Chapter 1: Face and Neck Regions

Superior

• Superior (Top)
  • Toward or nearer to the top of the head
  • Example: The hip is inferior to the shoulder. (The shoulder is superior to the hip.)
• Inferior
  • Toward or nearer to the soles of the feet
  • Example: The knee is inferior to the hip. (The hip is superior to the knee.)

Inferior

• Inferior (Bottom)
  • Toward or nearer to the soles of the feet
  • Note: This page reinforces the concept with the examples above.

Anterior (Front) and Posterior (Dorsal)

• Anterior (Front)
  • Toward or nearer to the front of the body
• Posterior (Dorsal)
  • Toward or nearer to the back of the body
• Ventral/Dorsal pairs:
  • Anterior = Ventral
  • Posterior = Dorsal

Posterior (Dorsal)

• Posterior (Back)
  • Toward the back of the body

Medial and Lateral

• Medial
  • Closer to the midline of the body
  • Example: The nose is medial to the ear.
• Lateral
  • Farther from the midline of the body
  • Example: The ear is lateral to the nose.
• Note: The upper limb is lateral to the hip; the hip is medial to the upper limb.

Proximal and Distal

• Proximal (Limbs only)
  • Toward/nearer to the attachment of the limb to the trunk
  • Example: The elbow is proximal to the wrist.
• Distal (Limbs only)
  • Away from the attachment of the limb to the trunk
  • Example: The wrist is distal to the elbow; the thigh is proximal to the foot.

Superficial (External) and Deep (Internal)

• Superficial (External)
  • Closer to the surface of the body
  • Example: Hello Kitty's skin is superficial to her bones.
• Deep (Internal)
  • Farther from the surface or toward the inside
  • Example: Hello Kitty's heart is deep to her ribs.

Prone and Supine

• Prone (face-down)
  • Lying face-down on the stomach
• Supine (face-up)
  • Lying face-up on the back

Fowler's Position

• Fowler's Position
  • Elevating the patient's head and upper body
  • Angle between $45^\circ$ and $60^\circ$

Planes and Planar Sections

• Planes used to describe sections of the body:
  • Coronal section (from the coronal plane)
  • Midsagittal section (from the midsagittal plane)
  • Transverse section (from the transverse plane)
• Key directional terms in cross-sections:
  • Superior, Inferior, Medial, Lateral, Anterior, Posterior

Lesion and Etiology

• Lesion
  • Any change in the structure of an organ or part from a typical finding ("normal")
  • May be the first indication of systemic pathologic processes
  • Common in head and neck; oral cavity of adults
• Etiology
  • Definition: cause or set of causes
  • Could involve:
  • Pathologic condition
  • Developmental disturbance
  • Injury
• Etymology
  • The word "etiology" comes from Greek: etio- (causation) + -ology (the scientific study of something)

Lesion: Variants and Pathology

• Atypical Finding (variation from normal)
  • Most lesions fall into this category
• Abnormal Finding
  • Not only typical, but may be a serious pathologic condition
  • Functionally damaging or fatal (e.g., cancer)
• Neoplasm (tumor)
  • Abnormal mass of tissue that forms when cells grow and divide more than usual or never die off
  • Can be benign (more-controlled) or malignant (less-controlled)

Physiologic Pigmentation

• Normal or typical finding
• Localized color variation from melanin pigment
• More common with darker skin tones
• Mainly found localized to certain lingual papillae or within the attached gingiva

Regions of the Face

• Frontal region
• Orbital region
• Nasal region
• Infraorbital region
• Zygomatic region
• Buccal region
• Oral region
• Mental region

Lymph Nodes of the Head and Face

• Located in specific areas of the face and head
• Bean-shaped clusters along connecting lymphatic vessels
• Function: filter toxic products from lymph to prevent their entry into the blood
• Key groups:
  • Facial lymph nodes
  • Superficial parotid lymph nodes
  • Facial vein (anatomic relationship shown)
  • Deep parotid lymph nodes
  • Retropharyngeal lymph node
  • Superficial nodes vs. Deep nodes
  • Occipital lymph nodes
  • Anterior auricular lymph nodes
  • Retroauricular lymph node

Frontal Region

• Forehead
• Area above the eyes
• Related anatomy:
  • Outline of orbit
  • Zygomatic arch
  • Temporomandibular joint (TMJ)
  • Masseter muscle
  • Angle of the mandible

Orbital Region

• Contains the eyeball and all supporting structures
• Located in the orbit, the bony eye socket

Infraorbital Region

• Inferior to the orbital region
• Lateral to the nasal region

Nasal Region

• External nose
• Root of the nose (between eyes)
• Apex (tip) of the nose
• Naris (Nares)
• Nasal Septum
• Ala (winglike cartilaginous structures)

Zygomatic Region

• Overlies the zygomatic arch (bony support for the cheek)
• Extends from just inferior to the lateral margin of the eye toward the middle part of the external ear
• TMJ lies inferior to the zygomatic arch
• Relationship notes:
  • Just anterior to the external ear
  • Where the upper skull forms a joint with the lower jaw
  • Moves when opening/closing the jaw or moving jaw side to side

Buccal Region

• Composed of soft tissue of the cheek
• Forms the side of the face; broad area between the nose, mouth, and ear
• Contains most of the upper cheek
• Structure largely formed by fat and muscle groups; significant masseter muscle
• Related glands and ducts:
  • Parotid salivary gland
  • Parotid duct
  • Parotid papilla
  • Ducts of Rivinus (multiple small ducts from sublingual/submandibular glands)
  • Submandibular gland and submandibular duct
  • Sublingual gland and caruncle with duct openings from submandibular and sublingual glands

Oral Region

• Lips (upper and lower)
  • Soft tissue folds that mark gateway to the oral cavity
  • Region inside the jaws bounded by the mucocutaneous junction at the vermilion border
  • Inner vermilion zone
  • Vermilion border: mucocutaneous junction
• Philtrum
  • Midline vertical groove of the upper lip extending inferiorly from the nasal septum
• Labial Commissure
  • Corner where upper and lower lips meet
• Vermilion Zone
  • The redder/darker area at the mouth border

Upper Lip Anatomy (A-B labeling in the slides)

• A: Upper lip features include tubercle and vermilion border
• B: Philtrum, Labial commissure, Vermilion zone, mucocutaneous junction at vermilion border

Oral Region - Detailed Structures

• Maxilla
  • Upper jaw bone underlying the upper lip
• Mandible
  • Lower jaw bone
• Angle of the mandible
  • Sharp angle of the lower jaw
• Canine eminence
• Alveolar process of the maxilla
• Mandibular teeth
• Alveolar process of the mandible
• Body of the mandible
• Body of the maxilla
• Maxillary tuberosity
• Articulating surfaces and processes:
  • Coronoid notch
  • Coronoid process
  • Condyle (head of mandibular condyle; articulating surface)
  • Mandibular notch
  • Ramus
  • Neck of mandible

Mental Region

• Chin
• Mandibular symphysis (midline of the mandible)
• Mandibular ramus (lateral part of the mandible; superiorly/posteriorly from body on each side)
• Temporomandibular joint (TMJ)
• Mandibular condyle
• Mandibular notch
• Coronoid process and Coronoid notch
• Outline of mandibular symphysis

Mental Region - Details

• Coronoid process
  • At the anterior border of the ramus is a thin, sharp margin that terminates in the coronoid process
• Coronoid notch
  • Main part of the anterior border of the ramus; forms a concave forward curve
• Mandibular condyle
  • Thickened posterior border of the ramus; extends from the angle of the mandible to a projection
  • Articulating surface is the head of the mandibular condyle within the TMJ
• Mandibular notch
  • Between the coronoid process and the condyle is a depression
• Coronoid process and notch; outline of mandibular symphysis

Neck Regions

• Extend from the skull and lower jaw down to the clavicles and sternum
• Regions are subdivided into cervical triangles using large bones and neck muscles
• Key bones and muscles:
  • Hyoid bone
  • Sternocleidomastoid muscle (SCM)
  • Thyroid cartilage
  • Trachea
  • Cricoid cartilage
• Thyroid gland and parathyroid glands are located in the neck

Hyoid Bone and Thyroid Cartilage

• Hyoid bone
  • Moveable bone suspended in the neck at the anterior midline
  • Muscles attached to it help control the position of the base of the tongue
• Thyroid cartilage
  • Prominence of the larynx ("voice box")
  • Vocal cords are ligaments of the larynx attached to the posterior surface of the thyroid cartilage
• Cricoid cartilage
• Isthmus (of the thyroid gland)

Thyroid and Parathyroid Glands

• Thyroid gland
  • Endocrine gland located in the midline of the neck, inferior and lateral to the thyroid cartilage, at the junction of the larynx and trachea
  • Right lobe and left lobe
• Parathyroid glands
  • Endocrine glands located close to or within the posterior aspect of each side of the thyroid gland
  • Not typically palpable in a healthy patient
• Trachea

Ducts and Glands in the Neck and Cheek Regions

• Submandibular salivary gland
  • Submandibular duct
• Sublingual caruncle with duct openings from submandibular and sublingual glands
• Parotid salivary gland
• Parotid duct
• Parotid papilla
• Ducts of Rivinus
• Sublingual salivary gland

Summary of Key Landmarks by Region (quick reference)

• Facial landmarks: frontal, orbital, nasal, infraorbital, zygomatic, buccal, oral, mental regions
• Neck landmarks: hyoid bone, thyroid and cricoid cartilages, thyroid gland, trachea, SCM, parathyroid glands
• Planes and sections for reference: coronal, midsagittal, transverse
• Common clinical concepts: lesions, etiology, benign vs malignant neoplasms, physiologic pigmentation
• Facial lymph nodes: superficial parotid, facial, deep parotid, retropharyngeal, occipital, anterior auricular, retroauricular
• Oral cavity structures: lips, philtrum, vermilion border, labial commissures, maxilla, mandible, coronoid process, ramus, condyle, coronoid notch, alveolar processes
• Glandular anatomy: parotid, submandibular, sublingual glands; related ducts and caruncles