INTEGRATED NATIONAL BOARD DENTAL
EXAMINATION (INBDE) PREP 2026 Updated Practice
Questions Comprehensive Integrated Dental Board Review •
Detailed Explanations • Verified Answers • Complete
Success Workbook
High-Yield Foundation Areas:
• Anatomy/Biochemistry: ~12.2%
• General Pathology: ~11.8%
• Microbiology: ~10.6%
• Pharmacology: ~10.6%
SECTION 1: DENTAL ANATOMY AND OCCLUSION
QUESTION 1
Which permanent tooth has the longest root of any tooth in the human dentition?
A) Maxillary central incisor
B) Mandibular canine
C) Maxillary canine
D) Mandibular first molar
RATIONALE:
Correct Answer: C) Maxillary canine
The maxillary canine has the longest root of any permanent tooth, typically
measuring 16-18 mm. This long, robust root is designed to withstand the lateral
forces encountered during canine guidance in excursive movements. The maxillary
canine is also the last anterior tooth to erupt and is often called the "cornerstone" of
the dental arch due to its strategic position and root length.
,Option A: Maxillary central incisors have the longest root among incisors but are
shorter than canine roots.
Option B: Mandibular canines have shorter roots than maxillary canines.
Option D: Mandibular first molars have multiple roots; while the roots are
substantial, no single root is as long as the maxillary canine root.
QUESTION 2
Which tooth is MOST frequently congenitally missing in the permanent dentition?
A) Maxillary lateral incisor
B) Mandibular second premolar
C) Maxillary second premolar
D) Mandibular central incisor
RATIONALE:
Correct Answer: B) Mandibular second premolar
The mandibular second premolar is the most commonly congenitally missing tooth
in the permanent dentition, followed by the maxillary lateral incisor and maxillary
second premolar. Congenital absence (hypodontia) is more common in the
permanent dentition than in the primary dentition. Agenesis can be associated with
genetic syndromes or may occur as an isolated trait.
Option A: Maxillary lateral incisors are commonly missing but are second to
mandibular second premolars.
Option C: Maxillary second premolars are also commonly missing but less
frequently than mandibular second premolars.
Option D: Mandibular central incisors are rarely congenitally missing.
QUESTION 3
The occlusal surface of a mandibular first molar typically exhibits how many
cusps?
,A) 3
B) 5
C) 4
D) 6
RATIONALE:
Correct Answer: B) 5
The mandibular first molar typically has five cusps: three buccal cusps
(mesiobuccal, distobuccal, and distal) and two lingual cusps (mesiolingual and
distolingual). This distinguishes it from the mandibular second molar, which
usually has four cusps. The five-cusp pattern is one of the key identifying features
of the mandibular first molar in dental anatomy.
Option A: Three cusps are seen in mandibular premolars.
Option C: Four cusps are seen in mandibular second molars.
Option D: Six cusps are not typical for any permanent tooth.
QUESTION 4
Which nerve provides sensory innervation to the mandibular teeth?
A) Maxillary nerve (V2)
B) Inferior alveolar nerve (branch of V3)
C) Lingual nerve
D) Buccal nerve
RATIONALE:
Correct Answer: B) Inferior alveolar nerve (branch of V3)
The inferior alveolar nerve, a branch of the mandibular division of the trigeminal
nerve (V3), provides sensory innervation to the mandibular teeth, the gingiva on
the mandibular arch, and the lower lip via its mental branch. The inferior alveolar
nerve enters the mandibular foramen and travels through the mandibular canal,
giving off dental branches to the teeth.
, Option A: The maxillary nerve (V2) innervates the maxillary teeth, not the
mandibular teeth.
Option C: The lingual nerve provides sensation to the anterior two-thirds of the
tongue and the lingual gingiva, not the teeth.
Option D: The buccal nerve provides sensation to the buccal gingiva of the
mandibular molars but not the teeth themselves.
QUESTION 5
The temporomandibular joint (TMJ) is classified as which type of joint?
A) Hinge joint
B) Condylar (modified hinge) joint with sliding capabilities
C) Ball and socket joint
D) Pivot joint
RATIONALE:
Correct Answer: B) Condylar (modified hinge) joint with sliding capabilities
The temporomandibular joint is a modified hinge joint (ginglymoarthrodial joint)
that allows both rotational (hinge) and translational (sliding) movements. The
rotational movement occurs in the lower joint space between the condyle and the
articular disc, while the translational movement occurs in the upper joint space
between the disc and the articular eminence. This dual capability allows for the
complex movements required for mastication, speech, and other functions.
Option A: While the TMJ has hinge-like rotational movement, it also allows
sliding, making "modified hinge" more accurate.
Option C: Ball and socket joints (e.g., hip, shoulder) allow multi-axial rotation,
which the TMJ does not.
Option D: Pivot joints allow rotation around a single axis, which does not describe
the TMJ.
SECTION 2: ORAL PATHOLOGY
EXAMINATION (INBDE) PREP 2026 Updated Practice
Questions Comprehensive Integrated Dental Board Review •
Detailed Explanations • Verified Answers • Complete
Success Workbook
High-Yield Foundation Areas:
• Anatomy/Biochemistry: ~12.2%
• General Pathology: ~11.8%
• Microbiology: ~10.6%
• Pharmacology: ~10.6%
SECTION 1: DENTAL ANATOMY AND OCCLUSION
QUESTION 1
Which permanent tooth has the longest root of any tooth in the human dentition?
A) Maxillary central incisor
B) Mandibular canine
C) Maxillary canine
D) Mandibular first molar
RATIONALE:
Correct Answer: C) Maxillary canine
The maxillary canine has the longest root of any permanent tooth, typically
measuring 16-18 mm. This long, robust root is designed to withstand the lateral
forces encountered during canine guidance in excursive movements. The maxillary
canine is also the last anterior tooth to erupt and is often called the "cornerstone" of
the dental arch due to its strategic position and root length.
,Option A: Maxillary central incisors have the longest root among incisors but are
shorter than canine roots.
Option B: Mandibular canines have shorter roots than maxillary canines.
Option D: Mandibular first molars have multiple roots; while the roots are
substantial, no single root is as long as the maxillary canine root.
QUESTION 2
Which tooth is MOST frequently congenitally missing in the permanent dentition?
A) Maxillary lateral incisor
B) Mandibular second premolar
C) Maxillary second premolar
D) Mandibular central incisor
RATIONALE:
Correct Answer: B) Mandibular second premolar
The mandibular second premolar is the most commonly congenitally missing tooth
in the permanent dentition, followed by the maxillary lateral incisor and maxillary
second premolar. Congenital absence (hypodontia) is more common in the
permanent dentition than in the primary dentition. Agenesis can be associated with
genetic syndromes or may occur as an isolated trait.
Option A: Maxillary lateral incisors are commonly missing but are second to
mandibular second premolars.
Option C: Maxillary second premolars are also commonly missing but less
frequently than mandibular second premolars.
Option D: Mandibular central incisors are rarely congenitally missing.
QUESTION 3
The occlusal surface of a mandibular first molar typically exhibits how many
cusps?
,A) 3
B) 5
C) 4
D) 6
RATIONALE:
Correct Answer: B) 5
The mandibular first molar typically has five cusps: three buccal cusps
(mesiobuccal, distobuccal, and distal) and two lingual cusps (mesiolingual and
distolingual). This distinguishes it from the mandibular second molar, which
usually has four cusps. The five-cusp pattern is one of the key identifying features
of the mandibular first molar in dental anatomy.
Option A: Three cusps are seen in mandibular premolars.
Option C: Four cusps are seen in mandibular second molars.
Option D: Six cusps are not typical for any permanent tooth.
QUESTION 4
Which nerve provides sensory innervation to the mandibular teeth?
A) Maxillary nerve (V2)
B) Inferior alveolar nerve (branch of V3)
C) Lingual nerve
D) Buccal nerve
RATIONALE:
Correct Answer: B) Inferior alveolar nerve (branch of V3)
The inferior alveolar nerve, a branch of the mandibular division of the trigeminal
nerve (V3), provides sensory innervation to the mandibular teeth, the gingiva on
the mandibular arch, and the lower lip via its mental branch. The inferior alveolar
nerve enters the mandibular foramen and travels through the mandibular canal,
giving off dental branches to the teeth.
, Option A: The maxillary nerve (V2) innervates the maxillary teeth, not the
mandibular teeth.
Option C: The lingual nerve provides sensation to the anterior two-thirds of the
tongue and the lingual gingiva, not the teeth.
Option D: The buccal nerve provides sensation to the buccal gingiva of the
mandibular molars but not the teeth themselves.
QUESTION 5
The temporomandibular joint (TMJ) is classified as which type of joint?
A) Hinge joint
B) Condylar (modified hinge) joint with sliding capabilities
C) Ball and socket joint
D) Pivot joint
RATIONALE:
Correct Answer: B) Condylar (modified hinge) joint with sliding capabilities
The temporomandibular joint is a modified hinge joint (ginglymoarthrodial joint)
that allows both rotational (hinge) and translational (sliding) movements. The
rotational movement occurs in the lower joint space between the condyle and the
articular disc, while the translational movement occurs in the upper joint space
between the disc and the articular eminence. This dual capability allows for the
complex movements required for mastication, speech, and other functions.
Option A: While the TMJ has hinge-like rotational movement, it also allows
sliding, making "modified hinge" more accurate.
Option C: Ball and socket joints (e.g., hip, shoulder) allow multi-axial rotation,
which the TMJ does not.
Option D: Pivot joints allow rotation around a single axis, which does not describe
the TMJ.
SECTION 2: ORAL PATHOLOGY
