Sinus Comp Flashcards
How many cranial bones are there?
8
- frontal
- parietals (2)
- occipital
- temporals (2)
- sphenoid
- ethmoid
What bones make up the calivarium?
- frontal
- parietals (2)
- occipital
What bones make up the floor?
- sphenoid
- ethmoid
- temporals (2)
How many facial bones are there?
14
- maxilla (2)
- zygoma (2)
- lacrimal (2)
- nasal (2)
- inferior nasal conchae (2)
- palantine (2)
- vomer
- mandible
Sutures?
- Sagittal : side to side
- Coronal: front to back
- Lambdoidal: parietals to occipital
- Squamosal: parietals to temporals
Portions of the frontal bone?
- squamous/vertical (forehead)
- orbital/horizontal (superior orbit)
What passes through the supraorbital notch?
-orbital nerve/artery
What forms the superior part of the orbit?
-orbital plate, separated buy the ethmoid notch
What does the frontal bone articulate with?
- R/L parietals
- sphenoid
- ethmoid
What parts of the skull so the parietals form?
The lateral portion and part of the roof
What is the widest part of the skull?
Parietal tubercles
What do the parietals articulate with?
- frontal
- occipital
- temporals
- sphenoid
- opposite parietal
What does the occipital bone articulate with?
- 2 parietals
- 2 temporals
- sphenoid
- atlas (C1)
What do the temporal bones house?
-organs of hearing and balance
What forms the zygomatic arch?
- Zygomatic process of the temporal bone
- Temporal process of the zygoma
Where is the temporomandibular fossa located?
Anterior to the EAM and inferior to the zygomatic process
3 parts of the temporal bones?
- Squamous portion: thin, most vulnerable
- Mastoid portion: posterior to EAM, contains air cells
- Petrous portion: petrous ridges (pyramids), housing for hearing/balance
What transmits nerves of hearing and equilibrium?
Internal acoustic meatus
What is an anchor for all 8 cranial bones?
Sphenoid
Where is the sphenoid sinus located in the sphenoid?
Body
Another name for sella turcica?
Turkish saddle
What sits in the sella turcica?
Pituitary gland
What is the clivus for?
Base of support for the pons and basilar artery
Where are the anterior and posterior clinoid processes located?
Anterior: lesser wings of the sphenoid
Posterior: dorsum sellae
What do the greater wings of the sphenoid help form?
Portion of the floor of the cranium and walls
3 foramina in the sphenoid?
- foramen rotundum
- foramen ovale
- foramen spinosum
What help form part of the lateral walls of the nasal cavities?
Pterygoid processes of the sphenoid
Upper horizontal part of ethmoid bone?
Cribriform plate
Crista gali is also known as?
“Roosters comb”
What helps for the nasal septum?
Perpendicular plate of the ethmoid
Where are the ethmoid sinuses located in the ethmoid bone?
In the lateral masses (labyrinths)
Lateral labyrithns
- help form lateral walls of nasal cavity and medial walls of the orbits
- superior and middle nasal conchae/turbinates
What are soft spots in infants at the sutures of the skull called?
Fontanels
“Sutural” or “wormian” bones most commonly form in what suture in adults?
Lambdoidal
The maxillary bones assist in formation of ?
- mouth
- nasal cavity
- one orbit
Point where the nose and upper lip meet?
Acanthion
What forms the hard palate? What does the hard palate form?
- palantine process of the maxillae
- anterior roof of mouth
What is cleft palate?
Incomplete closing of the palantine processes of the maxillae
What form the posterior hard palate?
Palantine bones
Another name for zygomatic bones?
Malar bones
What are the thinnest, most fragile bones in the body?
Lacrimal
Nasal
What is the nasion?
Nasal bone articulation with the frontal bone
Where do the inferior nasal conchae project from? What do they do?
- project laterally from the walls of the nasal cavity and extend medially
- divide the nasal cavity into different compartments
- incoming are is warmed and cleaned as it comes in contact with the mucous membrane
When do the 2 mandibular bones join?
1yr old
Area anterior and posterior to gonion on the mandible?-
Anterior: angle (body)
Posterior: ramus
Parts of the end of the ramus of the mandible??
- Coronoid process: anterior to mandibular notch
- Condyloid process: posterior to mandibular notch
TMJ joint classification?
- synovial
- diarthrodial
- bicondylar AND plane/gliding
Alveoli and roots of teeth joint classification?
- fibrous
- synarthrodial
- gomphosis
What are the paranasal sinuses?
-large air filled cavities lines with mucous membranes continuous with the nasal cavity
Bones and their number of sinuses?
- maxilla: 2
- frontal: 2
- ethmoid: many
- sphenoid: 1 or 2
Whats different about the structure of the frontal sinuses?
-the frontal sinuses are part of the facial bone structure and the other sinuses are contained in their respective cranial bones
Which sinuses are present at birth?
Maxillary
When are the frontal and sphenoid sinuses visible?Q
Age 6
Which sinuses develop last?
Ethmoid
Another name for the maxillary sinuses?
Antrum
How/from where can infection spread to the maxillary sinuses?
From the teeth through the roots
What is the opening to the nasal cavity in the maxillary sinus?
Middle nasal meatus passageway
Where are the frontal sinuses located?
Between the inner and outer tables of the skull, posterior to the glabella
Frontal sinuses are generally larger in men or women?
Men
What are the groups of ethmoid sinuses?
Anterior, middle,m and posterior collections, but they all communicate
In what sinus do skull pathologies usually present themselves? What will you see?
Sphenoid sinuses because they lie close to the floor of the cranium
“Sphenoid effusion”
What is the osteomeatal complex?
- communication/drainage between the sinuses
- can be obstructed leading to infection
- “sinusitis”
2 key passageways of the osteomeatal complex?
- infundibulum
- middle nasal meatus
maxillary sinus drains through the infundibulum through the middle nasal meatus into the inferior nasal meatus
.
ethmoid bulla received drainage from the frontal and ethmoid sinus cells
.
frontal and ethmoids drain through the MNM to the INM and exit the body through the external nasal orifice
.
How does the orbit project?
Upwards and to the midline
To radiograph the optic foramen, extend the pts chin to ____ dgrees and rotate the head ______ degrees?
Extend: 30 degrees
Rotate: 37 degrees
What 7 bones compose the orbits?
- frontal
- maxilla
- zygoma
- lacrimal
- sphenoid
- ethmoid
- palantine
Opening in posterior orbit from superior to inferior
- Optic foramen
- Superior orbital fissure
- Inferior orbital fissure
-sphenoid strut between the optic foramen and superior orbital fissure
Types of skull fractures?
- Linear: may appear as jagged or irregular lucent lines that lie 90 degrees to the axis of bones
- Depressed: “ping pong” fragments of bone that is separated and depressed into the cranial cavity
- Basal: fracture through dense, inner temporal bone-if bleeding, air fluid levels in sphenoid sinus on the lateral view
Types of neoplasms?
- Metastases
- Multiple myeloma
- Pituitary edenoma
Type of metastases?
- Osteolytic: destructive, irregular
- Osteoblastic: proliferative, increased density
- Combo: “moth-eaten” appearance
What is multiple myeloma?
1 or more bone tumours that originate in the bone marrow
Pituitary adenoma?
- tumour of pituitary gland
- enlargement of sella turcica, erosion of dorsum sellae
- increase technique because of decreased field size
Pagets disease (osteitis deformans)
- bone destruction/repair
- dense, soft bone
- increase technique
Mastoiditis?
- bacterial infection of the mastoid process
- fluid filled abscess replaced mastoid air cells
- progressive hearing loss
Acoustic neuroma?
- benign tumour of auditory nerve
- hearing loss, dizziness, loss of balance
- widened internal auditory canal
Cholesteatoma?
- benign mass/tumour most common in middle ear of mastoid region secondary to trauma
- destroys bone
Polyp?
-growth that arises from the mucous membrane
Osteosclerosis?
- excessive spongey bone formation in the middle and inner ear
- most common cause of adult hearing loss
Blowout fracture?
Fracture of the floor of the orbit
Inferior rectus muscle forced into maxillary sinus causing entrapment and diplopia (double vision)
Tripod fracture?
- fracture of the zygoma in 3 places
- orbital process
- maxillary process
- arch
LeFort fracture?
- bilateral, horizontal fracture of the maxillae
- can result in unstable detachment fragment
Contrecoup fracture?
-fracture on one side, impact on the other
Osteomyelitis?
- infection of bone or bone marrow
- caused by bacteria from trauma, post op, fractures
- may spread via blood
Sinusitis?
- acute or chronic infection of the sinus mucosa
- headache, pain, swelling, low grade fever
Secondary osteomyelitis?
- infection of bone/bone marrow secondary to sinusitis
- erosion of bony margins of the sinuses
TMJ syndrome?
- pain and clicking that indicate dysfunction of the TMJ
- may be caused by malocclusion, stress, muscle spasm, or inflammation
Classifications of the skull?
- Mesocephalic (average): petrous ridges to MSP = 47 deg
- Brachycephalic (wider): greater than 47 deg
- Dolichocephalic (longer): less than 47 deg
Degree difference between the IOML and OML?
-7-8 degrees
Another name for the IOML?
Reids baseline
What is the glabellalveolar line used for?
Tangential nasal bones
Why is erect preferred for facial bones?
-moving head to line up is easier
Exposures for paranasal sinuses?
Medium kVp (70-80 A, 75-90 D) to provide sufficient contrast of paranasal sinuses Small focal spot for max detail
Exposure for facial bones?
Medium kVp (65-85 A, 75-90 D)
Small focal spot
Short exposure time
5 skull positioning errors?
- rotation
- tilt
- excessive flexion
- excessive extension
- incorrect CR angle
In a Caldwell, the CR is perpendicular to what anatomy?
The frontal and ethmoid sinuses, orbital margins, and nasal septum
What happens if the patient chin is tucked to much on a Townes?
-dorsum sellae will be foreshortened and superimposed over the atlas’ posterior arch
What happens if the C1 vertebral foramina are seen on a lateral?
-tip of head is tilted away from the IR
SMV: neck overextended?
The mandibular mentus too far anterior to ethmoid sinuses
How is the OML compared to the IR in a Water’s?
37 degrees
Maxillary sinuses superimposed over the posterior molars and alveolar processes during a Waters?
Chin raised too much
What is perpendicular to the IR when doing a modified waters?
The orbital floors
- OML 55 degrees to IR
- LML perpendicular to IR
- petrous ridges in maxillary sinuses
