tooth and periodontium practicals Flashcards
why is periodontitis hardest to treat in furcation
Furcation region hardest to reattach
less AEFC there
Regeneration requires sharpey’s fibres (AEFC)
why has periodontal space been described as an hourglass?
fucrum, more attachment in middle, the apex and cervical region has less attachment, more mobile, can roate about fubrum
what does an increasing hourglass shape represent on xray
Greater mobility, hourglass shape increases
how do collagen fibres attach in the concept of collagen crimping
at cementum more compact
at bone more spread
benefits of collagen crimping
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.
is bone or cemetum softer
bone is softer, deforms easier
what property of teeth make it not mobile
collagen crimping, wavy fibres
wavy, can stretch and cushion, provide tension in the PDL to resist the forces making it not too mobile
what fibres make it hard to correct rotated teeth
horiztonal fibres
periapical cysts caused by what
periapical cysts caused by cell rests of malassez
function of Rete ridges and pegs projections onto the lamina propria
stability of the tissue
is JE, sulcular and gingival epithelium keratinized?
JE and sulcular are non
gingival is parakeratinied
is healing faster at the oral mucosa or the gingival epithelium
oral mucosa faster
, because the keratinization for the gingival epithelium is slow process
what happens to attachment as long JE forms?
attachment loss
think about it, if JE prolifertaes downwards and forms long JE, the long JE prevents attachment of PDL fibres to cementum
what is interdental col
interdental area epithelium
is col keratinzied?
no
what is the significane of scalloping at theADJ
provides stronger mechincal stregnth of bond between enamel and dentine, interlocking
PREVENTS ABFRACTION
what is abfraction
loss of enamel at cervical regions due to excessive occlusal forces
perikymata
striae of retzius reaching the surface
what about the tooth structure gives caries the shape of being wider at the adj and narrower at the pulp
dentinal tubules are wider and closer tgt at the pulp
how does beveling create a better etching surface
exposes more of the sides of the prisms, increasing the surface area
how does high speed possibly result in pulpitis?
more tooth structure lost, goes closer to the pulp which is more permeable, results in more chances of chemicals permeating
2 reasons for pit and fissure caries
- plaque traps
- reduced enamel thickness at fissures so caries rapidly progress into dentine
why is dentine tagging better at surfaces compared to nearer the pulp?
at surface, the dentinal tubules are narrower so there is more dentine surface for better adhesion
how to know if a tooth is mature or not?
look at the apex
is tertiary dentine formed faster in indirect or direct pulp cap?
faster in indirect pulp cap because layer of odontoblasts not lost unlike in direct cap
when do you leave caries on purpose?
indirect cap
flat bones have what type of ossification
intramembranous - condensed CT membrane within which the centre of ossification appears
remainder CT that does not get ossified becomes what
remainder CT surrounding the developing intramembranous bone becomes periosteum
what type of CT is periosteum
fibrous
function of periosteum
joins skin to the submucosa of bone
the membrane of blood vessels and nerves that wraps around most of your bones.
Meckel’s cartilage function
forms the cartilaginous skeleton of the developing jaw
DOES NOT FORM MANDIBLE
is the mandibular bone found on the outside or the inside of the Meckel’s cartilage
outside
what happens to Meckel’s cartilage As the mandible grows
Meckel’s cartilage regresses
It has a few remnants, such as the malleus and incus of the middle ear, and the sphenomandibular ligament.
important structures between the developing mandible and Meckel’s cartilage
inferior alveolar nerve and the inferior alveolar artery
are palatal cysts odontogenic or non odontogenic cysts?
non odontogenic because formed above the maxilla
cleft lip vs palate
lip usually earlier
what happens to bone as roots grow
As the roots grow, the bone will resorb to accommodate them.
sella turcica
concave saddle that contains the pituitary gland
advantage of having endochondral calcification on the base of the skull
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.
shape of condyle,coronoid process, angle, eminence and fossa in adult vs child vs edentulous patient
