line angles

-imaginary line formed by junction of two crown surfaces
-every tooth has 8
-naming: replaces "ial" or "al" with "o", separate 2 "o's" by hyphen
-(disto,medio)>(linguo, facio, labio, bucco)>(incisal, occlusal)

point angles

-point at which there is a junction of 3 crown surfaces
-4 per tooth
-naming similar to line angles

crown elevations



-elevated projections on crowns of various sizes/shapes
-form bulk of occlusal/incisal surfaces
-not found on incisors
-canines-1 cusp; premolars-2 to 3; molars-3+
-each cusp has 4 cusp ridges


-mini crowns
-not uncommon, but unusual
-most likely on lingual surface of maxillary anterior teeth


-a large rounded eminence on the lingual surface of permanent and deciduous anterior teeth, which encircles the lingual surface from mesial to distal in the cervical third


-inclined plane


-small rounded projection of enamel on the incisal ridges of newly erupted permanent incisors
-smallest is positioned mid facially
-get worn away

marginal ridges

-linear elevations found at the mesial and distal terminations of the occlusal surface of posterior teeth
-also found on anterior teeth, but less prominent

triangular ridges

-linear ridges which descend form the tips of cusps of posterior teeth towards the central area of the occlusal surface
-named for direction in which it faces; ex: tri. ridge from the buccal cusp tip is "lingual triangular ridge"

transverse ridge

-combination of 2 triangular ridges which transversely cross the occlusal surface on a posterior tooth to merge with each other

oblique ridge

-special type of transverse ridge that crosses the occlusal surface of maxillary molars in an oblique direction form the distobuccal to mesiolingual cusps

cusp ridge

-each cusp has four cusp ridges extending in diff directions (mesial, distal, facial, lingual)
-named by direction toward which they extend

inclined plane

-the sloping are found between two cusp ridges
-named by combing name of two ridges
-normally each cusp exhibits four inclined planes

crown depressions

-developmental (primary) groove
-supplemental (secondary) groove


-an irregular, usually rounded depression on the surface of tooth
-normally a large shallow fossa on the lingual surface of anterior teeth, while post. teeth exhibit 2 or more on the occlusal surf.


-long narrow depression, usually v shaped cross section
-often located on occlusal surfaces of posterior teeth
-groove found at bottom of sulcus

developmental (primary) groove

a groove or line which denotes the coalescence of the primary parts, or lobes of the crown of a tooth

supplemental (secondary) groove

an auxiliary groove which branches form the developmental groove


-small depressed area which developmental grooves join
-often deepest portion of fossa


-triangularly shaped spaces located between the proximal surfaces of adjacent teeth.
-four embrasures for every contact area: facial (also called labial or buccal), lingual (or palatal), occlusal or incisal, and cervical or interproximal space.
-The cervical embrasure usually is filled by the interdental papilla from the gingiva

fissured groove

formed by imperfect union of lobes

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