MORPHOLOGY Flashcards
(19 cards)
distinguish the anatomical crown from the clinical crown
anatomical
* part of tooth covered in enamel
* constant length
clinical
* part visible in oral cavity
* length changes throughout life according to gingival position
draw the divisions of a tooth
- horizontal crown
root
mesiodistally and labio/buccolingually
horz/occlusocervically
- incisal/occ. third
middle third
cervical third
root div into
cervical third
middle third
apical third
mesiodistally
mesial third
middle third
distal third
compare line angles from point angles
line angles
- intersection of TWO planes eg DI line angle
point angles
- junction of THREE tooth surfaces eg DLingO point angle
compare the morphological/eruption aspects of the max perm central and lateral incisor
**max central incisor **
FDI - 11 21
evi.calcification - 3-4 mths
enamel formation - 4-5 yrs
eruption - 7-8 years
root completion - 10 years
func
- cuts into food
- assists tongue/lips in phonation
- supports lips
rounded DI angle, sharper MI angle
square/rectangular appearance - widest M-D of all ant. teeth
incisal mamelons wear down w age
root tapers palatally
**max lateral incisor **
FDI - 12 22
evi.calcification - 10-12 mths
enamel formation - 4-5 yrs
eruption - 8-9 years
root completion - 11 years
form varies more than any other tooth in mouth [except 8s]
labial surf more convex than cen.incis
func
- similar to max incis
long root - crown:root = 1:1.5
rounded DI, sharper MI angle
increased CEJ curvature
compare the morphological/eruption aspects of the mand perm central and lateral incisor
**mand perm central incisor
**FDI - 31 41
evi.calcification - 3-4 mths
enamel formation - 4-5 yrs
eruption - 6-7 years
root completion - 9 years
smallest teeth in mouth
bilaterally symettrical - hard to diff. M/D
DI angle more rounded than M
**mand perm lateral incisor
**FDI - 32 42
evi.calcification - 3-4 mths
enamel formation - 4-5 yrs
eruption - 7-8 years
root completion - 10 years
greater labial curvature - more rounded M-D appearance
M side longer than D [view from labial aspect]
more devel ridges + fossa
compare the morphological/eruption aspects of the mand/max canines
max canine
FDI - 13 23
evi.calcification - 4-5mth
enamel formation - 6-7 years
eruption - 11- 12 yrs
root completion - 13-15 years
**mand canine **
FDI - 33 43
evi.calcification - 4-5 yrs
enamel formation - 6-7 yrs
eruption - 9-10 years
root completion - 12-14 years
func
- holding/tearing tools, assist incis/premo.
- phonation
- dissipation of pressure at corner of mouth
longest teeth in mouth
D slope longer than M slope
thickest of all ant.teeth
differences of mand
- narrower + smoother + sometimes longer
- root = shorter
- cusp tip not as well devel [thinner]
- cingulum less developed
compare the morphological/eruption aspects of the max first/second premolars
**max first premolar **
FDI - 14 24
evi.calcification - 1.5 - 1.75 yr
enamel formation - 5-6 yr
eruption - 10-11 yrs
root completion - 12-13 yrs
devel from 4 lobes
2 roots [B/P] –> 2 pulp canals
B cusp usually 1mm longer than P cusp
M groove crosses M marginal ridge [identifies M surface]
hexagonal occlusal shape
func = ripping
- form/func similar to canines
**max second premolar **
FDI - 15 25
evi.calcification - 2-2.25 yr
enamel formation - 6-7 yr
eruption - 10-12 yr
root completion - 12-13 yr
devel from 4 lobes
less angular - more rounded [crown is larger than first.prem]
NO devel groove crossing M marginal ridge
B/P cusps = nearly same length
ovoid occlusal shape
func = like molars - crushing [mastication]
FDI -
evi.calcification -
enamel formation -
eruption -
root completion -
FDI -
evi.calcification -
enamel formation -
eruption -
root completion -
FDI -
evi.calcification -
enamel formation -
eruption -
root completion -
FDI -
evi.calcification -
enamel formation -
eruption -
root completion -
explain the general development of the crown from lobes and idenitfy how many lobes are found in each tooth
- lobes grow and fuse = creating developmental grooves on the erupted tooth
ant. teeth + most premolars = 4 lobes [3 buccal/labial + 1 lingual/palatal]
1st molars = 5 lobes
upper from 2B + 3P
lower from 3B + 2 lingual
2nd molars = 4 lobes [2B + 2lingual/palatal]
contrast triangular, transverse and oblique ridges
triangular
- descend from tips of cusps –> central occlusal surface
transverse
- created when buccal/lingual triangular ridges join
- horizontally across tooth
eg 34 44
oblique
- connects specific cusps at an angle
eg 16 26
compare developmental and supplemntal grooves
developmental
sharply defined, narrow and linear depression formed during development
usually separates lobes
supplemental
shallow linear depression
less distinct + more variable than devel groove
does NOT mark junctions of primary parts of teeth
