Radiology Flashcards
What is the risk of developing a fatal radiation-induced malignancy after having had a dental bitewing taken?
a. 1 in 2k
b. 1 in 200k
c. 1 in 2 million
d. 1 in 20 million
e. 1 in 200 million
D. 1 in 20 million
The Australian Dental Association estimates this to be the risk of a fatal malignancy.
Which of the following has the greatest impact on reducing the amount of radiation to which a patient will be exposed during the taking of a periapical radiograph?
a. The size of the film
b. The use of a film holder
c. The use of circular collimation
d. The use of rectangular collimation
e. The use of a lead apron
D. The use of a rectangular collimator
The use of rectangular collimation has a risk reduction of 61% with regards to a patient developing a fatal malignancy as a result of having had a periapical radiograph.
Under the Ionising Radiation (medical exposure) Regulations (IR(ME)R) 2000, which one of the following best describes the three roles that a qualified dental practitioner is automatically entitled to take on?
a. Medical physics expert, operator, referrer
b. Medical physics expert, practitioner, radiation protection adviser
c. Radiation protection adviser, referrer, practitioner
d. Radiation protection adviser, practitioner, operator
e. Referrer, practitioner, operator
E. Referrer, practitioner, operator
If a patient had a ‘bucket handle’ fracture, what would the fracture be?
a. A unilateral condylar fracture
b. A bilateral condylar fracture
c. A unilateral body of mandible fracture
d. A bilateral parasymphysial fracture
e. A fracture of the angle of the mandible and contralateral condylar fracture
D. A bilateral parasymphysial fracture
It is known as a bucket handle fracture because the unfavourable muscle pull causes the anterior fragment to be pulled downwards leading to the appearance of a bucket handle.
Post-operatively, after a treatment for a bucket-handle fracture, the patient has anaesthesia of a very small circular area of the chin. However, they have full sensation of the lip. Which one of the statements below correctly explains this deficit in sensation?
a. The lingual nerve has cross-over with the IDN leading to an anomaly in sensation
b. The nerve to the stylohyoid has been damaged
c. The marginal mandibular branch of the facial nerve has been damaged
d. The mental nerve has been damaged
e. A few aberrant nerve fibres from the nerve to mylohyoid have been stretched during retraction - leading to anaesthesia of the chin
E. A few aberrant nerve fibres from the nerve to mylohyoid have been stretched during retraction - leading to anaesthesia of the chin.
If the mental nerve had been damaged, there would be loss of sensation to the lower lip. If the marginal mandibular branch of the facial nerve had been damaged, there would be drooping in the corner of the mouth (but no loss of sensation).
When a patient has a fractures zygoma, which nerve is commonly damaged, leading to paraesthesia or anaesthesia?
a. IDN
b. Facial nerve
c. Infraorbital nerve
d. Supraorbital nerve
e. Supratrochlear nerve
C. Infraorbital nerve
The infraorbital nerve is commonly damaged, leading to paraesthesia or anaesthesia. Rarely there is permanent damage to the nerve structure, and the vast majority of patients recover.
Which eponymous hook is commonly used to reduce a zygomatic fracture?
a. Barnes
b. Gilles
c. Howarth
d. Bowdler-Henry
e. McIndoe
B. Gilles
The Gilles Hook is commonly used to reduce a fractured zygoma into its correct anatomical position. Howarth, Bowdler-Henry and McIndoe are also eponymous instruments (named after the person who made it).
Which one of the following is not a complication of a fractured zygoma?
a. Diplopia
b. Infraorbital nerve paraesthesia
c. Trismus
d. Subconjunctival haemorrhage
e. Facial nerve palsy
E.
Facial nerve palsy us usually produced by wounding with a sharp weapon such as a knife or broken glass. Trismus occurs with fractured zygomas because the masseter is attached to the zygomatic arch.
Which one of the following things would you not warn the patient about when consenting for extractions of supernumeraries, the mandibular first molar and mandibular third molar?
a. Paraesthesia/anaesthesia of the IDN
b. Paraesthesia/anaesthesia of the lingual nerve
c. Paraesthesia/anaesthesia of the facial nerve
d. Pain, swelling and bruising
e. Antibiotics given may interfere with the contraceptive pill
C. Paraesthesia/anaesthesia of the facial nerve
All the other statements are valid complications of the procedure described.
Which one of the following radiographic features would not suggest that the patient would be at high risk of damage to their IDN during removal of a mandibular third molar?
a. Loss of tramlines of the ID canal
b. Deviation of the tramlines of the ID canal
c. Widening of the tramlines of the ID canal
d. Narrowing of the tramlines of the ID canal
e. Radiolucent band across the tooth
C.
All of the other radiographic features indicate that the patient is at high risk of damage to their ID nerve during extraction of their mandibular 3rd molars.
What is the radiation exposure when taking an OPG?
a. 0.001mSv
b. 0.01mSv
c. 0.1mSv
d. 1.0mSv
e. 10.0mSv
B. 0.01mSv
Which of the following is the most commonly associated pathology with wisdom teeth?
a. Pericoronitis
b. Mesio-angular impaction
c. Disto-angular impaction
d. Horizontal impaction
e. Cystic change
A. Pericoronitis
Pericoronitis is one of the most common presentations of pain with wisdom teeth. It is inflammation of the operculum, which is soft tissue, therefore does not show radiographically. Mesio-angular impaction > Disto-angular impaction > Horizontal impaction.
Which are the most common type of cysts to be found accidentally on an xray?
a. Eruption cyst
b. Odontogenic keratocyst
c. Dentigerous cyst
d. Apical periodontal cyst
e. Lateral periodontal cyst
D. Apical periodontal cyst
Other than DPT, what other X-ray may be appropriate to when assessing cysts in the mandible?
a. PA mandible
b. AP mandible
c. OM 0 degrees
d. Lower occlusal
e. Reverse Towne’s
D. Lower occlusal
The lower occlusal enables you to assess the bucco-lingual expansion of the cyst
Which syndrome is associated with odontogenic keratocysts?
a. Gorlin-Goltz
b. Peutz-Jeghers
c. Gardner’s syndrome
d. Apert’s syndrome
e. Horner’s syndrome
A. Gorlin-Goltz
Odontogenic keratocysts are associated with with Gorlin-Goltz syndrome. This syndrome consists of fronto-temporal bossing, calcified falx cerebri and multiple basal cell naevi.
