Exam 1.12: Panographic Radiology Viewing and Evaluating Flashcards
What should you do to create an environment suitable for reading a pan?
Viewbox with strong illumination and reduced ambient light
Hot spot, magnifying glass, and hood are helpful too
What order should you evaluate in?
Bone structures
Soft Tissue Shadows
Air spaces
Teeth are last
What is the first bony structure to evaluate
Right Coronoid Process
How might the coronoid process appear in relation to the zygomatic arch
Inferior, Superimposed, or slightly above
How do you know if the coronoid process is usually tall
If it is more than 1 cm above the midpoint of the superior border of the arch
What is the term for a tall coronoid arch?
Coronoid hyperplasia
What type of movement is hindered by coronoid hyperplasia?
Anteriomedial translatory…..patient has trouble fully opening mouth
What can be suspected if the coronoid hyperplasia is only on one side?
Osteochondroma
What patients will you see bilateral coronoid hyperplasia on?
Teen males thanks to excess growth hormone receptors on coronoid process
This appears as a semilunar rarefaction just below and medial to the sigmoid notch.
Medial sigmoid depression
What do you examine after the coronoid process?
The condylar head of the mandible
How might you determine if bone pathology is due to a break or inflammatory disease?
A break would include damage to the cancellous bone
Inflammatory disease would be limited to the cortical bone
If you see cortical rim degeneration and the patient’s blood work has elevated RA factor, IgM, and erythrocyte sedimentation rate, what would you suggest is the problem?
Rheumatoid arthritis
What fibrous structure covers the articular surfaces of the joint in RA?
A pannus
What does the pannus have that physically destroys the joint surfaces and cartilage?
The pannus is filled with macrophages, proteases, and collagenases
If too much of the condylar head is resorbed, it leaves a sharp residual shape…what often occurs next
Perforation of the disk Crepitus Fibrous adhesions Bony ankylosis Open bite
What are two rare causes of the condylar degeneration in patient’s without RA?
Regional spread of a parotid gland cancer
Primary osseous or cartilaginous neoplasm
If we are talking about osteoarthritis as opposed to RA, in what direction would we expect to see the remodeling progressing
Anteromedially
Once the condylar head has flattened enough, what anatomic feature will be visible?
Osteophyte, aka bone spur
How will subchondral cysts show up on the image
small ovoid RLs just beneath the cortical rim
Where might sclerosis be found in an osteoarthritic TMJ
On the condylar head and/or the temporal bone
What is it called when an osteophyte breaks loose
Loose bodies
How do you treat osteoarthritis patients with no pain?
You don’t.
With pain you give them a condylar shave procedure
What is the condylar fovea
Large ovoid RL on the medial aspect of condyle
Not all patients have this
Just means that the bone is thinner here and attenuated less radiation
What direction is more common for bifid condyles
Mediolateral
What section of the mandible do we look at after the condylar head?
Cortical border starting by moving down the right ramus around the inferior border, and up to the left condyle looking for fractures
What is the first thing you need to determine if you see a jaw fracture?
Its age
For the first 4-6 weeks post-fractures what can you see
Only the RL fracture line
5-6 weeks post fracture what can you see
Fuzzy organic callus RP superimposed over the fracture line
How long does it takes for the callus to completely remodel and disappear from the radiograph
1 year
What happens if the fracture lines in the buccal and lingual corticies do not superimpose?
It will look like there are two fractures when there is actually only 1
What is a greenstick fracture
One corex that is broken and one which is bent
What is a communited fracture
One in which the bone is shattered
What percent of jaw fractures are compound?
75%
Besides the mucosa, what tissue can the fracture involve that would make it compound?
PDL
What is required in order to properly treat compound fractures?
Prophylactic ABX in order to prevent osteomyelitis
What is the most common part of the jaw for a fracture?
Body
Middle of body is slightly more common than posteror
What is the least common part of the mandible to get fractured?
Condyle
What can masseteric hypertrophy, gum chewing, or parafunctional habits cause in the mandible?
Antegonial notch
Where is the lingula normally located
opposite the occlusal surface of the second molars
but sometimes it is superior to this position, good to know for nerve block administration
When would third molar extraction be expected to cause at least temporary parasthesia?
If it is causing downward displacement of the mandibular canal
Most IAN nerve fibers exit out of the mental foramen, where do the rest exit?
They continue anteriorly and exit at the lingual foramen between the genial tubercles
What is another name for a lingual submandibular salivary gland depression
Staphne defect
What does a staphne defect look like on the pan
Well defined Ovoid Unilocular Radiolucency Inferior to mand. canal Near angle of mandible
What thin, fuzzy, trabeculae with affected lamina dura indicate?
Osteopenic pattern, refer to physician
The RL caused by the external auditory meatus should be just lateral to what bony structure?
Condylar head
What bony structure that is just medial to the condyle should not be mistaken for a fracture?
Zygomatico-temporal suture
What does a zygomatic air cell defect look like
Uni or multiocular RL in the articular eminence of the distal half of the zygomatic arch
Upside down teardrop shaped radiolucency adjacent to the lateral border of the maxillary sinus
Pterygomaxillary fissure
Erosion of the corticies of the pterygomaxillary fissure indicates what
Pharyngeal malignancy
Two triangular RPs inferior to the pterygomaxillary fissure and superimposed over the coronoid process of the mandible
Pterygoid plates
A RP spiny structure just lateral to the maxillary tubersoity, and this is best appreciated radiographically if the area is edentulous
Hamular process
What do the two RP lines in the inferior orbit represent?
Infraorbital canal
Vertical band of bone immediately medial to the pterygomaxillary fissure
Malar process of the zygoma
Why does the lateral 1/3 of the maxillary sinus always appear more opaque than the medial 2/3?
Because the malar process of the zygoma is always superimposed over it
Which wall of the maxillary sinus is not well visualized on a pan?
Posterior
What should the antrum of the maxillary sinus be evaluated for?
Degree of pneumatization vs. opacification
This linear horizontal RP is superimposed over the midportion of the maxillary sinuses and over the nose
Hard palate
Eagle’s Syndrome or Carotid Artery Syndrome require treatment for….
Calcified Stylohyoid ligaments
This bone has the soft tissue shadow of the base of the tongue and epiglottis superimposed over it
Hyoid
Which part of the hyoid rises out of the body at a 45 degree angle
Lesser Horns
Which is the only cervical vertebra that has a transverse foramina?
C2
Which is the soft tissue, Conchae or Turbinates?
Conchae
A soft tissue opacity just beneath the shadow of the tongue and just above the hyoid
epiglottis
A crescent shaped RL will be superimposed on the roots of the maxillary teeth and floor of sinus
Palatoglossal air space
how do you prevent the palatoglossal air space?
Have patient place tongue against the roof of their mouth
If the patient places their tongue correctly this wedge-shaped RL over the ramus which represents air around the tonsils will be present instead
Oropharyngeal airspace
Two thin oblique slit-shaped RLs superimposed over the soft tissue shadow of the nose represents this
Nasal air in the nasal fossa
