Anatomy

Question 1

Enamel

Answer 1

Outer white layer of the tooth
Hardest structure in the body
Made up of hydroxyapatite
No nerve endings - feels no pain
Formed from ameloblasts during tooth development

Question 2

Dentine

Answer 2

Second layer in the tooth
Forms the main bulk of the tooth and lies beneath the enamel & cementum
Harder than bone but softer than enamel
Contains dentine tubules that contain soft tissue - makes it slightly elastic which absorbs shock
The tubules contain fibrils which are sensory endings from the cells
that form the dentine
Living dentine can/ tissue can transmit sensitivity if damaged
Formed by odontoblast cells, and are located in the outer-part of the pulp

Question 3

Pulp

Answer 3

Innermost tissue within the tooth
Contains sensory nerves and blood vessels
Allows the teeth to feel hot, cold, and touch, as well as pain when there is decay.

Question 4

Cementum

Answer 4

Outer covering of the root
Meets enamel at the neck of the tooth
Similar in structure to bone
Thickness can change throughout life depending on forces exerted on it
Darker in colour than enamel
Allows attachment of the tooth to the support structure - the PERIODONTAL LIGAMENT

Question 5

Periodontal ligament

Answer 5

Specialist fibrous tissue that attaches teeth to the alveolar bone

Question 6

Gingival crevice/ gingival sulcus

Answer 6

Shallow space between the tooth surface and gingival margin

Question 7

Skull temporal bone

Answer 7

Dense bone that forms the base and sides of the skull
Protects the brain

Question 8

Zygomatic arch

Answer 8

Cheek bones
Formed by 3 bones of the skull:
Front - maxilla
Side - zygomatic bone
Back - extension of the temporal bone

Question 9

Maxilla

Answer 9

Fixed to the skull (immobile)
Holds upper teeth in the alveolar process
Ends with tuberosity behind the upper 8’s
Joined below the nose

Question 10

Soft palate

Answer 10

Flap of soft tissue attached to the back of the hard palate
Seals the oral cavity off from the nasal cavity when swallowing

Question 11

Hard palate

Answer 11

Forms the roof of the mouth
Separates the oral and nasal cavity

Question 12

Rugae

Answer 12

Asymmetrical ridges of connective tissue
Found behind the incisive papilla over the hard palate
Superimposition landmarks for tooth movement

Question 13

Tuberosity

Answer 13

A moderate prominence where muscles and connective tissues attach
Function similarly to trochanters
Tibial, deltoid and ischial tuberosities

Question 14

Cleft palate

Answer 14

Hole/gap affecting the soft tissues in the palate
Can cause difficulty swallowing

Question 15

Maxillary air sinus

Answer 15

A type of paranasal sinus which is a hollow space in the bones around the nose
There are two sinuses - one in each bone

Question 16

Oropharynx

Answer 16

The middle part of the throat behind the mouth
It includes the soft palate, the side & back walls of the throat, tonsils, and the back 1/3 of the tongue

Question 17

Mandible

Answer 17

Jaw that moves
Shaped like a horseshoe - bends up at right angles
Attached to the ramus - muscles of mastication to close the mouth

Question 18

Coronoid process

Answer 18

Beaklike process in the ramus of the mandible
Point at which jaw muscles can attach

Question 19

Ramus

Answer 19

The curved part of the bone that give structural support to the rest of the bone - superior and inferior pubic and mandibular rami

Question 20

Body

Answer 20

The bones largest, most prominent segment

Question 21

Tongue

Answer 21

Attached to the floor of the mouth by the lingual fraenum
Covered in taste buds
Helps swallow, speech, taste and cleaning

Question 22

Lamina dura/compact bone

Answer 22

Radiographic landmark on PA x-rays
Thin layer of dense cortical bone which lines the roots of sound teeth

Question 23

Spongy/cancellous bone

Answer 23

This is the light porous bone enclosing numerous large spaces - honeycombed appearance
Marrow or blood vessels

Question 24

Alveolar process

Answer 24

Alveolar bone, the thick ridge of bone which contains the tooth sockets
Located on both jaw bones

Question 25

Oral mucosa

Answer 25

Mucus membrane that lines structures within the oral cavity It is a soft, wet tissue

Question 26

Philtrum

Answer 26

The groove that runs from the top of the lip to the nose Genetically determined

Question 27

Fraenum

Answer 27

Attaches the tongue to the floor of the mouth

Question 28

What is the position of the parotid salivary gland?

Answer 28

Lies partly over and behind the ramus, the stensons duct allows saliva to flow into the mouth at the upper 6 position

Question 29

What is the position of the submandibular salivary gland?

Answer 29

Lies on the floor of the mouth and are characterised by a frilly ridge. The Wharton's duct delivers saliva

Question 30

What is the position of the sublingual salivary gland?

Answer 30

Lies on the floor of the mouth with the ducts by the fraenum of the tongue A spurt of saliva can sometimes happen during treatment

Question 31

How can the following affect the salivary glands? Ageing Mumps Mucocele Salivary stone

Answer 31

Ageing - More likely to have dry mouth (Xerostomia) Can lead to more decay, as lack of self cleansing saliva. Can also cause periodontal issues Mumps - Can cause swelling of the salivary glands, as well as pain when swallowing. Less saliva is produced and is harder to fight infection Mucocele - Blocked salivary gland. Caused by minor trauma, a fluid-filled cyst. Can stop/lessen saliva flow into the mouth Salivary stone - Can block salivary glands, preventing flow of saliva into the mouth, can cause xerostomia over extended period of time

Question 32

What is the position and function of the masseter?

Answer 32

Extends from the zygomatic arch to the outside of the ramus of the mandible It is used to close the maxilla

Question 33

What is the position and function of the temporalis?

Answer 33

Extends from the side of head to the coronoid process of the mandible, through the zygomatic arch It closes and pulls back the mandible

Question 34

What is the position and function of the buccinator?

Answer 34

Muscle of the cheek Attached above and below the buccal surface of the alveolar process of each jaw

Question 35

What is the position and function of the orbicularis oris?

Answer 35

Found around the mouth Used to smile and move the lips