Intra-oral radiography Flashcards
(23 cards)
Systematic approach to dentistry
Chart
Radiograph
Scale and polish
Plan treatment from combination of radiographs and chart
Carry out treatment
Post treatment radiographs
Teeth that will be marked as abnormal on charting
All must be radiographed as a bare minimum
○ Persistent deciduous teeth
○ Missing teeth
○ Fractured teeth
○ Tooth resorption
○ Discoloured teeth
○ Increased probing depth
○ Furcation exposure
○ Mobile teeth
○ Abnormal gingival height
○ Oral masses
Parallel radiographing technique
Sensor parallel to tooth/root, beam directed perpendicular
Only possible in caudal mandible due to flat palate and mandibular symphysis
Bisecting angle radiographing technique
Sensor placed as parallel to the tooth / root as possible
Beam directed perpendicular to a line which bisects the angle of the tooth / root and the sensor
Give true – size representation of tooth / root on image
Intra-oral radiography equipment
Generator
Computed radiography (CR)
Digital radiography (DR)
Generator for intra-oral radiography
On most units KV and mA are fixed and the only variable factor is exposure time
Mobile head which moves in three dimensions
Wall or ceiling mounted or on wheeled trolley
Hand-held devices are available
Computed radiography for intra-oral radiographs
Photo-stimulable phosphor (PSP) sensors
Sensor must be removed from mouth and processed in a scanner
Slower than DR but sider range of sensor sizes
Digital radiograpy (DR) for intra-oral radiography
Solid state sensors
Image can be processed without moving sensor
Quicker than CR
Limited size range (size 2 and 4)
High cost of sensors
Vertical bone loss in periodontitis
Vertical bone loss creates pockets alongside roots
Increased probing depth will be apparent
Widening of periodontal ligament space
Infrabony pocket alongside root, probe will disappear into this
Perio-endo lesions
occur when periodontal infection enters pulp system causing pulp necrosis and periapical lucency at the other root apex
Peroidontitis causing vertical bone loss distal root -> infection entering pulp at apex of distal root -> periapical lesion mesial root
Often difficult extractions
Horizontal bone loss
Probing depth will depend on gingival height – if gingiva receding with bone then may have normal sulcus depth
Furcation exposure
Gingival will often recede at same rate so may be no increased probing depth, but in this case will see exposed furcations
How can you estimate an animals age on dental radiographs?
Whether or not deciduous teeth can be seen
How thick the pulp cavity is (wider in younger dogs)
What does wider pulp of one tooth individually represent?
Pulp necrosis and cessation of dentine production
Endodontic disease
Pink/purple/grey likely due to pulpitis/pulp necrosis
Usually due to blunt trauma
Majority of fully discoloured teeth will progress to pulp necrosis
Wide pulp cavity represents cessation of dentine deposition at the time of injury
Periapical lucency and apical resorption evident
Tooth resorption
Usually in cats but also fairly common in dogs
Type 1 and Type 2
Impossible to differentiate between types 1 and 2 without radiographs, and so is impossible to treat appropriately.
Type 1 tooth resorption
localized resorption with rest of root structure intact and complete periodontal ligament visible
Whole root must be extracted
Type 2 tooth resorption
root material is replaced by bone
Lack of discernible periodontal ligament and pulp canal
Crown amputation or partial extraction acceptable
Type 3 tooth resorption
Combination of type 1 and type 2 in different roots
What is the most common tooth to be unerupted?
Lower first premolars
Dentigerous cysts
Form around unerupted teeth
Persisten deciduous teeth
Should all have exfoliated by 6mo
Radiograph to check whether root has resorbed prior to extraction
Note wide pulp and lack of apex in immature adult canine
Root remnants
Radiograph after extractions to ensure all root material has been removed
Common finding following incomplete extractions
This cat had “full mouth extractions” performed previously
Post-extraction radiographs ensure that there are no remaining root remnants.
