Midterm I: Intro perio + Odontogenesis

Question 1

what is root dilaceration

Answer 1

projection from root

Question 2

concrescence

Answer 2

cementum of two teeth join together.

Question 3

talons cusp

Answer 3

extra cusp on labial aspect of maxillary lateral incisor

Question 4

crown dilaceration

Answer 4

projection from crown

Question 5

taurodontism

Answer 5

vertical enlargement of body/pulp of tooth taking up part of the root, as a result the forcation of the root is moved down

Question 6

enamel pearl

Answer 6

enamel spot on root surface (often at furcation)

Question 7

what genes are involved in dental anomalies

Answer 7

1. bone morphogenic protein (MPG)
2. fibroblast growth factor (FgF)
3. Sonic hedgehog (SHH)
4. Wingless-related integration site (Wnt)
5. ectodysplasin A (Eda)

Question 8

what are some types of drugs that may cause dental anomalies

Answer 8

chemotherapy and anti-epilepsy drugs

Question 9

what are the 3 risk factors for teeth deformities

Answer 9

genetic
medications
malnutrition (vitamins and minerals)

Question 10

what occurs in the initiation stage of odontogenesis

Answer 10

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

Question 11

what occurs in the bud stage of odontogenesis

Answer 11

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

Question 12

what occurs at the cap stage of odontogenesis

Answer 12

‘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)

Question 13

what occurs in the bell stage of odontogenesis

Answer 13

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

Question 14

when does permanent tooth formation occur?

Answer 14

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

Question 15

what is the late bell stage

Answer 15

ending of bell stage- increase amounts of minerals, increased size of crystals. maturation of crystals, completion of crown formation.

Question 16

what are the topics to address for gingival health?

Answer 16

color
contour
consistency
bleeding upon probing?

Question 17

what will determine the color of gingiva

Answer 17

vascular supply and thickness/degree of keratinization.

should be a coral pink/salmon

Question 18

what is the contour/shape of gingiva

Answer 18

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)))

Question 19

what should gingiva consistency be?

Answer 19

firm and resilient, orange peel texture is healthy (not always there).

Question 20

where on tooth should bone be

Answer 20

normal/healthy bone should be 1-2 mm apical to the CEJ

Question 21

what are the symptoms of inflammation

Answer 21

heat, edema , erythmea (red), pain

Question 22

what are characteristics for gingivitis

Answer 22

• 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

Question 23

what are characteristics of periodontitis

Answer 23

• clincial evidence of attachment loss : does probe stop at cej? does radiograph show bone loss?
• clinical signs of inflammation

Question 24

how prevalent is periodontal disease

Answer 24

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%

Question 25

what is experimental periodontitis model

Answer 25

-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)

Question 26

what bacteria leads to periodontitis?

Answer 26

Gram+ facultative rods and cocci - acinomyces streptococci and

Question 27

from healthy to gingivitis to periodontitis- what is the shift in bacteria?

Answer 27

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+

Question 28

what does the host inflammatory response use for CT and bone metabolism

Answer 28

cytokines and prostanoids, matrix metalloproteinases

Question 29

what are the two types of plaque control

Answer 29

chemical (dentrifices, mouthwashes) and mechanical (toothbrush, etc)

Question 30

how often should a toothbrush be replaced

Answer 30

every 3 months

Question 31

what is interdental cleaning

Answer 31

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

Question 32

what are the types of floss

Answer 32

multifilament, wax vs unwaxed, thick vs thin. up to patient

Question 33

what kinds of instruments are used for treating periodontal disease (non surgical)

Answer 33

curettes, scalers, ultra-sonics (etc)

Question 34

what are the delivery modes for periodontal treatments (non surgical)

Answer 34

topical, local (irrigation/sustained release), systemic

Question 35

what are occlusal splints

Answer 35

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

Question 36

what are typical amounts of time between periodontal maintenance procedures

Answer 36

3, 4 or 6 (rarely)

Question 37

what is a gingivectomy

Answer 37

(removing gum tissue) for patients with deep pockets at re-evaluation that cant be naintained with good home care..

Question 38

what is an apically positioned flap

Answer 38

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 -

Question 39

what is bone resection used for with flap procedure

Answer 39

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)

Question 40

what is a root resection

Answer 40

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.

Question 41

what is a hemisection procedure and which teeth is it done on

Answer 41

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

Question 42

what is bicuspidization of a mandibular molar

Answer 42

after hemisection (cutting in half) prosthodontist restores it as two bicuspids.

Question 43

what are options for creating positive architecture

Answer 43

bone resection (cut away) or bone graft

Question 44

what is a membrane placement for

Answer 44

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

Question 45

what is functional crown lengthening

Answer 45

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

Question 46

what are the 3 types of periodontal plastic surgery

Answer 46

soft tissue grafting, ridge augmemtation, esthetic crown lengthening

Question 47

what is soft tissue grafting

Answer 47

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)

Question 48

what is a ridge augmentation

Answer 48

adding bone graft/soft tissue graft - instances like an extracted tooth leads to loss of bone - adding soft tissue for an esthetic bridge

Question 49

what is esthetic crown lengthening

Answer 49

removing bone to expose that 1-2 mm before the CEJ if teeth are very small.

Question 50

what aspect of implants are periodontists involved in

Answer 50

preparation of site (not restoring it- general dentist or prosthodontist does this) -prepare site for implant, placement of implant, and maintaining the implant!!