endo radiology Flashcards
how are x rays a 2D representation?
static 2-dimensional shadow of a dynamic 3-dimensional situation.
X rays are subject to?
ALL the distortions and
false interpretations
that you can imagine
X rays as a snapshot and continuum?
“ Snapshot in time ” . . . glimpse of a
continuum
“DIAGNOSTIC” RADIOGRAPHS:
Optimization of image quality
and relationship to the area of
concern are paramount in
helping to determine a correct
Diagnosis
what must x rays include to be diagnostic
Must be distinct and include all of the areas of concern in proper orientation without cone cuts, overlapping, elongation or foreshortening. Must include all of the tooth and at least 5 mm. apical to the end of the root.
All Posterior teeth REQUIRE what radiographs
All Posterior teeth REQUIRE 2 P/A radiographs (straight-on and 20 degree H.
angled).
why is it a good idea to take multiple x rays
Always a good idea to take multiple angles to help guess the 3-D anatomy
taking curent radiographs
Think of all the STAGES of a HEALTHY pulpal-
periodontal environment to a DISEASED state. You will SEE most of these stages.
It should tell you to take current radiographs!
Current is 1-2 mos. (UNLESS SOMETHING HAS CHANGED)
Drop-off perio pocket or a DST could indicate a new vertical root Fx
A new restoration or any new information, complaint.
SEE WHAT IS HAPPENING NOW*
historical value of radiographs
A SERIES of RADIOGRAPHS over
time with similar angulation and
exposure can be very helpful when
following a new, developing or
healing lesion.
. Benefits of Endodontic Radiology
Suggests LEOs & other Pathosis
*May Indicate Unseen Canals & Proximal Anatomy
*Largely locates most curvatures
*Assists in Working-Length Determination
determining canals with radiographs
2 CANALS: Which Canal?
Changes of Horizontal
Angulation = “SLOB” rule
RISKS of Endodontic Radiology
Modern diagnostic digital radiography is without risk when appropriate radiation hygiene techniques are employed.
There should be no question about X-Ray safety for adequate diagnostic/TX purposes.
radiogrpahs develop:
mental image
can be due to?
mental risks of endo radio
Opportunities exist for CONFUSION and
Inaccurat Interpretation
Universal Temptation to Dx from
X-RAY alone.
Result can be Inaccurate Dx
leading to INCORRECT Treatment
can be due to:
The 3 Biggest Risks of
Endodontic Radiology
The Court deals with both:
The Court deals with both:
ERRORS of COMMISSION
ERRORS of OMISSION
if confused during tx you should:
take another radiograph to be sure of access
MD vs BL curvatures on radiographs
Mesio-distal curvatures are
more easily noticed than
buco-lingual
bullseyes of radiographs at roots
When you see a “Bullseye”
on an image, You are seeing
a facial or lingual root tip “on
end”. You don’t know if it
curves to the Facial or the
Lingual (good opportunity to
refer).
4th root
unusaul anatomy seen on radiographs
This 4th (Disto-Lingual) root is seen
most frequently in Native American
and Asian populations. Often the D-L
root and canal curve sharply to the
facial to present this classic
appearance.
This information can be of great value
to the operator in being able to
visualize the unusual anatomy
and avoid misadventures.
radio assistance in length determination
what is typical WL?
If we place a file in a single canal at a known length, and radiograph it, we can thereby measure the length of the canal & adjust our file’s length to the desired length (WL) at which we want to do our work inside the tooth.
Radiographs extend our effective vision
We want to work and fill at 1.0 mm. short of the canal exit in most cases.
what is the easiet way to see unusual anatomy
shift shot
3 possible methods
How do you tell WHICH canal to work on?
- You could take a separate XR of each canal with a single file in a known canal. You would then need to label the X-rays carefully/correctly not to become
confused. Wastes TIME* - You could place files of varying radiographic appearance in each of the canals and remember which file went in which canal. (Usually only 1 type of file available)
- You could increase the vertical angle of the radiograph; the lingual canal would be longer, the buccal shorter. However the true lengths would be
grossly distorted & it would be virtually useless for accurate length determination.
preffered methods for determining which canal
- You should take a straight-on
radiograph and then a second
radiograph with a 20º change in
horizontal angulation as in taking a “Shift-Shot”.
All you have to remember is which direction the X-Ray cone was moved from straight-on (i.e. Mesial or Distal
SLOB rule of shift shot
Same Lingual, Opposite Buccal
As the angle of the X-Ray cone is shifted, the object furthest from the XR
cone (lingual) will move with the XR cone. (Conversely, the object closest to the cone will move away from the cone)
A distal cone shift will result in:
the M-buccal canal appearing to shift to the mesial and the M-lingual canal will appear to be distal to it.
why take straight on and shift shots for PMs
possibilty of two canals, must be certain of which to tx
Common periapical Lesions of Endodontic Origin (LEO’s) signs
thickened PDL and PA lucency
is radio capable of dx? look for?
thickened PDL
We can see the thickening of the PDL on this radiograph but this does NOT PROVE it is a LEO. (could be traumatogenic occlusion)
The radiograph is NOT DIAGNOSTIC as the crown is NOT shown and we have no idea if the etiology is a LEO (e.g. caries) or merely thickening arising from traumatic occlusion or recent trauma. Look 4 the INJURY
We must employ: Diagnostic XRs, History, Clinical Examination, and Clinical & Sensibility
Testing to arrive at an ETIOLOGY to know.
Only then do we have our Supported Diagnosis.
must determine what about these?
P/A Radiolucency
must determine if endodontic, periodontic or combined lesion
A radiolucency of endodontic origin association with necrotic pulp?
A radiolucency of endodontic origin is often BUT not always associated with a pulpal DX of necrotic pulp.
The lesion does NOT move away from the apex when the XR angulation is changed; therefore associated w/ tooth.
what could it be?
could be: granuloma, cyst, abcess
usually heal with RCT
dx from radiographs?
what should we do with RCTs of PA lesions when concern of dx?
It is NOT possible to accurately diagnose these conditions from the radiograph.
*If it is important or there is a question that it may be something else of concern, a BIOPSY may be taken.
*Some recommend a BIOPSY of all surgical tissue removed – some
can VRF be seen on x ray
no (unless segementation occurs)
*Crack is either in the plane of the film or obscured by the root itself (esp. in the case of RCT teeth)
can HRF be seen on x rays
*HRF often visible on XR
what can be a clue of fx
mobility
pocket/ j shaped lesion
possible dif dx of pa lucency
*Anatomical Landmark?
*Radiographic Artifact?
*Another (non-endodontic lesion)?
*Oral Manifestation of Systemic
Disease?
A distinguishing characteristic of a radiographic lesion
of endodontic pathosis (LEO) is:
A distinguishing characteristic of a radiographic lesion
of endodontic pathosis (LEO) is that the radiolucency
stays at the apex regardless of cone angulation.
VRF most commonly occur in:
teeth tx endodontically
Can YOU tell the LEOs from normal
anatomy or systemic pathology?
*It is NOT TRUE that ALL “periapical
radiolucencies” that will be presented
radiographically are, in fact, LEOs.
*Again, it is a mistake to diagnose primarily from the radiograph as Differential Diagnosis must be made on a logical basis as supported by evidence beyond the appearance of the radiographic image itself.
*While it is true that “Most periapical (P/A) radiolucencies are of endodontic origin and result from the destruction of bone secondary to a necrotic pulp”.
possible lucencies
common antomical landmarks for dif dx
Maxillary Sinus
Nasal Cavities
Incisive Canal
Mental foramen*
Mandibular Depression (Concavity)
max sinus as a dif dx
The Maxillary sinus is often
superimposed on maxillary
posterior apices. Do not be
fooled!
Learn to carefully examine the
lamina dura and periodontal
ligament at the apex. You should
see the PDL space distinctly
uniform width and un-
interrupted.
nasal cavities as a dif dx
the nasal cavities are often superimposed on the central and lateral apices (especially when a
high bisecting angle technique is used)
Do your pulp testing, percussion, palpation.
Also take additional angled radiographs to see the anatomical area move away from the apices.
Lamina Dura remains intact with normal teeth.
Look for a REASON for this to show pathology
(caries, trauma, etc.) if none seen, there IS no reason and this is not LEO pathology.
Pathology is SELDOM bilaterally symmetrical
.
Again, the Lamina
Dura & Pulp Tests are
the key!
incisivie canal dif dx
Don’t confuse normal anatomy with
pathology (Lamina Dura is key)
If radiolucent area moves AWAY FROM the apex on multiple films, it is NOT associated with the apex and therefore is probably NOT a P/A lesion.
Test vitality of teeth in area. Why?
We MUST pulp test every
tooth which we plan to restore.
mental foramen as a dif dx
Possibly the most common
Anatomical Landmark to be
confused w LEO* = Classic
Can masquerade as P/A lesion. Angled XR
shows it moves AWAY from the apex = NOT a
P/A lesion. Confirm with Pulp Testing.
Lamina Dura is not disturbed. Is there a
REASON for pathology?
If radiolucent area moves WITH the apex on
multiple angled films, it is associated with the
apex and therefore is probably a P/A lesion.
Suspect all apparent bilateral lesions as being
anatomical or systemic and NOT of pulpal
origin until proven otherwise.
mandibular depression dif dx
bilateral luceny on inferior man border
Non-endodontic Radiolucencies which may mimic LEOs including oral manifestations of systemic disease
Lateral Periodontal Cyst (abscess)
PCOD
FOD
Hyper-parathyroidism
Central giant cell granuloma
Neoplasias
Lateral Periodontal cyst (abscess)
symptoms?
where at?
pulp?
lamina dura?
etiology?
draining?
May be asymptomatic OR: may mimic symptoms of SAP or AA (CC = pain, swelling, palpation +, perc++????).
Lesion is NOT generally at apex.
*PT’s =vital pulp VIP!
*LD may or may not be intact
*No restorations or clinical aberrations . . .
CAUSE??
*Etiology=infected perio. Pocket
–If it is able to drain = asymptomatic
–If unable to drain = symptomatic
Periapical Cemental Osseous Dysplasia (PCOD)
AKA: “Cementoma”
Periapical fibrous dysplasia,
Periapical cemental dysplasia
A dysplastic, rather than pathologic or
inflammatory condition.
Characteristics:*
All teeth were vital and asymptomatic
Radiolucent vs radiopaque (mixed)
This is also one of the more common
radiolucencies that causes unneeded endo treatment!!!
Restorations as needed
No further TX is
Focal (or Florid) Osseous Dysplasia (FOD) x ray
two stages
HYPER PARATHYROIDISM
hyPER calcemia, hyPO phosphatemia “Brown’s Tumors”
Clinical Testing Results are very important here to eliminate
unnecessary RCT.
Medical History is essential to avoid being mislead by radiographic
appearance.
Careful examination/questioning of the patient is critical to a correct
Central Giant Cell
Granuloma
benign intraosseous lesion found in the anterior of the maxilla and the mandible in younger people (before age 20).
characterized by large lesions that expand the cortical plate and can resorb roots and move teeth.
It is composed of multi-nucleated
giant cells.
It has a slight predilection for females.
Radiographically it appears as multilocular radiolucencies of bone.
If it doesn’t look right or make
sense in a diagnostic sense,
DON’T do ANYTHING except
REFER to Oral Pathologist,
Endodontist, Oral Surgeon, MD
Asymmetrical lesion
Asymptomatic PTs WNL
Neoplasias
Non Endodontic Lesions: Neoplasias
Metastastic Breast CA
*Causes “spiking” & resorption of roots
*Poorly defined borders of lesion
*Loosening of teeth
*Pulps may still be vital
*Symptoms of neoplasia, esp in mandible—may be pain as well as paresthesia
*VIP lesion is usually ragged and asymmetrical!
*REFER STAT
Careful review of Health
History is essential. This is
WHY we take the HH
BEFORE anything is done.Non Endodontic Lesions: Neoplasias
what is necessary with radiographs for dx?
It is ALWAYS NECESSARY to complete Examination and Clinical Testing to arrive at both a PULPAL and a PERI-RADICULAR DX.
CBCT Radiography
*Capable of essential creating multiple sections
of an area to accurately display:
–Unusual or extra canals
–Location & Extent of cracks
–Aberrant anatomical features
–Otherwise unseen pathology
Becoming the STD. of CARE in advanced endodontics today
