COA COA Radiography & Diagnostic Imaging 1 — Questions and Answers
Question 1: Which radiograph captures a full panoramic view of all teeth, both jaws, and surrounding structures in a single image?
- Periapical radiograph
- Bitewing radiograph
- Panoramic (OPG) radiograph (Correct answer)
- Occlusal radiograph
Correct answer: Panoramic (OPG) radiograph
A panoramic radiograph (orthopantomograph) sweeps around the patient to capture a broad view of all dental and skeletal structures in one film.
Question 2: What is the primary use of a cephalometric radiograph in orthodontic practice?
- Detecting interproximal cavities
- Analyzing skeletal and dental relationships for treatment planning (Correct answer)
- Evaluating periodontal bone levels
- Detecting impacted third molars only
Correct answer: Analyzing skeletal and dental relationships for treatment planning
Cephalometric radiographs provide standardized lateral skull views used to measure skeletal and dental relationships for orthodontic diagnosis and treatment planning.
Question 3: Which cephalometric landmark represents the most anterior point of the mandibular symphysis (chin)?
- Nasion
- Pogonion (Correct answer)
- Gonion
- Sella
Correct answer: Pogonion
Pogonion (Pg) is the most anteriorly projecting point on the bony chin on a lateral cephalometric tracing.
Question 4: What does the SNA angle measure in cephalometric analysis?
- The inclination of the lower incisors to the mandibular plane
- The anteroposterior position of the maxilla relative to the cranial base (Correct answer)
- The sagittal relationship of the mandible to the maxilla
- The total anterior facial height
Correct answer: The anteroposterior position of the maxilla relative to the cranial base
The SNA angle (Sella-Nasion-A point) measures how far forward or backward the maxilla is positioned relative to the cranial base.
Question 5: What is the standard focal-film distance used for cephalometric radiography to minimize magnification?
- 60 cm
- 90 cm
- 150 cm (Correct answer)
- 200 cm
Correct answer: 150 cm
A standardized focal-film distance of 150 cm (approximately 5 feet) is used in cephalometric radiography to minimize magnification and ensure reproducibility.
Question 6: Which radiation protection items should patients wear during orthodontic radiographs?
- Gloves only
- Lead apron with thyroid collar (Correct answer)
- Lead apron only
- Thyroid collar only
Correct answer: Lead apron with thyroid collar
Both a lead apron and thyroid collar are used together to shield the patient's body and thyroid gland from scatter radiation during dental X-rays.
COA COA Radiography & Diagnostic Imaging 1
Which radiograph captures a full panoramic view of all teeth, both jaws, and surrounding structures in a single image?