Maxillary Incisors Flashcards
central maxillary incisors erupt
between 7-8 years of age
lateral maxillary incisors erupt
between 8-9 years of age
R max central incisor #
8
L max central incisor #
9
R max lateral incisor #
7
L max lateral incisor #
10
convex
bulges out at you like santa’s stomach or the side of a bubble
convexity or contour means rounded or bulging
concave
scooped out, hollow - think of a cave
describing “thirds”
can be used a number of ways -
CROWN
incisal third
middle third
cervical third (closest to CEJ)
CROWN
distal third
middle third
mesial third
ROOT
apical
middle
cervical
8/9 coronal dimensions (relatively)
inciso-coronal distance greater than mesio-distal distance (widest of all incisors)
8/9 crown to root ratio
close to 1
8/9 coronal outline
- D more curved/convex, M more angular
- D is more constricted/pinched in, like the tooth is wearing a belt
- incisal edge can be flatter in adults due to grinding or can have mamelons
8/9 contacts
M in incisal third of crown
D at the junction of the incisal and middle thirds
8/9 angles
MI approx 90 deg
DI more rounded
8/9 CEJ
smooth, convex curve toward the apex of the root
8/9 cervical height of contour
means where the bulge of the tooth is the biggest!
it is biggest in the cervical one third, running mesiodistally (best seen from a proximal view)
8/9 notable markings on facial
two developmental depressions sometimes evident in the middle and incisal thirds of the facial surface
8/9 root
smoothly tapered
apex may curve distal or facial
smooth flat facial surface forms one side of the triangular root
mamelons
developmental protuberances of enamel on the incisal edges of newly erupted teeth that represent lobes of development
often wear down with time
anterior teeth develop from 4 lobes - three on the facial, one forms the cingulum
8/9 key differences from on lingual side
- CEJ: smooth convex curve, not as apical as on the facial side (doesn’t curve as much)
- prominent cingulum (4th lobe of development) displaced to the D to accommodate for incisive foramen
- lingual fossa a concavity
- two flattened surfaces of the root - forms a triangle
- more of mesial surface of root is visible than distal (MESIAL OUTLINE OF ROOT IS LONGER IN CROSS SECTION)
- triangular root unique to maxillary central incisors
4 convexities on facial side of #8/9
M & D marginal ridges
cingulum
incisal ridge
8/9 mesial view
- facial height of contour in the cervical third
- lingual height of contour in the cervical third (cingulum)
- usu incisal edge is centered F-L and usually in line with center of apex
- proximal contact - incisal third
8/9 mesial view - CEJ notes
CEJ is curved toward the incisal edge - so concave toward the apex
*greater CEJ curvature on the mesial than the distal
8/9 distal view
- contact where the incisal third meets the middle third
- heights of contact in cervical third again
- CEJ less curved than M
- crown might seem wider because tooth is curved a bit
- flattened surface of root like M
- smooth root
8/9 incisal view / “down the barrel”
- M/D greater than F/L
- facial surface convex
- lingual surface - tapered, cingulum to D
- may see ridges on facial
- straight line drawn over incisal edge from M to D
maxillary lateral incisor differences from central incisor
- all dimensions smaller except for a longer root
- more rounded MI and DI edges
- facial surface not as flat, developmental depressions not as prominent
lingual view - lateral incisors compared
- lingual concavities and convexities may be MORE pronounced
- root more tapered and more curved
distolingual groove
a groove in a lateral incisor that can be a plaque trap - a developmental feature
roots of lateral incisors
- longer than central incisors
- curves toward the distal but can curve toward facial or lingual
- cross section is ovoid, not triangular
peg-shaped laterals
smaller than normal, like little pegs, with smaller roots too
often don’t touch neighbors
lingual tubercle
supersized cingulum
aka talon cusp
random facts about max lateral incisors
- possible to have a fused central and lateral!!
- most often congenitally missing tooth
- more variable shape/features
