pre molars and molars_ ora; ana

• Mandibular 1st Premolar Unique Characteristics

  • Smallest of all premolars
• Maxillary 1st Premolar Crown Morphology

  • Has prominent buccal ridge
  • Only permanent tooth with mesial cusp ridge> distal ridge
  • Has a prominent mesial marginal ridge groove, which can make scaling difficult
• Mandibular 1st Premolar Occlusal Morphology


  • Occlusal shape is diamond-shaped, proximal shape is rhomboidal (tilted lingually)
  • Only posterior tooth with an occlusal plane tilted lingually
  • Has most prominent transverse ridge of all premolars, which splits mesial and distal fossae. NO CENTRAL GROOVE.
  • 2 cusps: buccal (functional), lingual (nonfunctional)
  • Buccal cusp is larger (2/3 of occlusal surface) than the lingual
  • Occlusal surface configuration is commonly called SNAKE EYES
• Maxillary 1st Premolar Root Morphology

  • Only premolar with two roots (B>P)
  • Has prominent mesial root concavity
  • Sits most vertically (B-L) in alveolar bone
• Maxillary 2nd Premolar Root Morphology

  • Only premolar without a mesial root depression
• Maxillary 2nd Premolar Crown Morphology


  • Distal cusp ridge>mesial cusp ridge
  • Has buccal ridge, but not as prominent as 1st premolar
• Mandibular 1st Premolar Occlusal Contacts

  Occludes with maxillary canine and 1st premolars
• Mandibular 2nd Premolar Unique Characteristics

  • Most congenitally missing premolar
  • The gingival papilla between the 1st and 2nd premolar is the shortest
• Mandibular 2nd Premolar Occlusal Morphology

  • Occlusal shape is square, proximal shape is rhomboidal (tilted lingually
  • Occlusal surface can have three configurations:
  • Y (most common configuration): 3 cusps- buccal > ML> DL with a single central pit
  • H : 2 cusps- buccal and lingual with short central groove
  • U : 2 cusps- buccal and lingual with crescent-shaped central groove
  • Buccal cusp is shorter and blunter than lingual cusps
  • ML cusp is larger than the DL cusp
  • Mesial marginal ridge has slight concavity
• Maxillary 1st Premolar Occlusal Contacts

  Occludes with mandibular 1st and 2nd premolars
• Maxillary 1st Premolar Occlusal Morphology

  • Occlusal shape is hexagonal; proximal shape is trapezoidal
  • Occlusal table has long central groove with fewer supplemental grooves
  • No central pit, but has mesial and distal pits
  • 2 cusps: buccal (slightly distal), palatal (slightly mesial)
  • Buccal cusp height> palatal
• Mandibular 1st Premolar Root Morphology


  • Root is broader (B-L), and may have proximal concavities
• Maxillary 2nd Premolar Unique Characteristics

  • Shorter and smaller than maxillary 1st premolar
• Maxillary 2nd Premolar Occlusal Morphology

  • Occlusal shape is hexagonal; proximal shape is trapezoidal
  • Occlusal table is more ovoid and symmetrical than maxillary 1st premolar
  • Occlusal table has short central groove with more supplemental grooves.
  • Has a WRINKLED appearance
  • 2 cusps: buccal, palatal (slightly mesial)
  • Buccal cusp height = palatal
• Maxillary 1st Premolar Unique Characteristics

  • Largest of all premolars
• Maxillary 2nd Premolar Occlusal Contacts

  Occludes with mandibular 2nd premolar and 1st molar
• Mandibular 1st Premolar Crown Morphology


  • Has prominent mesio-lingual groove
  • MMR<DMR
• Mandibular 2nd Premolar Root Morphology

  • Root is longer than the mandibular 1st premolar
  • Apex closest to mental foramen
• Mandibular 2nd Premolar Crown Morphology

  • Lingual surface is wider (M-D) than that of the mandibular 1st premolar
  • Shorter and wider than the mandibular 1st premolar (from buccal)
  • Mesial marginal ridge has slight concavity
  • Only premolar with five lobes: 3 buccal and 2 lingual
• Maxillary 1st Molar occludes with


  Maxillary 1st and 2nd premolars
• Crown morphology of Mandibular 1st Molar

  • Can see all 5 cusps from buccal
  • Buccal cusps are shorter and blunter than the lingual cusps
• Crown morphology of Maxillary 2nd Molar

  • Has a short buccal groove without pit
• Mandibular 1st Molar occludes with

  Maxillary 2nd premolar and 1st molar
• Crown morphology of Maxillary 1st Molar

  • Only tooth with a pronounced distal concavity at the CEJ, which can make scaling difficult
  • Has a long buccal groove with a central pit
  • Has a distolingual groove with a pit (on all maxillary molars)
• Maxillary 2nd Molar occludes with

  Information incomplete
• Root morphology of Mandibular 1st Molar

  • Roots are usually widely separated
  • The mesial root is longer and wider (B-L)
  • Both roots have concavities (mesial slightly more prominent)
  • The root trunk is typically shorter than the mandibular 2nd molar
• Crown morphology of Maxillary 1st Molar

  • Largest permanent tooth
  • Only tooth that is broader lingually than buccally
  • Widest tooth (B-L)
  • First permanent maxillary tooth to erupt
• Unique characteristics of Mandibular 1st Molar

  • Largest mandibular tooth
  • Widest tooth (M-D)
  • First permanent tooth to erupt, and most often restored/extracted
• Root morphology of Maxillary 1st Molar

  • 3 roots: MB, DB (shortest), palatal (longest)
  • Apices are closest to maxillary sinus
  • MB and DB roots are often shaped like “plier handles”
  • MB root has more common (94%) and deeper (0.3mm) concavities than other roots
• Unique characteristics of Maxillary 2nd Molar

  • Similar to maxillary 1st molar but smaller and more angular
  • 2nd most common tooth to have cervical enamel projections (next to mandibular 2nd molar)
  • Closest tooth to the opening of Stenson’s (parotid) duct
• Root morphology of Maxillary 2nd Molar

  • Information incomplete
• CROWN MORPHOLOGY


  • Has a short buccal groove without pit
• MANDIBULAR 2ND MOLAR OCCLUSAL CONTACTS

  Occludes with the maxillary 1st and 2nd molar
• MANDIBULAR 2ND MOLAR UNIQUE CHARACTERISTICS

  • Most symmetrical molar
  • Most common tooth to have cervical enamel projections
• ROOT MORPHOLOGY

  • Roots are typically longer, closer together, and more distally inclined than the maxillary 1st molar. Occasionally fused
  • Longer root trunk than maxillary 1st molar
• MANDIBULAR 2ND MOLAR OCCLUSAL MORPHOLOGY

  • Occlusal shape is rectangualar, proximal shape is rhomboidal (tilted lingually 15-20°)
  • 4 cusps: MB (largest) DB, ML, DL
  • Occlusal pattern resembles a “+” with a straight central groove
  • Has 2 transverse ridges, 3 fossae with pits , 3 secondary grooves, 1 buccal groove with a pit, and a short lingual groove
• MAXILLARY 3RD MOLAR CROWN MORPHOLOGY

  • Shortest maxillary crown
• MAXILLARY 3RD MOLAR ROOT MORPHOLOGY

  • Roots are often fused and distally inclined
• MANDIBULAR 3RD MOLAR UNIQUE CHARACTERISTICS

  • Most variable morphology (with maxillary third molar)
  • Most common congenitally missing tooth
  • Most frequently impacted tooth
  • Most common tooth to have enamel pearls (with maxillary 3rd molars
• MANDIBULAR 3RD MOLAR OCCLUSAL CONTACTS

  Occludes with maxillary 2nd and 3rd molar