Lectures 7 & 8

Question 1

T/F - Gingiva is the part of the oral mucosa which surrounds & is attached to teeth & alveolar bone.

Answer 1

True

Question 2

Describe Alveolar Mucosa

Answer 2

• translucent & bright pink
• epithelium is thick & non-keratinized
• has a loose submucosa which allows movement, including numerous elastic fibres (as well as collagen)
• has minor salivary glands
• joins attached gingiva at mucogingival junction
• not present on palatal surface of maxillary teeth, attached gingiva blends with palatal mucosa

Question 3

Describe Attached Gingiva

Answer 3

• whitish, opaque
• epithelium is para or orthokeratinised
• bound firmly to alveolar bone by coarse collagen, sparse elastin
• no minor salivary glands
• may show stippling (due to collagen fibres in lamina propria inserting directly into periosteum)

Question 4

T/F - mucogingival junction marks the abrupt change in epithelium & composition of lamina propria

Answer 4

True

Question 5

Describe Free Gingiva

Answer 5

• a fold of mucosa which is not bound to underlying hard tissues
• extends from bottom of gingival sulcus adjacent to tooth to free gingival groove
• free gingival groove, if present, is opposite bottom of gingival sulcus (occurs in about 40% of individuals)
• apex of fold is gingival margin

Question 6

T/F - gingival sulcus lies between free gingiva & tooth

Answer 6

True

Question 7

T/F - gingival sulcus should be more than about 2mm deep,

Answer 7

False

Question 8

Deeper than 2mm of the gingival sulcus is called a ___________ ______ and is considered to be diseased.

Answer 8

Periodontal pocket

Question 9

T/F - Junctional epithelium is deep to bottom of gingival sulcus to CEJ

Answer 9

True

Question 10

T/F - junctional epithelium is not bound to underlying tooth

Answer 10

False

Question 11

T/F - in junctional epithelium, there is slow cell turnover with cells migrating towards the gingival sulcus

Answer 11

False, there is high rapid turnover

Question 12

In anterior teeth, the interdental tissue forms a pointed elevation called a ________. In posterior teeth with a broader area of contact between adjacent teeth, the interdental tissue forms two peaks on the buccal and lingual sides with an indented central region in between called a ______.

Answer 12

papilla, COL

Question 13

T/F - Gingival ligament is part of the periodontal ligament and helps maintain the functional integrity of the teeth

Answer 13

False, it is not part of PDL

Question 14

T/F - Periodontal ligament extends from alveolar crest to apex of tooth

Answer 14

True

Question 15

T/F - periodontal ligament is connective tissue fibre bundles connecting cementum or alveolar bone to lamina propria of gingiva or binding other fibres in gingiva together

Answer 15

False, it is specialised connective tissue joining anchoring cementum to cribriform plate of alveolus / socket

Question 16

T/F - gingival ligament is located from the alveolar crest to apex of tooth

Answer 16

False, it’s above alveolar crest

Question 17

T/F - gingival ligament contains connective tissue fibre bundles connecting cementum or alveolar bone to lamina propria of gingiva

Answer 17

True

Question 18

List the major fibre groups of the gingival ligament

Answer 18

• Dentogingival
• Circular
• Alveolar gingival
• Dentoperiosteal
• Transseptal

Question 19

T/F - Dentogingival fibres are the least numerous and stretch from cervical cementum to lamina propria of both free & attached gingiva.

Answer 19

False, they are the most numerous

Question 20

T/F - circular fibres of gingival ligament encircle tooth as a band, some attaching to cementum or alveolar bone .

Answer 20

True

Question 21

T/F - circular fibres interlace with other fibres & hold them together & also bind free gingiva to tooth

Answer 21

True

Question 22

T/F - Alevolar gingival fibres stretch from free gingiva to lamina propria of both free & attached gingiva

Answer 22

False, it stretches from alveolar crest to LP

Question 23

T/F - Dentoperiosteal fibres stretch from cementum over alveolar crest to insert into periosteum on the inner surface of the alveolar bone

Answer 23

False, outer surface of alveolar bone

Question 24

T/F - Transseptal fibres stretches from cementum of tooth to cementum of root of adjacent tooth over alveolar crest

Answer 24

True

Question 25

List the minor fibre groups of gingival ligament

Answer 25

- Longitudinal - semicircular fibres - transgingival fibres - interdental/interpapillary fibres - vertical

Question 26

T/F - longitudinal fibres of gingival ligament goes from cervical cementum via gingiva to cementum of same tooth

Answer 26

False, it's in free gingiva for long distances

Question 27

T/F - semicircular fibres goes from cervical cementum to gingiva of adjacent tooth

Answer 27

False, it's in cervical cementum, and travels via gingiva to cementum of same tooth

Question 28

T/F - Transgingival fibres goes from cervical cementum to gingiva of adjacent tooth

Answer 28

True

Question 29

T/F - Interdental/interpapillary fibres connect buccal & lingual papillae via interdental gingiva

Answer 29

True

Question 30

T/F - Vertical fibres of gingival ligament connect alveolar mucosa to free gingiva towards marginal gingiva & interdental papilla

Answer 30

False, it connects from attached gingiva

Question 31

List the functions of gingival fibres

Answer 31

- stabilising & providing rigidity to gingiva, especially during mastication - join gingiva to cementum & bone - circular (& longitudinal fibres) bind the other tissues in place - stabilise positions of teeth - experimental evidence - cut labial & gingival fibres following orthodontic repositioning & repositioned teeth are less likely to re-rotate

Question 32

T/F - Bone is mineralized connective tissue

Answer 32

True

Question 33

T/F - Bone consists of about 67% mineral in the form of calcium hydroxyapatite while remainder is made of organic matrix & collagen.

Answer 33

True

Question 34

T/F - osteoblasts, osteocytes, osteoclasts are in bone

Answer 34

True

Question 35

Anatomical bones consist of a dense outer layer called ______________ & an inner medullary region called ____________ ______________

Answer 35

Compact bone, spongy or cancellous bone.

Question 36

Compact bone is proportionally ______ bone & ______ soft tissue. It has a mechanical function and has a _____ turnover of components than spongy bone. It may have __________ but these are not marrow cavities (contain fatty connective tissue rather than marrow.)

Answer 36

more, less, low, small connective tissue

Question 37

Spongy bone consists of bars of bone called _________ plus soft tissue called _______ (containing blood forming tissue). Spongy bone is proportionally _____ bone & more _____ tissue components in spongy bone over more readily than compact bone - calcium store.

Answer 37

trabeculae, marrow, less, soft

Question 38

Lamellae on the outer surface are arranged parallel to the surface & are called __________________.

Answer 38

outer circumferential lamellae

Question 39

Layering in the deeper parts of the compact bone consist of a series of cylinders called ____________________ whose walls are formed of a series of concentric layers with a central vascular channel called a _____________.

Answer 39

Osteons or haversian systems, haversian canal

Question 40

Larger channels carrying blood vessels into the Haversian systems are called ___________

Answer 40

perforating canals or volkmann's canals

Question 41

T/F - regions between the Haversian systems are interstitial bone & are the remains of earlier Haversian systems which have been partly broken down.

Answer 41

True

Question 42

Except in bone when it is first formed, Haversian systems are surrounded by a layer of mineral rich collagen poor bone called a ________

Answer 42

cement line

Question 43

T/F - trabeculae of spongy bone consists of layers mostly parallel to the surface

Answer 43

True, larger trabeculae may have a few Haversian systems

Question 44

T/F - Dark cavities in bone contain more dense bone

Answer 44

False, its air

Question 45

Describe remodelling of bone

Answer 45

First DESTRUCTION of existing bone by osteoclasts (not symmetrical - cuts across existing bone layers) Then RECONSTRUCTION by osteoblasts. (symmetrical - lays down complete Haversian rings or lamellae

Question 46

What is periosteum?

Answer 46

specialized connective tissue covering the outside of bone

Question 47

What does periosteum consist of?

Answer 47

An inner layer adjacent to the surface of the bone with osteoblasts & precusors, small blood vessels plus a small amount of connective tissue & an outer fibrous layer contiguous with adjacent tissue - fascia, muscle

Question 48

T/F - Endosteum is a lining of osteoblasts on all inner surfaces including marrow spaces & Haversian canals

Answer 48

True

Question 49

T/F - Bone marrow only has developing blood cells

Answer 49

False, it has variable proportions of developing blood cells, fat cells & a delicate support of reticular fibres & reticular cells

Question 50

T/F - Osteoblasts are cells that break down bone by means of secreted enzymes

Answer 50

False, they make bone

Question 51

T/F - When osteoblasts are active, they synthesise both collagen & ground substance (osteoid - unmineralized bone).

Answer 51

True

Question 52

T/F - Active osteoblasts do not secrete matrix vesicles & enzymes involved in the extracellular mineralization of the matrix

Answer 52

False, they do secrete

Question 53

T/F - Osteoblasts are stratified and dark staining

Answer 53

False, they are cuboidal

Question 54

T/F - Osteocytes are surrounded by bone

Answer 54

True

Question 55

Osteocytes in cavities called _______ with narrow extensions called _______ containing osteocyte processes. _______ interconnect & processes are connected by gap junctions. ______ are easily seen in ground sections.

Answer 55

Lacunae, canaliculi, canaliculi, canaliculi

Question 56

________ are very large multinucleate cells (derived from blood monocytes like other phagocytic cells), often in shallow troughs on the surface of bone (due to erosion) called _______ _____

Answer 56

Osteoclasts, Howships Lacunae

Question 57

T/F - howship's lacunae are frequently seen since bone constantly remodels in response to mechanical stimuli and metabolic needs (calcium store)

Answer 57

True

Question 58

_________ - bone of the alveolar processes of maxilla & mandible which forms alveoli or sockets of teeth

Answer 58

Alveolar bone

Question 59

T/F - alveolar bone has cortical compact bone and spongy bone within, and the lining of the alveolus has a fibrous layer

Answer 59

False, the lining of the alveolus lacks a fibrous layer and just has cellular periosteum

Question 60

Compact bone lining the alveolus has ________ because it is perforated by foramina transmitting numerous blood vessels & nerves.

Answer 60

Cribriform plate

Question 61

Compact bone lining the alveolus has _______ beacuse it contains the terminal ends of the periodontal fibres

Answer 61

Bundle bone , PDL are sharpey's fibres

Question 62

Compact bone lining alveolus has name ________ because it is particularly opaque to X-rays (appears as a white line).

Answer 62

Lamina dura

Question 63

T/F - Orthodontic tooth movement relies on differentiation of odontoblasts & resorption of bone on the pressure side

Answer 63

True

Question 64

Orthodontic tooth movement needs remodelling of ______ on the opposite (tension) side & __________ on the socket wall.

Answer 64

collagen, bone deposition

Question 65

Orthodontic tooth movement: _______ is much more resistant to pressure induced changes & although there is evidence of a minor amount of ______ _____ this seems to be followed by rapid repair

Answer 65

cementum, root resorption