COA COA Radiography & Diagnostic Imaging 2

Question 1

Where is the cephalometric landmark Sella (S) located?

Accepted Answer

At the geometric center of the sella turcica

Answer

Sella is the midpoint of the sella turcica, a saddle-shaped depression in the sphenoid bone housing the pituitary gland.

Question 2

What does the ANB angle indicate in orthodontic diagnosis?

Accepted Answer

The sagittal (Class I/II/III) relationship between the maxilla and mandible

Answer

The ANB angle (the difference between SNA and SNB) reveals the anteroposterior skeletal relationship between the maxilla and mandible, indicating skeletal Class I, II, or III patterns.

Question 3

What is the primary purpose of periapical radiographs in orthodontic records?

Accepted Answer

To assess root length, morphology, and monitor for root resorption

Answer

Periapical radiographs reveal the entire tooth including the root apex, allowing orthodontists to monitor root length and detect iatrogenic root resorption.

Question 4

Which radiation safety principle guides minimizing patient X-ray exposure to the lowest dose that still achieves diagnostic quality?

Accepted Answer

ALARA principle

Answer

The ALARA principle (As Low As Reasonably Achievable) is the guiding standard in dental radiography to minimize unnecessary patient radiation exposure.

Question 5

Where is the cephalometric landmark Nasion (N) located on a lateral cephalometric radiograph?

Accepted Answer

At the most anterior point of the frontonasal suture

Answer

Nasion is located at the most anterior point of the frontonasal suture, where the nasal and frontal bones join at the bridge of the nose.

COA - Certified Orthodontic Assistant Practice Test

COA - Certified Orthodontic Assistant Practice Test

COA COA Radiography & Diagnostic Imaging 2