Anterior tooth anatomy Flashcards
READ OVER THE PPT AND DRAWING EXERCISES AGAIN BEFORE OSCE!
Do this ik youre reading this :)
how far above the central incisor does the gingival zenith show?
1mm
what are central incisors needed for?
Aesthetics, occlusion (function), phonetics/speech
what is the midline of the central incisors vertical and parallel and perpendicular to?
incisal edge should be perpendicular to interpupillary line
parallel to middle of nose/septum
what is the ratio for length to width of central incisors?
central incisor width should be 75-80% of its length, e.g., 10mm x 8 mm
is the distal or mesial edge more rounded on incisors?
distal edge is more rounded than mesial edge
what is an incisal embrasure?
a space existing on the incisal aspect of the inter-proximal contact area between adjacent anterior teeth
how does incisal embrasure vary as you move distally?
increases in depth as you move distally
difference between central and lateral incisors?
lateral incisors are smaller - usually 0.5-1mm shorter than central and canine
how do teeth vary - what factors?
basic shape, length, axis, rotation, gingival zenith, display on smiling
what happens to incisors as you age?
incisal wear - similar length
incisal embrasures decrease
what is the gingival zenith?
the gingival zenith is the highest visible point on the gingival margin (highest part of the curve)
(laterals are 0.5-1mm below centrals and incisors)
how big is the width of the lateral incisor in comparison to central?
lateral width is usually about 2/3 of the central
what is the golden ratio?
1.618 (central) : 1 (lateral) : 0.618 (canine)
widths
what is the most pleasing long axis of anterior teeth?
mesial axis inclinations are more pleasing than the distal
what area of the mouth do the canines control?
canines control width, size and character of smile by the occluding part of the buccal corridor
what are mamelons?
grooves on the incisal edge
what are developmental grooves?
v-shaped grooves which run between lobes and align with the long axis
compare the size of the developmental grooves in the centrals
mesial groove is longer than distal groove
accessory ridges may be present within v-shape groove
compare size of developmental grooves in the laterals
mesial groove similar to central incisor
distal groove diminished
compare size of developmental grooves in canines
mesial groove shorter than longer distal groove
what is the emergence profile?
the contour of the tooth extending from the alveolus
what are perikymata?
very small surface striations in young teeth
what are imbrication lines?
subtle/broken/crescent-shaped ridges from cervical line to gingival bulge
parallel to CEJ
less apparent on laterals
what happens to incisors with age?
increased enamel translucency and dentine opacity
intrinsic staining, cracks, craze lines
palatal contour of incisors
concavity
marginal ridges
cingulum
lower lateral and central sizes?
laterals are slightly sider than central
width of uppers and lowers compared
lower incisors can be used to define upper incisor widths
width of upper central incisor = width of lower central + 0.5 width of lower lateral
lower incisor lingual contour
lower incisors and canines have poorly developed cingula compared to upper anterior teeth
what is the gap between 2 teeth called?
diastema (plural = diastemata)
