Dental MCQ
Jaw movement, pain, clicking, and force · Head & Neck · INBDE Patient Cases

Mastication & TMJ INBDE Patient Cases

By Dr. Isaac Sun, DDS

12 ADA INBDE-format patient cases on mastication & tmj. 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.

12 patient cases60 linked questionsADA INBDE formatFull distractor explanations

Twelve ADA INBDE-format patient cases on the muscles of mastication and the temporomandibular joint. Topics include post-injection trismus from medial pterygoid trauma after an inferior alveolar nerve block, myofascial masticatory pain, bruxism with masseter hypertrophy and stabilization splint therapy, temporalis tendinitis mimicking a maxillary toothache, lateral pterygoid myospasm with acute posterior open bite, anterior disc displacement with and without reduction (reciprocal click versus closed lock), TMJ osteoarthritis with crepitus and condylar remodeling, acute anterior TMJ dislocation with manual (Hippocratic) reduction, bilateral coronoid hyperplasia, pediatric TMJ bony ankylosis with mandibular growth deficiency, and a guardsman-pattern subcondylar fracture after a chin-impact fall.

Case Coverage Map
What each case is testing
Trismus the day after an IAN block:
Medial pterygoid trauma; trismus versus odontogenic infection.
Bilateral preauricular ache, no click:
Myofascial masticatory pain, masseter and temporalis trigger points.
Squared lower face with tooth wear:
Bruxism, masseter hypertrophy, fracture risk, splint and botulinum toxin.
Temple ache and a phantom upper tooth ache:
Temporalis tendinitis at the coronoid, trigeminal convergence, vital tooth protection.
Woke with one-sided posterior open bite:
Lateral pterygoid myospasm; do not equilibrate the occlusion.
Reciprocal click on opening and closing:
Anterior disc displacement with reduction, natural history, when to escalate.
Click gone, opening limited to 28 mm:
Anterior disc displacement without reduction (closed lock), conservative care.
Crepitus and morning stiffness in an older patient:
TMJ osteoarthritis, CBCT findings, rheumatoid differential.
Yawned wide and the jaw stuck open:
Acute anterior TMJ dislocation past the articular eminence, manual reduction.
Progressive painless limited opening:
Coronoid hyperplasia, extracapsular bony block, surgical referral.
Childhood ear infection, restricted opening, asymmetric face:
TMJ ankylosis with secondary mandibular growth deficiency.
Chin laceration with right-side posterior premature contact:
Subcondylar fracture, guardsman pattern, closed reduction and pediatric ankylosis risk.
Patient case: Can't open the day after an IAN block
0 of 5 answered, 0 correct
Patient
Female, 32 years old
Chief Complaint
"I had a filling on my lower molar yesterday and now I can barely open my mouth."
Background and/or Patient History
  • Returned 24 hours after IAN block and restoration of tooth #19
  • Progressive jaw stiffness overnight
  • Dull aching deep behind the right mandibular angle
  • No fever, no visible swelling
  • Healthy
Allergies
NKDA
Medications
  • Oral contraceptive
Dental History
  • Two prior IAN blocks without issue
  • Uneventful restoration; required two cartridges of lidocaine with epinephrine
Current Findings
  • Afebrile
  • Maximum interincisal opening 18 mm
  • No facial swelling
  • No erythema or fluctuance intraorally
  • Mild tenderness deep to the right mandibular angle
  • Tooth #19 percussion negative
  1. Question 1
    Easy
    The most likely cause of this patient's limited opening is:
  2. Question 2
    Moderate
    Which muscle does the IAN block needle most commonly traverse?
  3. Question 3
    Moderate
    Which feature best distinguishes post-injection trismus from a developing odontogenic infection?
  4. Question 4
    Moderate
    The most appropriate initial management is:
  5. Question 5
    Hard
    If this patient's opening has not improved after 4 weeks of conservative care, the most appropriate next step is:

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Patient case: Bilateral preauricular ache, no click
0 of 5 answered, 0 correct
Patient
Female, 36 years old
Chief Complaint
"Both sides of my face ache by the end of the day and I get headaches at my temples."
Background and/or Patient History
  • Several months of dull bilateral preauricular and temporal aching
  • Worse in the afternoon and during work deadlines
  • No joint click, no locking
  • Denies night grinding
  • Acknowledges daytime clenching at her desk
  • Anxiety
  • Tension-type headaches
Allergies
NKDA
Medications
  • Escitalopram 10 mg daily
Dental History
  • Class I occlusion
  • Intact dentition
  • Mild incisal wear
Current Findings
  • Tender to palpation over both masseters and anterior temporalis
  • Palpation reproduces her familiar ache
  • No TMJ click or crepitus
  • Maximum opening 45 mm without pain
  • Lateral excursions symmetric
  • Occlusion stable
  1. Question 1
    Easy
    The most likely diagnosis is:
  2. Question 2
    Moderate
    Pain referred from a masseter trigger point most commonly radiates to:
  3. Question 3
    Moderate
    Which finding most reliably separates myofascial pain from internal derangement?
  4. Question 4
    Moderate
    Appropriate first-line management is:
  5. Question 5
    Hard
    Which patient education point best supports daytime symptom control?

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Patient case: Squared lower face with tooth wear and morning headaches
0 of 5 answered, 0 correct
Patient
Male, 41 years old
Chief Complaint
"My partner says I grind my teeth all night. I wake up with a sore jaw and a headache at my temples, and my face looks wider than it used to."
Background and/or Patient History
  • Years of reported night grinding
  • Morning jaw stiffness and bilateral temporal headache that improves after a few hours
  • Daytime clenching at work
  • Sleep partner reports loud grinding sounds
  • High-stress sales role
Allergies
NKDA
Medications
  • None
Dental History
  • Bilaterally worn cuspid tips and posterior occlusal wear facets
  • Two cracked posterior teeth restored in the past 3 years
  • No orthodontic history
Current Findings
  • Visibly prominent bilateral masseter bulges at the mandibular angles
  • Masseters firm and ropey on clench
  • Generalized wear facets on cuspids and posterior teeth
  • Scalloped lateral borders of the tongue
  • Linea alba along the buccal mucosa
  • Maximum opening 48 mm without click
  • No TMJ crepitus
  1. Question 1
    Easy
    The most likely cause of the squared lower face is:
  2. Question 2
    Moderate
    Which intraoral findings most strongly support a parafunctional habit?
  3. Question 3
    Moderate
    Why are cracked teeth and recurrent restoration fractures common in this patient?
  4. Question 4
    Moderate
    First-line management is:
  5. Question 5
    Hard
    If the patient is bothered by the cosmetic squared face and asks about reducing the masseter bulge, the most appropriate option is:

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Patient case: Temple pain and a phantom upper tooth ache
0 of 5 answered, 0 correct
Patient
Female, 45 years old
Chief Complaint
"I have a deep aching at my temple and it feels like one of my upper back teeth is killing me, but my dentist says all those teeth are fine."
Background and/or Patient History
  • Six weeks of right temple ache
  • Referred pain to the upper right molars
  • Worse with chewing tough food
  • Two prior dental opinions and a maxillary occlusal radiograph: no pathology
  • Occasional retro-orbital pressure
  • History of clenching
Allergies
NKDA
Medications
  • Ibuprofen as needed
Dental History
  • Posterior teeth recently checked, no caries or periapical pathology
  • Crowns on #2 and #3
Current Findings
  • Tenderness to deep palpation over the right temporalis tendon at the coronoid process (intraoral access along the anterior border of the ramus)
  • Palpation reproduces the temple and upper molar ache
  • Pulp testing of #2, #3, and #14: all vital and normal
  • No periapical changes on PA
  • Maximum opening 42 mm, no click
  • Mild tenderness over the anterior temporalis belly
  1. Question 1
    Moderate
    The most likely diagnosis is:
  2. Question 2
    Easy
    Which muscle and bony landmark are the anatomic source of the pain?
  3. Question 3
    Hard
    Why does temporalis tendon pain refer to the upper molars?
  4. Question 4
    Moderate
    Appropriate initial management is:
  5. Question 5
    Moderate
    Failure to recognize this pattern most often leads to:

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Patient case: Woke up with the back teeth not meeting on one side
0 of 5 answered, 0 correct
Patient
Female, 34 years old
Chief Complaint
"I woke up this morning and my back teeth on the left don't touch anymore. My bite feels wrong and my left jaw is sore."
Background and/or Patient History
  • Sudden onset overnight
  • Dull deep ache in front of the left ear
  • No trauma, no recent dental work
  • High-stress week with disrupted sleep
  • Mild prior episodes of jaw soreness that resolved on their own
  • No prior locking
Allergies
NKDA
Medications
  • None
Dental History
  • Stable Class I occlusion at last hygiene visit 3 months ago
  • No restorations on posterior teeth
Current Findings
  • Left posterior open bite of approximately 2 mm with heavy contact only on the contralateral canine
  • Tender to palpation over the left lateral pterygoid (high in the buccal vestibule behind the maxillary tuberosity)
  • Maximum opening 38 mm, slight deviation to the right at end-opening
  • No click, no crepitus
  • Panoramic radiograph: no fracture, condyles symmetric
  1. Question 1
    Moderate
    The most likely cause of this acute unilateral posterior open bite is:
  2. Question 2
    Hard
    Which palpation point is most specific for the lateral pterygoid?
  3. Question 3
    Moderate
    Which finding most reliably separates lateral pterygoid spasm from a true condylar fracture?
  4. Question 4
    Moderate
    First-line management is:
  5. Question 5
    Hard
    If the open bite has not resolved after 4 weeks of conservative therapy and the patient now also reports clicking with limited opening, the differential should expand to include:

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Patient case: Reciprocal click on opening and closing, opening preserved
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Patient
Female, 26 years old
Chief Complaint
"My right jaw clicks every time I open and close my mouth. It doesn't really hurt, but I'm worried it'll get worse."
Background and/or Patient History
  • Right TMJ click present for 6 months
  • Click on opening and a quieter click on closing
  • No locking, no limitation of opening
  • Mild jaw fatigue with chewing tough food
  • Acknowledges nighttime clenching
Allergies
NKDA
Medications
  • None
Dental History
  • Stable Class I occlusion
  • Intact dentition with no restorations
Current Findings
  • Audible click on opening at approximately 22 mm and again on closing (reciprocal click)
  • Maximum interincisal opening 47 mm
  • Brief deviation to the right that corrects when the click occurs
  • No tenderness over TMJ or muscles
  • Symmetric lateral excursions
  • No crepitus
  1. Question 1
    Easy
    The most likely diagnosis is:
  2. Question 2
    Moderate
    The opening click occurs because:
  3. Question 3
    Moderate
    The natural history of disc displacement with reduction is most accurately described as:
  4. Question 4
    Moderate
    Appropriate management for this asymptomatic clicking patient is:
  5. Question 5
    Hard
    Which feature on follow-up should prompt urgent re-evaluation for progression to closed lock?

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Patient case: Click gone, opening limited to 28 mm
0 of 5 answered, 0 correct
Patient
Female, 38 years old
Chief Complaint
"My jaw used to click for years and now it doesn't click but I can't open as wide."
Background and/or Patient History
  • Chronic right-sided jaw click for several years
  • Click disappeared about a month ago
  • Opening since then restricted to roughly two finger widths
  • Jaw pulls to the right when she opens
  • Dull right preauricular ache
  • Healthy
Allergies
NKDA
Medications
  • Ibuprofen 400 mg as needed
Dental History
  • Stable occlusion
  • Mild incisal wear consistent with bruxism
Current Findings
  • Maximum interincisal opening 28 mm
  • Persistent deviation to the right on opening that does not correct
  • No click
  • Tender to palpation over the right TMJ
  • Left lateral excursion restricted
  • Right lateral excursion preserved
  • Occlusion unchanged
  1. Question 1
    Easy
    The most likely diagnosis is:
  2. Question 2
    Moderate
    Why is opening limited to roughly 28 mm in this scenario?
  3. Question 3
    Moderate
    Why does the mandible deviate toward the affected (right) side and not correct?
  4. Question 4
    Moderate
    First-line management for this patient is:
  5. Question 5
    Hard
    If conservative care fails after 8 weeks, the most appropriate next step is:

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Patient case: Crepitus, morning stiffness, and joint pain in an older patient
0 of 5 answered, 0 correct
Patient
Female, 67 years old
Chief Complaint
"My right jaw has been crunching and aching for about a year. It's stiff in the morning and loosens up after I move it."
Background and/or Patient History
  • Right preauricular ache for roughly 12 months
  • Audible grinding (not clicking) with chewing
  • Morning jaw stiffness lasting 15 to 30 minutes
  • History of generalized osteoarthritis in the hands and knees
  • Long-standing right-sided clicking that resolved years ago into the current grinding pattern
Allergies
NKDA
Medications
  • Acetaminophen as needed
  • Calcium and vitamin D
Dental History
  • Multiple posterior restorations
  • Partial denture replacing #18 and #19
Current Findings
  • Palpable and audible crepitus over the right TMJ on opening and lateral excursion
  • Maximum opening 36 mm
  • Tender to lateral palpation of the right TMJ
  • Cone-beam CT (right TMJ): condylar flattening, subchondral cysts, and a small osteophyte on the anterior condyle
  • Occlusion stable; mild posterior cant on right
  1. Question 1
    Moderate
    The most likely diagnosis is:
  2. Question 2
    Moderate
    Crepitus, as opposed to a discrete click, indicates:
  3. Question 3
    Moderate
    Which imaging modality best demonstrates the bony changes of TMJ osteoarthritis?
  4. Question 4
    Easy
    First-line management is:
  5. Question 5
    Hard
    If the same patient developed sudden bilateral, symmetric TMJ pain with morning stiffness lasting hours and bilateral hand MCP swelling, the most likely diagnosis would shift to:

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Patient case: Yawned wide and the jaw stuck open
0 of 5 answered, 0 correct
Patient
Female, 58 years old
Chief Complaint
"I yawned during my cleaning and now my mouth is stuck wide open."
Background and/or Patient History
  • Yawned during a long hygiene appointment and unable to close
  • Onset 15 minutes ago
  • Two similar prior episodes, each reduced at urgent care
  • Generalized joint hypermobility
  • Anxiety
Allergies
NKDA
Medications
  • None
Dental History
  • Periodontal maintenance every 3 months
  • No recent dental trauma
Current Findings
  • Vitals stable
  • Mouth held open at approximately 50 mm
  • Chin protruded
  • Bilateral preauricular depressions on palpation
  • Unable to close
  • Speech muffled
  • No facial trauma
  1. Question 1
    Easy
    What has happened at the TMJ?
  2. Question 2
    Moderate
    Which muscles hold the dislocation by reactive spasm?
  3. Question 3
    Moderate
    What is the standard manual reduction technique?
  4. Question 4
    Moderate
    Appropriate post-reduction counseling includes:
  5. Question 5
    Hard
    Given recurrent episodes and underlying joint hypermobility, the best long-term plan is:

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Patient case: Progressive painless limited opening
0 of 5 answered, 0 correct
Patient
Male, 22 years old
Chief Complaint
"I can barely open enough to brush my back teeth, and it's been getting worse for two years."
Background and/or Patient History
  • Gradual painless reduction in mouth opening since adolescence
  • No click, no pain, no locking episode
  • No trauma
  • Cannot bite into an apple
  • Struggles with hygiene on posterior teeth
  • Healthy
Allergies
NKDA
Medications
  • None
Dental History
  • Routine care
  • No restorations
  • No orthodontic history
Current Findings
  • Maximum interincisal opening 21 mm with a straight opening path
  • No joint noise
  • No tenderness over the TMJ or muscles
  • Lateral excursions symmetric
  • Occlusion stable
  • Panoramic radiograph: bilaterally elongated coronoid processes extending above the zygomatic arches
  1. Question 1
    Moderate
    The most likely diagnosis is:
  2. Question 2
    Easy
    Which muscle inserts on the coronoid process and is anatomically relevant to this diagnosis?
  3. Question 3
    Moderate
    Which feature on history and exam best distinguishes coronoid hyperplasia from internal TMJ derangement?
  4. Question 4
    Moderate
    The most appropriate next imaging study is:
  5. Question 5
    Hard
    The appropriate definitive management is:

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Patient case: Childhood ear infection, now restricted opening and asymmetric face
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Patient
Female, 14 years old
Chief Complaint
"My daughter can barely open her mouth. It's gotten worse over the last few years and her chin looks crooked."
Background and/or Patient History
  • Severe right ear infection at age 4 requiring hospital admission
  • Progressive limitation of mouth opening since age 7
  • Difficulty with hygiene on posterior teeth and dietary modifications to soft foods
  • Facial asymmetry noted by family and confirmed in school photos
  • No pain at rest
Allergies
NKDA
Medications
  • None
Dental History
  • Multiple posterior caries due to poor access for cleaning
  • Class II div 1 occlusion with deep overbite
Current Findings
  • Maximum interincisal opening 8 mm
  • Mandibular midline deviated to the right (the affected side)
  • Right-sided ramus and condyle shorter than left on panoramic radiograph
  • Cone-beam CT: bony continuity between the right condylar head and the glenoid fossa with loss of joint space
  • No click, no joint sounds (the joint is fused)
  1. Question 1
    Moderate
    The most likely diagnosis is:
  2. Question 2
    Moderate
    The mandibular deviation in unilateral TMJ ankylosis points toward:
  3. Question 3
    Moderate
    The most common etiology of TMJ ankylosis worldwide is:
  4. Question 4
    Hard
    Definitive treatment of established bony TMJ ankylosis is:
  5. Question 5
    Moderate
    Why is restoration of opening important not only for hygiene but also for airway and growth?

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Patient case: Chin laceration after a fall, posterior teeth meet first on one side
0 of 5 answered, 0 correct
Patient
Male, 28 years old
Chief Complaint
"I fell off my bike and hit my chin. Now my back teeth on the right hit first and my jaw shifts to the right when I close."
Background and/or Patient History
  • Fall from a bicycle 6 hours ago with direct chin impact
  • Brief reported loss of consciousness, no current neurologic symptoms
  • Pain in front of the right ear, worse on opening and chewing
  • Subjective malocclusion: "my bite feels off"
  • No vision change, no hearing change
Allergies
NKDA
Medications
  • None
Dental History
  • Class I occlusion previously
  • Intact dentition with no posterior restorations
Current Findings
  • Sutured chin laceration
  • Tenderness and edema over the right preauricular region
  • Premature contact on right posterior teeth with anterior open bite
  • Mandibular midline deviates to the right on opening
  • Maximum opening 22 mm with right preauricular pain
  • Panoramic radiograph: subcondylar fracture on the right with medial displacement of the condylar segment
  • Mental status normal, GCS 15
  1. Question 1
    Easy
    The most likely injury is:
  2. Question 2
    Moderate
    Why does the right side close on the posterior teeth first?
  3. Question 3
    Moderate
    Which examination finding most strongly suggests a condylar fracture beyond TMD?
  4. Question 4
    Hard
    Initial management for a minimally displaced unilateral subcondylar fracture in an adult with restorable occlusion is most often:
  5. Question 5
    Hard
    A feared late complication of an inadequately treated pediatric condylar fracture is:

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