tooth and periodontium practicals

Question 1

why is periodontitis hardest to treat in furcation

Answer 1

Furcation region hardest to reattach

less AEFC there

Regeneration requires sharpey’s fibres (AEFC)

Question 2

why has periodontal space been described as an hourglass?

Answer 2

fucrum, more attachment in middle, the apex and cervical region has less attachment, more mobile, can roate about fubrum

Question 3

what does an increasing hourglass shape represent on xray

Answer 3

Greater mobility, hourglass shape increases

Question 4

how do collagen fibres attach in the concept of collagen crimping

Answer 4

at cementum more compact

at bone more spread

Question 5

benefits of collagen crimping

Answer 5

same force applied in tooth can be distributed to a larger area in bone. This is extremely advantageous as bone is not as resistant to force as teeth tissues.

Question 6

is bone or cemetum softer

Answer 6

bone is softer, deforms easier

Question 7

what property of teeth make it not mobile

Answer 7

collagen crimping, wavy fibres

wavy, can stretch and cushion, provide tension in the PDL to resist the forces making it not too mobile

Question 8

what fibres make it hard to correct rotated teeth

Answer 8

horiztonal fibres

Question 9

periapical cysts caused by what

Answer 9

periapical cysts caused by cell rests of malassez

Question 10

function of Rete ridges and pegs projections onto the lamina propria

Answer 10

stability of the tissue

Question 11

is JE, sulcular and gingival epithelium keratinized?

Answer 11

JE and sulcular are non

gingival is parakeratinied

Question 12

is healing faster at the oral mucosa or the gingival epithelium

Answer 12

oral mucosa faster

, because the keratinization for the gingival epithelium is slow process

Question 13

what happens to attachment as long JE forms?

Answer 13

attachment loss

think about it, if JE prolifertaes downwards and forms long JE, the long JE prevents attachment of PDL fibres to cementum

Question 14

what is interdental col

Answer 14

interdental area epithelium

Question 15

is col keratinzied?

Answer 15

no

Question 16

what is the significane of scalloping at theADJ

Answer 16

provides stronger mechincal stregnth of bond between enamel and dentine, interlocking

PREVENTS ABFRACTION

Question 17

what is abfraction

Answer 17

loss of enamel at cervical regions due to excessive occlusal forces

Question 18

perikymata

Answer 18

striae of retzius reaching the surface

Question 19

what about the tooth structure gives caries the shape of being wider at the adj and narrower at the pulp

Answer 19

dentinal tubules are wider and closer tgt at the pulp

Question 20

how does beveling create a better etching surface

Answer 20

exposes more of the sides of the prisms, increasing the surface area

Question 21

how does high speed possibly result in pulpitis?

Answer 21

more tooth structure lost, goes closer to the pulp which is more permeable, results in more chances of chemicals permeating

Question 22

2 reasons for pit and fissure caries

Answer 22

1. plaque traps
2. reduced enamel thickness at fissures so caries rapidly progress into dentine

Question 23

why is dentine tagging better at surfaces compared to nearer the pulp?

Answer 23

at surface, the dentinal tubules are narrower so there is more dentine surface for better adhesion

Question 24

how to know if a tooth is mature or not?

Answer 24

look at the apex

Question 25

is tertiary dentine formed faster in indirect or direct pulp cap?

Answer 25

faster in indirect pulp cap because layer of odontoblasts not lost unlike in direct cap

Question 26

when do you leave caries on purpose?

Answer 26

indirect cap

Question 27

flat bones have what type of ossification

Answer 27

intramembranous - condensed CT membrane within which the centre of ossification appears

Question 28

remainder CT that does not get ossified becomes what

Answer 28

remainder CT surrounding the developing intramembranous bone becomes periosteum

Question 29

what type of CT is periosteum

Answer 29

fibrous

Question 30

function of periosteum

Answer 30

joins skin to the submucosa of bone

the membrane of blood vessels and nerves that wraps around most of your bones.

Question 31

Meckel’s cartilage function

Answer 31

forms the cartilaginous skeleton of the developing jaw

DOES NOT FORM MANDIBLE

Question 32

is the mandibular bone found on the outside or the inside of the Meckel’s cartilage

Answer 32

outside

Question 33

what happens to Meckel’s cartilage As the mandible grows

Answer 33

Meckel’s cartilage regresses

It has a few remnants, such as the malleus and incus of the middle ear, and the sphenomandibular ligament.

Question 34

important structures between the developing mandible and Meckel’s cartilage

Answer 34

inferior alveolar nerve and the inferior alveolar artery

Question 35

are palatal cysts odontogenic or non odontogenic cysts?

Answer 35

non odontogenic because formed above the maxilla

Question 36

cleft lip vs palate

Answer 36

lip usually earlier

Question 37

what happens to bone as roots grow

Answer 37

As the roots grow, the bone will resorb to accommodate them.

Question 38

sella turcica

Answer 38

concave saddle that contains the pituitary gland

Question 39

advantage of having endochondral calcification on the base of the skull

Answer 39

needs to grow to compensate the growth of calvaria

importance in orthodontics
The proper growth and development of the base of the skull influence the alignment and positioning of the jaws. Abnormalities in endochondral ossification can contribute to malocclusion, where the teeth do not align correctly.

Question 40

shape of condyle,coronoid process, angle, eminence and fossa in adult vs child vs edentulous patient