class I occlusion
when the mesiobuccal cusp of the maxillary 1st molar fits into the mesiobuccal groove of the mandibular 1st molar; person has an orthognathic profile
distal occlusion or class II occlusion
mandible is retruded; person has a retrognathic profile
mesial occlusion of class III occlusion
mandible is protruded; called an “overbite” and person has a prognathic profile
space between the two maxillary central incisors
diastema
function of incisors
- cut food
- articulate speech
- support the lips (esthetic)
- guide mandible during movement
the longest incisor crown
the maxillary central incisor crown
three ____ reflect three labial developmental lobes for incisors (before wear)
mamelons
characteristics of ALL incisors from the facial view
- relatively straight incisal edge
- rectangular shape: longer incisocervically than mesiodistally
- taper narrower from contact to CEJ
- CEJ curves toward the apex
- root tapers to apex and is longer than the crown
characteristics of all incisors EXCEPT mandibular centrals from the facial view
- distal crown surface is more convex than mesial
- mesioincisal line angle is sharper than distoincisal
- distal contact located more cervically than on mesial
- incisal edges slope cervically to distal
characteristics of ALL incisors from the lingual view
- lingual surface narrower (seen best incisally)
- marginal ridges converge toward cingulum
- lingual fossa
Characteristics of ALL incisors from the proximal views
- wedge shaped (triangular) outline
- height of contour in cervical third both facially and lingually (cingulum)
- lingual outline is “S” shaped
- CEJ curves incisally
- root tapers to apex
characteristics of ALL incisors from the incisal view
- concave lingual fossa incisal to cingulum
- incisal edge runs across between widest points on mesial and distal
- labial outline is broader (less convex) than lingual
- marginal ridges converge toward cingulum
mandibular incisors (versus maxillary) have:
- smaller crowns
- flatter proximal outlines
- contacts closer to incisal edge
- roots relatively longer (compared to crowns)
mandibular incisors (vs maxillary) have relatively____ crowns ______ and ____ lingual surfaces
wider; faciolingually; smoother
mandibular incisors (vs maxillary) have incisal edges that are more likely ____ to the midroot axis
lingual
there is more incisal ridge faceting on the ____ of mandibular incisors vs ____ of maxillary incisors
labial; lingual
the maxillary central has a ___ and ____ crown than the maxillary lateral; from labial view
wider (2.0); longer (0.5)
the maxillary later is relatively _____ mesiodistally (compared to max central); from labial view
narrower
maxillary lateral is more often ____ or ____ (compared to maxillary central); from labial view
peg shaped; missing
maxillary central has ____ angle at nearly a right angle
mesioincisal
maxillary lateral has both ____ and _____ angles more rounded than on max centrals ; from the labial view
mesioincisal; mesiodistal
central incisors have ____ shaped cross section, and lateral incisors have more of an ____ shaped cross section
triangular; oval
Maxillary central incisor cingulum is more developed and is off center toward the _____ (best seen from incisal view); cingulum of lateral incisor is more ______
distal; centered
Maxillary lateral incisor has the ______ appear ______ (more so than on centrals) due to slope of incisal edge toward distal, on central this is also due to distal placement of cingulum
distal marginal ridge; shorter than mesial
