1 Oral cavity

Question 1

Describe the bones and structures that form the boundaries of the oral cavity

Answer 1

Anteriorly: The cavity extends from the upper and lower lips
Posteriorly: To the palato-glossal arches
Laterally: To the cheeks

The cavity “proper” is between the teeth, the vestibule is outside the teeth

Bones: Hard palate (made up of maxilla and horizontal plate of palatine), Teeth, Mandible

Question 2

Describe the orientation of the B, R, A of the mandible

Answer 2

The Body and Ramus is divided by the Angle.

The Ramus then divides into condylar and coronoid processes

Question 3

What is the importance of the Retromolar fossa on the medial aspect of the mandible?

Answer 3

Retromolar fossa for attachment of the lower end of the pterygomandibular raphe, between buccinator and superior constrictor

Question 4

What is the importance of the mandibular foramen on the medial aspect of the mandible?

Answer 4

Mandibular foramen for the inferior alveolar or dental nerve to the lower teeth

Question 5

What is the importance of the submandibular fossa on the medial aspect of the mandible?

Answer 5

Submandibular fossa for the submandibular gland

Question 6

What is the importance of the mylohyoid line on the medial aspect of the mandible?

Answer 6

Mylohyoid line, for the attachment of mylohyoid muscle, forming the
floor of the mouth

Question 7

What is the importance of the sublingual fossa on the medial aspect of the mandible?

Answer 7

Sublingual fossa for the sublingual gland

Question 8

What actions at the temporomandibular joint allow opening and closing of the mouth?

Answer 8

Closing: Retraction and elevation
Opening: Protrusion and depression

Question 9

Opening of the mouth:
What is the primary muscle of the action and how?
Which joint cavity does the movement occur in?
What contributes the movement and how?

Answer 9

Primary muscle of opening: Lateral pterygoid muscle by drawing the disc + condyle forwards and downwards
Cavity: Movement in upper cavity
Gravity and digastric muscle contribute by rotation occurring the in lower joint cavity

Question 10

Closing of the mouth (elevation):

Main muscles?

Answer 10

Main muscles: Medial pterygoid, masseter and temporalis

Question 11

Facial muscles:
Name 4 main muscles?
Name their general attachment?

Answer 11

Main muscles: Buccinator, orbicularis oris, levator anguli oris, and depressor anguli oris

Question 12

What is the structural similarity of the lips and cheeks? And what lies externally and internally?

Answer 12

The lips and cheeks are a “sandwich” of muscles of facial expression, with skin externally and non-keratinised, stratified squamous epithelium lining the mucous membrane internally

Question 13

Buccinator:
Relation between fibres and lips
Modiolus?
How does it allow continuity between the oral cavity and the pharynx?

Answer 13

The upper fibres contribute to the upper lip and cross over into the lower lip. Vice versa for the lower fibres
Modiolus= The point of cross over between the upper and lower buccinator fibres
Buccinator attaches to the maxilla and mandible but also fuses with the superior pharyngeal constrictor at the pterygo-mandibular raphe

Question 14

What is the upper and lower attachments for the pterygo-mandibular raphe?

Answer 14

Lower: Over the retromolar fossa
Upper: Pterygoid hamulus (at the lower end of the medial pterygoid plate)

Question 15

Sensation to the skin of the cheeks and lips, and the corresponding, internal mucous membrane is by branches from ???

Answer 15

By branches from the Maxillary and Mandibular divisions of the Trigeminal Nerve (Cranial V), V2 and V3

Question 16

What is the main muscle of the floor of the mouth?

Answer 16

Mylohyoid - suspended between mandible and hyoid bone

Question 17

Tongue muscles:
Made up of which main muscles?
Nervous supply?
Muscular interplay?
Actions of extrinsic muscles?

Answer 17

1. Genioglossus - protrudes
2. Palatoglossus (from palatine aponeurosis) - draw tongue upwards and backwards
3. Stylo glossus (from styloid process) - draw tongue upwards and backwards
4. Hyoglossus - draws sides downwards

Nervous supply - all supplied by hypoglossal cranial nerve (XII) except palotoglossus (CN X)

Extrinsics alter position
Intrinsics alter shape

Question 18

What structure divides the tongue?

Answer 18

Terminal sulcus - anterior 2/3 (oral) and posterior 1/3 (pharyngeal)

Question 19

Nervous supply of tongue sensation?

Answer 19

1. Anterior 2/3 (oral):
   (a) General sensation - mandibular division (V3) of trigeminal cranial nerve
   (b) Taste - facial cranial nerve (VII)
2. Posterior 1/3 (pharyngeal)
   General sensation and taste - glossopharyngeal cranial nerve (IX)

Question 20

Arterial and venous supply of the tongue?

Answer 20

Lingual artery (from external carotid artery)

2 systems of lingual veins (deep + dorsal) - converge on internal jugular vein

Question 21

Tongue lymph drainage

Answer 21

1. Tip - submental lymph nodes
2. Middle sides - submandibular lymph nodes
3. Middle middle - cross midline to inferior deep cervical lymph nodes
4. Back - superior deep cervical lymph nodes

Question 22

What are the 3 salivary glands?
What is their function?
What is their nervous supply?

Answer 22

1. Parotid (serous)
2. Submandibular glands (mucous + serous)
3. Sublingual glands (mucous)

Parasympathetic secretomotor supply from facial (VII) + glossopharyngeal (IX) cranial nerves

Question 23

Where and how does the sublingual gland drain?

Answer 23

Open by separate ducts into floor of mouth

Question 24

Where and how does the submandibular gland drain?

Answer 24

Lie beside the sublingual glands & open at the sublingual papillae on either side of the frenulum

Question 25

What 3 structures are contained within the parotid gland?

Answer 25

1. Facial nerve
2. External carotid artery
3. Retromandibular vein

Question 26

Two muscles of the palate?

Answer 26

1. Hard palate

2. Soft palate (aponeurosis of tensor veil palatini covered by mucous membrane)

Question 27

What makes up the Pillars of the Fauces?

Answer 27

Palotoglossal and palotopahryngeal arches

Question 28

Tensor veli palatini:
Attachment?
Nerve?

Answer 28

Attaches to fossa above medial pterygoid plate + cartilage of auditory tube

Nerve to medial pterygoid from mandibular division (V3) of trigeminal cranial nerve

Question 29

Levator veli palatini:
Attachment?
Nerve?

Answer 29

Arises from apex of petrous temporal bone + cartilage of auditory tube

Vagus cranial nerve (X) via pharyngeal plexus

Question 30

Nervous and arterial supply of palates?

Answer 30

Greater + lesser palatine branches of maxillary nerve (plus parasympathetic secretomotor) and artery (hard and soft respectively)

Addition from nasopalatine nerve anteriorly

Question 31

The Uvula receives the ___ ___ and hangs off the soft palate, contributing to its functions

Answer 31

Musculus uvulae

Question 32

Changes that occur in the oral cavity during chewing?

Answer 32

• Palotoglossus + palatopharyngeus contract (draw palate down + tongue slightly upwards)
• Drawing palatoglossal and palatopharyngeal arches downwards + medially

Question 33

Changes that occur in the oral cavity during swallowing?

Answer 33

-Tensor veli palatini makes aponeurosis tense so levator veli palatini can lift it (close nasopharyngeal isthmus)

Question 34

Teeth:
4 quarters of teeth?
Total?
Nervous supply?

Answer 34

Each quarter:

• 3 molars
• 2 premolars
• 1 canine
• 2 incisors
• Total: 8

Upper teeth: superior alveolar/ dental branches of maxillary division (V2) of trigeminal cranial nerve (V)

Lower teeth: inferior alveolar/ dental branch of mandibular division (V3) of trigeminal cranial nerve