PERMANENT MANDIBULAR MOLARS

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PERMANENT MANDIBULAR MOLARS
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MANDIBULAR 1st MOLAR

• the largest and the strongest mandibular molars
• not considered succedaneous
• first permanent molars to eruptsix year molars
• 5 cusps
• 2 roots D M (3 canals 1-D, 2-M)

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UNIQUE FUTURES

• largest mesiodistal crown dimension of any tooth
• he occlusocervical and faciolingual dimensions of
  the first molar are greater than any other
  mandibular molar
• Mandibular first molars have three facial cusps
  as do some mandibular third molars
• the longest roots of any molar
• the greatest mesiodistal root separation of any
  molar
• The mesial root has the greatest faciolingual
  dimension of any root in the mouth

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Buccal view

• The mesiofacial (mesiobuccal) cusp is the
  largest, widest, and highest of the 3 facial
  cusps
• The facial (buccal) cervical line is nearly
  straight but there can be enamel that dips
  cervically nearly into the furcation
• The two lingual cusps (mesiolingual and
  distolingual) are visible because they are taller
  cusps

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• The mesial root averaged 1 mm longer than the
  distal root
• Both roots have an overall distal inclination
• The distal root is straighter than the mesial
  root

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Lingual view

• The greater height of the lingual cusps hide the
  facial cusps
• portions of the proximal surfaces are visible
  from a lingual view
• The lingual cervical line is nearly straight

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Mesial view

• Two cusps can be seen (ML MB)
• Only one root can be seen (FL length twice MD)
• The mesial cervical line curves occlusally
• The lingual height of contour (area of greatest
  convexity) has been located in the middle third
  of the crown
• The faciolingual (buccolingual) crown, root,
  cusps dimension is greater M than D
• The two major mesial cusps (mesiofacial and
  mesiolingual) are larger than the distal cusps

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Distal view

• Distolingual cusp is largest
• distal proximal contact has been located facial
  to the crown center (Fuller/Denehy/Schulein
  Renner), centered over the root
• From a distal view, more of the facial surface
  can be seen than from a mesial view because the
  crown tapers distally
• More of the occlusal surface is visible from a
  distal view than mesial view because the distal
  surface is shorter occlusocervically

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Occlusal view

• 5 cusps. All of them functional
• The mesiofacial cusp is the largest cusp
• The crown tapers lingually
• The outline form has been described as pentagonal
  

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• There are four developmental grooves on the
  occlusal surface central mesiofacial
  (mesiobuccal) distofacial (distobuccal) and
  lingual
• There are three fossae central mesial and
  distal
• The central developmental groove has a zigzag
  mesiodistal form
• The central development groove forms a Y shape
  with the lingual developmental groove. This is
  one of the principal occlusal groove patterns

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MANDIBULAR 2nd MOLAR

• Resemble 1st B and L except there no 5th cusp or
  D cusp
• Rooth shorter, closer more D inclined
• 4 cusp nearly equal size

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UNIQUE FUTURES

• F the roots curve laterally and then toward each
  other in a manner that resembles the handles of a
  pair of pliers a unique form shared with only the
  maxillary first molar
• a MF prominence, a unique feature for mandibular
  molars
• The D proximal contact is centered both FL and
  occlusocervically, a characteristic shared with
  four other teeth (Max lateral incisor, Max
  canine, Max 1st molar and Max 2nd molar)

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Facial view

• Shorter MD and cervicoolcclusally than 1st
• Just 2 B cusps
• Roots shorter, closer, more D inclined

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Lingual view

• Little if any of the mesial and distal surfaces
  are visible lingually due to the limited lingual
  crown taper
• The lingual groove may terminate on the occlusal
  surface or extend onto the lingual surface in the
  occlusal third (L pit)
• Contact areas lower D and M

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Mesial view

• The FL dimension of the M root is greater than
  the distal , but less rhan 1st molar
• mesial proximal contact - similar to the 1st
  molar, slightly to the facial of the center of
  the crown
• The cervical line is more cervically positioned
  on the facial surface than lingual

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Distal view

• No Distal cusp
• Little of the facial surface is visible from a
  distal view
• proximal contact has been located at the center
  of the crown
• Distal root is narrower than M

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Occlusal view

• The outline form has been described as
  rectangular
• A number of supplemental grooves are present,
  wrinkled appearance
• mesiobuccal cusp is normally the largest cusp,
  but almost equal in size
• developmental grooves facial central and
  lingual, forming a cross
• 3 fossae, 3 B, L M pitsgrooves may present

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MANDIBULAR 3RD MOLAR

• more varied in size and shape than all other
  teeth except the maxillary third molars
• small apical-occlusal dimension
• the D half of the crown has a noticeably shorter
  than the M half
• crown resembles a mandibular second molar with 4
  cusps
• Some mandibular third molars have three facial
  cusps
• The mesiolingual cusp is the largest of all the
  cusps. The lingual cusps are often larger and
  longer than the facial cusps and more rounded

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• The roots are usually pointed, inclined D, often
  fused, short
• There may be multiple roots and as many as 8
  roots
• The facial surface is very convex and the tooth
  has a bulbous form
• occlusal outline form is often ovoid
• The occlusal table is distinctly ovoid in outline
  form and highly restricted
• The occlusal surface is quite wrinkled due to
  numerous supplemental grooves and ridges

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MANDIBULAR MOLAR ROOTS

• 2 roots 1-M, 2 D with single root trunk
• M root longer and stronger, curves M then turns
  D near apex
• Root trunk short and grooved on B and L surfaces

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CHARCTERISTICS
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PULP CAVITY