4. Periodontium

Question 1

Components of periotondium

Answer 1

Tissues surrounding and supporting the teeth

Question 2

Function of periodontium (3)

Answer 2

Retain the tooth in the socket
Resist masticatory loads
Defensive barrier, protecting tissues against threats from the oral environment

Question 3

Function of epithelial attachment

Answer 3

Attaches organic tissue to mineral tissue

Question 4

Definition of junctional epithelium

Answer 4

Physical barrier separating body tissues from the oral environment

Question 5

Definition of gingivitis (2)

Answer 5

Inflammation of the gingiva

A response to bacterial plaque in adjacent teeth

Question 6

Characterisation of gingivitis (4)

Answer 6

Erythema
Oedema
Fibrous enlargement of gingiva
No resorption of underlying alveolar bone

Question 7

Definition of periodontitis (3)

Answer 7

Inflammation of periodontium
Chronic inflammatory disease of the periodontium
A response to bacterial plaque in adjacent teeth

Question 8

Characterisation of periodontitis (2)

Answer 8

Gingivitis

Destruction of alveolar bone and PDL

Question 9

Outcome of periodontitis (2)

Answer 9

Apical migration of epithelial attachment resulting in formation of periodontal pockets
Loosening and exfoliation of teeth

Question 10

Definition of cementum

Answer 10

Covers root dentine (similar structure to bone)

Question 11

Structure of cementum (2)

Answer 11

Collagen matrix

Lamellar arrangment

Question 12

What does cementum provide

Answer 12

Attachment for some periodontal fibres

Question 13

Types of cementum (2)

Answer 13

Acellular cementum

Cellular cementum

Question 14

Features of acellular cementum (3)

Answer 14

No cells within
Usually adjacent/closer to dentine
Primary/first formed

Question 15

Features of cellular cementum (3)

Answer 15

Contains cementocytes
Present in apical part of root and in furcations
Secondary/later formed

Question 16

Alternative classifications of cementum types (2)

Answer 16

Acellular extrinsic fibre cementum

Cellular intrinsic fibre cementum

Question 17

Features of acellular extrinsic fibre cementum (4)

Answer 17

Contains Sharpey’s fibres
Function in tooth attachment
Equivalent to primary acellular cementum
Present on cervical 2/3 of root

Question 18

Features of cellular intrinsic fibre cementum (4)

Answer 18

No Sharpey’s fibres
No role in tooth attachment
Intrinsic collagen fibres parallel to surface
Equivalent to secondary cellular cementum and may represent transitional form

Question 19

Function of alveolar bone

Answer 19

Support tooth

Question 20

Function of PDL (2)

Answer 20

Attach tooth to jaw

Transmit biting forces to alveolar bone

Question 21

Structure of PDL (2)

Answer 21

0.2mm wide

Organised (regular) CT

Question 22

Components of PDL (5)

Answer 22

Cells
ECM
Fibres
Nerves (sensory, autonomic)
BVs

Question 23

Types of PDL fibres (4)

Answer 23

True PDL fibres
Gingival ligament fibres
Types I and III collagen fibres
Oxytalan

Question 24

Types of sensory PDL nerve receptors (3)

Answer 24

Mechanoreceptors
Proprioceptors
Nociceptors

Question 25

Formation of odontogenic cysts

Answer 25

Formed from debris/cell rests of Malassez (HERS breakdown)

Question 26

Principle PDL fibre group ligaments (2)

Answer 26

Alveolo-dental ligament (alveolar crest, horizontal, oblique, apical, interradicular)
Interdental ligament (transeptal)

Question 27

Definition of interdental col

Answer 27

Depression in interdental tissues just below inter proximal contact area

Question 28

Function of interdental col

Answer 28

Connect buccal and lingual papilla

Question 29

Keratinisation of interdental col

Answer 29

Non-keratinised