS CAPITIS INFERIOR
ORIGIN AND INSERTION:
ORIGIN: SPINOUS PROCESS OF
THE AXIS
INSERTION: LATERAL MASS OF
ATLAS
BLOOD SUPPLY:
DEEP DESCENDING BRANCH OF
THE OCCIPITAL ARTERY.
NERVE:
BRANCH OF SUBOCCIPITAL
NERVE.
ACTIONS:
ROTATION OF HEAD AND NECK.9/11/2018 104

105. OBLIQUUS CAPITIS SUPERIOR
ORIGIN AND INSERTION:
ORIGIN: LATERAL MASS OF ATLAS.
INSERTION: LATERAL HALF OF
THE INFERIOR NUCHAL LINE.
BLOOD SUPPLY:
DEEP DESCENDING BRANCH OF
THE OCCIPITAL ARTERY.
NERVE SUPPLY:
BRANCHES OF SUBOCCIPITAL
NERVE.
ACTION:
EXTENDS HEAD AND FLEX HEAD
TO THE IPSILATERAL SIDE.9/11/2018 105

106. TRIANGLES OF NECK
STERNOCLEIDOMASTOIDEUS
DIVIDES THIS SPACE INTO
TWO TRIANGLES.
THE TRIANGULAR SPACE IN
FRONT OF THIS MUSCLE IS
CALLED THE ANTERIOR
TRIANGLE.
THE TRIANGLE BEHIND IT,
THE POSTERIOR TRIANGLE.
9/11/2018 106

107. ANTERIOR TRIANGLE
BOUNDARIES:
ANTERIORLY: BY THE MEDIAN LINE OF THE
NECK.
POSTERIORLY: BY THE ANTERIOR MARGIN
OF STERNOCLEIDOMASTOID.
BASE: INFERIOR BORDER OF THE
MANDIBLE AND ITS PROJECTION TO THE
MASTOID PROCESS.
APEX: MANUBRIUM STERNI.
IT CAN BE SUBDIVIDED INTO SUPRAHYOID
AND INFRAHYOID AREAS ABOVE AND BELOW
THE HYOID BONE.9/11/2018 107

108. ANTERIOR TRIANGLE OF NECK
CONSISTS OF 4 TRIANGLES NAMELY:
1. DIGASTRIC
2. SUBMENTAL
3. MUSCULAR
4. CAROTID TRIANGLES
9/11/2018 108

109. DIGASTRIC TRIANGLE
9/11/2018 109
BOUNDARIES:
ANTERO-INFERIORLY – ANTERIOR
BELLY OF DIGASTRIC
POSTERO-INFERIORLY – POSTERIOR
BELLY OF DIGASTRIC
SUPERIORLY (BASE) – BASE OF THE
MANDIBLE
ROOF: SKIN, SUPERFICIAL FASCIA
AND DEEP FASCIA.
FLOOR: MYLOHYOID MUSCLE
(ANTERIORLY) AND HYOGLOSSUS
POSTERIORLY.

110. CONTENTS OF DIGASTRIC TRIANGLE
ANTERIORLY:
STRUCTURES SUPERFICIAL TO MYLOHYOID –
• SUBMANDIBULAR GLAND
• FACIAL VEIN
• SUBMANDIBULAR LYMPH NODES
• MYLOHYOID NERVE.
STRUCTURES SUPERFICIAL TO THE
HYOGLOSSUS –
• INTERMEDIATE TENDON OF DIGASTRIC.
• HYPOGLOSSAL NERVE.
POSTERIOR PART:
• LOWER PART OF PAROTID.
• EXTERNAL CAROTID ARTERY.
• GLOSSOPHARYNGEAL NERVE
• STYLOID PROCESS.
9/11/2018 110

111. SUBMENTAL TRIANGLE
BOUNDARIES:
ON EACH SIDE BY THE ANTERIOR
BELLY OF DIGASTRIC MUSCLES.
BASE: BODY OF HYOID
APEX: LIES AT THE CHIN.
FLOOR: RIGHT AND LEFT
MYLOHYOID AND MEDIAN RAPHE
UNITING THEM.
CONTENTS:
• 2-4 SUBMENTAL NODES
• ANTERIOR BELLIES OF
DIGASTRIC MUSCLES.
• SUBMENTAL VEIN.
9/11/2018 111

112. MUSCULAR TRIANGLE
BOUNDARIES:
ANTERIORLY: ANTERIOR MEDIAN
LINE OF THE NECK FROM THE
HYOID BONE TO THE STERNUM.
POSTERO-SUPERIORLY: SUPERIOR
BELLY OF OMOHYOID
POSTERO-INFERIORLY: ANTERIOR
BORDER OF THE
STERNOCLEIDOMASTOID.
CONTENTS: INFRA-HYOID MUSCLES –
STERNOHYOID, STERNOTHYROID,
THYROHYOID, OMOHYOID.
9/11/2018 112

113. CAROTID TRIANGLE
BOUNDARIES:
ANTERO-SUPERIORLY – POSTERIOR
BELLY OF DIGASTRIC AND
STYLOHYOID
ANTERO-INFERIORLY – SUPERIOR BELLY
OF OMOHYOID
POSTERIORLY – ANTERIOR BORDER OF
STERNOCLEIDOMASTOID.
ROOF:
SKIN, SUPERFICIAL FASCIA, INVESTING
LAYER OF DEEP CERVICAL FASCIA.
FLOOR:
THYROHYOID, HYOGLOSSUS, MIDDLE
AND INFERIOR CONSTRICTOR
MUSCLES.9/11/2018 113

114. CONTENTS OF CAROTID TRIANGLE
ARTERIES: CCA, ICA, ECA AND BRANCHES (SUPERIOR THYROID, LINGUAL,
FACIL, ASCENDING PHARYNGEAL AND OCCIPITAL BRANCHES.
VEINS: INTERNAL JUGULAR VEIN.
NERVES: VAGUS, SPINAL ACCESSORY NERVES, HYPOGLOSSAL NERVE.
9/11/2018 114

115. POSTERIOR TRIANGLE
BOUNDARIES:
ANTERIORLY BY THE POSTERIOR EDGE OF
STERNOCLEIDOMASTOID
POSTERIORLY BY THE ANTERIOR EDGE OF
TRAPEZIUS
INFERIORLY BY THE MIDDLE THIRD OF
THE CLAVICLE
APEX IS BETWEEN THE ATTACHMENTS OF
STERNOCLEIDOMASTOID AND
TRAPEZIUS
9/11/2018 115

116. DEVISIONS OF POSTERIOR
TRIANGLE
THE POSTERIOR TRIANGLE IS
DIVIDED INTO TWO BY THE
OMOHYOID MUSCLE
(INFERIOR BELLY)
I. OCCIPITAL TRIANGLE.
II. SUBCLAVIAN TRIANGLE.
9/11/2018 116

117. OCCIPITAL TRIANGLE
BOUNDARIES:
ANTERIORLY – SCM
POSTERIORLY – TRAPEZIUS
INFERIORLY – LOWER BELLY OF
OMOHYOID
FLOOR: SPLENIUS CAPITIS,
LEVATOR SCAPUALE AND SCALENI
MEDIUS AND POSTERIOR.
ROOF: FORMED BY CUTANEOUS
NERVES OF CERVICAL PLEXUS
AND THE EXTERNAL JUGULAR
VEIN AND PLATYSMA MUSCLE,
DEEP FASCIA , SUPERFICIAL FASCIA
AND BY SKIN.9/11/2018 117

118. SUBCLAVIAN TRIANGLE
BOUNDARIES:
SUPERIORLY – INFERIOR BELLY OF
OMOHYOID
INFERIORLY – CLAVICLE
ANTERIORLY (BASE) – POSTERIOR
BORDER OF SCM
FLOOR: FORMED BY THE FIRST RIB
WITH THE FIRST DIGITATION OF THE
SERRATUS ANTERIOR.
ROOF: FORMED BY THE
INTEGUMENT, SUPERFICIAL AND
DEEP FASCIAE AND THE PLATYSMA
AND CROSSED BY
SUPRACLAVICULAR NERVES9/11/2018 118

119. CONTENTS OF POSTERIOR
TRIANGLE:
• LYMPH NODES (LEVEL V)
• SPINAL ACCESSORY NERVE
• CUTANEOUS BRANCHES OF
THE CERVICAL PLEXUS
• INFERIOR BELLY OF
OMOHYOID
• BRANCHES OF THE
THYROCERVICAL TRUNK
(TRANSVERSE CERVICAL AND
SUPRASCAPULAR ARTERIES)
• THE THIRD PART OF THE
SUBCLAVIAN ARTERY, AND
THE EXTERNAL JUGULAR
VEIN.
9/11/2018 119

120. APPILED ANATOMY
• THE EXTERNAL JUGULAR VEIN
LIES DEEP TO THE PLATYSMA.
AS IT PIERCES THE FASCIA, THE
MARGINS OF THE VEIN GETS
ADHERENT TO THE FASCIA. SO
IF THE VEIN GETS CUT, IT
CANNOT CLOSE AND AIR IS
SUCKED IN DUE TO NEGATIVE
INTRA-THORACIC PRESSURE
CAUSING AIR EMBOLISM.
9/11/2018 120

121. • THE MOST COMMON SWELLING IN THE POSTERIOR TRIANGLE IS
DUE TO ENLARGEMENT OF SUPRACLAVICULAR LYMPH NODES. IT
COULD ALSO BE DUE TO LIPOMA CYSTIC HYGROMA OR
LYMPHANGIOMA, PHARYNGEAL POUCH OR A CERVICAL RIB.
9/11/2018 121

122. SUPRACLAVICULAR FLAP:
IT IS A FASCIOCUTANEOUS FLAP BASED ON SUPRACLAVICULAR
ARTERY, A BRANCH OF THE TRANSVERSE CERVICAL ARTERY. IT IS A
THIN AND EASY TO HARVEST, WITH GOOD COSMETIC AND
FUNCTIONAL OUTCOME FOR RECONSTRUCTION OF COMPLEX
HEAD AND NECK ONCOLOGIC DEFECTS.
9/11/2018 122

123. PLATYSMA FLAP:
THE PLATYSMA FLAP MAY BE USED TO CLOSE DEFECTS ON THE
FACE. DISADVANTAGE OF THIS FLAP IS REMOVAL OF THE
PLATYSMA INTERFERES WITH THE BLOOD SUPPLY TO THE
OVERLYING SKIN AND CAN LEAD TO NECROSIS OF SKIN.
9/11/2018 123

124. SUBMENTAL FLAP:
ITS USE IN RECONSTRUCTION OF BUCCAL DEFECTS. IT PROVIDES
A RELIABLE FLAP WITH GOOD REACH AND MINIMAL DONOR SITE
MORBIDITY . DONOR DEFECT CAN BE CLOSED PRIMARILY ON THE
DONOR SITE SCAR IS HIDDEN UNDER THE MANDIBLE.
9/11/2018 124

125. MYLOHYOID ADVANCEMENT
FLAP:
IT IS USED IN THE
RECONSTRUCTION OF
COMPOSITE ORAL CAVITY
DEFECTS. THE MYLOHYOID IS
RELEASED FROM THE
MENTAL SPINE. THE
MUSCULAR FLAP IS THEN
TRANSPOSED INTRAORALLY
AND DRAPED OVER
THE SURFACE OF THE RIM
MANDIBULECTOMY, FILLING
THE VERTICAL
HEIGHT OF THE DEFECT.
9/11/2018 125

126. STERNOMASTOID FLAP:
THE SKIN PADDLE OF SUPERIORLY BASED STERNOMASTOID
FLAP IS HAIRLESS AND THIN AND IS AN IDEAL
RECONSTRUCTIVE OPTION FOR MEDIUM SIZED CHEEK
DEFECTS.
9/11/2018 126

127. TRAPEZIUS MYOCUTENEOUS FLAP:
IT CAN BE USED FOR RECONSTRUCTING DEFECTS OF HEAD AND
NECK REGION AND UPPER BACK. ITS LOCATION MAKES IT THE
FLAP OF CHOICE FOR DEFECTS OF THE OCCIPITAL, PAROTID AND
CERVICAL SPINE REGIONS.
9/11/2018 127

128. CONCLUSION:
9/11/2018 128
• UNDERSTANDING THE FUNCTION AND LOCATION OF THE
MUSCLES ALLOWS US TO RECOGNIZE ANY ABNORMALITIES IN
A PATIENT’S ANATOMY.
• THOROUGH UNDERSTANDING OF ANATOMY IS IMPORTANT IN
TREATING THE ABNORMALITY.
“You cannot successfully treat dysfunction unless you
understand function.”
-J.P.Okeson

129. • B.D CHAURASIA’S HUMAN ANATOMY
• SICHER AND DUBRUL’S ORAL ANATOMY
• ANATOMY OF HUMAN BODY- HENRY GRAY’S
• CUNNINGHAM’S MANUAL OF PRACTICAL ANATOMY
• GRANT’S ATLAS OF ANATOMY
• NETTERS HEAD AND NECK ANATOMY
• TEXTBOOK OF HEAD AND NECK ANATOMY – HIATT GARNER
• DEVELOPMENT OF MUSCULOSKELETAL SYSTEM - HUMAN
DEVELOPMENTAL ANATOMY; KURT E JOHNSON
REFERENCES
9/11/2018 129

130. • CLARIFICATION OF ERB’S POINT AS AN ANATOMIC LANDMARK
IN THE POSTERIOR CERVICAL TRIANGLE, LANDERS ET.AL
CLINICAL ANATOMY 2:29-134(1989);
• VARIATIONS IN THE FACIAL MUSCLES AT THE ANGLE OF THE
MOUTH – KAZUYUKI SHIMADA AND RAYMOND F.
GASSERROGERS C, MEARA J, MULLIKEN J (2014) THE PHILTRUM
IN CLEFT LIP. J CRANIOFAC SURG 25(1):9-13
• CORRECTION OF SKELETAL DEFECTS IN SECONDARY CLEFT LIP
AND PALATE DEFORMITIES – KENNETH E SALYER ET.AL
• CONTEMPORARY ORAL ONCOLOGY ORAL AND MAXILLOFACIAL
RECONSTRUCTIVE SURGERY BY KURIAKOSE.
9/11/2018 130

131. • PRINCIPLES AND PRACTICE OF HEAD AND NECK SURGERY
AND ONCOLOGY BY PETER H. RHYS EVANS
• STELL AND MARAN’S TEXTBOOK OF HEAD AND NECK
SURGERY AND ONCOLOGY
• B. HELL, E. HEISSLER, H. GATH, H. MENNEKING, A. LANGFORD:
THE INFRAHYOID FLAP. A TECHNIQUE FOR DEFECT CLOSURE
IN THE FLOOR OF THE MOUTH, THE TONGUE, THE BUCCAL
MUCOSA, AND THE LATERAL PHARYNGEAL WALL. INT. J. ORAL
MAXILLOFAC. SURG. 1997; 26.“ 35-41.
• THE PLATYSMA MYOCUTANEOUS FLAP BY DANIEL NITZAN ET
AL.
9/11/2018 131

132. • MYLOHYOID ADVANCEMENT FLAP FOR CLOSURE OF
COMPOSITE ORAL CAVITY DEFECTS BY RAJA SAWHNEY.
• CLINICAL ANATOMY - APPLIED ANATOMY FOR STUDENTS AND
JUNIOR DOCTORS, 11 EDITION-HAROLD ELLIS
• COLOR ATLAS OF ANATOMY - A PHOTOG. STUDY OF THE
HUMAN BODY 7TH ED [TAHIR99] VRG
• PRINCIPLES OF ANATOMY AND PHYSIOLOGY 13TH ED - G.
TORTORA, B. DERRICKSON (WILEY, 2012) BBS
• COLOR ATLAS OF ANATOMY - A PHOTOGRAPHIC STUDY OF THE
HUMAN BODY; JOHANNES W.ROHEN, CHIHIRO YOKOCHI, ELKE
LÜTJEN-DRECOLL
9/11/2018 132

133. 9/11/2018 133