radio graphic surface anatomy of head neck e-learning

8/3/2019 Radio Graphic Surface Anatomy of Head Neck E-learning

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Thyroid GlandThyroid Gland

2 Lobes (C5-T1)

&

isthmus

(2nd & 3rd tracheal rings)

Covered by pretracheal layer

Of deep cervical fascia


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Thyroid RelationsThyroid Relations

Anterolateral:

sup. Belly of omo. (upper)

ant. border of SCM (lower)

sternohyoid & sternothyroid

muscles (middle)

Medial:

thyroid & cricoid cartilages(upper)

upper 6 tracheal rings (lower)

Posterior:

CCA

inf. thyroid a.

parathyroid glands


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Vasculature of Thyroid GlandVasculature of Thyroid Gland

Read your text for detailed

arterial bld. Supply & venous

drainage of the thyroid gland


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Clinical Notes:Clinical Notes:

Thyroid GlandThyroid Gland


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Pyramidal Lobe of Thyroid GlandPyramidal Lobe of Thyroid Gland

Accessory thyroid tissue superior to the isthmus of the gland

- Attached sup. To hyoid bone

- 50% of population

- A remnant of thyroglossal duct:

endodermal tube carrying thyroid

forming tissue from post. 1/3 of

the tongue in the embryo


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Risks of Surgery on Thyroid GlandRisks of Surgery on Thyroid Gland

Thyroid surgery is often necessitated due to several reasons,mainly neoplastic growth (cancer) into the gland

Risks:

1. Recurrent laryngeal nerve dysphonia (hoarseness)

2. Parathyroid glands:

inadvertent removalserum Ca2+ Tetany

3. Postoperative Bleeding:

2 a. + 3 v.

* hemorrhage can be confined within the space

surrounded by pretracheal fascia compress the

trachea

difficulty in breathing


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TetanyTetanygeneralized convulsive disorder characterized by

involuntary muscle spasms


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Radiological AnatomyRadiological Anatomyof Head & Neckof Head & Neck


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Radiographic PrinciplesRadiographic Principles

1. The radiograph is a record of radiodensity of structuresThrough which x-ray beam has passed:

Radiodensity: (radioopacityradiolucency)

bone > soft tissue > space (air)

Tooth: enamel > dentin & cementum > pulp

2. The radiograph is a 2-dimensional representation of

3-dimensional objects:

superimposition

3. Magnification:

x-ray beam spreads

depends on distance between ??


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Head & Neck RadiographyHead & Neck Radiography

Extra-Oral:

Post.-Ant. of skull

lat. View of the skull

oblique post.-ant. (occipitomental)

Panorama

Intra-Oral:

Bitewing

Periapical

Occlusal


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Post.Post. Ant. of The SkullAnt. of The Skull

Forehead & nose against the

film cassette

X-ray tube perpendicular to

the film at level of??

X-ray beam passes from post.

to ant.

Forcranial vault examination(fractures)

& frontal air sinuses


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Lateral View of The SkullLateral View of The Skull

Sagittal plane parallel

to the cassette.

X-ray tube is centered

over the region of

??


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Lateral View of The SkullLateral View of The Skull

For:

Cranial base & vault

examination

diploic bone str.(tables of c.v. bones)

Paranasal sinuses:

frontal, maxillary,

sphenoidal, mastoid

ethmoid (obsecured)


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Occipitomental (oblique PA)Occipitomental (oblique PA)

Chin touching the cassette &

head tilted backwards (45O)

For:

Investigation of max. sinus

Avoid superimposition by

petrous part of temporal bone


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Panoramic RadiographPanoramic RadiographFor:

Mandibular Fractures

Minor Oral Surgeries (MOS):

Extraction of impacted

wisdom teeth

Orthodontics


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Bitewing RadiographsBitewing Radiographs

Taken in initial & routine

dental examination

To disclose caries in post.

teeth*specially class II

Provides view of the

crowns & pulp chambers

only


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Periapical RadiographsPeriapical Radiographs

To examine the roots of teeth &surrounding tissues

Fields of Application:

Endodontics

Perodontics

Crowns & Bridges

(Post & Core)

Extraction of curved orremnant roots

*14 films are required for entire

dentition


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Surface AnatomySurface Anatomy

of The Head & Neckof The Head & Neck

Self ReadingSelf Reading


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Midline StructuresMidline Structures

Symphesis Menti: union of 2 halves of mandible in midline

Hyoid Bone: U-shaped bone located in midline posterior to the

mandible & at the level of C3

Thyroid Cartilage: located at level of C4-C5, easily felt & moves

with swallowing

Suprasternal Notch: between medial ends of clavicles & opposite

to lower border of T2 vertebra


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Arterial PulsesArterial Pulses

Carotid Pulse: opposite to anterior border of SCM

(Common carotid artery)

Facial Pulse: palpated on the inferior border of the mandible

(facial artery)

Temporal Pulse: palpated anterior to the auricle of the ear,

specifically opposite to the tragus.

(superficial temporal artery)


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Lateral & Posterior LandmarksLateral & Posterior Landmarks

LateralZygomatic Arch: from anterior aspect beneath the orbit to the ear,

it provide attachment for masseter muscle

Mastoid process of temporal bone: projects downwards forwards

behind the ear

Posterior

External Occipital Protuberance (EOP): at midline posteriorly

Superior Nuchal Line: curved ridge that runs laterally from EOP to

the mastoid process

radio graphic surface anatomy of head neck e-learning

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