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Surface marking helps identify underlying anatomical structures through external landmarks, assisting in examination, clinical diagnosis and surgical procedures. Radiological anatomy correlates these landmarks with imaging, improving interpretation of X-rays, CT, and MRI.
These are palpable or easily visible points on the face, head, and neck, used to project deeper structures.
(Information taken from the section beginning at L38–L41 of the retrieved document)
• Frontozygomatic suture – felt as a depression at the upper lateral orbital margin.
• Infraorbital margin – sharp border below the orbit, useful for nerve block positioning.
• Zygomatic arch – easily felt; marks the position of the temporalis muscle and its fascia.
• Mandibular notch – felt as a curved depression between the condylar and coronoid processes; used to locate masseteric nerve entry.
• Jugal point – anterior end of the upper border of zygomatic arch; an orientation point for fractures.
(Information supported by L41–L42 and additional parts of file result 1)
• Marginal tubercle of the zygoma – projects along the frontal process of the zygomatic bone, used in surgical approaches.
• Pterion – junction of frontal, parietal, temporal and sphenoid bones; thinnest part of skull, overlies middle meningeal artery.
• Frankfurt plane – line from infraorbital margin to external acoustic meatus; standard anthropometric reference.
• Mandibular notch and neck of mandible – visible and palpable during intraoral nerve blocks and maxillofacial examination.
(Supported by L43–L44 and elaborated using the content in file result 1 under “Landmarks on Anterior Aspect of Neck”)
• Mandible – lower border forms base of the face; angle of mandible helps assess facial nerve injury or swelling.
• Hyoid bone – felt just above the thyroid cartilage; used to assess swallowing and floor of mouth pathology.
• Thyroid cartilage – prominent "Adam’s apple”; key guide to laryngeal structures.
• Cricoid cartilage – felt as a complete ring below thyroid cartilage; landmark for emergency airway access (cricothyrotomy).
• Tracheal rings – palpable in the midline; deviation suggests mediastinal shift.
• Sternocleidomastoid muscle – defines anterior and posterior triangles of the neck; guides identification of major vessels and nerves.
• Mandible
The lower border of the mandible forms the base of the face. The angle of the mandible lies opposite the second cervical vertebra. The mental protuberance forms the chin.
• Hyoid Bone
Located in the midline just above the thyroid cartilage. It moves upwards during swallowing.
• Thyroid Cartilage
Forms the prominent laryngeal prominence (Adam’s apple). More prominent in males.
• Cricothyroid Membrane
A soft interval between the thyroid and cricoid cartilages. Important for emergency cricothyrotomy.
• Cricoid Cartilage
A complete ring of cartilage located below the thyroid cartilage. Serves as a key landmark for subglottic space and upper trachea.
• Trachea
Tracheal rings can be palpated in the midline. Deviation to either side indicates mediastinal shift.
• Suprasternal Notch
A depression between the medial ends of the clavicles. Used to identify tracheal deviation and measure jugular venous pressure.
• Frontozygomatic Suture
Felt as a slight depression at the upper part of the lateral orbital margin.
• Marginal Tubercle of Zygoma
A small projection on the posterior border of the frontal process of the zygomatic bone.
• Frankfurt Plane
A reference plane used in skull orientation—extends from the infraorbital margin to the upper margin of the external acoustic meatus.
• Jugal Point
Represents the anterior end of the upper border of the zygomatic arch.
• Mandibular Notch
A curved depression between the condylar and coronoid processes of the mandible.
The following structures are projected onto the skin surface using reliable anatomical planes and palpable points.
• Draw a vertical line from the sternoclavicular joint to the upper border of the thyroid cartilage.
• The artery lies deep to the sternocleidomastoid along this line.
• Begins at the upper border of the thyroid cartilage.
• Passes upward anterior to the ear.
• Ends behind the neck of the mandible by dividing into maxillary and superficial temporal arteries.
• Starts at the angle of the mandible, just anterior to the masseter.
• Winds upward and medially across the face to the corner of the mouth, then to the side of the nose, and finally to the medial canthus.
• Mark a point just above the tragus of the ear.
• The artery then ascends vertically in front of the ear within the temporal region.
• Begins opposite the facial artery origin.
• Runs posteriorly toward the mastoid region, then ascends to the occiput.
• Lies deep in the neck and not directly palpable.
• Projected from the transverse process of C6 upward through the cervical transverse foramina to the foramen magnum.
• Begin at the mastoid process.
• Draw a straight line to the sternoclavicular joint.
• The vein lies deep to the sternocleidomastoid along this entire course.
• Starts just behind the angle of the mandible.
• Runs obliquely across the sternocleidomastoid.
• Ends above the middle of the clavicle.
• Begins near the midline below the chin.
• Runs downward close to the midline and dips deep above the sternum.
• Mark a midline curve from the glabella to the external occipital protuberance.
• Lies deep to the sagittal suture.
• Draw a horizontal line from the inion toward the mastoid process on each side.
• Curves downward from the end of the transverse sinus to the jugular foramen behind the mastoid.
• Emerges at the stylomastoid foramen (just below and medial to the mastoid tip).
• Runs forward into the parotid gland, dividing into temporofacial and cervicofacial branches.
• Appears at the middle of the posterior border of sternocleidomastoid.
• Crosses the posterior triangle obliquely to the trapezius.
• Mark a point midway between the mastoid process and angle of mandible.
• It curves forward across the carotid arteries and goes deep to the mylohyoid toward the tongue.
• Courses below the submandibular duct, approaching the lateral tongue.
• Marked indirectly: below the mandible, near molar region inside oral cavity.
• Emerges at the infraorbital foramen, one fingerbreadth below the infraorbital margin.
• Occupies the area:
– Between zygomatic arch and angle of mandible
– Anterior to the mastoid process
• Draw an inverted triangle covering this region.
• Lies beneath the mandibular body.
• Mark the area in the submandibular fossa between the angle and chin.
• Two lobes lie beside the trachea from the 5th cervical vertebra to 1st thoracic vertebra.
• The isthmus crosses the 2nd–4th tracheal rings.
• Small nodules located on the posterior surface of the thyroid lobes, near the middle and lower thirds.
• Located above the medial third of the supraorbital margin.
• Usually marked as a rectangle above the eyebrows.
• Occupies the region of the cheek.
• Surface marking corresponds to an area bounded by the infraorbital margin above and the upper teeth below.
• Lie deep between the medial orbit walls.
• Surface marking corresponds to the medial canthus region.
• Situated deep in the skull.
• Surface marking approximates to the area deep behind the nasal root.
Radiological anatomy defines how major bones, sinuses and foramina appear on standard X-ray views, helping correlate surface landmarks with imaging.
Key structures visible:
• Frontal, parietal, occipital, temporal bones
• Sphenoid (greater and lesser wings)
• Sella turcica
• Frontal and maxillary sinuses
• Mastoid air cells
• Coronal and lambdoid sutures
• External acoustic meatus
• Mandible: ramus, angle, condyle, coronoid
• Zygomatic arch
• Cranial fossae outline
• Tip of the odontoid process
• Best shows maxillary sinuses.
• Also visualizes orbital rims, nasal cavity, zygoma.
• Visualizes frontal sinus and ethmoidal cells.
• Petrous ridges appear in the lower orbit.
• Shows sphenoidal sinus, zygomatic arches, and skull base.
• Shows cervical, petrous, cavernous and cerebral parts.
• Carotid siphon appears as an S-shaped curve.
• Anterior and middle cerebral arteries branch in characteristic patterns.
• Shows branching into maxillary, superficial temporal, facial and lingual arteries.
• Identifies aneurysms, stenosis, arteriovenous malformations.
• Assesses collateral circulation in stroke.
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