RAD 230 - TEMPORAL BONES

TRUE

(TRUE/FALSE) When radiographing the TMJ's, usually open and closed mouth images are taken and both sides are radiographed for comparison.

AP AXIAL

- 8x10 - Flex neck enough so orbitomeatal baseline is perpendicular to the IR. - CR 35º caudal midway between TMJ entering 3" above nasion. - Expose 1 image with mouth closed and 1 mouth open unless contraindicated. - Structures Shown: condyles of the mandible and mandibular fossa of temporal bones.

AXIOLATERAL PROJECTION (RIGHT AND LEFT)

- 8x10 crosswise - Center a point 1/2" anterior to EAM to IR, place pt's head in true lateral position with affected side down. Adjust head so inter pupillary line is perpendicular to IR. - 25-30º caudal entering 1/2 anterior and 2" superior to upside EAM. - Open and closed mouth views preferable and both sides are viewed for comparison. - Structures shown: TMJ in open and closed mouth.

AXIOLATERAL OBLIQUE PROJECTION (RIGHT AND LEFT)

- 8x10 crosswise. - Examine both sides for comparison. - Center a point 1/2" anterior to the EAM to the IR, and place pt's cheek on grid device. Rotate midsagittal plane of head 15º toward IR. Adjust inter pupillary line perpendicular to IR. Adjust flexion so the AML is parallel with the transverse axis of the IR. - CR 15º caudal and exiting through TMJ closest to IR and enters about 1 1/2" superior to upside EAM. - Structures shown: Images in the open and closed mouth positions show condyles and necks of the mandible. Show the relationship between the mandibular fossa and the condyle. Open mouth position shows the mandibular fossa and inferior and anterior excursion of the condyle. Closed mouth position shows fractures of the neck and condyle of the ramus.

EAR

- The organ or hearing and balance. - Composed of the peripheral sensory apparatus of equilibrium and acoustic apparatus. - The essential parts are found in the petrous portion of the temporal bone.

TYMPANIC CAVITY

- The part of the middle ear that is the air filled compartment. - Narrow irregularly shaped chamber that lies just posterior and medial to the mandibular fossa. - Separated from the external ear by the tympanic membrane and from the internal ear by the structures called the fen ester vestibule (oval window) and fenestra cochlea (round window) which are located on the labyrinth wall.

TYMPANIC MEMBRANE (EARDRUM)

- Thin membranous disk with an elliptical shape. - Forms a partition between the external and middle ear. - Function is to transmit sound vibrations.

COCHLEAE

Communicated with the middle ear through the fenestra cochleae.

VESTIBULE

Communicated with the middle ear through the fenestra vestibuli at the base of the stirrup.

PETROMASTOID PORTION

Forms the inferior, posterior part of the temporal bone.

HELIX

Identify A

MASTOID PORTION

Identify A

SQUAMOUS PORTION

Identify A

AURICLE

Identify B

EXTERNAL ACOUSTIC MEATUS

Identify B

PETROUS PORTION

Identify B

CONCHA

Identify C

MASTOID PORTION

Identify C

MASTOID PROCESS

Identify C

CARTILAGE

Identify D

STYLOID PROCESS

Identify D

TYMPANIC PORTION

Identify D

EXTERNAL ACOUSTIC MEATUS

Identify E

STYLOID PROCESS

Identify E

MANDIBULAR FOSSA

Identify F

TYMPANIC MEMBRANE

Identify F

ARTICULAR TUBERCLE

Identify G

TYMPANIC CAVITY

Identify G

AUDITORY (EUSTACHIAN) TUBE

Identify H

ZYGOMATIC PROCESS

Identify H

ROUND WINDOW

Identify I

COCHLEA

Identify J

COCHLEAR NERVE

Identify K

INTERNAL ACOUSTIC MEATUS

Identify L

STAPES IN OVAL WINDOW

Identify M

SEMICIRCULAR CANALS

Identify N

ANTERIOR

Identify O

POSTERIOR

Identify P

LATERAL

Identify Q

AUDITORY OSSICLES

Identify R

MASTOID ANTRUM

Identify S

ARE NOT

If the patient has had a recent injury or trauma to this area, open mouth views (ARE OR ARE NOT) taken for fear of displacing fragments.

INFRAORBITOMEATAL

In a normally shaped head, the upper border of the pyramid lies in the ___________________ line.

TEMPORAL BONES

Irregular in shape and are situated on each side of the base of the cranium between the greater wings of the sphenoid bone and the occipital bone. Each has a squamous portion, tympanic portion, a styloid process and a petromastoid portion.

MIDDLE EAR

Lies between the external and internal ear.

PUBERTY

Shortly before or after birth the smaller air cells begin to develop around the mastoid antrum and continue to increase in number and size until full development of the process which is around ______________.

STYLOID PROCESS

Slender pointed bone which projects inferiorly, anteriorly, and slightly medially from the posteroinferior portion of the tympanic part of the temporal bone.

DISLOCATION

TMJ images are also taken on patients who experience slippage or _______________ of the TMJ when opening and closing their mouths.

CARTILAGINOUS

The EAM is about 1" long with the outer third of the canal wall being ______________ and the inner two thirds bony.

1"

The EAM is approximately _______ in length and projects medially, slightly posteriorly, and slightly superiorly.

MASTOID (TYMPANIC) ANTRUM

The FIRST air cell communicates with the tympanic cavity and is called the ______________ ______________ to distinguish it from the other air cells.

SQUAMA

The _____________ is the thin upper portion of the temporal bone.

TYMPANIC

The _______________ portion is located below the squamous portion and in front of the mastoid and petrous portions of the temporal bone to form the posterior part of the mandibular fossa.

SQUAMOUS

The ________________ portion includes the zygomatic process which articulates with the zygomatic bone to complete the zygomatic arch.

MODIFIED LAW METHOD

The axiolateral oblique projection is sometimes called the _______________ _______ ___________ because it consists of approximately the same positioning details and CR orientation as the _____________ _______ ____________ for the petromastoid portion of the temporal bone.

COCHLEAE, VESTIBULE, 3 SEMICIRCULAR CANAL

The bony labyrinth contains what 3 things?

HEARING

The cochlea is involved with ______________.

MIDDLE EAR

The eustachian tube equalizes air pressure in the ___________ _____ with the outside air passages.

MIDDLE

The external acoustic meatus ends at the tympanic membrane of the ______________ ear.

AURICLE

The external ear consists of an ____________ or pinna and external auditory meatus. It has a deep centra; a depression called the ONCHA, whose lower part leads into the EAM.

PETROUS PYRAMID

The internal ear houses the essential sensory apparatus of hearing and equilibrium and lies on the densest part of the _____________ ____________.

PARIETAL

The mastoid portion articulates with the _____________ bone at its superior border, the occipital bone at its superior and posterior border.

MALES

The mastoid process varies in size and is larger in ______________.

TYMPANUM

The middle ear proper is called the ______________ and has 3 parts.

HEARING

The petrous portion contains the organ of ___________.

PARS PETROSA, PETROUS PYRAMID

The petrous portion, also called the ________ _________ or _____________ ___________, is the thickest, densest bone in the cranium. From its base at the squamous and mastoid portions, the petrous portion projects medially and anteriorly between the greater wing of the sphenoid bone and the occipital bone to the posterolateral angle of the body of the sphenoid bone with which its apex articulates.

COCHLEA

The promontory located on the labyrinth wall accommodates the first turn of the ____________. The oval window lies above and behind the promontory, and the round window is below and behind it.

EQUILIBRIUM

The semicircular canals are involved with _______________.

SQUAMA

The superior wall or roof of the canal are formed by the _____________.

NASOPHARYNX

The tympanic cavity connects with the ________________ through the auditory or eustachian tube.

EAM

The tympanic portion forms the anterior, inferior and part of the posterior walls of the ______________ (auditory canal).

AXIOLATERAL PROJECTION

This projection is sometimes referred to as the Shuller method because it consists of approximately the same positioning details and CR orientation as the Shuller method for the petromastoid portion of the temporal bone.

EXTERNAL, MIDDLE, INNER

What are the 3 main divisions of the ear?

TYMPANIC MEMBRANE (EARDRUM), TYMPANIC CAVITY, AUDITORY OSSICLES

What are the 3 parts of the Middle Ear?

ANTERIOR, POSTERIOR AND LATERAL

What are the 3 semicircular canals?

VESTIBULOCOCHLEAR ORGAN

What is the ear also known as?

HELIX

What is the ear's outer rim called?