panoramics

Question 1

What are indications?

Answer 1

• Lesion/uneducated tooth can’t be demonstrated fully w intra oral
• Pathology in all 4 quadrants
• Perio disease when pockets >6mm
• Assessment of third molars prior to surgery
• Ortho assessment in mixed dentition
• Following trauma
• Implant planning

Question 2

How is the image formed?

Answer 2

Tomogram through jaws
Slice is thin anteriorly, thick posteriorly
Patient positioned so jaws in focal trough
Structures within trough are sharp, distorted outside
X-ray tube and image receptor orbit around head (20-30s)- film moves inside cassette carrier

Question 3

How should the patient be prepared?

Answer 3

Take out jewellery
Keep tongue pressed to hard palate
Position patient on chin rest w bite peg and line up w midline, Frankfort plane and canine light (between upper lateral incisor and canine)

Question 4

What are common positioning errors?

Answer 4

Too far in- anterior teeth in both jaws narrow and blurred, premolars overlapped, loss of cervical spine

Too far out- incisors widened and blurred, condyles missed off edges

Chin up- roots of upper incisors blurred, hard palate can overlap upper teeth apices, condyles lost off film edges (grumpy face)

Chin down- lower incisors blurred, hyoid bone projected over mandible (smiley face)

Head rotated to one side- one side magnified

Slumped- radiopaque ghost image of cervical spine projected over midline

Movement- blurring (may mimic fracture)

Swallowing- well defined air density lucency above tongue dorsum, unilateral distortion of hyoid bone

Question 5

What are ghost images?

Answer 5

Opposite side, higher up and blurred compared to real image