Mandible, Scalp & Face Anatomy 2024-2025 PDF

MANDIBLE, SCALP& FACE Prof. Dr. Mona Zoair & Prof Dr. Doaa Haiba 13- 17/10/2024  Objectives of the lecture 1. Identify the surfaces, borders and features of the body and rami of the mandible 2. Define the scalp, its extension and identify its layers. 3. Defi...

MANDIBLE, SCALP& FACE Prof. Dr. Mona Zoair & Prof Dr. Doaa Haiba 13- 17/10/2024  Objectives of the lecture 1. Identify the surfaces, borders and features of the body and rami of the mandible 2. Define the scalp, its extension and identify its layers. 3. Define origin, insertion, nerve supply and action of occipitofrontalis muscle 4. Identify nerves, vessels and lymphatics of the scalp 5. Define extension of the face and identify facial skeleton. 6. Identify nerves, vessels and lymphatics of the face. 7. Define origin, insertion, nerve supply and action of important muscles of the face (orbicularis oculi, orbicularis oris, buccinator) MANDIBLE  MANDIBLE It is formed of: Body: horseshoe –shaped 2 rami right and left  Body of mandible (outer surface) It shows the following features: 1. Symphysis menti ; faint ridge in midline 2. Mental protuberance ; a triangular area on each side of symphysis menti 3. Mental tubercle; the raised base of mental protuberance. 4. Oblique line turns upwards and backwards to become continuous with ramus Mental foramen Oblique line 5. Mental foramen; lies above oblique line for mental nerve and vessels Mental Mental tubercle protuberance Symphysis menti  Body of mandible (inner surface) It shows the following features: 1. Mylohyoid line; begins behind 3rd molar and passes to symphysis menti 2. Submandibular fossa for submandibular salivary gland below mylohyoid line Superior 3. Sublingual fossa for genial sublingual salivary gland tubercle above mylohyoid line 4. Superior genial tubercle Inferior 5. Inferior genial tubercle genial tubercle  Ramus of Mandible (inner surface) Lingula It shows the following features: 1. Mandibular foramen; lies little above the center and leads to mandibular canal for inferior alveolar nerve and vessels Mandibular foramen 2. Lingula; overhang antero-medial margin of foramen. Mylohyoid groove 3. Mylohyoid groove; behind lingula and runs downwards and forwards encloses mylohyoid nerve and vessels  Processes of mandible Head Coronoid process Condyloid process Neck 1. Coronoid process; flat triangular process and its apex points upwards and forwards. 2. Condyloid process; consists of head and neck of mandible: Head; convex and elongated transversely, articulate with mandibular fossa and articular eminence in temporomandibular joint. Neck; its anterior surface shows pterygoid fovea  Borders of Ramus of Mandible Anterior border Superior border Anterior border; sharp and continues inferiorly with oblique line of body and superiorly with coronoid process. Posterior border; smooth, blunt and meet inferior border at angle of mandible Posterior border Superior border; sharp and bounds wide mandibular notch. It is surrounded infront by coronoid process and behind by condylar Angle of process. mandible SCALP  SCALP It is the soft tissue covering the skull cap. It extends from the superciliary arches anteriorly to the external occipital protuberance and superior nuchal lines posteriorly and to the temporal lines laterally.  LAYERS OF SCALP It consists of the following layers: 1. Skin 2. Connective tissue 3. Aponeurosis (Epicranial) 4. Loose areolar tissue 5. Pericranium (periosteum)  LAYERS OF SCALP 1. Skin: thick and hair bearing. 2. Connective tissue: It is a dense fibrofatty layer containing fibrous septa that unite the skin to the underlying epicranial aponeurosis. It contains numerous blood vessels (from the external and internal carotid arteries with free anastomosis between them).  LAYERS OF SCALP 3. Epicranial aponeurosis: This is a thin, tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle. The lateral margins of the aponeurosis are attached to the temporal fascia.  LAYERS OF SCALP Emissary vein 4. Loose areolar tissue: It occupies the subaponeurotic space and loosely connects the epicranial aponeurosis to the periosteum of the skull (the pericranium). It is the plane of movement of the scalp, the first three layers (SCA) slide along this layer. It contains a few small arteries and some important emissary veins. 5. Pericranium: it is the periosteum of skull bones.  MUSCLES OF SCALP Occipitofrontalis muscle: Origin: 1. Occipital belly: from highest nuchal line. 2. Frontal belly: from skin and superficial fascia of eyebrow. Insertion: epicranial aponeurosis. Facial Nerve supply: facial nerve nerve Action: moves scalp on skull and raises eyebrow.  SENSORY NERVE SUPPLY OF SCALP The nerves are arranged in two main groups: 1) Branches of the trigeminal nerve located anterior to the ear. 2) Branches of cervical spinal nerves located posterior to the ear.  SENSORY NERVE SUPPLY OF SCALP Trigeminal branches: 1. Supratrochlear nerve, a branch of the ophthalmic nerve. It supplies scalp close to the median plane as far as the vertex. 2. Supraorbital nerve, a branch of the ophthalmic nerve. It supplies the scalp as far backward as the vertex. 3. Zygomaticotemporal nerve, a branch of the maxillary nerve, supplies the scalp over the temple. 4. Auriculotemporal nerve, a branch of the mandibular nerve. It supplies the skin over the temporal region.  SENSORY NERVE SUPPLY OF SCALP Cervical spinal nerve branches: The lesser occipital nerve (C2), a branch of the cervical plexus, ascends along the posterior edge of the sternocleidomastoid muscle and supplies the scalp over the lateral part of the occipital region and the skin over the medial surface of the auricle. The greater occipital nerve, a branch of the posterior ramus of the second cervical nerve, ascends over the back of the scalp and supplies the skin as far forward as the vertex of the skull  Supraorbital Nerve For Supratrochlear Nerve scalp as far as vertex For scalp close to midline as far as vertex Zygomatico-temporal Auriculo-temporal Nerve Branches of Ophthalmic Nerve Nerve For skin over temple For skin over temporal region Branches of Branches of Trigeminal Branches of Maxillary Nerve Mandibular Nerve Nerve SENSORY NERVE SUPPLY OF SCALP Branches of Cervical Plexus Greater Occipital Nerve Lesser Occipital Nerve For skin of lateral part of For skin of dorsal part of occipital region scalp as far as vertex  ARTERIAL SUPPLY OF SCALP 1. The supratrochlear and the supraorbital arteries, branches of the ophthalmic artery, ascend over the forehead in company with the supratrochlear and supraorbital nerves. 2. The superficial temporal artery, the smaller terminal branch of the external carotid artery with the auriculotemporal nerve. It divides into anterior and posterior branches, which supply the skin over the frontal and temporal regions. 3. The posterior auricular artery, a branch of the external carotid artery, ascends behind the auricle to supply the scalp above and behind the auricle. 4. The occipital artery, a branch of the external carotid artery. It supplies the skin over the back of the scalp and reaches as high as the vertex of the skull.  VENOUS DRAINAGE OF SCALP Superficial temporal vein unites with the maxillary vein to form retromandibular vein. Posterior auricular vein unites with the posterior division of the retromandibular vein to form the external jugular vein. Occipital vein drains into the vertebral veins or the internal jugular vein.  LYMPH DRAINAGE OF SCALP Anterior part of the scalp and forehead drain into the submandibular lymph nodes. Lateral part of the scalp above the ear drains into the superficial parotid (preauricular) nodes. Part of the scalp above and behind the ear drain into the mastoid nodes. Back of the scalp drains into the occipital nodes. FACE  FACE The face extends from the superciliary arches superiorly to the lower margin of the mandible inferiorly and to the auricles laterally. Facial skeleton: 1. Frontal bone above orbit 2. Zygomatic bone lateral to orbit 3. Zygomatic bone and the maxilla below orbit 4. maxillary process of the frontal bone and the frontal process of the maxilla medial to orbit. 5. Nasal bones  SENSORY NERVE SUPPLY OF FACE The skin of the face is supplied by branches of the three divisions of the trigeminal nerve (ophthalmic, maxillary & mandibular). Small area over the angle of the mandible is supplied by great auricular nerve. Great auricular nerve  SENSORY NERVE SUPPLY OF FACE Branches of ophthalmic nerve: 1. Lacrimal nerve supplies the skin of the lateral part of the upper eyelid. 2. Supraorbital nerve supplies skin on the central part of the upper eyelid and skin of forehead. 3. Supratrochlear nerve supplies skin on the medial part of the upper eyelid and skin over the lower part of the forehead, close to the median plane. 4. Infratrochlear nerve supplies the skin on the medial part of the lower eyelid and the adjoining part of the side of the nose. 5. External nasal nerve supplies the skin on the side of the nose down as far as the tip.  SENSORY NERVE SUPPLY OF FACE Branches of maxillary nerve: 1. Infraorbital nerve supplies the skin of the lower eyelid and cheek, the side of the nose, and the upper lip. 2. Zygomaticofacial nerve supplies the skin over the prominence of the cheek. 3. Zygomaticotemporal nerve supplies the skin over the temple.  SENSORY NERVE SUPPLY OF FACE Branches of mandibular nerve: 1. Mental nerve supplies the skin of the lower lip and chin. 2. Buccal nerve supplies the skin over a small area of the cheek. 3. Auriculotemporal nerve supplies the skin of the auricle, and the skin of the scalp above the auricle.  Supraorbital Nerve Supratrochlear Nerve Inratrochlear Nerve For central part of For medial part of upper For medial part of lower eye lid upper eye lid eye lid and forehead and side of nose Lacrimal Nerve close to midline For lateral part External Nasal Nerve of upper eye lid For side of nose as far as tip Branches of Ophthalmic Nerve SENSORY NERVE Branches of Branches of Maxillary SUPPLY OF THE FACE Mandibular Nerve Nerve Infraorbital Nerve Zygomatico- Zygomatico- Auriculo- For : facial Nerve temporal Mental Buccal temporal Lateral part of For skin over Nerve Nerve Nerve Nerve Lower eye lid prominence of For skin of For skin of lower For skin of For skin of auricle Side of nose cheek temple lip and chin cheek and scalp over it Upper lip  ARTERIAL SUPPLY OF FACE The face receives a rich blood supply from two main vessels: 1. Facial artery 2. Superficial temporal artery  FACIAL ARTERY Facial artery arises from the external carotid artery. It curves around the inferior margin of the body of the mandible at the anterior border of the masseter muscle. It next runs upward in a tortuous course toward the angle of the mouth. It then ascends and runs along the side of the nose to the medial angle of the eye.  FACIAL ARTERY Branches: 1. Submental artery supplies the skin of the chin and lower lip. 2. Inferior labial artery supplies the lower lip. 3. Superior labial artery supplies the upper lip and septum and ala of the nose. 4. Lateral nasal artery supplies the skin on the side and dorsum of the nose. 5. Angular artery is the terminal part of the facial artery at angle of the eye.  SUPERFICIAL TEMPORAL ARTERY It is the smaller terminal branch of the external carotid artery. It ascends in front of the auricle to supply the scalp. Branches: 1. Transverse facial artery runs just below the zygomatic arch. 2. Anterior (frontal) and posterior (temporal) terminal branches.  VENOUS DRAINAGE OF FACE 1. Facial vein: It is formed at the medial angle of the eye by the union of the supraorbital and supratrochlear veins. It descends behind the facial artery to the lower margin of the body of the mandible. It is joined by the anterior division of the retromandibular vein to form common facial vein which ends into the internal jugular vein. 2. Transverse facial vein: it joins superficial temporal vein.  LYMPH DRAINAGE OF FACE Forehead and the anterior part of the face drains into the submandibular lymph nodes. lateral part of the face, including the lateral parts of the eyelids drains into the parotid lymph nodes. The central part of the lower lip and the skin of the chin drain into the submental lymph nodes  IMPORTANT MUSCLES OF FACE Orbicularis oculi: Origin: Orbital and palpebral parts arise from medial palpebral ligament. Insertion: a. Palpebral part is inserted into lateral palpebral raphe b. Orbital part loops returning to origin. Nerve supply: temporal and zygomatic branches of facial nerve Action: close the eye lids and dilates lacrimal sac  IMPORTANT MUSCLES OF FACE Orbicularis oris: Origin: maxilla, mandible, skin Insertion: encircles the oral orifice. Nerve supply: buccal and mandibular branches of facial nerve Action: compresses lips together  IMPORTANT MUSCLES OF FACE Buccinator: Origin: a. Alveolar process of maxilla b. Alveolar process of mandible c. Pterygomandibular ligament Insertion: a. Fibers from below enter upper lip b. Fibers from above enter lower lip c. Decussation occurs at angle of mouth. Nerve supply: buccal branch of facial nerve Action: compresses the cheeks and lips against the teeth, thus positioning food for efficient chewing.  FACIAL NERVE It divides into its five terminal branches as it runs forward within the substance of the parotid salivary gland: 1. Temporal branch supplies the frontal belly of the occipitofrontalis and the orbicularis oculi. 2. Zygomatic branch supplies the orbicularis oculi. 3. Buccal branch supplies the buccinator and orbicularis oris 4. Mandibular branch supplies the muscles of the lower lip (orbicularis oris). 5. Cervical branch supply the platysma muscle. IN CLASS EXERCISE Which of the following sensory nerves of the scalp is a branch from cervical spinal nerves ? A. Auriculotemporal B. Greater occipital C. Supraorbital D. Supratrochlear After a car accident, a 30-year-old man was transported to emergency department with fracture of the ramus of mandible including the mandibular canal. Which of the following structures is most likely liable to be injured by the fractured part of mandible? A. Inferior alveolar nerve and vessels B. Mylohyoid nerve and vessels C. Sublingual salivary gland D. Submandibular salivary gland List the layers of the scalp.  IN CLASS EXERCISE Which of the following arteries supplying the scalp is labeled by black arrow? A. Posterior auricular B. Occipital C. Superficial temporal D. Supratrochlear Which of the following branches of the facial nerve supplies the buccinator muscle? A. Buccal B. Cervical C. Mandibular D. Zygomatic Define the insertion of buccinator muscle.  SOURCES& REFERENCES Books Videos Mandible https://www.youtube.com/watch?v=_lHosB-c_fQ Anatomy of Scalp https://www.youtube.com/watch?v=0ujnbGsu9cc Superficial arteries of face https://www.youtube.com/watch?v=6F_RM0cWzEw Sensory nerves of face https://www.youtube.com/watch?v=Di-Qej7-w04 Chapter : Head& Neck Scalp; Pages: 1515-1522 Face; Pages:1525- 1538 Lecture Notes PDF Thank You [email protected]