, CHAPTER LIST
UNIT I: Orofacial Structures
Chapter 1: Face and Neck Regions
Chapter 2: Oral Cavity and Pharynx
UNIT II: Dental Embryology
Chapter 3: Prenatal Development
Chapter 4: Face and Neck Development
Chapter 5: Orofacial Development
Chapter 6: Tooth Development and Eruption
UNIT III: Dental Histology
Chapter 7: Basic Cell Properties and Processes
Chapter 8: Basic Tissue Properties and Processes
Chapter 9: Oral Mucosa
Chapter 10: Gingival and Dentogingival Junctional Tissue
Chapter 11: Head and Neck Structures
Chapter 12: Enamel
Chapter 13: Dentin and Pulp
Chapter 14: Periodontium: Cementum, Alveolar Process, and Periodontal
Ligament
UNIT IV: Dental Anatomy
Chapter 15: Overview of Dentitions
Chapter 16: Permanent Anterior Teeth
Chapter 17: Permanent Posterior Teeth
Chapter 18: Primary Dentition
Chapter 19: Temporomandibular Joint
Chapter 20: Occlusion
,Chapter 1: Face and Neck Regions
Integrated Context: Surface anatomy, skeletal framework, muscles of facial
expression and mastication, cranial nerves, and vascular/lymphatic pathways
with clinical relevance to extraoral examination, local anesthesia, oral surgery,
and recognition of externally presenting pathology.
Source text: Illustrated Dental Embryology, Histology, and Anatomy
Question 1
During an extraoral examination, a patient is unable to close the right eye and
exhibits drooping of the right corner of the mouth. Which cranial nerve is most
likely affected?
A. Trigeminal nerve (CN V)
B. Facial nerve (CN VII)
C. Glossopharyngeal nerve (CN IX)
D. Hypoglossal nerve (CN XII)
Answer: B
Very Deep Rationale:
The facial nerve (CN VII) innervates the muscles of facial expression, including
orbicularis oculi (eye closure) and orbicularis oris (lip movement). Lesions
result in ipsilateral facial paralysis, inability to close the eye, and mouth
drooping. CN V provides facial sensation and mastication, not facial
expression. CN IX and XII control swallowing and tongue movement,
respectively. Recognition of facial nerve deficits is critical during extraoral
exams and parotid or mandibular procedures.
Key words: facial nerve, facial paralysis, extraoral exam, muscles of facial
expression
Question 2
Which muscle is primarily responsible for elevating the mandible during
mastication and is palpated at the angle of the mandible during clenching?
,A. Medial pterygoid
B. Lateral pterygoid
C. Masseter
D. Temporalis
Answer: C
Very Deep Rationale:
The masseter is a powerful elevator of the mandible and is superficial and
easily palpated at the angle of the mandible when the patient clenches. The
temporalis also elevates the mandible but is palpated over the temporal fossa.
The medial pterygoid assists elevation but is deep, while the lateral pterygoid
primarily protrudes and depresses the mandible. Accurate identification is
important during muscle-related pain assessment and injections.
Key words: masseter, mastication, mandibular elevation, surface anatomy
Question 3
Loss of sensation to the lower lip and chin following oral surgery most likely
indicates injury to which nerve?
A. Buccal nerve
B. Lingual nerve
C. Mental nerve
D. Inferior alveolar nerve (proximal)
Answer: C
Very Deep Rationale:
The mental nerve, a terminal branch of the inferior alveolar nerve, exits the
mental foramen to supply sensation to the lower lip and chin. Injury distal to
the foramen affects only these areas, whereas proximal inferior alveolar nerve
injury would affect mandibular teeth as well. This distinction is critical in
postoperative sensory assessments and anesthesia complications.
Key words: mental nerve, lower lip sensation, mandibular surgery, nerve
injury
Question 4
,Which structure serves as the primary landmark for locating the mental
foramen during local anesthesia administration?
A. Angle of the mandible
B. Midline of the chin
C. Apex of the mandibular second premolar
D. Zygomatic arch
Answer: C
Very Deep Rationale:
The mental foramen is typically located near the apex of the mandibular
second premolar. This landmark guides mental nerve block placement and
reduces the risk of nerve trauma. Surface landmarks such as the angle of the
mandible and zygomatic arch are unrelated to the mental nerve location.
Key words: mental foramen, local anesthesia, surface landmark, nerve block
Question 5
A deep facial infection spreading toward the cavernous sinus poses the greatest
risk due to drainage through which vein?
A. External jugular vein
B. Facial vein
C. Maxillary vein
D. Retromandibular vein
Answer: B
Very Deep Rationale:
The facial vein communicates with the cavernous sinus via the angular vein
and ophthalmic veins, forming a valveless pathway that allows retrograde
spread of infection. This “danger triangle” of the face is clinically significant
because infections can rapidly become life-threatening.
Key words: facial vein, cavernous sinus, infection spread, danger triangle
Question 6
,Which bone forms the inferior portion of the nasal septum and contributes to
midface structure?
A. Ethmoid
B. Vomer
C. Maxilla
D. Palatine
Answer: B
Very Deep Rationale:
The vomer forms the inferior and posterior portion of the nasal septum. The
ethmoid contributes superiorly, while the maxilla and palatine form parts of
the hard palate. Knowledge of midfacial skeletal anatomy is essential for
trauma assessment and surgical planning.
Key words: vomer, nasal septum, facial skeleton, midface anatomy
Question 7
Injury to which muscle would most directly impair protrusion of the mandible?
A. Temporalis
B. Masseter
C. Medial pterygoid
D. Lateral pterygoid
Answer: D
Very Deep Rationale:
The lateral pterygoid is the primary muscle responsible for mandibular
protrusion and assists in opening the jaw. Damage can result in deviation and
limited forward movement. Other muscles mainly elevate the mandible.
Key words: lateral pterygoid, mandibular protrusion, mastication muscles
Question 8
Which cranial nerve provides motor innervation to the muscles of mastication?
,A. Facial nerve (CN VII)
B. Trigeminal nerve – mandibular division (CN V3)
C. Glossopharyngeal nerve (CN IX)
D. Hypoglossal nerve (CN XII)
Answer: B
Very Deep Rationale:
The mandibular division of the trigeminal nerve (CN V3) supplies motor
innervation to the muscles of mastication. CN VII innervates facial expression
muscles, not mastication. This distinction is crucial for diagnosing chewing
dysfunction.
Key words: CN V3, mastication, trigeminal nerve, motor innervation
Question 9
Which lymph nodes are most likely involved first in infections of the lower lip?
A. Submental lymph nodes
B. Submandibular lymph nodes
C. Deep cervical lymph nodes
D. Preauricular lymph nodes
Answer: A
Very Deep Rationale:
The submental lymph nodes drain the lower lip, floor of the mouth, and
anterior tongue. Early involvement helps localize infection sources during
extraoral examination.
Key words: submental lymph nodes, lymphatic drainage, lower lip infection
Question 10
Damage to the hypoglossal nerve would most directly affect which function?
A. Facial expression
B. Tongue movement
C. Swallowing reflex
D. Salivary secretion
,Answer: B
Very Deep Rationale:
The hypoglossal nerve (CN XII) provides motor innervation to intrinsic and
extrinsic tongue muscles. Injury results in tongue deviation and impaired
speech and swallowing coordination.
Key words: hypoglossal nerve, tongue movement, cranial nerve lesion
Question 11
Which muscle elevates the upper lip and is commonly involved in expressions
of disgust?
A. Zygomaticus major
B. Levator labii superioris
C. Buccinator
D. Risorius
Answer: B
Very Deep Rationale:
The levator labii superioris elevates the upper lip, exposing the maxillary teeth.
Its function is clinically relevant when evaluating facial nerve integrity.
Key words: levator labii superioris, facial expression, upper lip
Question 12
A fracture of the zygomatic arch would most likely impair which muscle’s
function?
A. Masseter
B. Buccinator
C. Temporalis
D. Lateral pterygoid
Answer: C
, Very Deep Rationale:
The temporalis muscle passes deep to the zygomatic arch. Fracture or
compression can limit mandibular elevation and cause trismus.
Key words: zygomatic arch, temporalis, facial fracture
Question 13
Which artery is palpated anterior to the masseter muscle as it crosses the
mandible?
A. Maxillary artery
B. Facial artery
C. Lingual artery
D. External carotid artery
Answer: B
Very Deep Rationale:
The facial artery crosses the inferior border of the mandible just anterior to the
masseter and is a key pulse point and landmark during surgery.
Key words: facial artery, mandibular landmark, vascular anatomy
Question 14
Paralysis of the buccinator muscle would most likely result in which functional
deficit?
A. Inability to elevate the mandible
B. Difficulty retaining food during chewing
C. Loss of tongue protrusion
D. Impaired swallowing reflex
Answer: B
Very Deep Rationale:
The buccinator compresses the cheek against the teeth, preventing food from
accumulating in the vestibule. Dysfunction affects mastication efficiency.
Key words: buccinator, mastication, food control
UNIT I: Orofacial Structures
Chapter 1: Face and Neck Regions
Chapter 2: Oral Cavity and Pharynx
UNIT II: Dental Embryology
Chapter 3: Prenatal Development
Chapter 4: Face and Neck Development
Chapter 5: Orofacial Development
Chapter 6: Tooth Development and Eruption
UNIT III: Dental Histology
Chapter 7: Basic Cell Properties and Processes
Chapter 8: Basic Tissue Properties and Processes
Chapter 9: Oral Mucosa
Chapter 10: Gingival and Dentogingival Junctional Tissue
Chapter 11: Head and Neck Structures
Chapter 12: Enamel
Chapter 13: Dentin and Pulp
Chapter 14: Periodontium: Cementum, Alveolar Process, and Periodontal
Ligament
UNIT IV: Dental Anatomy
Chapter 15: Overview of Dentitions
Chapter 16: Permanent Anterior Teeth
Chapter 17: Permanent Posterior Teeth
Chapter 18: Primary Dentition
Chapter 19: Temporomandibular Joint
Chapter 20: Occlusion
,Chapter 1: Face and Neck Regions
Integrated Context: Surface anatomy, skeletal framework, muscles of facial
expression and mastication, cranial nerves, and vascular/lymphatic pathways
with clinical relevance to extraoral examination, local anesthesia, oral surgery,
and recognition of externally presenting pathology.
Source text: Illustrated Dental Embryology, Histology, and Anatomy
Question 1
During an extraoral examination, a patient is unable to close the right eye and
exhibits drooping of the right corner of the mouth. Which cranial nerve is most
likely affected?
A. Trigeminal nerve (CN V)
B. Facial nerve (CN VII)
C. Glossopharyngeal nerve (CN IX)
D. Hypoglossal nerve (CN XII)
Answer: B
Very Deep Rationale:
The facial nerve (CN VII) innervates the muscles of facial expression, including
orbicularis oculi (eye closure) and orbicularis oris (lip movement). Lesions
result in ipsilateral facial paralysis, inability to close the eye, and mouth
drooping. CN V provides facial sensation and mastication, not facial
expression. CN IX and XII control swallowing and tongue movement,
respectively. Recognition of facial nerve deficits is critical during extraoral
exams and parotid or mandibular procedures.
Key words: facial nerve, facial paralysis, extraoral exam, muscles of facial
expression
Question 2
Which muscle is primarily responsible for elevating the mandible during
mastication and is palpated at the angle of the mandible during clenching?
,A. Medial pterygoid
B. Lateral pterygoid
C. Masseter
D. Temporalis
Answer: C
Very Deep Rationale:
The masseter is a powerful elevator of the mandible and is superficial and
easily palpated at the angle of the mandible when the patient clenches. The
temporalis also elevates the mandible but is palpated over the temporal fossa.
The medial pterygoid assists elevation but is deep, while the lateral pterygoid
primarily protrudes and depresses the mandible. Accurate identification is
important during muscle-related pain assessment and injections.
Key words: masseter, mastication, mandibular elevation, surface anatomy
Question 3
Loss of sensation to the lower lip and chin following oral surgery most likely
indicates injury to which nerve?
A. Buccal nerve
B. Lingual nerve
C. Mental nerve
D. Inferior alveolar nerve (proximal)
Answer: C
Very Deep Rationale:
The mental nerve, a terminal branch of the inferior alveolar nerve, exits the
mental foramen to supply sensation to the lower lip and chin. Injury distal to
the foramen affects only these areas, whereas proximal inferior alveolar nerve
injury would affect mandibular teeth as well. This distinction is critical in
postoperative sensory assessments and anesthesia complications.
Key words: mental nerve, lower lip sensation, mandibular surgery, nerve
injury
Question 4
,Which structure serves as the primary landmark for locating the mental
foramen during local anesthesia administration?
A. Angle of the mandible
B. Midline of the chin
C. Apex of the mandibular second premolar
D. Zygomatic arch
Answer: C
Very Deep Rationale:
The mental foramen is typically located near the apex of the mandibular
second premolar. This landmark guides mental nerve block placement and
reduces the risk of nerve trauma. Surface landmarks such as the angle of the
mandible and zygomatic arch are unrelated to the mental nerve location.
Key words: mental foramen, local anesthesia, surface landmark, nerve block
Question 5
A deep facial infection spreading toward the cavernous sinus poses the greatest
risk due to drainage through which vein?
A. External jugular vein
B. Facial vein
C. Maxillary vein
D. Retromandibular vein
Answer: B
Very Deep Rationale:
The facial vein communicates with the cavernous sinus via the angular vein
and ophthalmic veins, forming a valveless pathway that allows retrograde
spread of infection. This “danger triangle” of the face is clinically significant
because infections can rapidly become life-threatening.
Key words: facial vein, cavernous sinus, infection spread, danger triangle
Question 6
,Which bone forms the inferior portion of the nasal septum and contributes to
midface structure?
A. Ethmoid
B. Vomer
C. Maxilla
D. Palatine
Answer: B
Very Deep Rationale:
The vomer forms the inferior and posterior portion of the nasal septum. The
ethmoid contributes superiorly, while the maxilla and palatine form parts of
the hard palate. Knowledge of midfacial skeletal anatomy is essential for
trauma assessment and surgical planning.
Key words: vomer, nasal septum, facial skeleton, midface anatomy
Question 7
Injury to which muscle would most directly impair protrusion of the mandible?
A. Temporalis
B. Masseter
C. Medial pterygoid
D. Lateral pterygoid
Answer: D
Very Deep Rationale:
The lateral pterygoid is the primary muscle responsible for mandibular
protrusion and assists in opening the jaw. Damage can result in deviation and
limited forward movement. Other muscles mainly elevate the mandible.
Key words: lateral pterygoid, mandibular protrusion, mastication muscles
Question 8
Which cranial nerve provides motor innervation to the muscles of mastication?
,A. Facial nerve (CN VII)
B. Trigeminal nerve – mandibular division (CN V3)
C. Glossopharyngeal nerve (CN IX)
D. Hypoglossal nerve (CN XII)
Answer: B
Very Deep Rationale:
The mandibular division of the trigeminal nerve (CN V3) supplies motor
innervation to the muscles of mastication. CN VII innervates facial expression
muscles, not mastication. This distinction is crucial for diagnosing chewing
dysfunction.
Key words: CN V3, mastication, trigeminal nerve, motor innervation
Question 9
Which lymph nodes are most likely involved first in infections of the lower lip?
A. Submental lymph nodes
B. Submandibular lymph nodes
C. Deep cervical lymph nodes
D. Preauricular lymph nodes
Answer: A
Very Deep Rationale:
The submental lymph nodes drain the lower lip, floor of the mouth, and
anterior tongue. Early involvement helps localize infection sources during
extraoral examination.
Key words: submental lymph nodes, lymphatic drainage, lower lip infection
Question 10
Damage to the hypoglossal nerve would most directly affect which function?
A. Facial expression
B. Tongue movement
C. Swallowing reflex
D. Salivary secretion
,Answer: B
Very Deep Rationale:
The hypoglossal nerve (CN XII) provides motor innervation to intrinsic and
extrinsic tongue muscles. Injury results in tongue deviation and impaired
speech and swallowing coordination.
Key words: hypoglossal nerve, tongue movement, cranial nerve lesion
Question 11
Which muscle elevates the upper lip and is commonly involved in expressions
of disgust?
A. Zygomaticus major
B. Levator labii superioris
C. Buccinator
D. Risorius
Answer: B
Very Deep Rationale:
The levator labii superioris elevates the upper lip, exposing the maxillary teeth.
Its function is clinically relevant when evaluating facial nerve integrity.
Key words: levator labii superioris, facial expression, upper lip
Question 12
A fracture of the zygomatic arch would most likely impair which muscle’s
function?
A. Masseter
B. Buccinator
C. Temporalis
D. Lateral pterygoid
Answer: C
, Very Deep Rationale:
The temporalis muscle passes deep to the zygomatic arch. Fracture or
compression can limit mandibular elevation and cause trismus.
Key words: zygomatic arch, temporalis, facial fracture
Question 13
Which artery is palpated anterior to the masseter muscle as it crosses the
mandible?
A. Maxillary artery
B. Facial artery
C. Lingual artery
D. External carotid artery
Answer: B
Very Deep Rationale:
The facial artery crosses the inferior border of the mandible just anterior to the
masseter and is a key pulse point and landmark during surgery.
Key words: facial artery, mandibular landmark, vascular anatomy
Question 14
Paralysis of the buccinator muscle would most likely result in which functional
deficit?
A. Inability to elevate the mandible
B. Difficulty retaining food during chewing
C. Loss of tongue protrusion
D. Impaired swallowing reflex
Answer: B
Very Deep Rationale:
The buccinator compresses the cheek against the teeth, preventing food from
accumulating in the vestibule. Dysfunction affects mastication efficiency.
Key words: buccinator, mastication, food control
