Midterm I: Intro perio + Odontogenesis Flashcards
what is root dilaceration
projection from root
concrescence
cementum of two teeth join together.
talons cusp
extra cusp on labial aspect of maxillary lateral incisor
crown dilaceration
projection from crown
taurodontism
vertical enlargement of body/pulp of tooth taking up part of the root, as a result the forcation of the root is moved down
enamel pearl
enamel spot on root surface (often at furcation)
what genes are involved in dental anomalies
- bone morphogenic protein (MPG)
- fibroblast growth factor (FgF)
- Sonic hedgehog (SHH)
- Wingless-related integration site (Wnt)
- ectodysplasin A (Eda)
what are some types of drugs that may cause dental anomalies
chemotherapy and anti-epilepsy drugs
what are the 3 risk factors for teeth deformities
genetic
medications
malnutrition (vitamins and minerals)
what occurs in the initiation stage of odontogenesis
the dental lamina forms - it is a ‘swelling’ on the oral epithelium (stratified squamous)
- within the dental lamina a DENTAL PLACODE (or initiation knot/transient signaling center) sends signals to dental mesenchyme below. informing cells around that odontogenesis will begin. SHH, WNT, BMP and FGF are all involved.
- odontogenic potential of oral epithelium - if you transferred dental placode to another part of the body, will form a tooth
what occurs in the bud stage of odontogenesis
start of morphogenic stage
-dental lamina continues to extend into mesenchyme forming ‘tooth bud’ protrusion at the end
-a condensation of ectomesenchyme cells forms around the tooth bud
(still label with oral epithelium at the top, then dental lamina then tooth bud)
-ectomesenchyme assumes the odontogenic potential
what occurs at the cap stage of odontogenesis
‘enamel organ’ forms- consists of outer enamel epithelium- cuboidal ep, inner enamel epithlelium- columnar ep, and stellate reticulum in the middle.
- condensation fo ectomesenchyme becomes the dental sac or dental follicle. a little groove in the enamel organ /protrusiion of dental sac is called the dental papilla
- outer and inner enamel epithelium start to store glycogen
- stellate reticulum cells produce glycosaminoglycans
- enamel knot is cluster of nondividing epithelial cells involved in signaling and pattern formation of cusps- differential gene expression starts :
- – for incisors: Msx-1 , Msx-2, and Alx-3 in presumptive incisor mesenchyme
- – for presumptive molar region : Barx-1, Dlx-1/-2
(btw, dental lamina is still above the enamel organ)
(dental papilla will become dental pulp and odontoblasts, and dental follicle will become cementoblasts, PDL, and alveolar bone proper-part coming in direct contact w root viapdl)
what occurs in the bell stage of odontogenesis
in bell->cap stage - secondary enamel knots form for premolars and molars - two protrusions with enamel knots (signalers)
Bell stage:
-crown shape is established
-enamel knot dissapears
-formation of stratum intermedium (inside of IEE)
-dental lamina breaks into islands of epithelial cells (epithelial rest of serres)
-cervical loop at edges ; starts root formation
-mineralization starts - amelogenesis dentinogenesis
when does permanent tooth formation occur?
starts during cap and bell stage of the deciduous predecessor . arises from the dental lamina of deciduous tooth for incisors, premolars and canines.. Molars have no deciduous predecessors
what is the late bell stage
ending of bell stage- increase amounts of minerals, increased size of crystals. maturation of crystals, completion of crown formation.
what are the topics to address for gingival health?
color
contour
consistency
bleeding upon probing?
what will determine the color of gingiva
vascular supply and thickness/degree of keratinization.
should be a coral pink/salmon
what is the contour/shape of gingiva
contour is the papilla filling the embrasure space (b/w teeth) comes to a point when gingiva is healthy.
also free gingival margin - should come to a knife edge.
((((-will be impacted by location/size of proximal contact and dimensions of gingival embrasures)))
what should gingiva consistency be?
firm and resilient, orange peel texture is healthy (not always there).
where on tooth should bone be
normal/healthy bone should be 1-2 mm apical to the CEJ
what are the symptoms of inflammation
heat, edema , erythmea (red), pain
what are characteristics for gingivitis
- clinical signs of inflammation (free gingival margins rolled rather than knife edge, red, inflamed)
- no evidence of attachment loss (bone stops at cej)- bone is still 1-2 mm apical to cej
- soft tissue margins coronal to cemento enamel junction
what are characteristics of periodontitis
- clincial evidence of attachment loss : does probe stop at cej? does radiograph show bone loss?
- clinical signs of inflammation
how prevalent is periodontal disease
74% of adults had some form of periodontal disease 1969
adults over 30 had 47.2% prevalence of periodontitis (highest for males, smokers, low education, below poverty line)
-mexican americans -66.7%, non hispanic blacks - 58.6%, non hispanic whites - 42.6%
what is experimental periodontitis model
-do you get gingivitis from not brushing (students–yes)
yon lindhe: dog experiment- it concludes that conversion from gingivitis to periodontitis cant be explained by palque accumulation alone.
-conversion factors possible : microbiological and host factors (susceptible host)
what bacteria leads to periodontitis?
Gram+ facultative rods and cocci - acinomyces streptococci and
from healthy to gingivitis to periodontitis- what is the shift in bacteria?
G+ facultative rods and cocci- actinomyces streptococci are predominant in healthy mouths, to G- anacrobic rods, (mostly bacteroides fusobacteria) which are predominant in periodontitis. In gingivitis there is a larger portion that is G- and by periodontitis, it is more prevalent than G+
what does the host inflammatory response use for CT and bone metabolism
cytokines and prostanoids, matrix metalloproteinases
what are the two types of plaque control
chemical (dentrifices, mouthwashes) and mechanical (toothbrush, etc)
how often should a toothbrush be replaced
every 3 months
what is interdental cleaning
like flossing- brushing doesnt get all the stuff in between teeth
-purpose of floss is to remove plaque not to dislodge food. useful for narrow embrasures with intact papillae and tight contacts
what are the types of floss
multifilament, wax vs unwaxed, thick vs thin. up to patient
what kinds of instruments are used for treating periodontal disease (non surgical)
curettes, scalers, ultra-sonics (etc)
what are the delivery modes for periodontal treatments (non surgical)
topical, local (irrigation/sustained release), systemic
what are occlusal splints
like night guards- used to ease muscle tension/stabilize the jaw.
temporary acrylic splints used to stabilize teeth teeth– connecting them together so they function better. but needs to be a big enough space for flossing
what are typical amounts of time between periodontal maintenance procedures
3, 4 or 6 (rarely)
what is a gingivectomy
(removing gum tissue) for patients with deep pockets at re-evaluation that cant be naintained with good home care..
what is an apically positioned flap
a way to address deep pockets- more commonly used.
-gives access to bone (unlike gingivectomy) so you can work on the bone
teeth are longer but pockets are reduced
-
what is bone resection used for with flap procedure
cutting part of bone to create a contour that the gingiva can follow when it heals. (going from negative architecture back to healthy positive architecture)
what is a root resection
if having issues in a furcation, can remove one of the root extensions -first sever from rest of tooth then remove, then they can clean there.
what is a hemisection procedure and which teeth is it done on
for mandibular molars !
-cut tooth in half, take out bad root and keep good root. usually remove a tooth and put an implant instead these days
what is bicuspidization of a mandibular molar
after hemisection (cutting in half) prosthodontist restores it as two bicuspids.
what are options for creating positive architecture
bone resection (cut away) or bone graft
what is a membrane placement for
it blocks out the epithelial cells overlying it , allowing time for the osteoblasts, cementoblasts etc to regenerate and pdl to regenerate.
good way to buy time for healing etc
what is functional crown lengthening
increasing tooth structure exposed so the tooth can be restored , cant retain a crown when theres hardly any tooth exposed.
there are also aesthetic ones
what are the 3 types of periodontal plastic surgery
soft tissue grafting, ridge augmemtation, esthetic crown lengthening
what is soft tissue grafting
aka subepithelial connective tissue graft
- do a splint thickness flap - reflect a flap and place some CT from the palate and suture there, then close flap over that.
- small part of graft is exposed when tissue is brought down , the CT is covering that would be exposed part of the root (slide 76)
what is a ridge augmentation
adding bone graft/soft tissue graft
- instances like an extracted tooth leads to loss of bone
- adding soft tissue for an esthetic bridge
what is esthetic crown lengthening
removing bone to expose that 1-2 mm before the CEJ if teeth are very small.
what aspect of implants are periodontists involved in
preparation of site (not restoring it- general dentist or prosthodontist does this)
-prepare site for implant, placement of implant, and maintaining the implant!!
