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NBDHE NATIONAL BOARD DENTAL
HYGIENE EXAM PRACTICE EXAM – 40
QUESTIONS WITH VERIFIED ANSWERS &
COMPLETE RATIONALES
## SECTION 1: SCIENTIFIC BASIS FOR DENTAL HYGIENE
PRACTICE
**1. The surface of the condyle articulates with the:**
A. External acoustic meatus
B. Styloid process
C. Temporal bone
D. Coronoid notch
**Correct answer:** Temporal bone
**Rationale:** The condyle articulates with the temporal bone,
forming the moving part of the temporomandibular joint (TMJ).
The external acoustic meatus is the ear canal and does not
articulate with the condyle. The styloid process is a pointed
bone projection below the ear. The coronoid notch is a
concavity on the anterior border of the mandibular ramus .
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**2. Which tooth is known for its bifurcated root?**
A. Mandibular second premolar
B. Maxillary second premolar
C. Maxillary first premolar
D. Mandibular first premolar
**Correct answer:** Maxillary first premolar
**Rationale:** In about 60% of maxillary first premolars, a
bifurcation occurs in the apical third to half of the root, forming
one facial and one lingual root. The mandibular second
premolar, maxillary second premolar, and mandibular first
premolar each have only one root .
---
**3. The junction of three surfaces on the crown of a tooth is
referred to as a:**
A. Line angle
B. Point angle
C. Occlusal surface
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D. Incisal edge
**Correct answer:** Point angle
**Rationale:** A point angle is formed by the junction of three
surfaces and derives its name from the combination of those
surfaces. Each tooth has four point angles. A line angle is
formed by the junction of two surfaces and each tooth has eight
line angles .
---
**4. The primitive oral cavity is called the:**
A. Branchial arches
B. Frontal processes
C. Forebrain
D. Stomodeum
**Correct answer:** Stomodeum
**Rationale:** At the beginning of the fourth week of embryonic
development, the stomodeum (primitive oral cavity) is the first
sign of facial development. It is located between the first
branchial arch and the frontal process (forebrain) .
NBDHE NATIONAL BOARD DENTAL
HYGIENE EXAM PRACTICE EXAM – 40
QUESTIONS WITH VERIFIED ANSWERS &
COMPLETE RATIONALES
## SECTION 1: SCIENTIFIC BASIS FOR DENTAL HYGIENE
PRACTICE
**1. The surface of the condyle articulates with the:**
A. External acoustic meatus
B. Styloid process
C. Temporal bone
D. Coronoid notch
**Correct answer:** Temporal bone
**Rationale:** The condyle articulates with the temporal bone,
forming the moving part of the temporomandibular joint (TMJ).
The external acoustic meatus is the ear canal and does not
articulate with the condyle. The styloid process is a pointed
bone projection below the ear. The coronoid notch is a
concavity on the anterior border of the mandibular ramus .
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---
**2. Which tooth is known for its bifurcated root?**
A. Mandibular second premolar
B. Maxillary second premolar
C. Maxillary first premolar
D. Mandibular first premolar
**Correct answer:** Maxillary first premolar
**Rationale:** In about 60% of maxillary first premolars, a
bifurcation occurs in the apical third to half of the root, forming
one facial and one lingual root. The mandibular second
premolar, maxillary second premolar, and mandibular first
premolar each have only one root .
---
**3. The junction of three surfaces on the crown of a tooth is
referred to as a:**
A. Line angle
B. Point angle
C. Occlusal surface
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D. Incisal edge
**Correct answer:** Point angle
**Rationale:** A point angle is formed by the junction of three
surfaces and derives its name from the combination of those
surfaces. Each tooth has four point angles. A line angle is
formed by the junction of two surfaces and each tooth has eight
line angles .
---
**4. The primitive oral cavity is called the:**
A. Branchial arches
B. Frontal processes
C. Forebrain
D. Stomodeum
**Correct answer:** Stomodeum
**Rationale:** At the beginning of the fourth week of embryonic
development, the stomodeum (primitive oral cavity) is the first
sign of facial development. It is located between the first
branchial arch and the frontal process (forebrain) .
