Head and Neck, week 1 class notes, MMED Anatomy notes,

MMED Anatomy Class notes –

Head and Neck - SR1

THE SKULL AND FACIAL BONES

v  THE SKULL VAULT

Ø  Bregma

Ø  Lambda

Ø  Pterion

§  Provides a surface marking for the anterior branch of the middle meningeal artery on lateral skull radiograph

v  THE SKULL BASE

v  INDIVIDUAL BONES OF THE SKULL BASE

Ø  Sella turcica or pituitary fossa

Ø  Tuberculum sella

Ø  Sulcus chiasmaticus

Ø  Anterior clinoid process

Ø  Dorsum Sellae

§  Posterior clinoid process

§  Lamina dura

Ø  Temporal Bone

§  Squamous part

§  Petrous part

§  Mastoid part

§  Styloid process

Ø  Zygomatic process

Ø  Foramen magnum

v  CRANIAL FOSSAE

v  FORAMINA OF THE SKULL BASE

Ø  Optic canals

§  The optic nerve and ophthalmic arteries

§  The optic foramen view

Ø  Superior orbital fissure

§  CN V1, III, IV, VI and the superior orbital vein and the muddle meningeal artery

§  Occipitofrontal view

Ø  Foramen rotundum

§  V2 – maxillary division of the fifth cranial nerve

§  Occipitofrontal view at 20-25 degrees

Ø  Foramen ovale

§  V3 (Mandibular Branch), of the fifth cranial nerve and the accessory meningeal artery

§  Submentovertical (SMV)

Ø  Foramen spinosum

§  Middle meningeal artery from the infratemporal to the middle cranial fossa

§  Submentovertical (SMV) projection

Ø  Foramen Lacerum

§  Internal Carotid Artery passes through this ragged foramen

§  Submentovertical (SMV) projection

Ø  Internal auditory meatus and canal

§  VII and VIII, and internal auditory artery

§  Straight AP view of the skull

Ø  Jugular Foramen

§  IX and X and XI cranial nerves, and Internal Jugular Vein. Inferior Petrosal Sinus (which drains into the internal Jugular Vein), and the Ascending occipital and pharyngeal Arterial branches

§  Special views required

Ø  Hypoglossal canal

§  XII

§  Special views required

Ø  Foramen Magnum

§  Medulla Oblongata, and spinal cord, vertebral and spinal arteries, and the roots of the XI cranial nerve

§  Submentovertical (SMV) projection

v  RADIOLOGICAL FEATURES OF THE SKULL BASE AND VAULT

Ø  Plain Films

§  Common projections: Lateral, OF20 degrees, and Towns projection

§  Pituitary Fossa is visible on OF20 degrees, FO30 , and SMV views. Most commonly use the lateral view

·         11 – 16mm in width and 8-12mm in depth

·         The dorsum sellae should have well defined margins anteriorly and posteriorly

·         Pneumatization of the sphenoid sinus – may be rudimentary, preseller, seller

·         Seller is most usefulview

·         Elongation of the pituitary fossa with a prominent sulcus chasmaticus is known as:

¨       “J-shaped”, “Omega” or “hour-glass” sella and in a normal variant in 5% of children

§  Middle meningeal vessels

§  Diplopic Markings

·         Stellate confluence is seen on lateral skull radiograph

§  Dural Sinuses

·         The transverse sinus are readily seen on Towns projection – running from the occipital protuberance laterally towards the mastoids before curving down to become the sigmoid sinuses, which run into the jugular vein.

§  Supraorbital artery – superiorly from the orbit on OF skull projections

§  Superficial temporal artery – on lateral projection

§  Arachnoid granulation pits

§  Sutures

·         Metopic suture

·         Spheno-occipital synchondrosis

§  Wormian bones

§  Thickness of the skull vault

Ø  Cross-Sectional imaging

v  THE NEONATAL AND GROWING SKULL

v  CALCIFICATION ON THE SKULL RADIOGRAPH IN THE NORMAL PERSON

Ø  Pineal gland

Ø  Habenular commissure

§ 

Ø  Glomus of the choroid plexus

§  In the lateral ventricles is frequently calcified – usually symmetrical and bilateral calcification

Ø  Dural Calcification

§  Petroclinoid and interclinoid ligaments calcification  – especially in the elderly

Ø  Arachnoid granulations calcification

Ø  Basal ganglia and dentate nucleus calcification

Ø  Internal carotid artery calcification ­ - especially in the region of siphon

Ø  Lens of the eye – may be calcified in the elderly

v  THE FACIAL BONES

Ø  THE ZYGOMA   

§  Lateral boundary of the temporal fossa above, and the infratemporal fossa below

§  OM projection, modified Towne’s and SMV views

Ø  THE BONY ORBIT

§  Apex

·         Optic foramen opens – optic nerve and ophthalmic artery from the optic canal

§  Lamina papyracea

§  Lacrimal gland

§  Lacrimal sac and its duct

§  Superior orbital fissure

§  Inferior orbital Fissure

·         Communicates with the pterygoidpalatine fossa

§  Infraorbital Groove

§  Periorbita -  fibrous ring around the orbit

Ø  RADIOLOGY OF THE BONY ORBIT

§  Plain Films

·         OF20 and OM projections

·         Innominate line

§  Computed tomography

Ø  THE NASAL CAVITY AND PARANASAL SINUSES

§  THE NASAL CAVITY

·         Turbinates or conchae – dividing the cavity into inferior, middle and superior meati – each laying below the turbinate with the corresponding name.

·         The space above the superior turbinate is the sphenoethmoidal recess

¨       Sphenoid air cells

§  THE PARANASAL SINUSES  

·         The frontal sinuses

·         The ethmoid sinuses

·         The sphenoid sinuses

·         The maxillary sinuses

¨       Orbital process

¨       Zygomatic process

¨       Alveolar process

¨       Palatine process

Uncinate process – medial wall of the maxillary sinus continued superiorly as the uncinate process

Maxillary ostium – opens superiorly to the infundibulum – ostiomeatal complex

§  RADIOLOGY OF THE NASALCAVITY AND PARANASAL SINUS

·         Plain Films

¨       Frontal sinus -  Not visible <2 years

¨       Pneumatization of the sphenoid sinus at >3 years

¨       Maxillary sinus – first to appear from a few weeks after birth. Tooth-bearing alveolar process only happen after 6 years. Full pneumatisation after all the teeth have erupted in early adulthood.

·         Computed tomography

Ø  THE MANDIBLE AND TEETH

§  THE MANDIBLE

·         Symphysis menti –

·         angle of the mandible

·         Coronoid process anteriorly and the condylar process posteriorly – separated by the mandibular notch

·         Body – alveolar border with its 16 tooth sockets

·         Madibular canal ­ - runs in the ramus and body of the bone, with the inferior alveolar vessels and nerve. Proximal opening in the mandibular foramen and distal opening is the mental forramen

Bone: Mandibular canal
The permanent teeth, viewed from the right. The external layer of bone has been partly removed and the maxillary sinus has been opened.
Gray's	subject #44 173

§  THE TEMPEROMANDIBULAR JOINT

Temporomandibular fossa: Temporal articular surface consists of a fossa posteriorly –  and anteriorly the articular tubercle

 

·        

§  THE TEETH – NOMENCLATURE AND ANATOMY

·         20  deciduous – two incisors, one canine, two molars in each quadrant

·        

·         32 Permanent teeth – two incisors, one canine, two premolars, tree molars in each quadrant

·          

·         Position plotted by a quadrant – milk teeth by Capital Letters and Permanent teeth by number and position.

·         Root – embedded in a separate socket

·         Neck of the tooth – covered by firm fibrous tissue of the gum covered by mucous membrane

·         Crown - Exposed intraoral part and is covered by enamel

·         Remainder of the tooth is composed of dentine

·         Radiolucent pulp cavity – middle of the tooth and is continuous with the root canal, which transmits nerves and vessels from the supporting bone.

·         Root and Neck are surrounded by periodontal membrane

·         Lamina dura

§  RADIOLOGY OF THE MANDIBLE AND TEETH

·         Plain films

¨       Mandible may be seen on OF, OF20, OM, OM30 and lateral projection

·         Cross-sectional imaging

¨       Excellent for TM joint anatomy

·         Orthopantomography

¨       Orthopantomography – panoramic image of both dental arches, as well as the mandible, temperomandibular joint and lower maxilla.

·         Arthrography

¨       Contrast injected into the synovial spaces under radiographic control

Ø  THE ORAL CAVITY AND SALIVARY GLANDS

Ø  THE ORAL CAVITY

§  RADIOLOGY OF THE ORAL CAVITY

§  THE SALIVARY GLANDS

§  RADIOLOGY OF THE SALIVARY GLANDS

Ø  THE ORBITAL CONTENTS

§  INTERNAL ANATOMY AND COVERINGS OF THE EYE

§  RADIOLOGY OF THE ORBIT AND EYE

Ø  THE LACRIMAL APPARATUS

§  RADIOLOGY OF THE LACRIMAL GLAND

v  THE EAR

Ø  THE EXTERNAL EAR

Ø  THE MIDDLE EAR

Ø  THE INNER EAR

Ø  THE INTERNAL AUDITORY MEATUS

Ø  CROSS-SECTIONAL ANATOMY

Ø  RADIOLOGY OF THE MIDDLE AND INNER EAR

v  THE PHARYNX AND RELATED SPACES

v  THE NASOPHARYNX AND RELATED SPACES

Ø  THE NASOPHARYNX

Ø  SPACES RELATED TO THE NASOPHARYNX

Ø  THE OROPHARYNX AND LARYNGOPHARYNX

Ø  CROSS-SECTION ANATOMY OF THE NASOPHARYNX

Ø  RADIOLOGY OF THE PHARYNX

v  THE LARYNX

Ø  CROSS SECTIONAL ANATOMY OF THE LARYNX

Ø  RADIOLOGY OF THE LARYNX

v  THE TYROID AND PARATHYROID GLANDS

Ø  THE TYROID GLAND

Ø  CROSS SECTIONAL ANATOMY OF THE THYROID GLAND

Ø  RADIOLOGY OF THE THYROID GLAND

Ø  THE PARATHYROID GLANDS

Ø  RADIOLOGY OF THE PARATYROID GLANDS

v  THE NECK VESSELS

Ø  THE CAROTID ARTERIES IN THE NECK

Ø  RADIOLOGY OF THE CAROTID VESSELS

Ø  VENOUS DRAINAGE OF THE HEAD AND NECK

Ø  RADIOLOGY OF THE VEINS OF THE HEAD AND NECK

Ø  THE SUBCLAVIAN ARTERIES IN THE NECK

Ø  THE SUBCLAVIAN VEINS IN THE NECK

Ø  RADIOLOGY OF THE SUBCLAVIAN VESSELS