Dental MCQ
Radiolucencies of the jaws · Oral Pathology · INBDE Patient Cases

Odontogenic Cysts & Tumors INBDE Patient Cases

By Dr. Isaac Sun, DDS

8 ADA INBDE-format patient cases on odontogenic cysts & tumors. Each case is a shared patient box (chief complaint, history, medications, allergies, exam) followed by linked multiple-choice questions with full distractor explanations. Practice the way the real exam is structured.

8 patient cases40 linked questionsADA INBDE formatFull distractor explanations

Eight ADA INBDE-format patient cases on odontogenic cysts and tumors read through pulp vitality and the relationship to the tooth: a radicular (periapical) cyst on a non-vital tooth and why a cyst cannot be distinguished from a granuloma on a radiograph, a dentigerous cyst around an impacted mandibular third molar, an aggressive odontogenic keratocyst with the Gorlin syndrome association, a multilocular soap-bubble ameloblastoma, a compound odontoma causing failed tooth eruption, a heart-shaped midline nasopalatine duct cyst with vital incisors, an adenomatoid odontogenic tumor (the two-thirds tumor) mimicking a dentigerous cyst, and a cementoblastoma fused to a vital tooth root. Topics include the odontogenic and developmental cysts, the odontogenic tumors, and the principles of reading a jaw radiolucency, with biopsy as the definitive diagnosis.

Case Coverage Map
What each case is testing
A radiolucency at the apex of a dead tooth:
Radicular cyst on a non-vital tooth, pulp testing, cyst versus granuloma, endodontic management, and submitting tissue.
A lucency around an impacted wisdom tooth:
Dentigerous cyst at the crown of an impacted tooth, reduced enamel epithelium, enucleation, and histology to exclude mimics.
An aggressive lucency in the ramus:
Odontogenic keratocyst, growth along the bone, high recurrence, the Gorlin syndrome association, and long-term follow-up.
A soap-bubble swelling of the mandible:
Ameloblastoma, the multilocular radiolucency, benign-but-aggressive behavior, removal with a margin, and referral.
A tooth that won't come in:
Compound odontoma as the most common odontogenic tumor (a hamartoma), failed eruption, surgical removal, and excellent prognosis.
A midline swelling behind the front teeth:
Nasopalatine duct cyst, the heart-shaped midline radiolucency, vital incisors, and the role of pulp testing.
An anterior maxilla lucency in a teenager:
Adenomatoid odontogenic tumor (the two-thirds tumor) mimicking a dentigerous cyst, distinguishing clues, and its benign course.
A radiopaque mass on a live tooth root:
Cementoblastoma fused to a vital tooth root, using vitality plus radiodensity, and surgical removal.
Patient case: A radiolucency at the apex of a dead tooth
0 of 5 answered, 0 correct
Patient
Male, 44 years old
Chief Complaint
"There's a dark spot on the x-ray at the root of a front tooth."
Background and/or Patient History
  • A well-defined radiolucency found at the apex of a maxillary incisor
  • History of trauma to that tooth years ago
  • The tooth is discolored
  • No swelling or pain currently
Allergies
NKDA
Medications
  • None
Current Findings
  • Round, well-corticated radiolucency at the apex of the incisor
  • The tooth does not respond to pulp (vitality) testing
  1. Question 1
    Moderate
    Given a periapical radiolucency on a non-vital tooth, the most likely diagnosis is a:
  2. Question 2
    Moderate
    The single most useful chairside test to support this diagnosis is:
  3. Question 3
    Hard
    Can a radicular cyst and a periapical granuloma be distinguished on the radiograph alone?
  4. Question 4
    Moderate
    A reasonable management option for this non-vital tooth with an apical lesion is:
  5. Question 5
    Moderate
    If a periapical lesion is removed surgically, the tissue should be:

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Patient case: A lucency around an impacted wisdom tooth
0 of 5 answered, 0 correct
Patient
Female, 26 years old
Chief Complaint
"My panoramic x-ray showed a cyst around an impacted wisdom tooth."
Background and/or Patient History
  • Asymptomatic finding on a routine panoramic radiograph
  • An impacted mandibular third molar
  • A radiolucency surrounding the crown
  • No pain or swelling
Allergies
NKDA
Medications
  • None
Current Findings
  • A well-defined unilocular radiolucency around the crown of the impacted third molar, attaching near the CEJ
  • Adjacent teeth vital
  1. Question 1
    Moderate
    A radiolucency surrounding the crown of an impacted tooth, attaching at the cementoenamel junction, is most consistent with a:
  2. Question 2
    Hard
    The dentigerous cyst arises from the:
  3. Question 3
    Moderate
    A reasonable management approach is:
  4. Question 4
    Hard
    Why is histopathologic examination still important even when the radiograph looks like a simple dentigerous cyst?
  5. Question 5
    Moderate
    The adjacent teeth testing vital supports that this lesion is:

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Patient case: An aggressive lucency in the ramus
0 of 5 answered, 0 correct
Patient
Male, 22 years old
Chief Complaint
"They found a large cyst in the back of my lower jaw."
Background and/or Patient History
  • A large radiolucency in the posterior mandible and ramus
  • Grows along the bone more than expanding it outward
  • History of skin lesions and a family history of jaw cysts
  • Found on imaging for an unrelated reason
Allergies
NKDA
Medications
  • None
Current Findings
  • A well-defined radiolucency extending along the ramus
  • Multiple similar lesions noted on the full radiographic survey
  1. Question 1
    Moderate
    An aggressive radiolucency of the posterior mandible/ramus that grows along the bone is most consistent with a(n):
  2. Question 2
    Moderate
    A behavioral feature that sets the keratocyst apart from a simple cyst is its:
  3. Question 3
    Hard
    The multiple keratocysts plus skin lesions and family history should prompt evaluation for:
  4. Question 4
    Moderate
    Appropriate management of this lesion includes:
  5. Question 5
    Moderate
    Long-term radiographic follow-up after treatment is important because the keratocyst:

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Patient case: A soap-bubble swelling of the mandible
0 of 5 answered, 0 correct
Patient
Male, 40 years old
Chief Complaint
"The back of my lower jaw has slowly swollen over months."
Background and/or Patient History
  • Slow, painless expansion of the posterior mandible
  • Noticeable facial asymmetry developing
  • No history of a non-vital tooth in the area
  • Otherwise healthy
Allergies
NKDA
Medications
  • None
Current Findings
  • A multilocular soap-bubble (honeycomb) radiolucency of the posterior mandible with cortical expansion
  • Adjacent teeth vital
  1. Question 1
    Moderate
    A multilocular soap-bubble radiolucency with slow expansion of the posterior mandible most suggests:
  2. Question 2
    Moderate
    The ameloblastoma is best described as:
  3. Question 3
    Hard
    Although it derives from odontogenic epithelium, the ameloblastoma:
  4. Question 4
    Moderate
    Appropriate management generally requires:
  5. Question 5
    Moderate
    The most appropriate role for the general dentist here is to:

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Patient case: A tooth that won't come in
0 of 5 answered, 0 correct
Patient
Male, 12 years old, accompanied by parent
Chief Complaint
Parent: "One of his permanent teeth hasn't come in."
Background and/or Patient History
  • A permanent tooth has failed to erupt on schedule
  • Found on radiograph during evaluation
  • No pain
  • Otherwise healthy child
Allergies
NKDA
Medications
  • None
Current Findings
  • A radiopaque lesion (cluster of small tooth-like structures) overlying the unerupted tooth
  • Surrounded by a thin radiolucent rim
  1. Question 1
    Moderate
    A radiopaque lesion of multiple small tooth-like structures blocking eruption is most consistent with a(n):
  2. Question 2
    Moderate
    The odontoma is:
  3. Question 3
    Moderate
    A common clinical consequence of an odontoma is:
  4. Question 4
    Moderate
    Typical management of a symptomatic odontoma blocking eruption is:
  5. Question 5
    Moderate
    The prognosis of an odontoma after complete removal is:

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Patient case: A midline swelling behind the front teeth
0 of 5 answered, 0 correct
Patient
Female, 47 years old
Chief Complaint
"There's a small swelling on the roof of my mouth behind my front teeth."
Background and/or Patient History
  • A slow-growing swelling just behind the maxillary central incisors
  • Occasional mild salty discharge
  • No history of trauma to the front teeth
  • Otherwise well
Allergies
NKDA
Medications
  • None
Current Findings
  • A well-defined heart-shaped radiolucency in the midline anterior maxilla
  • The maxillary central incisors test vital
  1. Question 1
    Moderate
    A heart-shaped midline radiolucency of the anterior maxilla with vital incisors is most consistent with a:
  2. Question 2
    Moderate
    The nasopalatine duct cyst is classified as:
  3. Question 3
    Moderate
    The fact that the central incisors test vital is important because it:
  4. Question 4
    Moderate
    Appropriate management of a symptomatic nasopalatine duct cyst is:
  5. Question 5
    Moderate
    This case reinforces that pulp vitality testing of teeth near a radiolucency:

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Patient case: An anterior maxilla lucency in a teenager
0 of 5 answered, 0 correct
Patient
Female, 16 years old, accompanied by parent
Chief Complaint
Parent: "Her canine hasn't come in and there's a cyst-like area on the x-ray."
Background and/or Patient History
  • An impacted maxillary canine
  • A well-defined radiolucency associated with the impacted canine
  • Found during orthodontic evaluation
  • No pain
Allergies
NKDA
Medications
  • None
Current Findings
  • A unilocular radiolucency around an impacted anterior maxillary canine, sometimes extending past the CEJ
  • Faint flecks of calcification within the lucency
  1. Question 1
    Hard
    In a young female with an anterior maxillary radiolucency around an impacted canine, a tumor that classically mimics a dentigerous cyst is the:
  2. Question 2
    Hard
    A radiographic clue that can help distinguish an AOT from a simple dentigerous cyst is:
  3. Question 3
    Moderate
    The behavior and prognosis of the AOT are:
  4. Question 4
    Moderate
    Why does the definitive diagnosis still require biopsy rather than the radiograph alone?
  5. Question 5
    Moderate
    Compared with an ameloblastoma, the AOT is:

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Patient case: A radiopaque mass on a live tooth root
0 of 5 answered, 0 correct
Patient
Male, 23 years old
Chief Complaint
"There's a round growth attached to the root of one of my back teeth on the x-ray."
Background and/or Patient History
  • A radiopaque mass fused to the root of a mandibular molar/premolar
  • Mild dull ache or swelling in the area
  • Found on a routine radiograph
  • Otherwise healthy
Allergies
NKDA
Medications
  • None
Current Findings
  • A well-defined radiopaque mass fused to the tooth root, surrounded by a thin radiolucent rim
  • The tooth tests vital
  1. Question 1
    Moderate
    A radiopaque mass fused to the root of a VITAL tooth with a thin radiolucent rim is most consistent with a:
  2. Question 2
    Hard
    The tooth testing VITAL is a key feature because it:
  3. Question 3
    Moderate
    The cementoblastoma is best classified as a(n):
  4. Question 4
    Moderate
    Typical management is:
  5. Question 5
    Moderate
    The broad lesson reinforced by this case is that, for periapical-region lesions:

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