Dental MCQ
Digestion and oral signs · Renal & GI · INBDE Patient Cases

Digestive System INBDE Patient Cases

By Dr. Isaac Sun, DDS

9 ADA INBDE-format patient cases on digestive system. 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.

9 patient cases45 linked questionsADA INBDE formatFull distractor explanations

Nine ADA INBDE-format patient cases on digestive physiology in the dental setting: vitamin B12 deficiency causing atrophic glossitis in a patient on long-term proton pump inhibitors, gastroesophageal reflux causing dental erosion, perimylolysis and parotid sialadenosis from bulimia with hypokalemic metabolic alkalosis, cirrhosis with coagulopathy and altered drug metabolism before an extraction, Crohn disease with oral cobblestoning and aphthous ulcers, celiac disease with symmetric enamel defects and recurrent ulcers, obstructive jaundice with vitamin K malabsorption and bleeding risk, antibiotic-associated Clostridioides difficile colitis after a dental prescription, and an NSAID and aspirin peptic ulcer with gastrointestinal bleeding. Topics include salivary and pancreatic enzymes, intrinsic factor and vitamin B12, bile and fat absorption, the liver's synthetic and metabolic roles, enterohepatic circulation, and the oral signs of malabsorption.

Case Coverage Map
What each case is testing
Smooth, burning tongue on long-term acid blockers:
Vitamin B12 deficiency and atrophic glossitis, the role of acid suppression and diet, ileal absorption, neurologic risk, and referral.
Worn, sensitive teeth from heartburn:
GERD dental erosion, the cupped acid-wear pattern, the lower esophageal sphincter, post-acid care, and esophageal risk.
See-through front teeth and a hidden cause:
Perimylolysis and parotid sialadenosis of bulimia, hypokalemic metabolic alkalosis, protective care, and compassionate referral.
Needs an extraction but has liver disease:
Cirrhosis coagulopathy and bleeding risk, pre-op assessment, acetaminophen dosing, hepatic drug metabolism, and jaundice.
Mouth ulcers, swollen lips, and gut trouble:
Crohn disease oral manifestations, transmural GI involvement, anemia, inflammation-driven ulcers, and GI referral.
A teen with odd enamel and mouth sores:
Celiac disease enamel defects and aphthous ulcers, villous atrophy, the timing of amelogenesis, and medical diagnosis.
Yellow eyes spotted at a cleaning:
Obstructive jaundice, pale stools and dark urine, vitamin K malabsorption and bleeding risk, and urgent referral.
Diarrhea after antibiotics for a tooth infection:
Antibiotic-associated C. difficile colitis after a dental prescription, microbiota disruption, stewardship, and dehydration.
Stomach pain and dark stools after dental NSAIDs:
NSAID and aspirin peptic ulcer with GI bleeding, prostaglandin protection, stopping the NSAID, and safer analgesia.
Patient case: Smooth, burning tongue on long-term acid blockers
0 of 5 answered, 0 correct
Patient
Female, 55 years old
Chief Complaint
"My tongue burns and looks smooth and shiny."
Background and/or Patient History
  • Presented complaining of a sore, burning tongue
  • Long-term proton pump inhibitor use for reflux
  • Reports fatigue and occasional tingling in the hands and feet
  • Follows a strict vegetarian diet
Allergies
NKDA
Medications
  • Omeprazole (long-term)
Current Findings
  • Smooth, glossy, beefy-red tongue with loss of papillae
  • Pale mucosa
  • No localized lesion or candidal plaque
  1. Question 1
    Moderate
    Her smooth, beefy-red tongue is most consistent with:
  2. Question 2
    Moderate
    Her long-term PPI and vegetarian diet contribute because both reduce:
  3. Question 3
    Moderate
    Vitamin B12 is normally absorbed in the:
  4. Question 4
    Moderate
    Beyond the tongue, untreated B12 deficiency is concerning because it can cause:
  5. Question 5
    Moderate
    The appropriate dental step is to:

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Patient case: Worn, sensitive teeth from heartburn
0 of 5 answered, 0 correct
Patient
Male, 44 years old
Chief Complaint
"My back teeth feel sensitive and look worn down."
Background and/or Patient History
  • Presented for a checkup
  • History of frequent heartburn and acid regurgitation, worse at night
  • Often takes antacids
  • No eating disorder; reports high intake of citrus and soda
Allergies
NKDA
Medications
  • Over-the-counter antacids
Current Findings
  • Smooth, cupped erosion on the occlusal and palatal surfaces of posterior and upper teeth
  • Restorations standing slightly proud of the dissolved tooth surface
  • No caries in the affected areas
  1. Question 1
    Moderate
    His tooth wear pattern is most consistent with:
  2. Question 2
    Moderate
    The most likely source of the acid is:
  3. Question 3
    Easy
    Reflux reaches the mouth because of a problem at the:
  4. Question 4
    Moderate
    Appropriate dental advice includes:
  5. Question 5
    Moderate
    Long-standing reflux also raises the patient's medical risk of:

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Patient case: See-through front teeth and a hidden cause
0 of 5 answered, 0 correct
Patient
Female, 22 years old
Chief Complaint
"My front teeth look see-through at the edges and feel sensitive."
Background and/or Patient History
  • Presented for sensitivity and esthetic concerns
  • On gentle questioning, discloses recurrent self-induced vomiting
  • Worried about weight; episodes several times a week
  • No reflux history
Allergies
NKDA
Medications
  • None
Current Findings
  • Erosion concentrated on the lingual and incisal surfaces of the maxillary anterior teeth
  • Bilateral painless parotid swelling
  • Thinned, translucent incisal edges
  1. Question 1
    Moderate
    The erosion pattern on the lingual surfaces of the upper front teeth is called:
  2. Question 2
    Moderate
    The painless bilateral parotid swelling in this setting is most likely:
  3. Question 3
    Hard
    Repeated vomiting can also cause which acid-base and electrolyte disturbance?
  4. Question 4
    Moderate
    Appropriate management of her teeth and care includes:
  5. Question 5
    Moderate
    After an acid episode, she should be advised to:

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Patient case: Needs an extraction but has liver disease
0 of 5 answered, 0 correct
Patient
Male, 58 years old
Chief Complaint
"I need a tooth pulled, but I have liver problems."
Background and/or Patient History
  • Presented for extraction of a non-restorable tooth
  • Cirrhosis from chronic hepatitis C
  • Reports easy bruising and bleeding gums
  • No current alcohol use
Allergies
NKDA
Medications
  • Diuretic for ascites
Current Findings
  • Mild scleral yellowing
  • Spider angiomas on the chest
  • Gingival oozing on probing
  1. Question 1
    Moderate
    His easy bruising and bleeding gums are best explained by reduced hepatic production of:
  2. Question 2
    Moderate
    Before the extraction, the most appropriate step is to:
  3. Question 3
    Hard
    For pain control after the extraction, the safest analgesic plan is:
  4. Question 4
    Moderate
    His cirrhosis also matters for drug selection because the liver:
  5. Question 5
    Easy
    His scleral yellowing reflects elevated:

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Patient case: Mouth ulcers, swollen lips, and gut trouble
0 of 5 answered, 0 correct
Patient
Male, 28 years old
Chief Complaint
"I keep getting mouth ulcers and my lips are swollen."
Background and/or Patient History
  • Presented with recurrent oral ulcers
  • History of crampy abdominal pain, diarrhea, and weight loss
  • Fatigue and occasional low-grade fevers
  • Not yet diagnosed with a bowel condition
Allergies
NKDA
Medications
  • None
Current Findings
  • Cobblestone appearance of the buccal mucosa
  • Diffuse lip swelling
  • Multiple aphthous-like ulcers
  • Pale conjunctiva
  1. Question 1
    Moderate
    His oral findings plus bowel symptoms most suggest:
  2. Question 2
    Moderate
    Crohn disease can involve the mouth because it is:
  3. Question 3
    Moderate
    His pale conjunctiva suggests he may also have:
  4. Question 4
    Moderate
    The recurrent aphthous-like ulcers in IBD are partly driven by:
  5. Question 5
    Moderate
    The appropriate dental action is to:

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Patient case: A teen with odd enamel and mouth sores
0 of 5 answered, 0 correct
Patient
Female, 15 years old, accompanied by parent
Chief Complaint
Parent: "Her adult teeth came in with strange enamel, and she keeps getting mouth sores."
Background and/or Patient History
  • Presented for a checkup
  • Symmetric enamel defects noted on the permanent teeth
  • Recurrent aphthous ulcers
  • History of bloating, diarrhea, and poor growth
Allergies
NKDA
Medications
  • None
Current Findings
  • Symmetric, banded enamel hypoplasia and discoloration on permanent teeth
  • Recurrent aphthous ulcers
  • Thin build with pallor
  1. Question 1
    Moderate
    Symmetric enamel defects plus recurrent ulcers and GI symptoms should raise suspicion for:
  2. Question 2
    Moderate
    Celiac disease causes malabsorption by damaging the:
  3. Question 3
    Moderate
    The enamel defects occurred because the developing teeth were affected during:
  4. Question 4
    Moderate
    Confirming celiac disease typically requires:
  5. Question 5
    Moderate
    The appropriate dental role is to:

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Patient case: Yellow eyes spotted at a cleaning
0 of 5 answered, 0 correct
Patient
Male, 64 years old
Chief Complaint
"My dentist's assistant noticed my eyes look yellow."
Background and/or Patient History
  • Presented for a routine cleaning
  • Reports pale stools, dark urine, and itching
  • Recent unintentional weight loss
  • Has an extraction planned next week
Allergies
NKDA
Medications
  • None
Current Findings
  • Yellow sclera and oral mucosa
  • Scratch marks on the skin
  • Otherwise alert and stable
  1. Question 1
    Moderate
    His yellow sclera and mucosa indicate:
  2. Question 2
    Moderate
    Pale stools and dark urine suggest:
  3. Question 3
    Hard
    A dental concern before his planned extraction is that bile obstruction can impair absorption of:
  4. Question 4
    Moderate
    The appropriate action is to:
  5. Question 5
    Moderate
    Painless jaundice with weight loss in an older adult is especially concerning for:

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Patient case: Diarrhea after antibiotics for a tooth infection
0 of 5 answered, 0 correct
Patient
Female, 68 years old
Chief Complaint
"Since the antibiotics for my tooth infection, I've had terrible watery diarrhea."
Background and/or Patient History
  • Finished a course of clindamycin prescribed for a dental abscess
  • Now has frequent watery diarrhea, cramping, and low-grade fever
  • Diarrhea began several days into the antibiotic
  • Feeling weak and dehydrated
Allergies
Penicillin
Medications
  • Recently completed clindamycin
Current Findings
  • Dry mucous membranes
  • Mild abdominal tenderness
  • Reports up to ten watery stools a day
  1. Question 1
    Moderate
    Her diarrhea after antibiotics is most concerning for:
  2. Question 2
    Moderate
    The underlying mechanism is that the antibiotic disrupted the normal:
  3. Question 3
    Moderate
    The most appropriate response is to:
  4. Question 4
    Moderate
    This case is a reminder that dentists should prescribe antibiotics:
  5. Question 5
    Moderate
    Her dehydration from heavy diarrhea risks loss of fluid and:

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Patient case: Stomach pain and dark stools after dental NSAIDs
0 of 5 answered, 0 correct
Patient
Male, 60 years old
Chief Complaint
"You gave me anti-inflammatories last visit, and now I have burning stomach pain and dark stools."
Background and/or Patient History
  • Took ibuprofen regularly for post-treatment dental pain
  • Now reports burning epigastric pain and black, tarry stools
  • History of a prior stomach ulcer
  • Also takes low-dose aspirin
Allergies
NKDA
Medications
  • Ibuprofen (recent)
  • Low-dose aspirin
Current Findings
  • Epigastric tenderness
  • Looks pale and tired
  • Reports dark, tarry stools (melena)
  1. Question 1
    Moderate
    His burning epigastric pain and black tarry stools most suggest:
  2. Question 2
    Moderate
    NSAIDs promote peptic ulcers mainly by reducing protective:
  3. Question 3
    Moderate
    His concurrent low-dose aspirin matters because it:
  4. Question 4
    Moderate
    The most appropriate action now is to:
  5. Question 5
    Moderate
    For future dental pain, a safer choice for this patient is:

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Keep studying
Digestive System core recall

Refresh the anatomy facts these cases depend on: nerve numbers, foramina, functions, and lesion findings.

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