DRC DRC Anatomy & Radiographic Landmarks 1 — Questions and Answers
Question 1: Which radiographic landmark appears as a radiopaque Y-shaped structure formed by the intersection of the floor of the nasal cavity and the anterior wall of the maxillary sinus?
- Inverted Y (Correct answer)
- Mental foramen
- Nasal spine
- Incisive foramen
Correct answer: Inverted Y
The inverted Y is a radiopaque landmark visible on periapical radiographs of the maxillary canine region where the nasal floor and maxillary sinus wall intersect.
Question 2: On a mandibular periapical radiograph, the mental foramen most commonly appears as which type of structure?
- Radiolucent oval or round shadow (Correct answer)
- Radiopaque triangular area
- Dense cortical band
- Trabecular pattern
Correct answer: Radiolucent oval or round shadow
The mental foramen appears as a radiolucent oval or round shadow typically located near the apex of the mandibular premolars.
Question 3: The lamina dura is the radiographic representation of which anatomical structure?
- Cortical bone lining the tooth socket (Correct answer)
- Periodontal ligament space
- Cementum covering the root
- Alveolar crest bone
Correct answer: Cortical bone lining the tooth socket
The lamina dura is the radiopaque line representing the dense cortical bone that lines the tooth socket (alveolus).
Question 4: Which structure appears as a radiopaque horizontal line running through the ramus on a panoramic radiograph?
- Hyoid bone
- Zygomatic arch (Correct answer)
- Cervical spine
- Inferior alveolar canal
Correct answer: Zygomatic arch
The zygomatic arch appears as a radiopaque horizontal band crossing the ramus of the mandible on panoramic radiographs.
Question 5: On a maxillary molar periapical radiograph, the floor of the maxillary sinus typically appears as a:
- Thin radiopaque line superior to the molar roots (Correct answer)
- Radiolucent band below the nasal cavity
- Dense radiopaque mass
- Irregular trabecular pattern
Correct answer: Thin radiopaque line superior to the molar roots
The floor of the maxillary sinus appears as a thin radiopaque line (cortical bone) visible superior to or adjacent to the roots of the maxillary molars.
Question 6: The nutrient canals visible in the mandibular incisor region on periapical radiographs appear as:
- Thin radiolucent vertical lines (Correct answer)
- Dense radiopaque bands
- Circular radiolucent areas
- Horizontal radiopaque lines
Correct answer: Thin radiolucent vertical lines
Nutrient canals appear as thin radiolucent vertical lines in the mandibular incisor region, representing channels for blood vessels and nerves.
DRC DRC Anatomy & Radiographic Landmarks 1
Which radiographic landmark appears as a radiopaque Y-shaped structure formed by the intersection of the floor of the nasal cavity and the anterior wall of the maxillary sinus?