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maxillary 2nd premolars
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MAXILLARY SECOND
PREMOLARS
Permanent Maxillary Second Premolar – Introductory Permanent Maxillary Second Premolar – Introductory PointsPoints
•The maxillary 2nd premolar has two cusps (facial & lingual) of nearly equal size and height
•The distal cuspal ridges of both cusps are longer than the mesial cuspal ridges
•This tooth typically has one root with 2 pulp canals. There is however an extreme variation in pulp morphology.
•Overall, this is a smaller tooth than the maxillary 1st premolar
•Root length for this tooth will be as great (14.0 mm) or occasionally even longer than the root of the maxillary 1st premolar.
•The facial ridge is not as prominent as that of the maxillary 1st premolar.
•When compared to the maxillary 1st premolar, this tooth will usually present with more supplemental occlusal anatomy (secondary ridges and grooves).
2
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
3
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
4
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
5
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
6
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
7
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
8
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
9
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
10
FacialFacial
M
D
The AVERAGE measurements suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. The outlines of the teeth will differ considerably from every visual aspect.
The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.
The facial cusp tip is more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.
Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.
The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.
The cervical outline of the crown is also smoothly (evenly) convex.
The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.
There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.
The root outline converges evenly toward a relatively blunt apex that may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.
11
LingualLingual
MD
The outline of the lingual surface is a reverse image of the facial outline.
Occlusally the outline of both cusps is visible. The tip of the lingual cusp is in line with the tip of the facial cusp. It is nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.
The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.
The lingual surface of the root is not quite as wide as the facial surface of the root.
The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector.
12
LingualLingual
MD
The outline of the lingual surface is a reverse image of the facial outline.
Occlusally the outline of both cusps is visible. The tip of the lingual cusp is in line with the tip of the facial cusp. It is nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.
The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.
The lingual surface of the root is not quite as wide as the facial surface of the root.
The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector. 13
LingualLingual
MD
The outline of the lingual surface is a reverse image of the facial outline.
Occlusally the outline of both cusps is visible. The tip of the lingual cusp is in line with the tip of the facial cusp. It is nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.
The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.
The lingual surface of the root is not quite as wide as the facial surface of the root.
The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector.
14
LingualLingual
MD
The outline of the lingual surface is a reverse image of the facial outline.
Occlusally the outline of both cusps is visible. The tip of the lingual cusp is in line with the tip of the facial cusp. It is nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.
The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.
The lingual surface of the root is not quite as wide as the facial surface of the root.
The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector.
15
LingualLingual
MD
The outline of the lingual surface is a reverse image of the facial outline.
Occlusally the outline of both cusps is visible. The tip of the lingual cusp is in line with the tip of the facial cusp. It is nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.
The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.
The lingual surface of the root is not quite as wide as the facial surface of the root.
The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector.
16
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
17
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.
The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
18
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.
The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
19
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.
The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
20
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).
The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
21
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.
The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
22
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.
The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
23
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.
The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
24
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.
The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
25
MesialMesial
F
L
The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.The lingual cusp tip is more rounded than the facial cusp tip and the tip is closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and is slightly facial to the facio-lingual long axis bisector.The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.
There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).
26
DistalDistal
FL
The distal outline is the reverse of the mesial outline.
The surface is very similar in all respects to the mesial surface except that the cervical line curves a little less occlusally and may even be relatively straight.
The root has a longitudinal depression on the distal aspect that is confined to the root.
Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.
Distal contact area is centered faciolingually.
27
DistalDistal
FL
The distal outline is the reverse of the mesial outline.
The surface is very similar in all respects to the mesial surface except that the cervical line curves a little less occlusally and may even be relatively straight.
The root has a longitudinal depression on the distal aspect that is confined to the root.
Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.
Distal contact area is centered faciolingually.
28
DistalDistal
FL
The distal outline is the reverse of the mesial outline.
The surface is very similar in all respects to the mesial surface except that the cervical line curves a little less occlusally and may even be relatively straight.
The root has a longitudinal depression on the distal aspect that is confined to the root.
Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.
Distal contact area is centered faciolingually.
29
DistalDistal
FL
The distal outline is the reverse of the mesial outline.
The surface is very similar in all respects to the mesial surface except that the cervical line curves a little less occlusally and may even be relatively straight.
The root has a longitudinal depression on the distal aspect that is confined to the root.
Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.
Distal contact area is centered faciolingually.
30
DistalDistal
FL
The distal outline is the reverse of the mesial outline.
The surface is very similar in all respects to the mesial surface except that the cervical line curves a little less occlusally and may even be relatively straight.
The root has a longitudinal depression on the distal aspect that is confined to the root.
Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.
Distal contact area is centered faciolingually.
31
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
32
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
33
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
34
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
35
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
36
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
37
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
38
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
39
OcclusalOcclusal
M D
Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.The triangular ridges are approximately the same length and the point at which they meet is located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges is separated by a central groove.The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is rectangular in outline.This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.
40
Main PointsMain PointsFACIALTrapezoidal crown outlineMiddle facial lobe most developed of three facial lobes but less prominent than that found on the maxillary 1 st premolar. Developmental depressions found on either side to the facial ridge more subtle as well
LINGUALCrown does have lingual convergence but not as conspicuous as that found on maxillary 1 st premolarLingual cusp in line with the facial cusp and very nearly the same height
MESIALContact area located in the high middle 1/3 (OG) of the tooth and facial to the faciolingual long axis bisector of the crownTrapezoidal crown outline with the longer parallel side at the cervicalDevelopmental root depression present but does not extend over the cervical line onto the crown
DISTALVery little (if any) curvature of the cervical line occlusallyDevelopmental root depression that is confined to the rootDistal contact area is centered faciolingually.
OCCLUSAL
Ovoid crown outline with MMR & DMR parallel to one anotherRounded facial line angles (compared to maxillary 1st premolar)Many supplemental grooves (wrinkled appearance)Short “pit-like” central groove
41
Permanent Maxillary PremolarsPermanent Maxillary Premolars
Aspect First Premolar Second Premolar
Facial > Prominent, broad shoulders
> Facial cusp tip distal of center
> Prominent facial lobes
> Narrow shoulders
> Facial cusp tip mesial of center
> Facial lobes not prominent
Lingual > Entire facial profile of crown visible > Little or none of the facial profile visible
Mesial > Mesial marginal ridge developmental groove interrupts mesial marginal ridge.
> Usually two roots, facial and lingual.
> Mesial developmental depression extends from bifurcation of root across the cervical line and well onto crown almost to contact area.
> No mesial marginal ridge developmental groove.
> Single root.
> Mesial depression restricted to root surface.
42
Permanent Maxillary PremolarsPermanent Maxillary Premolars
Aspect First Premolar Second Premolar
Occlusal > Crown profile hexagonal.
> Mesiofacial and distofacial line angles are sharp.
> Mesial and distal profiles converge lingually.
> Occlusal table outline trapezoidal.
> Facial cusp ridge has a slight mesial cant, giving the crown a twisted appearance.
> Facial cusp wider than lingual cusp.
> Central groove long.
> Supplemental grooves rare.
> Facial ridge, developmental depressions and lobes visible.
> Crown profile ovoid.
> Mesiofacial and distofacial line angles more rounded.
> Little lingual convergence; mesial and distal marginal ridges parallel.
> Occlusal table outline rectangular.
> Crown not twisted in appearance.
> Short central groove & wide marginal ridges
> Many supplemental grooves giving a “wrinkled” appearance
Cross Section of Root
> Outline is kidney shaped with concavity on mesial.
> One root canal at cervix, two root canals as root bifurcates
> Outline is ovoid.
> One root with one or two root canals with varied pulp morphology
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![Multirooted Bilateral Maxillary First Premolars - A …...maxillary premolars are from 0% to 6%.[5] The purpose of this article is to report as well as discuss the successful diagnosis](https://img.dokumen.tips/doc/110x75/5f46fb9518fed80f0c3adf57/multirooted-bilateral-maxillary-first-premolars-a-maxillary-premolars-are.jpg)
