Chapter 5: Radiology Flashcards
Image Gently
An initiative of The Society for Pediatric Radiology where dental professionals are expected to respect ALARA
Educational materials and resources for dental professionals
ALARA
As Low As Reasonably Achievable
Principle when exposing patients to ionizing radiation and to individualize and personalize prescription of radiographs to each patient
Biological risks of diagnostic dental radiation
Deterministic effects not at play
Stochastic effects are - the younger an individual and faster tissue grows, the higher the potential risk to develop a fatal cancer from being exposed to ionizing radiation
Dental radiographic exposure contribute ___% of total lifetime healthcare x-ray dose
2.5%
Guidelines for radiographs for patients in primary dentition at new patient exam
Individualized radiographic exam consisting of selected periapical/occlusal views and/or posterior bitewings if proximal surfaces cannot be visualized or probed
Guidelines for radiographs for patients in primary dentition at recall exam
With caries or high risk: Posterior bitewing exam at 6-12 month intervals if proximal surfaces cannot be visualized
Without caries or low risk: posterior bitewing exam at 12-24 month intervals if proximal surfaces cannot be examined
Guidelines for patient with periodontal disease
Clinical judgment as to need for and type of radiographic images
Guidelines for patient to monitor growth and development
Clinical judgment as to need for and type of radiographic images for primary and transitional dentition
Guidelines for patients in transitional dentition at new patient exam
Individualized radiographic exam consisting of posterior bitewings with panoramic exam or BWs and select PAs
Guidelines for patients in transitional dentition at recall
High caries risk/clinical caries: BWs 6-12 month intervals
No caries/low risk: BWs at 12-14 months
Guidelines for patients in permanent dentition at new patient exam
Individualized radiographic exam with posterior BWs, with panoramic exam or posterior BWs and select PAs. Full mouth intraoral radiographic exam preferred when patient has clinical evidence of generalized dental disease or history of extensive dental treatment
Guidelines for patients in permanent dentition at recall
High risk/caries: posterior bitewing at 6-12 month intervals
Low risk/no caries: BWs 18-36 month intervals
Radiation Protection Principles (3)
Justification Principle
Optimization Principle
Limitation Principle
Justification Principle
exposure only justified if there is no other way to obtain information and only after review of patient’s dental and medical history and clinical examination
Optimization Principle
One should always try to obtain best quality images
Limitation Principle
ALARA
Radiation dose as low as possible
Rectangular collimation (reduces 50%)
Thyroid shield
Largest image receptor possible (obtain most info)
Staff training for appropriate radiograph technique
Cone Beam CT Benefits
Enhanced imaging of impacted, supernumerary teeth
Enhanced imaging and quantification of craniofacial anomalies and trauma
Planning and follow-up complex orthodontic cases/orthognathic surgery
Image Interpretation - how to maximize interpretive yield
Review in environment free from distraction
Reduce room illumination to level of displayed images
Eliminate glare and adjust monitor luminance
Use magnificaiton
Utilize systemic approach
Use of software permitting adjustments of contrast, brightness and negative-positive viewing
Radiation Hygiene for Staff/Personnel
Position operator behind barrier at least 6 feet from tube head
Use personal dosimeters for clinical staff members
No guidelines for pregnant employees
Intraoral radiography types
Periapical radiograph (should include crown and 2mm beyond apices)
Bitewing radiograph (should not show overlap)
Occlusal radiograph
Oblique occlusal radiography
Extraoral radiography types
Panoramic radiography
Cephalometric
Lateral oblique
Type of speed of film that should be used if not using digital receptor
F speed
D speed should not be used
Types of Digital Receptors
CCD (charged coupled devices) - small image recptors enabling instant image on monitor
Phosphor Plates
Phosphor Plates
Exposure times comparable to E/F analog films, longer than CCD
Prone to bite marks and scratches
Smaller than solid state sensors (CCD)
X-ray Machines
Wall mounted should be between 60-70 kVp, either fixed or adjustable mA and equipped with precise timer
Handheld: require longer exposure time
Panoramic machine: exposure time determines radiation
CBCT: needs to be placed in special room
Pregnancy and radiation safety
Per American College/Congress of Obstetricians and Gynecologists say x-rays are safe for pregnant women (encourage patients to see dentist)
Should consent for radiography imaging be obtained?
Yes
Record number of exposures, including remakes and diagnosis - never erase a digital image or throw away images
Radiographs for patients with special health care needs
Assess patient, need, context for x-rays then engage
Assess if alternative techniques are needed or postpone exposure until patient can be managed
Can use occlusal radiographs, oblique occlusal radiographs, oblique lateral radiographs, extraoral bitewings
