RADIOGRAPHY Veterinary dental nursing procedures RADIOGRAPHY.
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Transcript of RADIOGRAPHY Veterinary dental nursing procedures RADIOGRAPHY.
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Radiology vs Radiography
• Radiography– taking and processing pictures
• Radiology– interpreting pictures
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Purpose
• Diagnosis
• Planning
• Post-treatment
• Prognosis
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Radiographs to diagnose
• Congenital e.g:– Malformations
• Acquired e.g:– Periodontal disease– Fractured teeth– Discoloured teeth– “Neck lesions”– Jaw lesions
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Planning
• Extractions– Root infections– Impacted teeth– Root fusion (ankylosis)– Feline “neck lesions”
• Endodontics– Root canal treatment
• XR v impt for measuring length of drills
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Monitoring
• Lesion progression
• Post op– Assess treatment success
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Film Types
• Screen Film– Intensifying screens within cassettes permit
shorter exposure times– But cassettes don’t fit into mouth
• Non-Screen Film– Normal
• Slow & longer exposure but good detail• Small & flexible
– Dental• Small pre-cut sizes• Has 2 sides:
– One incorporates foil/lead backing – Other with a raised dot – point to the beam
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Film positioning
• Intraoral– Less superimposition of teeth– Better detail
• Film closer to tooth• Less scattered radiation
– Usually need dental film
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Patient positioning
• Mandible- animal in dorsal recumbency
• Maxilla- animal in ventral recumbency
5888H - Veterinary Dental Nursing
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Full mouth views
• Would require 6-8 views to evaluate all 4 quadrants
5888H - Veterinary Dental Nursing
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Patient positioning
• Motionless– Heavy sedation– General anaesthesia
• Positioning aids– Sandbags, lead sleeves– Troughs, Foam wedges, Syringe cases– Tape– Cardboard or spring loaded devices
5888H - Veterinary Dental Nursing
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X-Ray Machines
• Normal
• Dental – Smaller – More manoeuvrable– Safer – Better images
5888H - Veterinary Dental Nursing
RADIOGRAPHY
X-Ray Machines
• General Purpose– Large and difficult to manipulate
• Ideally would want to get to within 15 cm
• Dental– Easy to manipulate close in– Safer (less scatter)– Wall or castor mounted– Simple to operate
• fixed kV and mA • Adjust time
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Developing
• Manual– Mini dark room boxes available
• Automatic– Needs to be able to handle small dental
film
• Within film envelope– Special dental films
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Accessories
• Film positioners
• Bite blocks (props)
• Film viewer with magnifier
• Film marker
• Film storage envelopes
5888H - Veterinary Dental Nursing
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How many views?
• At least 2 views at right angles– Plus extra obliques to highlight specific
problems
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Tooth image distortion
• Size accuracy & fine detail more important than for normal radiographs– Require exact measurements in
endodontics- measuring exact length of root canal
– Small & subtle lesions may need to be detected
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Types of distortion
• Anatomic– When film cannot be positioned parallel to
object being measured (tooth)
• Beam magnification– Point source effect
• Blurring– Movement – Aperture effect– Scatter
5888H - Veterinary Dental Nursing
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Blurring distortion
• Movement
• Aperture effect (depth of field)
• Scatter (thickness of tissue)
5888H - Veterinary Dental Nursing
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Reducing distortion
• Centering • Coning down (collimation)• Longer anode-film distance
– Reduces point source effect
• If possible– Film parallel to length of tooth
• Otherwise– Bisecting angle technique
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Radiographic Beam Direction
• 90° Angle (Parallel) Beam technique– Film & Tooth parallel (< 15° separation)
• Possible for lower PM2-3 M1-3 (film inside mouth)• Possible for lower PM1 and all Ms (film outside)
– Beam perpendicular
• Bisecting Angle Beam technique– Film & Tooth not parallel (>15° separation)
• Required for all Incisors and Cuspids (Canines)
– Beam angle is simply averaged to compensate
5888H - Veterinary Dental Nursing
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Mandibular molars
• Can position film parallel
• Place lingual side
• Perpendicular beam
5888H - Veterinary Dental Nursing
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Bisecting angle technique
1. Get Long Axis of tooth
2. Get Long Axis of film
3. Bisecting Axis = half way between 1 and 2
4. Aim beam perpendicular to Bisecting Axis
5888H - Veterinary Dental Nursing
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Bisecting angle technique
• Use a straight object (e.g. tongue depressor) to help imagine bisecting angle
5888H - Veterinary Dental Nursing
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Mandibular Canine
1. Film2. Tooth
3. Bisecting Angle
X-RA
Y BE
AM
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Rostral mandibular PMs
• Symphysis prevents placing film parallel
• Bisecting angle
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Mandibular incisors/canines
• Dorsal recumbency
• Bisecting angle
• Center on1st Incisors
5888H - Veterinary Dental Nursing
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Any problems?
• Apical lysis (probably apical abscess)
5888H - Veterinary Dental Nursing
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Any problems?
• Tooth hardening (sclerosis) after pulpitis
5888H - Veterinary Dental Nursing
RADIOGRAPHY
X-Ray Safety
• Usual precautions
• Remember: – 1 brick = 0.5 mm lead
5888H - Veterinary Dental Nursing
RADIOGRAPHY
Digital Imaging
• Still uses X-Rays
• Uses a small X-Ray sensor
• Immediate image obtained– Can easily manipulate
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