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HESI DENTAL HYGIENE STUDY GUIDE EXAM LATEST VERSION
QUESTIONS AND ANSWERS 2026 EDITION
HESI Dental Hygiene Exam: 250 Practice Questions with Rationales
SECTION 1: SCIENTIFIC BASIS FOR DENTAL HYGIENE PRACTICE (Questions 1-45)
A. Oral Embryology, Histology, and Anatomy
1. A 32-year-old patient presents with a firm, non-tender swelling on the hard
palate midline that has been present for six months. A well-circumscribed
radiolucency is noted on radiograph. The hygienist suspects a nasopalatine duct
cyst. Which embryologic structure gives rise to this cyst?
A. Thyroglossal duct
B. Nasolacrimal duct
C. Branchial cleft
D. Nasopalatine duct (incisive canal)
Answer: D. Nasopalatine duct (incisive canal)
Rationale: The nasopalatine duct cyst, also known as the incisive canal cyst, arises from
epithelial remnants of the incisive canal that connects the nasal and oral cavities during
development. The thyroglossal duct gives rise to cervical cysts, and branchial cleft
remnants are found in the neck region.
2. A dental hygiene student learns that the maxilla develops from which embryonic
process?
A. Mandibular prominence of the first pharyngeal arch
B. Frontonasal prominence
C. Maxillary prominence of the first pharyngeal arch
D. Second pharyngeal arch
Answer: C. Maxillary prominence of the first pharyngeal arch
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Rationale: The maxilla develops from the maxillary prominence of the first pharyngeal
arch (mandibular arch). The mandible forms from the mandibular prominence of the
same arch. The frontonasal prominence gives rise to the forehead and nose.
3. A patient presents with a congenital condition characterized by the absence of a
permanent tooth. This condition is correctly termed:
A. Anodontia
B. Hypodontia
C. Oligodontia
D. Hyperdontia
Answer: B. Hypodontia
Rationale: Hypodontia is the developmental absence of one or a few teeth (excluding
third molars). Anodontia is the complete absence of teeth (rare). Oligodontia is the
absence of six or more teeth. Hyperdontia is an excess number of teeth.
4. What tooth anomaly is a hereditary disorder of the dentin with
opalescent/discolored, poor dentin formation that compromises enamel?
A. Dentinogenesis imperfecta
B. Amelogenesis imperfecta
C. Enamel hypoplasia
D. Fluorosis
Answer: A. Dentinogenesis imperfecta
Rationale: Dentinogenesis imperfecta is a hereditary disorder affecting dentin
formation, resulting in opalescent, discolored teeth with poor dentin that compromises
the overlying enamel. The crown and pulp appear abnormal on radiographs.
5. Which statement about the anatomy of the maxillary first molar is correct?
A. It typically has three roots: two buccal and one palatal
B. It has four canals in the majority of cases
C. The lingual root is the longest root
D. The mesial root is the shortest root
Answer: A. It typically has three roots: two buccal and one palatal
Rationale: The maxillary first molar typically has three roots: two buccal (mesiobuccal
and distobuccal) and one palatal. The palatal root is the longest. The tooth most
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commonly has three to four canals (MB1, MB2, DB, P), with MB2 being present in a high
percentage of cases.
B. Oral Pathology
6. A 28-year-old patient presents with fever, malaise, and punched-out interdental
papillae covered by a pseudomembrane. The hygienist suspects ANUG. Which
organism is most strongly associated with this condition?
A. Streptococcus mutans
B. Aggregatibacter actinomycetemcomitans
C. Candida albicans
D. Prevotella intermedia
Answer: D. Prevotella intermedia
Rationale: Acute Necrotizing Ulcerative Gingivitis (ANUG) is strongly associated with
Prevotella intermedia, along with Fusobacterium nucleatum and spirochetes.
Streptococcus mutans is associated with dental caries. Aggregatibacter
actinomycetemcomitans is associated with aggressive periodontitis. Candida albicans
causes oral candidiasis.
7. A 45-year-old male with Sjögren's syndrome presents for a hygiene appointment.
The autoimmune destruction of salivary glands in this condition involves which
type of hypersensitivity reaction?
A. Type III (immune complex)
B. Type II (antibody-mediated cytotoxicity)
C. Type IV (cell-mediated)
D. Type I (IgE-mediated)
Answer: C. Type IV (cell-mediated)
Rationale: Sjögren's syndrome involves T-lymphocyte-mediated destruction of salivary
and lacrimal glands, which is a Type IV hypersensitivity reaction. Type I involves IgE and
allergic responses. Type II involves antibody-mediated cytotoxicity, and Type III involves
immune complexes.
8. A 55-year-old patient has a white, corrugated lesion on the lateral tongue that
cannot be wiped off. Biopsy confirms hyperkeratosis. Which clinical term
describes this finding?
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A. Erythroplakia
B. Pseudomembranous candidiasis
C. Erythema migrans
D. Leukoplakia
Answer: D. Leukoplakia
Rationale: Leukoplakia is a white patch or plaque that cannot be scraped off and cannot
be classified as another disease. It represents hyperkeratosis and is considered a
potentially premalignant lesion. Erythroplakia is red, pseudomembranous candidiasis
can be wiped off, and erythema migrans (geographic tongue) has a characteristic map-
like appearance.
9. A 60-year-old male smoker presents with a firm, nontender, fixed mass in the
right submandibular triangle. The overlying skin appears normal, but the patient
reports a 20-pack-year smoking history. What is the most appropriate action?
A. Reassure the patient that it is likely a benign lymph node and re-evaluate in 6 months
B. Perform an intraoral biopsy during the same appointment
C. Document the finding and refer the patient for an otolaryngology evaluation
D. Prescribe a 10-day course of antibiotics to rule out infection
Answer: C. Document the finding and refer the patient for an otolaryngology
evaluation
Rationale: A firm, fixed, nontender mass in a patient with significant smoking history
raises suspicion for oral or metastatic malignancy. This requires prompt referral for
otolaryngology evaluation. Benign lymph nodes are typically mobile and tender.
10. A patient presents with a non-healing extraction socket and exposed bone. She
has been taking alendronate (Fosamax) for osteoporosis for five years. What is the
most appropriate initial step in managing this patient?
A. Proceed with routine prophylaxis using ultrasonic scaling only
B. Prescribe a 7-day course of amoxicillin
C. Discontinue the alendronate immediately and refer for debridement
D. Consult with the prescribing physician and obtain imaging to rule out MRONJ
Answer: D. Consult with the prescribing physician and obtain imaging to rule out
MRONJ
Rationale: Patients on long-term bisphosphonates are at risk for medication-related
osteonecrosis of the jaw (MRONJ), especially after extractions. A non-healing socket
HESI DENTAL HYGIENE STUDY GUIDE EXAM LATEST VERSION
QUESTIONS AND ANSWERS 2026 EDITION
HESI Dental Hygiene Exam: 250 Practice Questions with Rationales
SECTION 1: SCIENTIFIC BASIS FOR DENTAL HYGIENE PRACTICE (Questions 1-45)
A. Oral Embryology, Histology, and Anatomy
1. A 32-year-old patient presents with a firm, non-tender swelling on the hard
palate midline that has been present for six months. A well-circumscribed
radiolucency is noted on radiograph. The hygienist suspects a nasopalatine duct
cyst. Which embryologic structure gives rise to this cyst?
A. Thyroglossal duct
B. Nasolacrimal duct
C. Branchial cleft
D. Nasopalatine duct (incisive canal)
Answer: D. Nasopalatine duct (incisive canal)
Rationale: The nasopalatine duct cyst, also known as the incisive canal cyst, arises from
epithelial remnants of the incisive canal that connects the nasal and oral cavities during
development. The thyroglossal duct gives rise to cervical cysts, and branchial cleft
remnants are found in the neck region.
2. A dental hygiene student learns that the maxilla develops from which embryonic
process?
A. Mandibular prominence of the first pharyngeal arch
B. Frontonasal prominence
C. Maxillary prominence of the first pharyngeal arch
D. Second pharyngeal arch
Answer: C. Maxillary prominence of the first pharyngeal arch
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Rationale: The maxilla develops from the maxillary prominence of the first pharyngeal
arch (mandibular arch). The mandible forms from the mandibular prominence of the
same arch. The frontonasal prominence gives rise to the forehead and nose.
3. A patient presents with a congenital condition characterized by the absence of a
permanent tooth. This condition is correctly termed:
A. Anodontia
B. Hypodontia
C. Oligodontia
D. Hyperdontia
Answer: B. Hypodontia
Rationale: Hypodontia is the developmental absence of one or a few teeth (excluding
third molars). Anodontia is the complete absence of teeth (rare). Oligodontia is the
absence of six or more teeth. Hyperdontia is an excess number of teeth.
4. What tooth anomaly is a hereditary disorder of the dentin with
opalescent/discolored, poor dentin formation that compromises enamel?
A. Dentinogenesis imperfecta
B. Amelogenesis imperfecta
C. Enamel hypoplasia
D. Fluorosis
Answer: A. Dentinogenesis imperfecta
Rationale: Dentinogenesis imperfecta is a hereditary disorder affecting dentin
formation, resulting in opalescent, discolored teeth with poor dentin that compromises
the overlying enamel. The crown and pulp appear abnormal on radiographs.
5. Which statement about the anatomy of the maxillary first molar is correct?
A. It typically has three roots: two buccal and one palatal
B. It has four canals in the majority of cases
C. The lingual root is the longest root
D. The mesial root is the shortest root
Answer: A. It typically has three roots: two buccal and one palatal
Rationale: The maxillary first molar typically has three roots: two buccal (mesiobuccal
and distobuccal) and one palatal. The palatal root is the longest. The tooth most
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commonly has three to four canals (MB1, MB2, DB, P), with MB2 being present in a high
percentage of cases.
B. Oral Pathology
6. A 28-year-old patient presents with fever, malaise, and punched-out interdental
papillae covered by a pseudomembrane. The hygienist suspects ANUG. Which
organism is most strongly associated with this condition?
A. Streptococcus mutans
B. Aggregatibacter actinomycetemcomitans
C. Candida albicans
D. Prevotella intermedia
Answer: D. Prevotella intermedia
Rationale: Acute Necrotizing Ulcerative Gingivitis (ANUG) is strongly associated with
Prevotella intermedia, along with Fusobacterium nucleatum and spirochetes.
Streptococcus mutans is associated with dental caries. Aggregatibacter
actinomycetemcomitans is associated with aggressive periodontitis. Candida albicans
causes oral candidiasis.
7. A 45-year-old male with Sjögren's syndrome presents for a hygiene appointment.
The autoimmune destruction of salivary glands in this condition involves which
type of hypersensitivity reaction?
A. Type III (immune complex)
B. Type II (antibody-mediated cytotoxicity)
C. Type IV (cell-mediated)
D. Type I (IgE-mediated)
Answer: C. Type IV (cell-mediated)
Rationale: Sjögren's syndrome involves T-lymphocyte-mediated destruction of salivary
and lacrimal glands, which is a Type IV hypersensitivity reaction. Type I involves IgE and
allergic responses. Type II involves antibody-mediated cytotoxicity, and Type III involves
immune complexes.
8. A 55-year-old patient has a white, corrugated lesion on the lateral tongue that
cannot be wiped off. Biopsy confirms hyperkeratosis. Which clinical term
describes this finding?
, Page 4 of 73
A. Erythroplakia
B. Pseudomembranous candidiasis
C. Erythema migrans
D. Leukoplakia
Answer: D. Leukoplakia
Rationale: Leukoplakia is a white patch or plaque that cannot be scraped off and cannot
be classified as another disease. It represents hyperkeratosis and is considered a
potentially premalignant lesion. Erythroplakia is red, pseudomembranous candidiasis
can be wiped off, and erythema migrans (geographic tongue) has a characteristic map-
like appearance.
9. A 60-year-old male smoker presents with a firm, nontender, fixed mass in the
right submandibular triangle. The overlying skin appears normal, but the patient
reports a 20-pack-year smoking history. What is the most appropriate action?
A. Reassure the patient that it is likely a benign lymph node and re-evaluate in 6 months
B. Perform an intraoral biopsy during the same appointment
C. Document the finding and refer the patient for an otolaryngology evaluation
D. Prescribe a 10-day course of antibiotics to rule out infection
Answer: C. Document the finding and refer the patient for an otolaryngology
evaluation
Rationale: A firm, fixed, nontender mass in a patient with significant smoking history
raises suspicion for oral or metastatic malignancy. This requires prompt referral for
otolaryngology evaluation. Benign lymph nodes are typically mobile and tender.
10. A patient presents with a non-healing extraction socket and exposed bone. She
has been taking alendronate (Fosamax) for osteoporosis for five years. What is the
most appropriate initial step in managing this patient?
A. Proceed with routine prophylaxis using ultrasonic scaling only
B. Prescribe a 7-day course of amoxicillin
C. Discontinue the alendronate immediately and refer for debridement
D. Consult with the prescribing physician and obtain imaging to rule out MRONJ
Answer: D. Consult with the prescribing physician and obtain imaging to rule out
MRONJ
Rationale: Patients on long-term bisphosphonates are at risk for medication-related
osteonecrosis of the jaw (MRONJ), especially after extractions. A non-healing socket
