Scalp, Temple, and Face Anatomy

Scalp and Superficial Temporal Region

Scalp

  • The scalp is the soft tissuecovering the cranial vault.

  • It extends:

    • Anteriorly: Up to the supraorbital margins.

    • Posteriorly: Up to the external occipital protuberance and superior nuchal lines. n

    • Laterally: Up to the zygomatic arch and external acoustic meatus. Some authors consider the superior temporal line as the lateral ‘ extent.

  • Layers of the Scalp (SCALP Mnemonic):

    1. Skin: Hairy and adheres to the epicranial aponeurosis.

      • It contains numerous hair follicles and sebaceous glands.

    2. Superficial Fascia (Connective Tissue): Dense connective tissue that contains blood vessels and nerves.

      • It binds the skin to the underlying aponeurosis and provides a medium for the passage of vessels and nerves.

    3. Deep Fascia (Epicranial Aponeurosis or Galea Aponeuro tica):

      • Serves as the insertion point for the occipitofrontalis muscle.

      • Freely movable on the pericranium along with the overlying skin and fascia.

      • Attached to the external occipital protuberance and superior nuchal lines.

      • Laterally, it attaches to the superior temporal line and sends an expansion over the temporal fascia to the mandible.

      • The occipitofrontalis muscle has two bellies:

        • Occipitalis (occipital belly): Small and separate, arising from the lateral two-thirds of the superior nuchal line and supplied by the posterior auricular branch of the facial nerve.

        • Frontalis (frontal belly): Longer, wider, and partly united in the median plane, arising from the skin of the upper eyelid and forehead, mingling with the orbicularis oculi and corrugator supercilii; supplied by the temporal branch of the facial nerve. This muscle raises the eyebrows and causes horizontal wrinkles in the forehead.

    4. Loose Areolar Tissue: Extends anteriorly into the upper eyelid and posteriorly to the superior nuchal line.

      • It gives passage to emissary veins, which connect extracranial veins to intracranial venous sinuses.

      • The frontalis muscle has no bony attachment. This extension allows fluids to pass into the eyelid.

    5. Pericranium: Periosteum of the cranial bones, loosely attached to the bones but firmly adherent at the sutures.

Superficial Temporal Region

  • Location: Area between the superior temporal line and the zygomatic arch.

  • Layers:

    1. Skin

    2. Superficial fascia

    3. Thin extension of the epicranial aponeurosis

    4. Temporal fascia

    5. Temporalis muscle

    6. Pericranium

  • The first three layers of the scalp are called surgical layers.

  • Greying of hair often starts in this region.

Arterial Supply

  • The scalp has a rich blood supply from both the internal and external carotid arteries, anastomosing over the temple.

  • In front of the auricle:

    1. Supratrochlear artery (branch of ophthalmic artery from internal carotid artery)

    2. Supraorbital artery (branch of ophthalmic artery from internal carotid artery)

    3. Superficial temporal artery (smaller terminal branch of the external carotid artery)

  • Behind the auricle:

    1. Posterior auricular artery (branch of external carotid artery)

    2. Occipital artery (tortuous, branch of external carotid artery)

Venous Drainage

  • Veins accompany the arteries and have similar names.

    1. Supratrochlear and Supraorbital Veins: Unite at the medial angle of the eye, forming the angular vein, which becomes the facial vein.

    2. Superficial Temporal Vein: Descends in front of the tragus, enters the parotid gland, and joins the maxillary vein to form the retromandibular vein, which divides into:

      • Anterior Division: Unites with the facial vein to form the common facial vein, which drains into the internal jugular vein.

      • Posterior Division: Unites with the posterior auricular vein to form the external jugular vein, which drains into the subclavian vein.

    3. Occipital Veins: Terminate in the suboccipital venous plexus.

    4. Emissary Veins: Connect extracranial veins with intracranial venous sinuses to equalize pressure; they are valveless.

      • Parietal emissary vein passes through the parietal foramen to enter the superior sagittal sinus.

      • Mastoid emissary vein passes through the mastoid foramen to reach the sigmoid sinus.

      • Extracranial infections may spread through these veins to intracranial venous sinuses.

    5. Diploic Veins: Start from the cancellous bone within the two tables of the skull and carry newly formed blood cells into general circulation.

      • Frontal Diploic Vein: Emerges at the supraorbital notch and opens into the supraorbital vein.

      • Anterior Temporal Diploic Vein: Ends in the anterior deep temporal vein or sphenoparietal sinus.

      • Posterior Temporal Diploic Vein: Ends in the transverse sinus.

      • Occipital Diploic Vein: Opens either into the occipital vein or the transverse sinus near the median plane.

Lymphatic Drainage

  • The anterior part of the scalp drains into the preauricular or parotid lymph nodes.

  • The posterior part of the scalp drains into the posterior auricular or mastoid and occipital lymph nodes.

Nerve Supply

  • Ten nerves supply the scalp and temple on each side: five in front of the auricle and five behind the auricle.

  • In Front of the Auricle:

    • Sensory Nerves:

      • Supratrochlear nerve (branch of the frontal nerve, ophthalmic division of trigeminal nerve)

      • Supraorbital nerve (branch of the frontal nerve, ophthalmic division of trigeminal nerve)

      • Zygomaticotemporal nerve (branch of the zygomatic nerve, maxillary division of trigeminal nerve)

      • Auriculotemporal nerve (branch of the mandibular division of trigeminal nerve)

    • Motor Nerve: Temporal branch of facial nerve

  • Behind the Auricle:

    • Sensory Nerves:

      • Posterior division of great auricular nerve (C2, C3) from the cervical plexus

      • Lesser occipital nerve (C2) from the cervical plexus

      • Greater occipital nerve (C2, dorsal ramus)

      • Third occipital nerve (C3, dorsal ramus)

    • Motor Nerve: Posterior auricular branch of the facial nerve

Clinical Anatomy

  • Sebaceous Cysts: Common due to the abundance of sebaceous glands.

  • Black Eye: Blood collection in the loose connective tissue layer extends anteriorly into the root of the nose and eyelids because the frontalis muscle has no bony origin.

  • Gaping Wounds: Wounds of the scalp gape when the epicranial aponeurosis is divided transversely, requiring careful stitching of the aponeurosis layer.

  • Profuse Bleeding: Wounds of the scalp bleed profusely because vessels are prevented from retracting by the fibrous fascia; bleeding can be arrested by applying pressure with a tight cotton bandage.

  • Limited Subcutaneous Hemorrhages: Due to the density of the fascia, subcutaneous hemorrhages are never extensive, and inflammations cause little swelling but much pain.

  • Cephalhematoma: Collections of fluid deep to the pericranium take the shape of the bone concerned when there is a fracture because the pericranium is adherent to sutures.

  • Safety-Valve Hematoma: Fractures of the cranial vault cause escape of intracranial hematoma into the subaponeurotic space, preventing compression of the cerebrum.

  • Dangerous Area of Scalp: The loose areolar tissue layer is dangerous because emissary veins connect the veins of this layer with dural venous sinuses, allowing infections to spread easily, potentially leading to thrombosis of the dural venous sinuses.

  • Safety Layer: The layer is also called safety layer because compression of the brain is not seen due to the spread of blood.

  • Healing of Avulsed Scalp: The richly supplied scalp and superficial temporal region allows avulsed portions to be replaced and stitched; they usually heal well.

  • Caput Succedaneum: Subcutaneous edema of the scalp produced during delivery due to interference in venous return, subsiding in a few days.

Face

  • The face extends superiorly from the adolescent hairline, inferiorly to the chin and base of the mandible, and laterally to the auricle.

Skin of the Face

  1. Vascularity: Facial skin is very vascular, causing blushing and blanching; wounds bleed profusely but heal rapidly, improving plastic surgery results.

  2. Glands: Rich in sebaceous and sweat glands; sebaceous glands cause acne in young adults, while sweat glands regulate body temperature.

  3. Laxity: Laxity of skin facilitates rapid spread of edema; renal edema appears first in the eyelids and face.

  4. Fixity: Boils in the nose and ear are acutely painful due to the fixity of the skin to the underlying cartilage.

  5. Elasticity: Very elastic and thick because facial muscles are inserted into it; wounds tend to gape.

Superficial Fascia

  • Contents:

    1. Facial muscles inserted into the skin

    2. Vessels and nerves to the muscles and skin

    3. Variable amount of fat; absent from eyelids but well-developed in cheeks (buccal pads in infants for sucking).

Note: Deep fascia is absent except over the parotid gland (parotid fascia) and buccinator (buccopharyngeal fascia).

Cleavage Lines of Skin

  • Cleavage Lines (Langer Lines): Topological lines resulting from the parallel orientation of collagen fibers in the dermis and underlying muscle.

  • Natural Wrinkle Lines: Result from repeated folding of skin perpendicular to the long axis of contracting facial expression muscles; become prominent in elderly due to loss of skin elasticity.
    Note: Incisions along natural wrinkle lines or cleavage lines produce less scarring.

Facial Muscles

  • Subcutaneous muscles responsible for facial expressions; have small motor units.

  • Develop from the mesoderm of the 2nd branchial arch and are supplied by the facial nerve.

  • Represent the best remnants of the panniculus carnosus and are all inserted into the skin.

  • Topographically grouped under six heads.

  • Functionally, they regulate the palpebral fissures, nostrils, and oral fissure.

  • Sphincters are circular, and dilators are radial.

Functional Groups

  1. Muscles of the Eyelids/Orbital Openings:

    • Corrugator supercilii

    • Orbicularis oculi

    • Levator palpebrae superioris

  2. Muscles of the Auricle:

    • Auricularis anterior

    • Auricularis superior

    • Auricularis posterior

  3. Muscles Around Nasal Opening:

    • Procerus

    • Compressor naris

  4. Muscles Around the Mouth:

    • Orbicularis oris

    • Buccinator

    • Dilator naris

    • Depressor septi

    • Levator labii superioris alaeque nasi

    • Zygomaticus major

    • Levator labii superioris

    • Levator anguli oris

    • Zygomaticus minor

    • Depressor anguli oris

    • Depressor labii inferioris

    • Mentalis

    • Risorius

  5. Muscle of the Neck:

    • Platysma

Facial Expressions

  • Surprise: Frontalis

  • Dislike: Corrugator supercilii and procerus

  • Anger: Dilator naris and depressor septi

  • Smiling/Laughing: Zygomaticus major

  • Grinning: Risorius

  • Sadness: Levator labii superioris and levator anguli oris

  • Grief: Depressor anguli oris

  • Closing Mouth: Orbicularis oris

  • Whistling/Kissing: Buccinator and orbicularis oris

  • Doubt: Mentalis

  • Horror/Terror/Fright: Platysma

Nerve Supply of Face

Motor Nerve Supply

  • Facial Nerve (VII): Motor nerve of the face, with five terminal branches emerging from the parotid gland:

    1. Temporal

    2. Zygomatic

    3. Buccal

    4. Marginal Mandibular

    5. Cervical
      Mnemonic: Ten Zebras Bit My Cat

Clinical Testing of Facial Muscles

  • Frontalis: Ask the patient to look upwards without moving their head.

  • Dilators of the Mouth: Showing the teeth.

  • Orbicularis Oculi: Tight closure of the eyes.

  • Buccinator: Puffing the mouth and then blowing forcibly as in whistling.

Facial Nerve Palsy

  • Bell's Palsy: Infranuclear lesion at the stylomastoid foramen, causing paralysis and atrophy of facial muscles on the same side, loss of taste in the anterior two-thirds of the tongue.

    • Face becomes asymmetrical, drawn to the normal side.

    • The affected side is motionless, and wrinkles disappear from the forehead.

    • The eye cannot be closed, leading to keratitis.

    • Attempts to smile draw the mouth to the normal side.

    • Food accumulates between the teeth and cheek during mastication.

    • Articulation of labials is impaired.

    • Tears and saliva flow from the eye and mouth.

  • Supranuclear Facial Nerve Palsy: Injury of corticonuclear fibers, resulting in paralysis of only the lower quarter of the opposite side of the face; the upper quarter escapes due to bilateral representation in the cerebral cortex.

    • Only voluntary movements are affected; emotional expressions remain normal.

    • No atrophy of facial muscles.

Sensory Nerve Supply

  • Trigeminal Nerve: Chief sensory nerve of the face through its three divisions.

  • Great Auricular Nerve (C2, C3): Supplies the skin over the angle of the jaw and parotid gland.

Cutaneous Nerves of the Face

  • Ophthalmic Division of Trigeminal Nerve:

    1. Supratrochlear nerve

    2. Supraorbital nerve

    3. Lacrimal nerve

    4. Infratrochlear nerve

    5. External nasal nerve

  • Maxillary Division of Trigeminal Nerve:

    1. Infraorbital nerve

    2. Zygomaticofacial nerve

    3. Zygomaticotemporal nerve

  • Mandibular Division of Trigeminal Nerve:

    1. Auriculotemporal nerve

    2. Buccal nerve

    3. Mental nerve

  • Cervical Plexus:

    1. Anterior division of great auricular nerve (C2, C3)

    2. Upper and lower divisions of the transverse cutaneous nerve of the neck (C2, C3)

    3. Lesser occipital

    4. Supraclavicular

Clinical Anatomy

  • Sensory Distribution: Headache is a common symptom in involvements of the nose, paranasal air sinuses, teeth, gums, eyes, and meninges due to trigeminal nerve distribution.

  • Trigeminal Neuralgia (Tic Douloureux): Involves one or more divisions of the trigeminal nerve, causing severe burning and scalding pain, relieved by injecting alcohol or sectioning the affected nerve.

Arteries of the Face

  • Face is richly vascular, supplied by:

    1. Facial artery

    2. Transverse facial artery

    3. Arteries accompanying cutaneous nerves

Facial Artery

  • Chief artery of the face, branch of external carotid artery.

  • Course:

    1. Enters the face by winding around the base of the mandible at the anteroinferior angle of the masseter muscle, called 'anaesthetist's artery'.

    2. Runs upwards and forwards, then ascends as the angular artery by the side of the nose up to the medial angle of the eye.

  • Large anterior branches include:

    1. Inferior labial

    2. Superior labial

    3. Lateral nasal

  • Small posterior branches are unnamed.

Transverse Facial Artery

  • Small artery branching off the superficial temporal artery.

  • Runs forwards over the masseter between the parotid duct and zygomatic arch.

  • Supplies the parotid gland and its duct, masseter, and overlying skin.

Veins of the Face

  1. Drainage:

    • Common facial vein

    • Retromandibular vein (communicate with the cavernous sinus)

  2. Veins arrange in a 'W' shape.

  3. Facial Vein

    • The largest vein of the face with no valves.

    • Originates as angular vein at the medial angle of eye.

    • The union of the supratrochlear and supraorbital veins.

Clinical Anatomy

  • Dangerous Area of Face: The lower part of the nose, upper lip, and adjoining parts of the cheek due to the venous drainage into the facial vein, which lacks valves and communicates with the cavernous sinus.

Lymphatic Drainage of the Face

  • Three lymphatic territories:

    1. Upper Territory: Drains into the preauricular parotid nodes.

      • Including the forehead.

      • Lateral eyelids.

      • Conjunctiva, lateral part of the cheek and parotid area.

    2. Middle Territory: Drains into the submandibular nodes.

      • A strip over the median forehead.

      • External nose.

      • Upper lip, lateral part of the lower lip.

    3. Lower Territory: Drains into the submental nodes.

      • central part of the lower lip.

      • The chin.

Eyelids or Palpebrae

  • The space between the two eyelids is the palpebral fissure.

  • Structure

    1. Skin

    2. Superficial fascia

    3. Orbicularis oculi

    4. Tarsal plate and palpebral fascia

    5. Palpebral conjuctiva

  • Medial halves of the lids drain into the submandi­bular nodes, and the lateral halves into the preauricular nodes.

Lacrimal Apparatus

  • Structures that concern with secretion and drainage
    Components

  • Lacrimal grand and its ducts

  • COnjunctival sac

  • Lacrimal puncta

  • Lacrimal canlliculi

  • Lacrimal sac

  • Nasolacrimal gland

  • lacrimal gland are supplied by lacrimal branches of opthalmic artery

Development of the Face

  • Processes: The face develops from five mesodermal processes in the 4th week:

    1. Frontonasal process (unpaired)

    2. Maxillary process (paired)

    3. Mandibular process (paired)

  • Various parts are derived as follows:

    1. The lower lip: from bilarteral mandibular processas in the mideline to form a lower lip and jawbone.

    2. The upper lips: from medial nasal proccess.

    3. lateral parts of upper lip: maxiallray process