More Tooth Identification

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More Tooth Identification

• Posterior

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Posterior

• Maxillary

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First Premolar

• These premolars have bifurcated roots. A
  Longitudinal groove is present on the root. The
  mesial surface shows a developmental fossa. The
  mesial marginal groove crosses the mesial
  marginal ridge and extends onto the mesial
  surface. The facial cusp is wider and longer
  than the lingual cusp. The mesial ridge of the
  facial cusp may have a slight concavity.

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• Number of roots 2
• Number of pulp horns 2
• Number of cusps 2
• Number of developmental lobes - 4

5
Second Premolar

• These premolars usually have a single root.
  About 40 have two root canals. The buccal and
  lingual cusps are nearly equal in length. The
  buccal cusp is shorter than that of the first
  premolar. The entire crown, especially the
  occlusal outline, is less angular and more
  rounded. The occlusal developmental grooves are
  shorter, shaloower, and more irregular.

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• Number of roots 1
• Number of pulp horns 2
• Number of cusps 2
• Number of developmental lobes - 4

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First Molar

• A cusp of Carabelli (5th cusp) may be present.
  The occlusal outline is square or rhomboidal
  rather than triangular. The distolingual cusp is
  well developed. There is a prominent oblique
  ridge and distal facial and lingual grooves. The
  crown is nearly as wide mesiodistally as
  buccolingually. The three roots are widely
  seperated.

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• Number of roots 3
• Number of pulp horns 4
• Number of cusps 5
• Number of developmental lobes - 5

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Second Molar

• These teeth are similar to the first molars
  except that the 5th cusp is usually absent and
  the distolingual cusp is less developed. The
  oblique ridge is less prominent. The crown is
  shorter occlusocervically and narrower
  mesiodistally. The occlusal outline of the drown
  is rhomoidal to heart shaped. The three roots
  are less seperated.

10

• Number of roots 3
• Number of pulp horns 4
• Number of cusps 4
• Number of developmental lobes - 4

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Third Molar

• These teeth vary more in form than the others.
  They usually do not have a distolingual cusp.
  The occlusal outline is heart shaped, with three
  cusps. The roots, usually three, have a tendency
  to be very close together or to fuse with an
  extreme distal inclination.

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• Number of roots 1 to 4
• Number of pulp horns 1 to 4
• Number of cusps 3 to 5
• Number of developmental lobes - 4

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Posterior

• Mandibular

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First Premolar

• These premolars have two cusps, one large buccal
  and one small lingual. The buccal cusps are
  centered directly over the root. The lingual
  cusps are centered lingual to the root and are
  afunctional and nonoccluding. The occlusal
  surface slopes sharply lingual in a cervical
  direction. The mesiobuccal cusp ridge is shorter
  than the distobuccal ridge. It has a
  mesiolingual developmental groove and one root.

15

• Number of roots 1
• Number of pulp horns 1 or 2
• Number of cusps 2
• Number of developmental lobes - 4

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Second Premolar

• These premolars have 2 or 3 cusps. The buccal
  cusp is very large. If two lingual cusps are
  present, the mesiolingual is the larger.
  Although the lingual cusps are larger than on the
  first premolar, they are afunctional and do not
  occlude with the maxillary teeth. A second
  premolar has more secondary anatomical features
  and more variation than any other tooth except a
  third molar.

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• The two-cusp forms a U- or H- groove pattern. A
  mesiolingual groove is rare and is poorly
  developed if present. The three-cusp form has a
  lingual developmental groove between the two
  lingual cusps and forms a Y- groove pattern. The
  single root is longer and larger than that of a
  first premolar.

18

• Number of roots 1
• Number of pulp horns 2 or 3
• Number of cusps 2 or 3
• Number of developmental lobes - 4

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First Molar

• The five cusps make these that largest mandibular
  teeth. They are wider mesiodistally than
  buccolingually. The crown converges lingually
  and slightly distally. The three buccal cusps
  are seperated by two buccal grooves. The two
  lingual cusps are seperated by one lingual
  groove. These three grooves converge to form a Y
  pattern. There are two roots, a mesial and a
  distal, and three root canals (the mesial root
  has two root canals).

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• Number of roots 2
• Number of pulp horns 5
• Number of cusps 5
• Number of developmental lobes - 5

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Second Molars

• These molars have four cusps of nearly equal
  size. The crown is smaller in all dimensions and
  has less lingual convergence. There is only one
  buccal groove and one lingual groove, which join
  together on the occlusal surface as they bisect
  the central developmental groove. The groove
  pattern is therefore a cross (). The two roots
  are closer together and incline slightly
  distally. There is one root canal in the distal
  root. The mesial root can have one or two root
  canals.

22

• Number of roots 2
• Number of pulp horns 4
• Number of cusps 4
• Number of developmental lobes - 4

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Third Molars

• These are the most variable mandibular teeth in
  form. They usually resemble the mandibular
  second molars, with four cusps and a shallower,
  smaller central fossa, with more secondary and
  teriary grooves. A five-cusp form is not
  unusual. The two roots (mesial and distal) and
  often fused and inclined toward the distal side.

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• Number of roots 2 (fused)
• Number of pulp horns 4 or 5
• Number of cusps 4 or 5
• Number of developmental lobes 4 or 5