RADIOLOGY Flashcards
On an OPG, you identify an irregular shaped mixed lesion in the angle of the mandible of Q3. The periphery is ill-defined and size of approximately 5cm. Which of the following is LEAST likely? A) Osteomyelitis B) Osteoradionecrosis C) Pericoronitis D) Fibrous dysplasia
C
Explain the frequency of taking BW radiographs in adults and children who are
- High risk
- Moderate risk
- Low risk
Adult:
- High risk: 6 months
- Moderate risk: 1 year
- Low risk: 2 years
Children
- High risk: 6 months
- Moderate risk: 1 year
- Low risk: 12 - 18 months in primary dentition and 2 years in adult dentition
Distinguish code 1 and 2 for root caries
Code 1 = < 0.5mm
Code 2 = > 0.5mm
You identify a circular well-defined radiolucent lesion of approximately 25mm at the apex of tooth 23. Clinically, the tooth does not respond to vitality tests. Which of the following is the most likely diagnosis?
A) Cementoblastoma
B) Periapical cemento osseous dysplasia
C) Lateral periodontal cyst
D) Radicular cyst
D) Always associated with non vital tooth
A) Lesion is <20mm
B) Teeth still vital and has radiopaque rim around radiolucency
C) Teeth still vital and usually <10mm
A patient presents at your clinic with pain in the posterior molar region. After taking an OPG, you notice a well-defined radiolucency of around 30mm at the bifurcation of the molars. Which of the following is the most likely diagnosis? A) OKC B) Buccal birfurcation cyst C) Pericoronitis D) Dentigerous cyst
B) Characteristic for radiolucency at the bifurcation of the molars.
A) Possible as appearance variable although commonly occurs at posterior body and ramus with epicentre above IAN and may be pericoronally placed.
C) <10mm in size
D) Associated with crowns (not at bifurcation)
In an adult, which of the following teeth are most likely to be missing in hypodontia? A) Canine B) Central incisor C) Second premolar D) First molar
C)
3rd molars > second premolars > maxillary lateral incisors (permanent dentition)
Last in each series generally affected.
Which of the following is true?
A) Fusion is the joining of two tooth germs by cementum
B) Fusion is more common in permanent teeth
C) Gemination involves two tooth buds attempting to divide
D) Gemination is most common in incisors
D)
A patient has an "outpouching" on his mandibular premolar. Which of the following is the most likely diagnosis? A) Dens invaginatus B) Dens evaginatus C) Talon cusp D) Enamel pearls
B)
A) Not an outpouching
C) Main site is incisors
D) At the furcation of molars
On OPG, you notice local hypomineralisation of the crowns in a patient's premolar teeth. Which is the most likely diagnosis? A) Amelogenesis imperfecta B) Dentine dysplasia C) Turner's hypoplasia D) Dentinogenesis imperfecta
C) Localised to the premolars
All of the following are characteristics of dentinogenesis imperfecta except: A) Bulbous crowns B) Exaggerated CEJ C) Enlarged pulp chamber D) Short roots
C)
Hypercementosis is common in which of the following? A) Down syndrome B) Paget's disease C) Gardener's syndrome D) Crouzon Syndrome
B)
On OPG, you notice a flocculent lesion with well-defined borders in the anterior-canine area. No root resorption is evident and the patient does not report any pain. Which of the following is likely to be the diagnosis?
A) Calcifying epithelial odontogenic tumour
B) Adenomatoid odontogenic tumour
C) Ameloblastoma
D) Cementoblastoma
B)
What are the 3 advantages and 3 disadvantages of an OPG?
o Advantages (compared to a full-mouth series of periapicals)
Broad coverage of facial bones and teeth
Lower radiation dose
Ease of radiographic technique
Can be used in patients with trismus – or who are unable to tolerate intraoral radiography
Quick and convenient technique
Useful visual aid in patient education and case presentation
o Disadvantages
Lower resolution images that do not provide fine details
Uneven magnification, making linear measurements unreliable
Superimposition of anatomic and pathologic details
Requires accurate patient positioning to avoid positioning errors and artifacts
Difficult to image both jaws when patient has severe maxillomandibular
Discrepancy
Distinguish real vs ghost image.
Real image = Lies between film and centre of rotation
Ghost image = Lies between centre of rotation and the xray source
- Always on the opposite side to the real image
- Located higher than the primary object
Which of the following is false? A) CT scan uses a detector ring B) CBCT is a single rotation C) CBCT has a flat panel D) CT scan has a cone-shaped beam
D)