HESI DENTAL HYGIENE EXAM AND PRACTICE EXAM NEWEST
2025/2026 ACTUAL EXAM 400 QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS)
Question 1
Under which classification of gingival diseases and conditions is puberty-associated gingivitis
found?
A) Dental plaque–induced gingival diseases
B) Plaque-induced gingival diseases modified by systemic factors
C) Gingival diseases modified by medications
D) Non-plaque-induced gingival lesions
Correct Answer: B) Plaque-induced gingival diseases modified by systemic factors
Rationale: Puberty causes hormonal fluctuations (systemic factors) that exaggerate the
inflammatory response of the gingiva to dental plaque, placing this condition in the
"modified by systemic factors" subcategory.
Question 2
A patient presents with a short, thick lingual frenum that results in limited tongue movement
affecting speech. Which is the most likely diagnosis of this condition?
A) Fissured tongue
B) Geographic tongue
C) Ankyloglossia
D) Median rhomboid glossitis
Correct Answer: C) Ankyloglossia
Rationale: Ankyloglossia, commonly known as "tongue-tie," is a congenital condition
characterized by an unusually short, thick, or tight lingual frenum, which restricts the
tongue's range of motion.
Question 3
When is tooth eruption considered complete?
A) When the crown first emerges through the gingiva.
B) When the entire crown is visible in the oral cavity.
,C) When the tooth has made contact with its antagonist(s) in the opposing jaw.
D) When the root apex is fully formed.
Correct Answer: C) When the tooth has made contact with its antagonist(s) in the opposing
jaw.
Rationale: Complete eruption is achieved when the tooth has moved occlusally into
functional occlusion, meaning it makes contact with the opposing tooth or teeth during
mastication.
Question 4
When does the mixed dentition period typically begin?
A) At birth
B) Around age 2
C) With the eruption of the first permanent tooth
D) After the last primary tooth has exfoliated
Correct Answer: C) With the eruption of the first permanent tooth
Rationale: The mixed dentition period is defined as the time when both primary and
permanent teeth are present in the oral cavity simultaneously. It begins with the emergence
of the first permanent molar, usually around age six.
Question 5
How many succedaneous teeth are there in the permanent dentition?
A) 12
B) 20
C) 28
D) 32
Correct Answer: B) 20
Rationale: Succedaneous teeth are the permanent teeth that replace, or succeed, the
primary teeth. There are 20 primary teeth, so there are 20 succedaneous teeth (incisors,
canines, and premolars). The permanent molars are non-succedaneous.
Question 6
The junction of a buccal and lingual triangular ridge is a transverse ridge. The oblique ridge of a
maxillary molar is an example of a transverse ridge.
, A) Both statements are true.
B) Both statements are false.
C) The first statement is true, the second is false.
D) The first statement is false, the second is true.
Correct Answer: C) The first statement is true, the second is false.
Rationale: The first statement correctly defines a transverse ridge. However, the oblique
ridge of a maxillary molar is a unique feature formed by the union of the triangular ridge
of the distobuccal cusp and the distal ridge of the mesiolingual cusp; it is not a transverse
ridge.
Question 7
Which factor makes aging enamel less susceptible to dental caries?
A) Increase in water content
B) Reduced permeability due to ionic exchange
C) Darkening color of the tooth
D) Thickening of the enamel layer
Correct Answer: B) Reduced permeability due to ionic exchange
Rationale: Over a lifetime, enamel crystals become larger and more perfect through a
process of maturation, incorporating ions like fluoride from the oral environment. This
makes the enamel denser and less permeable to acid, thus increasing its resistance to caries.
Question 8
Which groove is the most identifying characteristic of a three-cusp mandibular second premolar
(Y-type)?
A) Mesial marginal groove
B) Central developmental groove
C) Lingual groove
D) Distolingual developmental groove
Correct Answer: D) Distolingual developmental groove
Rationale: The three-cusp variety of the mandibular second premolar typically has a Y-
shaped groove pattern. A key feature separating the mesiolingual and distolingual cusps is
the distolingual developmental groove.
2025/2026 ACTUAL EXAM 400 QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS)
Question 1
Under which classification of gingival diseases and conditions is puberty-associated gingivitis
found?
A) Dental plaque–induced gingival diseases
B) Plaque-induced gingival diseases modified by systemic factors
C) Gingival diseases modified by medications
D) Non-plaque-induced gingival lesions
Correct Answer: B) Plaque-induced gingival diseases modified by systemic factors
Rationale: Puberty causes hormonal fluctuations (systemic factors) that exaggerate the
inflammatory response of the gingiva to dental plaque, placing this condition in the
"modified by systemic factors" subcategory.
Question 2
A patient presents with a short, thick lingual frenum that results in limited tongue movement
affecting speech. Which is the most likely diagnosis of this condition?
A) Fissured tongue
B) Geographic tongue
C) Ankyloglossia
D) Median rhomboid glossitis
Correct Answer: C) Ankyloglossia
Rationale: Ankyloglossia, commonly known as "tongue-tie," is a congenital condition
characterized by an unusually short, thick, or tight lingual frenum, which restricts the
tongue's range of motion.
Question 3
When is tooth eruption considered complete?
A) When the crown first emerges through the gingiva.
B) When the entire crown is visible in the oral cavity.
,C) When the tooth has made contact with its antagonist(s) in the opposing jaw.
D) When the root apex is fully formed.
Correct Answer: C) When the tooth has made contact with its antagonist(s) in the opposing
jaw.
Rationale: Complete eruption is achieved when the tooth has moved occlusally into
functional occlusion, meaning it makes contact with the opposing tooth or teeth during
mastication.
Question 4
When does the mixed dentition period typically begin?
A) At birth
B) Around age 2
C) With the eruption of the first permanent tooth
D) After the last primary tooth has exfoliated
Correct Answer: C) With the eruption of the first permanent tooth
Rationale: The mixed dentition period is defined as the time when both primary and
permanent teeth are present in the oral cavity simultaneously. It begins with the emergence
of the first permanent molar, usually around age six.
Question 5
How many succedaneous teeth are there in the permanent dentition?
A) 12
B) 20
C) 28
D) 32
Correct Answer: B) 20
Rationale: Succedaneous teeth are the permanent teeth that replace, or succeed, the
primary teeth. There are 20 primary teeth, so there are 20 succedaneous teeth (incisors,
canines, and premolars). The permanent molars are non-succedaneous.
Question 6
The junction of a buccal and lingual triangular ridge is a transverse ridge. The oblique ridge of a
maxillary molar is an example of a transverse ridge.
, A) Both statements are true.
B) Both statements are false.
C) The first statement is true, the second is false.
D) The first statement is false, the second is true.
Correct Answer: C) The first statement is true, the second is false.
Rationale: The first statement correctly defines a transverse ridge. However, the oblique
ridge of a maxillary molar is a unique feature formed by the union of the triangular ridge
of the distobuccal cusp and the distal ridge of the mesiolingual cusp; it is not a transverse
ridge.
Question 7
Which factor makes aging enamel less susceptible to dental caries?
A) Increase in water content
B) Reduced permeability due to ionic exchange
C) Darkening color of the tooth
D) Thickening of the enamel layer
Correct Answer: B) Reduced permeability due to ionic exchange
Rationale: Over a lifetime, enamel crystals become larger and more perfect through a
process of maturation, incorporating ions like fluoride from the oral environment. This
makes the enamel denser and less permeable to acid, thus increasing its resistance to caries.
Question 8
Which groove is the most identifying characteristic of a three-cusp mandibular second premolar
(Y-type)?
A) Mesial marginal groove
B) Central developmental groove
C) Lingual groove
D) Distolingual developmental groove
Correct Answer: D) Distolingual developmental groove
Rationale: The three-cusp variety of the mandibular second premolar typically has a Y-
shaped groove pattern. A key feature separating the mesiolingual and distolingual cusps is
the distolingual developmental groove.
