Paranasal sinuses and orbits

What view best demonstrates the basilar foramina?

submentovertex

What is the vertex of the head?

Topmost portion (crown)

What sinus is best visualized by submentovertex view?

sphenoid sinus

What is a mucocele?

Typically benign cyst/white density seen in the sinus

What is a floating palate fracture?

Le Fort I

What is a facial fracture of the maxilla?

Le Fort II - pyramidal

What is the fracture when all the facial bones are coming off the cranium?

Le Fort III

How many bones make up the orbits?

7

What are the holes/foramen of the orbits and what do they contain?

supraorbital fissure - nerves to innervate eye muscles

optic foramen/canal - optic nerve and ophthalmic artery

inferior orbital fissure - nerves to innervate skin of the face

Where is the lacrimal gland located? How many excretory ducts does it contain?

Upper outer quadrant of orbit. 6 - 12 ducts.

Where is the lacrimal sac located?

Inner canthus

Where does the nasolacrimal duct drain to?

inferior nasal meatus (this is why our nose runs when we cry)

What tube able do we need to use to get the orbits clear of the petrous ridges?

25 degrees caudal

Where do we want the petrous ridges to be for a parietoacanthial waters view?

Just below the floor of the maximally sinus

How is the modified waters different from the PA waters? Where will the petrous ridges be seen?

OMBL is 55 degrees to the plane of the IR. Petrous ridges seen mid maxillary sinus.

What view visualizes the optic foramen? How is it done?

Rhese view - Median sagittal 53 degrees to IR. AMBL perpendicular to IR. Enter 1” superior and 1” posterior to ear attachment.

What view is this?

Reverse Rhese

What is downward displacement of the eyeball called?

Proptosis

What is outward/anterior protrusion of the eyeball called?

Exophthalmos

What fracture involves the floor of the orbit?

Blow out fracture

What is a tripod fracture?

Fracture of zygoma away from the face. Three point fracture.

The modified Caldwell horizontal beam best demonstrates which sinuses?

Frontal and ethmoid

The lateral sinus projection best demonstrates which sinus(es)?

Sphenoid

What is the purpose of the paranasal sinuses?

lighten the skull, protect the brain from trauma, add resonance to voice

The antrum of highmore is another name for which sinus?

maxillary

What are the nasal turbinates/conchae?

supreme (very small), superior , middle, and inferior (its own bone)

Drainage from all the sinuses passes through what?

osteomeatal complex

What is the baseline for the parietoacanthial waters view?

OMBL 37 degrees to plane of IR

What is the odontoid seen in the exaggerated waters projection?

2” below the mandible

What is the baseline for the submentovertex?

IOMBL vertical - parallel to the plane of the IR