Autumn quiz II: Physio of permanent teeth

Question 1

what does masticatory apparatus function depend on

Answer 1

-musculature and nervous system 
depends on
-skeletal structures
-forces generated by musculature
-temporal mandibular joint function
-morpholgoy of the teeth
-angulations of the teeth
-anatomy of supporting structures
-periodontium

Question 2

how can improperly formed arches impact function

Answer 2

• speech
• chewing efficiency
• restorative procedures

Question 3

what occurs with a NARROW arch?

Answer 3

• if dental arch is too narrow and patient is young the teeth may correct themselves a bit. some teeth may be selected for extraction to allow more room for the other teeth
• frequently braces or other corrective measures like spacers are needed to widen the arch

Question 4

what occurs with a wide arch?

Answer 4

-teeth may come in with large spaces between them. braces can often be appleid in order to shift the teeth forward into proper position

Question 5

when does a tapered or v shape arch occur

Answer 5

• maxillary usually

- due to pathologic narrowing of the anterior palate. less commonly could be due to severe thumb sucking habit

Question 6

where do the canine and first molar sit with respect to ideal curvature in maxilla

Answer 6

they sit facial to the ideal curvature

Question 7

where does the canine sit with respect to ideal ellipse in mandible

Answer 7

facial to ideal ellipse

Question 8

what four forces does stability of and occlusion and maintenance of tooth position depend on?

Answer 8

• eruptive forces
• occlusal forces
• lip and cheek pressure
• tongue pressure

Question 9

what forces do restorations and extractions alter

Answer 9

restorations; occlusal

extractions; all forces

Question 10

whats a root axis line

Answer 10

imaginary line that divides root to halves md or fl at cervical line

Question 11

from a frontal view what are the angles of central incisors? sagittal view?

Answer 11

fronta;

• Max MD tilts distally less than 2 degrees
• Mand central incisors tilts medially (all ant) (MD) less than 2 degrees also

sagittal:
- max FL ; less than 28 degrees
- mand FL less than 22 degrees

Question 12

frontal/sagittal view; lateral incisor angles?

Answer 12

frontal:

• maxillary ; MD less than 7 degrees,
• mand less than 0 degrees?

sagittal:

• max less than 26 degrees FL
• mand; less than 23 degrees fl

Question 13

frontal/sagittal views; canines

Answer 13

frontal:

• maxillary; MD less than 17 degrees
• mand; md less than 6 degrees

sagittal:
- max; FL less than 16 degrees
- mand; fl less than 12 degrees

Question 14

which two teeth form contact most like a contact “point”

Answer 14

canine and first premolar in both arches

Question 15

where are contact points in anteriors vs posteriors generally

Answer 15

anteriors; contacts normally centered faciolingually

posteriors; contact centered OR located buccal to center BL direction

Question 16

what are general trends of interproximal contact areas?

Answer 16

• increase in size more cervically you move from anterior to posterior
• distal contact is usually more cervically located than the mesial contact

Question 17

whats teh function of interproximal contacts?

Answer 17

• stabilize arches
• prevent food from slipping between teeth
• define embrasures space and help direct blood flow
• pattern during mastication

Question 18

what stops third molars or second molars from drifting distally?

Answer 18

bc of lip, cheek, and tongue pressures directed anteriorly

Question 19

what occurs if inter-proximal contact areas are lost

Answer 19

-gingiva inflammation and irritation bc food is forced beyond contact area

Question 20

whats the base of the triangle of the interproximal space?

Answer 20

-base is alveolar process

Question 21

how large is the separation between enamel and alveolar bone in normal occlusion

Answer 21

1-1.5 mm

Question 22

what are all of the types of embrasures

Answer 22

• buccal/labial (seen from above)
• lingual
• incisal/occlusal
• gingival/cervical

Question 23

whats the function of embrasures

Answer 23

• creates a spillway for excape of food during mastication

- prevents food from being forced thru contact areas

Question 24

whats lamina dura

Answer 24

thin compact bone layer of alveolar crest

Question 25

what type of fibers are of PDL overall, and what are the 5 types? , where do they attach

Answer 25

collagen fibers

types:

• alveolar crest fibers
• horixontal fibers
• oblique fibers
• periapical fibers
• interradicular fibers

(transseptal = NOT PDL)

• attach from cementum of tooth root to the alveolar bone
• provides support and resistance.

Question 26

what is design/function of alveolar crest pdl fibers

Answer 26

• retain tooth in alveolus, oppose lateral forces, protect deeper pdl structures
• attach alveolar crest bone to cementum (apical to cej)

Question 27

whats design/function of horizontal PDL fibers

Answer 27

oppose lateral forces, perpendicularly from root to alveolar bone (apical to alveolar crest fibers)

Question 28

design function of oblique pdl fibers?

Answer 28

oppose axially directed forces. they are the MOST numerous ones!!!!

Question 29

design/function of apical pdl fibers?

Answer 29

-prevent tooth tipping and extrusion, protect vessel and nerve supply to the tooth, at apex of tooth

Question 30

design /function of interradicular fibers?

Answer 30

-prevent tooth tipping and extrusion, between roots of multirooted teeth

Question 31

whats the design and function of transseptal fiber

Answer 31

not pdl!

=prevent teeth from losing contact w eachother. cementum to cementum