Tooth Morphology

  1. What is the purpose of the tongue?
    • Mastication 
    • Assist the positioning of the teeth into alignment 
    • Speech – can not talk without your tongue 
    • Whistle 
    • Kissing 
  2. Four Types of Papillae
    • Circumvallate
    • Fungiform
    • Filiform
    • Foliate
  3. Circumvallate Papillae
    • V-shaped row of circular raised papillae 
    • About 13 elevations in the V 
    • Row anatomically divides the anterior 2/3 of the tongue from the posterior 1/3 
    • Microscopically the circumvallate appear to rest in troughs with numerous tiny taste buds all around the lateral surface 
  4. Fungiform Papillae
    Tiny, round raised spots on the anterior 2/3 of the tongue – taste buds present
  5. Filiform Papillae
    • Tiny, pointed projections on the anterior 2/3 of the tongue 
    • No taste function – tactile sensation is present 
    • White – filiform   & red - fungiform
  6. Foliate Papillae
    • Located on the posterior lateral border 
    • Not well developed & few taste buds
  7. What can piercing cause?
    • Infection 
    • Recession
  8. Fissured tongue
    A rare disorder characterized by grooves or depressions (fissures) on the tongue.
  9. Black hairy tongue
    Due to increased accumulation of keratin on the filiform papillae.
  10. Occlusion
    • Begins with the eruption of the primary teeth
    • Relationship of the maxillary and mandibular teeth when closed
  11. Malocclusion
    Abnormal alignment of the teeth  within the dental arches 
  12. Curve of Spee 
    Anatomic line beginning at the tip of the canines and following the buccal cusps of premolars and molars when viewed from the buccal aspect of the first molars 
  13. Curve of Wilson 
    Curve that follows the cusp tips, as seen from a frontal view.
  14. Sphere of Monson 
    Imaginary sphere that theoretically could rest on the mandibular arch 
  15. Centric Relation
    • Arch-to-arch relationship of the maxillae to the mandible when the condyles are in their most upward position, the mandible is in its most posterior position, and the jaw is most braced by its musculature. 
    • What does this mean?  Tilt head back and close your teeth together
  16. Centric Occlusion
    • Relationship of the occlusal surfaces of one arch to those of the other when the jaws are closed and the teeth are in maximum intercuspation 
    • What? Bite together…it is the way the teeth fit together 
  17. Over Jet
    Facial horizontal overlap of the maxillary teeth
  18. Over Bite
    Amount of facial vertical overlap
  19. Anterior Cross Bite
    Maxillary anterior teeth are lingual to mandibular anterior teeth.
  20. Posterior Crossbite
    The mandibular molar is facial to the maxillary counterpart.
  21. Open Bite
    • Space left between the teeth when the jaw is closed.
    • Anterior teeth do not touch
  22. Edge to Edge
    Incisal surfaces of maxillary teeth occlude with incisal surface of mandibular teeth instead of normal overlapping. 
  23. Occlusal Class I
    • The maxilla and the mandible are in normal relation. (mesognathic) 
    • The mesiobuccal cusp of the maxillary first molar is directly in line with the buccal groove of the mandibular 1st molar
  24. Occlusal Class II
    • The mandible is retruded…it has a distal relationship. (retrognathic) 
    • The buccal groove of the mandibular 1st molar is posterior to the mesiobuccal cusp of the maxillary 1st molar 
  25. Occlusal Class III
    • The mandible is protruded…it has a mesial relationship with the maxilla. (prognathic) 
    • The buccal groove of the mandibular 1st molar is more anterior than normal to the mesiobuccal cusp of the maxillary 1st molar.
  26. Canine Relation
    If both sides of the mandible are in different classes then the canines are used to classify the occlusion.
  27. Lateral excursion 
    When the mandible moves toward the right or left 
  28. Working side 
    The side in which the mandible moves towards 
  29. Nonworking side 
    No teeth are contacting on this side 
  30. Balancing side 
    When working with artificial teeth this nonworking side in considered the nonworking side. 
  31. Canine rise 
    During lateral excursion, the only teeth to touch are the maxillary and mandibular canines on the side to which the jaw is moving. 
  32. Protrusion
    when the mandible moves forward from centric occlusion…the only teeth to touch are the anterior. 
  33. Premature contact 
    This is when one tooth hits first when occluding the teeth together.
  34. Anterior coupling 
    The anterior incisors may also hit but not harder than the posteriors during centric occlusion. 
  35. Maxillary 1st Premolars
    • Premolars succeed the deciduous molars 
    • Four 1st premolars – one in each quadrant 
    • Buccal cusp 1 mm longer than lingual cusp 
    • 2 roots and 2 canals Where? buccal & lingual 
    • Eruption date 10-11 years 
    • Universal numbers 5 & 12
  36. Triangular ridge 
    cusp tip to central groove
  37. Maxillary 2nd Premolar
    • Resembles 1st premolar in form & function 
    • Root of 2nd is longer than the 1st 
    • Crown has a less angular and more rounded appearance 
    • Buccal and lingual cusp even out 
    • Eruption date 10-12 years 
    • Universal numbers 4 & 13
  38. Transverse ridge 
    union of two triangular ridges
  39. Mandibular 1st Premolar
    • Mandibular 1st premolars are always smaller than mandibular 2nd premolars 
    • Lingual cusp so small it does not occlude with teeth – considered afunctional 
    • Occlusal surface slopes towards the lingual 
    • Single root but can tend to bifurcate 
    • Eruption date 10-12 years 
    • Universal Numbers 21 & 28
  40. Mandibular 2nd Premolar
    • ALWAYS larger than a mandibular 1st premolar 
    • Cusps are much more developed – functioning as a molar. How different than a 1st ? 
    • May have 3 pits:  central, mesial & distal 
    • Longitudinal depression of the root in the middle third 
    • Eruption date 11-12 years 
    • Universal Numbers 20& 29
  41. Maxillary 1st Molar
    • Universal # 3 & 14 
    • Largest and strongest teeth in the mouth 
    • Nonsuccedaneous – do not replace a tooth 
    • Five lobes – Three major, one minor, one afunctional (cusp of Carabelli) 
    • Most developed teeth 1st molars – either Maxillary or Mandibular 
    • Erupt 6-7 years – aka 6 year molars 
    • Trifurcated root – Mesiobuccal, Distobuccal (shortest) & Lingual aka palatal 
  42. Oblique Ridge
  43. Maxillary 2nd Molar
    • Universal #  - 2 & 15 
    • Similar to 1st molar but anatomy in a lesser degree 
    • Roots tend to be more fused together 
    • Erupt 11 to 13 years 
    • Occlusal view more rounded
  44. Maxillary 3rd Molar
    • #’s – 1 & 16 
    • Varies the most of any molar in size, shape & position 
    • Roots tend to fuse in to one fused root 
    • Eruption age 17 to 22 years 
    • Most tend to remain impacted due to insufficient space or smaller jaw 
  45. Mandibular 1st Molar
    • Universal # 19 & 30 
    • Typically first permanent tooth to erupt 
    • Eruption – 6 years 
    • Five cusp – 4 major & one minor (distal) 
    • All 5 are functional 
    • Two roots – one mesial & one distal     Where are the roots of the maxillary 1st premolar? 
    • Occlusal view tapers towards the distal
  46. Mandibular 2nd Molar
    • Universal #18 & 31 
    • 4 major cusp nearly equal in size 
    • Eruption – 11 to 13 years 
    • Roots are shorter, closer together with the mesial root being longer and stronger of the two 
    • Occlusal view is rectangular
  47. Mandibular 3rd Molar
    • #'s 17 & 32
    • Roots are often fused together
Card Set
Tooth Morphology
premolars and molars