MOSBY anA HYGIE Flashcards

Question 1

Q

Which paired muscle covers most of the lateral aspect
of the ramus of the mandible?
A. Temporalis
B. Masseter
C. Lateral pterygoid
D. Medial pterygoid

Answer

A

ANS: B
The masseter (B) muscle is located on the lateral
aspect of the ramus of the mandible. The temporalis
(A) muscle is a large, fan-shaped muscle attached
to the coronoid process of the mandible. The lateral
pterygoid (C) has two heads and lies superiorly to the
medial pterygoid. The medial pterygoid (D) inserts on
the medial surface of the mandibular ramus. All these
muscles are muscles of mastication.

Question 2

Q

During periodontal surgery, a fenestration is exposed
on tooth #6. A fenestration is a defect of which type of
bone?
A. Compact
B. Cancellous
C. Interdental
D. Interradicular

Answer

A

ANS: A
A fenestration is an opening or window in the solid
plate of compact (A) cortical bone on the facial
surface over the root of a tooth. Cancellous (B) bone
is located between the alveolar bone proper and the
plates of cortical bone. The interdental septum (C)
is bone located between the roots of adjacent teeth.
Interradicular (D) bone is located between the roots of
the same tooth

Question 3

Q

The fibrous connective tissue membrane covering the
outside of bone is called the
A. endosteum.
B. periosteum.
C. hyaline cartilage.
D. articular cartilage.

Answer

A

ANS: B
Periosteum (B) is the fibrous connective tissue
membrane covering the outside of bone except at the
articular surfaces. Endosteum (A) is the connective
tissue membrane lining the marrow cavity of the bone.
Hyaline cartilage (C) is a flexible and slightly elastic
cartilage found in joints, costal cartilages, the nasal
septum, the larynx, and the trachea. Articular cartilage
(D) is specialized, thin, smooth hyaline cartilage
found on the joint surfaces of bones, for example, in a
synovial joint.

Question 4

Q

What is the purpose of the synovial membrane in a
synovial joint?
A. Secrete fluid into the joint cavity
B. Surround the joint like a fibrous sleeve
C. Innervate the muscles that move the joint
D. Convey a sense of position and movement

Answer

A

ANS: A
The synovial membrane secretes synovial fluid (A),
which lubricates the synovial joint. The capsular
ligament surrounds the joint like a fibrous sleeve (B).
The sensory nerve endings innervate the muscles
that move the joint (C). Proprioceptive nerve endings
convey a sense of position and movement (D).

Question 5

Q

Which component of a nerve conducts impulses
toward the cell body?
A. Axon
B. Soma
C. Neuron
D. Dendrite

Answer

A

ANS: D
Dendrites (D) are branching cellular extensions of a
nerve that conduct impulses toward the cell. An axon
(A) is a cellular extension of a nerve that conducts
impulses away from the cell. The soma (B) is the body
of the cell containing the nucleus. A neuron (C) is the
basic functional unit of the nervous system.

Question 6

Q

Which spinal vertebrae fuse together to form a
triangular mass?
A. Sacral
B. Lumbar
C. Cervical
D. Thoracic

Answer

A

ANS: A
The sacral (A) vertebrae of the spinal cord fuse
together to form a triangular mass, called the
sacrum. The lumbar (B) region comprises the five
large vertebrae located between the thoracic and
sacral regions. The cervical (C) region comprises
the seven vertebrae located between the base of the
neck and the thoracic region. The thoracic (D) region
comprises the 12 vertebrae between the cervical and
lumbar regions

Question 7

Q

The ophthalmic nerve is the first division of the fifth
cranial nerve V, the trigeminal nerve. The maxillary
nerve is the second division of the trigeminal nerve.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true, and the second statement
is false.
D. The first statement is false, and the second
statement is true.

Answer

A

ANS: A
Both statements are true (A). Cranial nerve V is the
trigeminal nerve, of which the ophthalmic nerve
is the first division (V1
) and the maxillary nerve
is the second division (V2
). The third division of
the trigeminal nerve (V3
) is the mandibular nerve.
Choices B, C, and D do not accurately reflect the
statements.

Question 8

Q

Which injections technique would be used to achieve
anesthesia of teeth #15 and #16?
A. Nasopalatine block
B. Anterosuperior alveolar block
C. Middle superior alveolar block
D. Posterosuperior alveolar block

Answer

A

ANS: D
The posterosuperior alveolar block (D) anesthetizes
the mesiobuccal root of the first maxillary molar
and the second and third maxillary molars. The
nasopalatine block (A) anesthetizes the premaxillary
area of the palate and the anterior maxillary teeth.
The anterosuperior alveolar block (B) anesthetizes
the gingiva and the anterior maxillary teeth. The
middle superior alveolar block (C) anesthetizes
the premolars and the mesiobuccal root of the first
maxillary molar.

Question 9

Q

All of the following are foramina in the sphenoid bone
EXCEPT the
A. incisive foramen.
B. superior orbital fissure.
C. foramen ovale.
D. foramen rotundum.

Answer

A

ANS: A
The incisive foramen (A) is an opening to the incisive
canal in the palatine process of the maxilla. The
superior orbital fissure (B), foramen ovale (C), and
foramen rotundum (D) are all located in the sphenoid
bone and are exit points for cranial nerve V

Question 10

Q

The infraorbital foramen is located in which bone?
A. Frontal
B. Maxilla
C. Zygomatic
D. Sphenoid

Answer

A

ANS: B
The infraorbital foramen passes through the maxilla
(B), not the frontal (A), zygomatic (C), or sphenoid
(D) bones.

Question 11

Q

Which muscle retracts the tongue?
A. Genioglossus
B. Hyloglossus
C. Styloglossus
D. Palatoglossus

Answer

A

ANS: C
When the styloglossus (C) muscle contracts, the tongue
retracts. In contrast, the hyloglossus (B) will depress
the tongue upon contraction, and the genioglossus (A)
will protrude the tongue and depress portions. The
palatoglossus (D) elevates the base of the tongue, and
depresses the soft palate

Question 12

Q

Which plane of dissection divides the body into
anterior and posterior portions?
A. Frontal
B. Sagittal
C. Horizontal
D. Median

Answer

A

ANS: A
The frontal (A) plane divides the body into anterior
and posterior portions. The sagittal plane (B) divides
the body in an anteroposterior direction. The horizontal
plane (C) separates the body into superior and inferior
portions, and the median plane (D) divides the body
into equal right and left halves.

Question 13

Q

Teeth #3 and #14 are
A. ipsilateral to each other.
B. contralateral to each other.
C. inferior to each other.
D. superficial to each other.

Answer

A

ANS: B
Teeth #3 and #14 are the first maxillary molars on the
opposite arches of the mouth, which means that they
are contralateral to each other (B). Ipsilateral (A)
would mean that they are on the same side. Inferior
(C) applies to a structure that is beneath or lower than
another structure, and superficial (D) applies to a
structure that is near the surface. These are not terms
used to describe the dentition.

Question 14

Q

The following characteristics describe muscle tissue
EXCEPT one. Which one is the EXCEPTION?
A. Each muscle has two ends.
B. Muscle cells are called sarcomeres.
C. Muscles are categorized according to their role in
movement.
D. The muscle origin is attached to the least movable
part.
E. The muscle insertion is attached to the most
movable part

Answer

A

ANS: B
The correct choice is B. Muscle cells are called
myocytes, whereas sarcomeres are the unit of contraction of the myofibrils of the muscle cell.
Muscles have two ends (A) and are categorized
according to their role in movement (C). The origin of
each muscle is defined by its least movable attachment
(D). In addition, the insertion is attached to the most
movable part (E)

Question 15

Q

Which lymph nodes drain both sides of the chin, the
lower lip, the floor of mouth, the apex of tongue, and
the mandibular incisors?
A. Facial
B. Submental
C. Submandibular
D. Retropharyngeal

Answer

A

ANS: B
The submental (B) lymph nodes drain both sides of
the chin, the lower lip, the floor of mouth, the apex
of tongue, and the mandibular incisors. The facial
lymph nodes (A) are superficial nodes located along
the length of the facial vein and are further categorized
into four subgroups that drain the areas they are named
for: malar, nasolabial, buccal, and mandibular. The
submandibular nodes (C) drain the cheeks, the upper
lip, the body of the tongue, the anterior hard palate,
and all teeth except the mandibular incisors and the
maxillary third molars. The retropharyngeal lymph
nodes (D) drain the pharynx, the palate, the paranasal
sinuses, and the nasal cavity.

Question 16

Q

Which endocrine gland matures T-lymphocytes for the
immune system and undergoes involution (reduces in
size) after puberty?
A. Thyroid
B. Thymus
C. Pancreas
D. Parathyroid

Answer

A

ANS: B
T-lymphocytes are processed in the thymus (B), where
they attain their mature function. The thymus is large
in infancy and shrinks after puberty. The thyroid
gland (A) produces two main hormones—thyroxine
(T4
) and triiodothyronine (T3
)—that circulate through
the bloodstream and have many effects on body
metabolism, growth, and development. The islet
cells of the pancreas (C) create and release important
hormones directly into the bloodstream. Two of the
main pancreatic hormones are insulin, which acts to
lower blood sugar, and glucagon, which acts to raise
blood sugar. Maintaining proper blood sugar levels
is crucial to the functioning of key organs, including
the brain, liver, and kidneys. The pancreas also has
an exocrine function in producing enzymes that aid
digestion. The parathyroid glands (D) regulate calcium
levels by secreting parathyroid hormone and calcitonin
into the bloodstream

Question 17

Q

The corrugator supercilii is a muscle of facial
expression in which region?
A. Eye
B. Nose
C. Mouth
D. Scalp

Answer

A

ANS: A
The corrugator supercilii is a muscle of facial
expression located just superior to the eye (A) and deep to the superior portion of the orbicularis oculi
muscle. The nose (B), mouth (C), and scalp (D) are not
moved by the corrugator supercilii muscle

Question 18

Q

Which muscle elevates the mandible?
A. Risorius
B. Buccinator
C. Medial pterygoid
D. Lateral pterygoid

Answer

A

ANS: C
Upon contraction, the medial pterygoid (C) elevates
the mandible. The risorius (A) stretches the lips
by pulling each labial commissure laterally. The
buccinator (B) compresses the cheeks during chewing
by retracting the labial commissure. The lateral
pterygoid (D) depresses, protrudes, and deviates the
mandible laterally.

Question 19

Q

Which muscle originates from the alveolar process of
the maxilla, the alveolar process of the mandible, and
the pterygomandibular raphe?
A. Masseter
B. Risorius
C. Buccinator
D. Sternocleidomastoid

Answer

A

ANS: C
The buccinator (C) muscle is a thin, quadrilateral muscle
originating from the three areas listed above. The masseter
(A) originates from the zygomatic arch; the risorius (B)
originates from a fascia superficial to the masseter muscle;
and the sternocleidomastoid (D) originates from the
clavicle.

Question 20

Q

Which part of the brain regulates homeostasis?
A. Medulla
B. Thalamus
C. Cerebellum
D. Hypothalamus

Answer

A

ANS: D
The hypothalamus (D) regulates homeostasis in
the body. The medulla (A) is part of the brain stem
and is involved in regulating the components of
the autonomic nervous system. The thalamus (B)
plays a major role in relaying nerve impulses. The
cerebellum (C) is responsible for the coordination of
voluntary movements and for maintaining posture
and balance.

Question 21

Q

Which branch of the trigeminal nerve contains both
sensory and motor components?
A. Ophthalmic V1
B. Maxillary V2
C. Mandibular V3

Answer

A

ANS: C
The mandibular or third division of the fifth cranial
nerve V3
(C), or the trigeminal nerve, has both afferent
or sensory and efferent or motor components. The
afferent component provides sensation to the teeth
and tissues of the mandible and the anterior two thirds
of the tongue. The efferent component innervates the
muscles of mastication, tensor tympani, and tensor veli
palatini. The ophthalmic V1
(A), or the first division
of the trigeminal nerve, provides sensation to the
conjunctivae, cornea, eyeball, orbit, forehead, ethmoid
and frontal sinuses, and part of the dura mater. The
second branch of the trigeminal nerve, maxillary V2
(B), carries sensory information for the maxillae and overlying skin, maxillary sinuses, nasal cavity, palate,
nasopharynx, and part of the dura mater.

Question 22

Q

Which of the following are the two main divisions or
systems of the autonomic nervous system?
A. Brain, spinal cord
B. Afferent impulse, efferent impulse
C. Sympathetic system, parasympathetic system

Answer

A

ANS: C
Sympathetic and parasympathetic (C) systems are the
two divisions of the autonomic nervous system. The
brain and the spinal cord (A) are structures within the
central nervous system. Afferent impulse is the sensory
nerve impulse traveling toward the central nervous
system, and efferent impulse is the motor nerve impulse
traveling to the muscles that will move in response (B).

Question 23

Q

Which cranial nerve provides parasympathetic innervation
to the cardiac muscles, thymus, and stomach?
A. IV
B. X
C. XI
D. XII

Answer

A

ANS: B
Cranial nerve X (B), the vagus nerve, sends
parasympathetic fibers to many organs, including the
thymus and the muscles of the heart and stomach.
Cranial nerve IV (A), the trochlear nerve, serves as an
efferent nerve for a muscle of the eye. Cranial nerve
XI (C), the accessory nerve, serves as an efferent nerve
for various muscles of the head and neck. Cranial
nerve XII (D), the hypoglossal nerve, innervates
intrinsic and extrinsic muscles of the tongue.

Question 24

Q

Which of the following is NOT innervated by the
middle superior alveolar nerve?
A. Tooth #4
B. Tooth #12
C. Distobuccal root of tooth #2
D. Mesiobuccal root of tooth #14

Answer

A

ANS: C
The distobuccal root of the maxillary second molar,
tooth #2 (C), is innervated by the posterosuperior
alveolar nerve, not the middle superior alveolar
nerve. The middle superior alveolar nerve innervates
maxillary premolars, teeth #4 and #5 (A) and, #12 and
#13 (B), and the mesiobuccal root of maxillary first
molars, teeth #3 and #14 (D).

Question 25

Q

The muscles of facial expression are innervated by
which nerve?
A. IV
B. V
C. VII
D. VIII

Answer

A

ANS: C
Cranial nerve VII (C), the facial nerve, innervates the
muscles of facial expression. Cranial nerve IV (A),
the trochlear nerve, serves as an efferent nerve for a
muscle of the eye. Cranial nerve V (B), the trigeminal
nerve, serves as an afferent nerve to the oral cavity,
teeth, and most of the skin of the face and head, as well
as efferent innervations for the muscles of mastication
and some of the muscles of the palate. Cranial nerve
VIII (D), the vestibulocochlear nerve, is an afferent
nerve for hearing and balance

Question 26

Q

Which vein receives blood flow from the superficial
temporal vein and the facial vein and drains into the
external jugular vein?
A. Maxillary
B. Ophthalmic
C. Inferior alveolar
D. Retromandibular

Answer

A

ANS: D
The retromandibular (D) vein receives blood flow
from the superficial temporal vein and the facial vein
and drains into the external jugular vein. It is situated
immediately posterior to the angle of the mandible. The
maxillary vein (A) receives blood flow from the pterygoid
plexus and drains into the retromandibular vein. The
ophthalmic vein (B) drains the tissue of the orbit and
proceeds into the facial vein. The inferior alveolar vein
(C) forms from the merging of the dental, alveolar, and
mental branches and drains into the pterygoid plexus

Question 27

Q

The articulation of the temporomandibular joint
involves which two bones?
A. Temporal bone, mental protuberance
B. Sphenoid bone, coronoid process of the mandible
C. Temporal bone, mandibular condyles

Answer

A

ANS: C
Temporal bone and mandibular condyle (C) articulate
to form part of the temporomandibular joint. Neither
temporal bone and mental protuberance (A) nor
sphenoid bone and the coronoid process of the
mandible (B) articulate with each other

Question 28

Q

Which artery supplies the mandibular teeth and
surrounding tissues with blood?
A. Facial
B. Lingual
C. Inferior alveolar
D. Pterygoid plexus

Answer

A

ANS: C
The inferior alveolar artery (C) is a branch of the
maxillary artery and supplies the mandibular teeth, the
floor of the mouth, and the mental region with blood.
The facial artery (A) is also known as the external
maxillary artery and extends to the mid-face region to
supply the oral, buccal, zygomatic, nasal, infraorbital,
and orbital regions. The lingual artery (B) is an anterior
branch from the external carotid artery and supplies the
tissue superior to hyoid bone, including the suprahyoid
muscles and the floor of the mouth. The pterygoid plexus
(D) supplies the deep facial areas and the posterosuperior
alveolar vein and the inferior alveolar vein.

Question 29

Q

Which major artery supplies the brain with blood and
is palpated during emergency situations?
A. Aorta
B. Subclavian
C. Internal carotid
D. Common carotid

Answer

A

ANS: D
The common carotid artery (D) runs superiorly along
the neck, lateral to the trachea and the larynx. When
palpated against the larynx, the most reliable arterial
pulse of the body can be monitored. The aorta (A) is a
major artery, which gives rise to the common carotid
artery and the subclavian artery (B) on the left side
of the heart and the brachiocephalic artery on the
right side of the heart. The internal carotid artery (C)
supplies the anterior part of the brain and the eye and sends branches to the forehead and the nose. The aorta
(A), the subclavian artery (B), and the internal carotid
artery (C) cannot be reliably palpated in an emergency.

Question 30

Q

Which artery is the source of the ophthalmic
artery, has NO branches, and is located deep to the
sternocleidomastoid muscle?
A. Aorta
B. Subclavian
C. External carotid
D. Internal carotid

Answer

A

ANS: D
The internal carotid artery (D) is a branchless division
of the common carotid artery, which is covered by the
sternocleidomastoid muscle, and supplies blood to the
ophthalmic artery. The aorta (A), a major artery that is a
portion of the heart itself gives rise to the common carotid
artery and the subclavian artery (B) on the left side of the
heart and the brachiocephalic artery on the right side of
the heart. The external carotid artery (C) travels superiorly
to the internal carotid artery and has four sets of branches.

Question 31

Q

The facial artery is a direct branch of which main
artery?
A. Subclavian
B. Internal carotid
C. External carotid
D. Brachiocephalic

Answer

A

ANS: C
The facial artery is the final anterior branch from
the external carotid artery (C), not the subclavian
artery (A), the internal carotid artery (B), or the
brachiocephalic artery (D).

Question 32

Q

The facial vein drains each region of the head and neck
EXCEPT one. Which one is the EXCEPTION?
A. Orbital region
B. Upper lip area
C. Lower lip area
D. Submental region

Answer

A

ANS: A
The orbital region (A) is drained by the cavernous
sinus and the pterygoid plexus, not the facial vein. The
facial vein drains the upper lip (B), the lower lip (C),
and the submental region (D).

Question 33

Q

Which of the following arteries supplies maxillary
anterior teeth with blood?
A. Incisive
B. Mylohyoid
C. Greater palatine
D. Anterior superior alveolar

Answer

A

ANS: D
Maxillary anterior teeth are supplied by the
anterosuperior alveolar artery (D). The incisive artery
(A) supplies the periodontium of the mandibular
anterior teeth, including the associated gingiva. The
mylohyoid artery (B) supplies the floor of the mouth
and the mylohyoid muscle. The greater palatine artery
(C) supplies the hard and soft palates.

Question 34

Q

Veins of teeth have alveolar branches and dental
branches. Which branch type would drain the pulp
tissue of teeth through the apical foramen?
A. Alveolar branches
B. Dental branches
C. Both A and B
D. Neither A nor B

Answer

A

ANS: B
The incisive artery branches off the inferior alveolar
artery, remaining within the mandibular canal to divide into dental and alveolar branches. The dental branches
(B) of the pulp drain the mandibular anterior teeth
by way of each tooth’s apical foramen. The alveolar
branches (A) of the periodontium drain the mandibular
anterior teeth, including the gingiva. Choices C and D
do not correctly address the statement.

Question 35

Q

Which vein has NO valves, drains most of the head
and neck region, and does NOT drain any of the
dentition?
A. Internal jugular
B. External jugular
C. Internal maxillary
D. Inferior alveolar

Answer

A

ANS: A
The internal jugular vein (A) drains most of the head
and the neck, except the dentition. The external jugular
vein (B) is the only vein the head and neck with valves.
The internal maxillary vein (C) drains the pterygoid
plexus, whereas the inferior alveolar vein (D) drains
the mandibular teeth and the periodontium

Question 36

Q

Many veins in the head and neck region lack valves.
Valveless veins of the head and neck contribute to the
severe and rapid spread of dental infections.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true, and the second statement
is false.
D. The first statement is false, and the second
statement is true.

Answer

A

ANS: A
The correct choice is A; both statements are true.
Most veins in the head and neck lack valves, with the
exception of the external jugular vein. The lack of
valves in the veins of the head and neck may contribute
to severe and rapid spread of dental infections. Choi

Question 37

Q

Each of the following is an afferent cranial nerve
EXCEPT one. Which one is the EXCEPTION?
A. Optic
B. Vagus
C. Olfactory
D. Hypoglossal

Answer

A

ANS: D
The hypoglossal nerve (D) is an efferent (motor) cranial
nerve for both intrinsic and extrinsic muscles of the
tongue. The optic nerve (A), the vagus nerve (B), and
the olfactory nerve (C) are afferent, or sensory, nerves.

Question 38

Q

Which muscle, upon contraction, protrudes the tongue?
A. Genioglossus
B. Hyloglossus
C. Styloglossus

Answer

A

ANS: A
The genioglossus muscle (A) protrudes the tongue
upon contraction. The hyloglossus muscle (B)
depresses the tongue when it contracts. Upon
contraction, the styloglossus muscle (C) retracts the
tongue.

Question 39

Q

Each of the following is a suprahyoid muscle EXCEPT
one. Which one is the EXCEPTION?
A. Mylohyoid
B. Geniohyoid
C. Stylohyoid
D. Sternohyoid

Answer

A

ANS: D
The sternohyoid muscle (D) is an infrahyoid muscle.
The mylohyoid (A), geniohyoid muscle (B), and
stylohyoid (C) muscles are all suprahyoid muscles.

Question 40

Q

Cervical lymph nodes run along which muscle?
A. Trapezius
B. Buccinator
C. Epicranial
D. Sternocleidomasto

Answer

A

ANS: D
The sternocleidomastoid muscle (D) is a landmark of
the neck during the extraoral examination to define
locations of superficial and deep cervical lymph
nodes. Cervical lymph nodes do not lie adjacent to the
trapezius (A), buccinator (B), or epicranial (C) muscles

Question 41

Q

Muscles of Facial
Expression:
1. Mentalis
2. Risorius
3. Corrugator supercilii
4. Levator anguli oris
5. Buccinator
———–
Facial Expression upon
Contraction of Muscle:
A. Frowning
B. Raising chin and protruding
lower lip
C. Chewing
D. Stretching lips
E. Smiling

Answer

A

For each numbered muscle, select the most closely
linked facial expression from the list provided.
ANS: 1B; 2D; 3A; 4E; 5C
When the mentalis muscle (1) contracts, the chin
is raised and the lower lip protrudes (B). When the
risorius muscle (2) contracts, the lips are stretched (D).
When the corrugator supercilii (3) contracts, this action
produces a frown (A). When the levator anguli oris
(4) contracts, this action produces a smile (E). When
the buccinator (5) contracts, food is pushed onto the
occlusal plane, facilitating the chewing of food (C).

Question 42

Q

For each numbered structure, select the most closely
linked primary nodes that drain those structures from
the list provided.

Anatomic Structure:
1. Sublingual salivary gland
2. Parotid salivary gland
3. Base of tongue
4. Paranasal sinus
5. Lower lip
————-
Lymph Node Drainage:
A. Deep parotid
B. Submandibular
C. Superior deep cervical
D. Submental
E. Retropharyngeal

Answer

A

For each numbered structure, select the most closely
linked primary nodes that drain those structures from
the list provided.
ANS: 1B; 2C; 3E; 4A; 5D
The sublingual salivary gland (1) is drained by the
submandibular lymph node (B). The parotid salivary
gland (2) is drained by the superior deep cervical
lymph node (C). The base of the tongue (3) is drained
by the retropharyngeal lymph node (E). The paranasal
sinus (4) is drained by the deep parotid lymph node
(A). The lower lip (5) is drained by the submental
lymph node (D).

Question 43

Q

For each numbered temporomandibular joint (TMJ)
disk position, select the most closely linked description
of the movement from the list provided

TMJ Disk Positions:
1. Elevation
2. Lateral
deviation
3. Retraction
4. Protrusion
5. Depression
—————–
Movement:
A. Shifting the mandible to one side
by unilateral contraction of the
lateral pterygoid muscle
B. Opening the mouth by contraction
of the inferior heads of the
lateral pterygoid muscles and the
suprahyoid muscles
C. Moving the jaw forward by
bilateral contraction of the lateral
pterygoid muscles
D. Raising the lower jaw by
contraction of all portions of the
temporalis, masseter, and medial
pterygoid muscles
E. Moving the jaw back by
contraction of the posterior
portions of both temporalis
muscles

Answer

A

ANS: 1D; 2A; 3E; 4C; 5B
Elevation of the TMJ disk (1) results in the raising
of the lower jaw through contraction of all portions
of the temporalis, masseter, and medial pterygoid
muscles (D). Lateral deviation of the TMJ disk
(2) results in shifting of the mandible to one side
via unilateral contraction of the lateral pterygoid
muscle (A). Retraction of the TMJ disk (3) results
in backward jaw movement through contraction of
posterior portions of both temporalis muscles (E).
Protrusion of the TMJ disk (4) produces forward jaw
movement through bilateral contraction of the lateral
pterygoid muscles (C). Depression of the TMJ
disk (5) produces opening of the mouth through
contraction of the inferior heads of the lateral
pterygoid and suprahyoid muscles (B).

Question 44

Q

Each of the following is a period of prenatal
development EXCEPT one. Which one is the
EXCEPTION?
A. Fetal
B. Ovulation
C. Embryonic
D. Preimplantation

Answer

A

ANS: B
The ovulation period (B) occurs during a woman’s
menstrual cycle with the release of an ovum. The
unfertilized egg is not part of prenatal development. The
three distinct periods of prenatal development are the
preimplantation period (D), occurring during the first week
after fertilization; the embryonic period (C), occurring
during the second to the eighth week; and the fetal period
(A), which occurs from the third to the ninth month.

Question 45

Q

The first branchial arch is also called the mandibular
arch. The cartilage forming within the mandibular arch
is known as Reichert cartilage.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true, and the second statement
is false.
D. The first statement is false, and the second
statement is true.

Answer

A

ANS: C
Choice C is correct; the first statement is true, and the
second statement is false. There are six branchial arches.
The first branchial arch is considered the mandibular
arch, and the second branchial arch is known as the hyoid
arch. The cartilage that forms within the mandibular arch
is Meckel cartilage, not Reichert cartilage, which forms
in the second branchial arch. Choices A, B, and D do not
correctly reflect the statements.

Question 46

Q

Which cells are responsible for producing dentin?
A. Osteoblasts
B. Ameloblasts
C. Odontoblasts
D. Cementoblasts

Answer

A

ANS: C
Odontoblasts (C) are responsible for producing dentin.
Osteoblasts (A) are bone-producing cells. Ameloblasts
(B) produce enamel and cementoblasts (D) produce
cementum

Question 47

Q

Each of the following is a component of the tooth germ
EXCEPT one. Which one is the EXCEPTION?
A. Enamel organ
B. Dental sac
C. Dental lamina
D. Dental papilla
E. Dental follicle

Answer

A

ANS: C
The dental lamina (C) is not part of the tooth germ,
although the proliferation of ectodermal cells into
specific sites is the first stage of odontogenesis. This
thickened sheet of epithelium will give way to become
the enamel organ. The three components that make up
the tooth germ are the enamel organ (A), the dental sac
(B), and the dental papilla (D). DENTAL FOLLICLE
(E) is another term for dental sac.

Question 48

Q

Order the stages of odontogenesis. Match each letter
with its proper sequence number.
___ A. Cap stage
___ B. Bud stage
___ C. Bell stage
___ D. Maturation stage
___ E. Initiation stag

Answer

A

ANS: 1E; 2B; 3A; 4C; 5D
Odontogenesis begins with the initiation stage (1E)
during the sixth to the seventh week. Next is the bud
stage (2B), beginning in the eighth week, which is followed by the cap stage (3A) during weeks nine and
ten. During the eleventh and twelfth weeks, the bell
stage (4C) occurs, and the final stage of odontogenesis
is the maturation stage (5D).

Question 49

Q

Division of a cell into two daughter cells occurs during
which phase of mitosis?
A. Prophase
B. Anaphase
C. Metaphase
D. Telophase

Answer

A

ANS: D
Telophase (D) is the last phase in which the individual
cell divides into two daughter cells. During prophase
(A), the DNA (deoxyribonucleic acid) in the form
of chromatin condenses into chromosomes. During
metaphase (C), the chromosomes move and align
themselves in the middle of the cell. Next is anaphase
(B), during which the chromosomes separate and
migrate to opposite poles of the cell.

Question 50

Q

The inner cells of the dental papilla will develop into
which structure?
A. Cementum
B. Dentin
C. Pulp
D. Enamel

Answer

A

ANS: C
The inner cells of the dental papilla develop into dental
pulp (C). Cementum (A) is produced by cementocytes
that come from the dental sac. Dentin (B) is produced
by the outer cells of the dental papilla. Enamel (D)
is produced by ameloblast cells that come from the
enamel organ.

Question 51

Q

The earliest indication of a part or an organ during
prenatal development is referred to as the
A. primordium.
B. stomodeum.
C. zygote.
D. nucleus.

Answer

A

ANS: A
The primordium (A) is the earliest indication of a
part or an organ during prenatal development. The
stomodeum (B) is also known as the primitive mouth
and begins as just a slight depression but subsequently
will give rise to the oral cavity. A zygote (C) is a
fertilized egg, resulting from the union of a man’s
sperm and a woman’s ovum. A nucleus (D) is a large
organelle found in most cells, responsible for the
regulation of all cellular function

Question 52

Q

Which stage of tooth development occurs between the
11th and 12th weeks of prenatal development?
A. Bud
B. Cap
C. Bell
D. Initiation

Answer

A

ANS: C
The bell stage (C) occurs between weeks 11 and 12 of
prenatal development. The initiation stage (D) occurs
between weeks 6 and 7 of tooth development. The bud
stage (A) occurs during week 8, whereas the cap stage
(B) happens between weeks 9 and 10.

Question 53

Q

Which of the following cells is/are DIRECTLY
responsible for immunoglobulin production?
A. Plasma
B. Basophils
C. Monocytes
D. Neutrophils
E. Eosinophils

Answer

A

ANS: A
Activated B-cell lymphocytes form plasma cells
(A), which are directly responsible for producing
immunoglobulins (antibodies). Basophils (B),
monocytes (C), neutrophils (D), and eosinophils (E)
are all white blood cells, and all contribute to the
immune response. A lymphocyte is a white blood cell
that has three functional types, one of which is a B-cell
lymphocyte.

Question 54

Q

Which primordial structure differentiates into the
ameloblasts that produce enamel?
A. Outer enamel epithelium
B. Stellate reticulum
C. Inner enamel epithelium
D. Stratum intermedium

Answer

A

ANS: C
Inner enamel epithelium (IEE) (C) comprises the
columnar cells of the enamel organ that differentiate
into ameloblasts. The outer enamel epithelium
(OEE) (A) comprises cuboidal cells that protect the
outer portion of the enamel organ. Between the IEE
and OEE is the stellate reticulum (B), composed of
star-shaped cells, and the stratum intermedium (D),
composed of flat to cube-shaped cells; both support the
production of enamel.

Question 55

Q

Incremental lines that stain brown in preparations of
mature enamel are
A. neonatal lines.
B. enamel tufts.
C. lines of Retzius.

Answer

A

ANS: C
Incremental lines that stain brown in preparations of
mature enamel are lines of Retzius (C). The neonatal
line (A) is an incremental line of Retzius; however, it
is more pronounced and marks trauma or stress placed
on ameloblasts during birth. Enamel tufts (B) appear as
small, dark hypocalcified, brushlike areas found near the
dentinoenamel junction (DEJ). Enamel spindles (D) are
actually short dentinal tubules that have been trapped
in the enamel matrix. Enamel lamellae (E) extend from
the DEJ all the way out to the occlusal surface and are
partially calcified sheets of enamel matrix

Question 56

Q

Which period of prenatal development occurs during
months 3 to 9?
A. Fetal
B. Embryonic
C. Preimplantation
D. A only
E. Both A and B

Answer

A

ANS: A
The final period of prenatal development is the fetal
period (A), which spans months 3 to 9 or delivery.
After fertilization, the zygote travels along until it
implants itself into the uterus. This period is known as
the PREIMPLANTATION PERIOD (C), which occurs
during week 1. The embryonic period (B) follows
during weeks 2 through 8. Choices D and E do not
correctly address the statement.

Question 57

Q

Each cell facilitates the exfoliation of a primary tooth
EXCEPT one. Which one is the EXCEPTION?
A. Ameloblast
B. Osteoclast
C. Odontoclast
D. Cementoclast

Answer

A

ANS: A
The ameloblast (A) is the enamel-producing cell
that does not facilitate exfoliation of teeth. The
osteoclast (B) is necessary to resorb the alveolar
bone anchoring the tooth. The odontoclast (C)
is responsible for resorption of dentin. The
cementoclast (D) is responsible for the resorption of
cementum

Question 58

Q

From the following list, select the structures of the
embryo that begin development in week 4 of prenatal
development.
A. Face
B. Neck
C. Palate
D. Tongue
E. Placenta

Answer

A

ANS: A, B, D
Facial development (A) begins during week 4
and continues into week 12. The neck (B) and the
tongue (D) begin to develop in conjunction with the
face. The placenta (E) begins development during
week 2 from the interaction of the trophoblast layer
and the endometrial tissues. The palate (C) begins
formation during week 5 and also continues through
week 12.

Question 59

Q

Down syndrome is a developmental disturbance that
occurs during which period of prenatal development?
A. Fetal
B. Embryonic
C. Preimplantation

Answer

A

ANS: C
Down syndrome is a developmental disturbance
that occurs during meiosis. The final stages of
meiosis occur just after fertilization, which takes
place during the preimplantation (C) period. The
division of chromosomes occurs prior to the zygote
being implanted and has already taken place by the
embryonic (B) or fetal (A) periods.

Question 60

Q

The cervical loop is responsible for development of
A. dentin.
B. pulp.
C. enamel.
D. root.

Answer

A

ANS: D
The cervical loop is responsible for root (D)
development. Dentin (A) is developed from
odontoblasts. Pulp (B) develops from the inner cells
of the dental papilla. The enamel of the crown of the
tooth (C) is formed from ameloblasts.

Question 61

Q

The incomplete developmental division of a tooth
germ is called FUSION. Fusion takes place during the
initiation stage of tooth development.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true, and the second statement
is false.
D. The first statement is false, and the second
statement is true

Answer

A

ANS: B
Both statements are false (B). Fusion is the union
of two tooth germs. Incomplete tooth germ division
is referred to as GEMINATION. Fusion takes place
during the cap stage of odontogenesis, not during the
initiation stage. Choices A, C, and D do not accurately
reflect the statements.

Question 62

Q

Which is the most common cell found in the lamina
propria of the oral mucosa?
A. Epiblast
B. Odontoblast
C. Osteoblast
D. Osteoclast
E. Fibroblast

Answer

A

ANS: E
The fibroblast (E) is the most common cell found
in the lamina propria of the oral mucosa. Epiblast
(A) layers are high-columnar cells of the bilaminar
embryonic disk. The odontoblast (B) is the cell
that will produce dentin. The osteoblast (C) is a
bone-forming cell, and the osteoclast (D) is a boneresorbing cell.

Question 63

Q

The cells responsible for the development of the
periodontal ligament come from the
A. dental sac.
B. dental papilla.
C. enamel organ.
D. successional lamellae

Answer

A

ANS: A
The dental sac or follicle (A) consists of
ectomesenchyme that surrounds the enamel organ and
will produce not only the periodontal ligament but
also cementum and alveolar bone. The dental papilla
(B) has inner cells that will produce the pulp and outer
cells that will produce dentin. The enamel organ (C)
will produce enamel. The successional lamellae (D)
comprise the epithelial tissue that will give rise to
succedaneous teeth.

Question 64

Q

The cusp of Carabelli is found on which permanent
molars?
A. #3, #14
B. #2, #15
C. #19, #30
D. #18, #31

Answer

A

ANS: A
The cusp of Carabelli is found on the lingual
surface of maxillary first molars, which includes
#3 and #14 (A). Teeth #2 and #15 (B) are maxillary
second molars; #19 and #30 (C) are mandibular first
molars; and #18 and #31 (D) are mandibular second
molars.

Answer 65

A

ANS: C
The correct answer is (C); the first statement
is true, and the second statement is false. Eight
bones compose the neurocranium: the frontal, the
sphenoid, the ethmoid, and the occipital bones,
which are single bones. The paired temporal and
parietal bones also are part of the neurocranium.
The second statement is false. There are 14 bones,
not 15, that make up the viscerocranium, including
the single mandible and the vomer. The paired
nasal, lacrimal, zygomatic, inferior nasal conchae,
palatine, and maxillae are the remaining bones
composing the face. Choices A, B, and D do not
accurately reflect the statements.

Answer 66

A

ANS: E
The correct answer is (E). The complex, threedimensional sphenoid bone contains the temporal fossa
(B), the superior orbital fissure (C), the base of the
skull anterior to occipital bone (D), and the pterygoid
processes. The palatine process (A) is part of the maxillae.

Answer 67

A

ANS: D
The mandibular teeth (D) and the bone of the
mandible are supplied by the inferior alveolar artery.
The lingual artery supplies the floor of the mouth (A),
and its branches supply the tongue (B). The sublingual
gland (C) is supplied by the sublingual and submental
arteries

Answer 68

A

ANS: D
The correct choice is D; thrombocytes are produced
in bone marrow and not in the lymphatic system. The
lymphatic system filters fluids (A), fights infection (B),
produces lymphocytes (C), and returns plasma to the
venous bloodstream (E).

Answer 69

A

ANS: 1C; 2A; 3B
Division I (1) is known as the ophthalmic V1
(C).
Division II (2) is the maxillary V2
(A). Division III (3)
is the mandibular V3
(B).

Answer 70

A

ANS: C
The correct choice is C. The first statement is true, and
the second statement is false. The abducens, trochlear,
and oculomotor nerves supply motor innervation to
the muscle of the eye. Choices A, B, and D do not
correctly reflect the statements

Answer 71

A

ANS: 1A; 2C; 3B
The endoderm (1) forms the gastrointestinal tract,
epithelium, and associated glands (A). The mesoderm (2) forms muscles, bone, cartilage, blood, dentin,
pulp, cementum, and periodontal ligament (C). The
ectoderm (3) forms the nervous system, epidermis,
sensory epithelium of the eye, ear, and nose; the tooth
enamel; and the oral epithelium (B).

Answer 72

A

ANS: 1D; 2A; 3B; 4C
Ameloblasts (1) give rise to enamel (D).
Cementoblasts (2) give rise to cementum (A).
Odontoblasts (3) give rise to dentin (B). The dental
follicle (4) gives rise to mesenchymal cells, which
give rise to alveolar bone (C), the periodontal
ligament, and cementum.

Answer 73

A

ANS: 1D; 2A; 3B; 4C
The mandibular arch (1) gives rise to the mandible,
muscles of mastication, and cranial nerve V (D).
The hyoid arch (2) gives rise to the muscles of facial
expression and cranial nerve VII (A). Branchial arch
III (3) gives rise to the tongue and cranial nerve IX
(B). Branchial arch IV (4) gives rise to the muscles
of the throat, the inferior hyoid cartilage, and cranial
nerve X (C).

Answer 74

A

ANS: D
The posterior superior alveolar artery (1), the pterygoid
plexus of veins (2) and the facial artery (4) are located in
the infratemporal fossa. This location may contain a high
volume of blood if a hematoma occurs. The vessels listed
in A, B, and C are not associated with the PSA nerve block.

Answer 75

A

ANS: A
The temporomandibular joint (TMJ) rotates and
glides (A). Rotational movement occurs between
the disk and the mandibular condyle in the lower
synovial cavity. As the jaw opens further, an anterior
gliding movement also occurs along the posterior
slope of the articular eminence. Movements B, C,
and D are not associated with the TMJ.

Answer 76

A

ANS: D
There are approximately eight main branches of
the external carotid artery. The terminal branches
are maxillary and superficial temporal branches
(D) given off deep to the neck of the condyle. The
superior thyroid and lingual (A) branches and the
facial and ascending pharyngeal (B) branches are
given off in the carotid triangle. The posterior
auricular and occipital (C) arteries are posterior
arteries given off below maxillary and superficial
temporal arteries.

Answer 77

A

ANS: A
The full deciduous dentition contains 20 teeth (A). The
full permanent dentition contains 32 teeth (D). Neither 24
(B) nor 28 (C) represents a full count of teeth at any stage.

Answer 78

A

ANS: B
Dentin in primary teeth is much thicker than dentin in
permanent teeth (B). Primary teeth are characterized as
having relatively thin enamel (A) and large pulp cavities
(C) and are whiter in color than permanent teeth (D).

Answer 79

A

ANS: B
Permanent maxillary incisors, teeth #7 and #10 (B),
are wider mesiodistally than faciolingually. Maxillary
premolars (A) and mandibular incisors (C and D) are
wider faciolingually than mesiodistally

Answer 80

A

ANS: A
Prevention of caries decay (A) is NOT a function of
the cementoenamel junction (CEJ). The CEJ functions
for self-cleansing by the natural spillways that are
formed, lending to self-cleansing properties (B), food
deflection (C), and both health and maintenance of
periodontal tissues in the interproximal spaces (D).

Answer 81

A

ANS: 1D; 2C; 3B; 4E; 5A; 6F
Dwarf roots (1) affect the crown-to-root ratio (D).
Concrescence (2) involves fusion after roots are
formed (C). In dilaceration (3), the crown or root demonstrates sharp bends or curves (B). Mulberry
molars (4) result from congenital syphilis (E).
Gemination (5) involves the partial splitting of the root
germ (A). Dens in dente (6) describes a tooth within a
tooth (F).

Answer 82

A

ANS: B
Both statements are false (B). The clinical crown-toroot ratio may change, depending on the location of
alveolar bone and the gingiva. The anatomic crown–toroot ratio (the crown and root are covered with enamel
and cementum, respectively) always remains the
same. Choices A, C, and D do not correctly reflect the
statements.

Answer 83

A

ANS: A
Both statements are correct and related (A). Active
eruption, mesial drift, and masticatory occlusal
and orthodontic corrective forces are all examples
of consistent forces in alveolar bone remodeling.
Traumatic occlusal force is an example of a type of
force that is NOT a consistent, constant force that
results in bone remodeling. Choices B, C, D, and E do
not correctly reflect the statements.

Answer 84

A

ANS: C
Mitochondria (C) are the “power plants” of the
cell and are responsible for the rate of energy production. Ribosomes (A) are the RNA (ribonucleic
acid) of the cell and are also responsible for protein
production. Lysosomes (B) act as “scavenger”
cells, removing debris from within the cellular
body. The Golgi apparatus (D) is involved in
merocrine secretion. The endoplasmic reticulum (E)
manufactures various products for use within and
outside cells.

Answer 85

A

ANS: A
Both statements are true (A). Enamel develops from
the enamel organ, which is derived from the ectoderm.
The enamel organ will differentiate into the inner
enamel epithelium, the stellate reticulum, the stratum
intermedium, and the outer enamel epithelium. The
inner enamel epithelium will give rise to ameloblasts.
The ectoderm’s production of ameloblasts is the signal
to the mesodermal structure of the dental papilla to
start the formation of dentin and pulp. Choices B, C,
and D do not correctly reflect the statements.

Answer 86

A

ANS: C
The correct choice is C. The first statement is true.
The frontonasal process will form the forehead and
the middle third of the face, including the nose, the
philtrum, maxillary incisors, and the premaxillary area
or the primary palate. The first pharyngeal (branchial)
arch I forms the mandibular and maxillary processes,
which will form the mandible, most of the maxillae,
and palatine bones. The zygomatic bones of the cheek
are also formed from these processes. The second
statement is false. This process begins during week 3
in embryologic development. By week 6, the major
facial structures have formed and are developing in
complexity. Choices A, B, and D do not accurately
reflect the statements

Answer 87

A

ANS: B
There is no structure called the mandibular sinus (B).
Paranasal sinuses include the frontal (A), maxillary
(C), sphenoidal (D), and ethmoidal (E) sinuses.

Answer 88

A

ANS: C
The orbicularis oris muscle (C) shapes and controls
the size of the mouth opening and is important
in the creation of lip positions and movements
during speech. The risorius muscle (A) stretches
the lips laterally, retracting the labial commissure
and widening the mouth to produce a grimace. The
zygomaticus major muscle (B) elevates the labial
commissure of the upper lip and pulls it laterally,
thus helping create to a smile. The levator anguli oris
muscle (D) elevates the labial commissure, as when a
person smiles

Answer 89

A

ANS: D
The abnormal invagination of the enamel organ
into the dental papilla results in the developmental
disturbance known as dens in dente (D) and appears as
a “tooth within a tooth” on radiographic examination.
In gemination (C), the single tooth germ tries unsuccessfully to divide into two tooth germs, resulting
in a large single-rooted tooth with a common pulp
cavity. With fusion (A), two adjacent tooth germs join
together, leading to a large, falsely macrodontic tooth
that can be verified with radiographic examination.
Tubercles (B) are extra cusps that appear as small,
round enamel extensions.

Answer 90

A

ANS: A
The occipital artery (A) is a posterior branch of the
external carotid artery. The external carotid artery has
four sets of branches, grouped according to location
in relation to the main artery: (1) anterior, (2) medial,
(3) posterior, and (4) terminal. The superior thyroid
(B), facial (C), and lingual (D) arteries are all anterior
branches of the external carotid artery.

Answer 91

A

ANS: C
Lacrimal glands (C) are paired exocrine glands that
secrete lacrimal fluid, or tears. With dry eye syndrome,
the lacrimal glands produce less fluid, a condition
often associated with aging or certain medications. The
thyroid (A), thymus (B), and parathyroid (D) glands
are all endocrine glands, not exocrine glands. The
thyroid gland (A) is the largest endocrine gland and
secretes thyroxine directly into the vascular system
to stimulate the body’s metabolic rate. The thymus
gland (B) is part of the immune system and helps fight
disease processes. The parathyroid gland (D) secretes
parathyroid hormone directly into the vascular system
to regulate phosphorus and calcium levels.

Answer 92

A

ANS: D
The correct choice is D. The first statement is false.
The face and its related tissues begin to form at the
beginning of week 4 in the embryonic period, not
during week 6 in the fetal period. However, the
second statement is true. Facial development starts
during weeks 3 and 4 and is completed in the twelfth
week. Choices A, B, and C do not correctly reflect the
statements.

Answer 93

A

ANS: C
Muscle tissue (C) is part of the muscular system and
is a classification of basic tissue in the same way
that connective tissue is also a classification of basic
body tissue. Bone (A) is a rigid type of specialized
connective tissue that makes up the majority of
the body’s mature skeleton. Blood (B) is a fluid
specialized connective tissue that transports nutrients
throughout the body. Cartilage (D) is a type of firm,
noncalcified, specialized connective tissue that forms
much of the temporary skeleton of the embryo and
structurally supports certain soft tissues after birth

Answer 94

A

ANS: C
Choice C is correct. The first statement is true.
Enamel may be lost through attrition (wearing
away from tooth-to-tooth contact), abrasion (loss
through friction from toothbrushing or toothpaste),
erosion (loss through chemical means that do not
involve bacteria), caries (loss through chemical
means from cariogenic bacteria), or abfraction (loss
through tensile and compressive forces during tooth
flexure). However, the second statement is false.
On radiographs, enamel appears more radiopaque
(lighter) than dentin or pulp, both of which appear
more radiolucent (darker). Choices A, B, and D do
not accurately reflect the statements.

Answer 95

A

ANS: D
The correct sequence of words used to describe a
tooth is based on the D-A-Q-T system (D), with D for
dentition, A for arch, Q for quadrant, and T for tooth
type. For example, a dental professional may refer
to a permanent (D) mandibular (A) left (Q) premolar
(T). Acronyms in choices A, B, and C are incorrectly
sequenced.

Answer 96

A

ANS: D
An adult mouth has 12 total permanent anterior teeth
(D): 8 incisors (4 each lateral and central incisors [two
in each arch]) and 4 canines (two in each arch). Figures
in choices A, B, and C are less than 12 (the normal
number of permanent anterior teeth).

Answer 97

A

ANS: A
Teeth #5 and #12 (A) are maxillary first premolars.
Teeth #4 and #13 (B) are maxillary second premolars.
Teeth #21 and #28 (C) are mandibular first premolars.
Teeth #24 and #25 (D) are mandibular central incisors

Answer 98

A

ANS: B, C, D
The correct choices are B, C, and D. Mandibular
molars have a bifurcated root: mesial and distal (B).
Maxillary molars have trifurcated roots: mesiobuccal,
distobuccal, and palatal (C). Maxillary first premolars
may have a bifurcated root: buccal and palatal (D).
Maxillary second premolars are rarely bifurcated (A).

Brainscape's Knowledge GenomeTM

MOSBY anA HYGIE Flashcards

Brainscape's Knowledge Genome^TM