1.2

• Heterodont


  Teeth are of different form and type to perform different functions
• Diphyodont dentition


  Have two successive set of teeth e.g. humans

  
• Polyphyodont dentition


  Teeth are continuously replaced e.g. alligators
• Monophyodont dentition


  Have only a single set e.g. whales
• Edentulous


  No teeth! e.g. anteater
• Homodont dentition


  All the teeth are the same in form and type

  
• Animals to research dentition type


  • Dog
  • Cat
  • Platypus
  • Mouse
  • Tiger
  • Monkey
• Deciduous/Primary dentition period


  Eruption (6 months - 2 years)
• Permanent/Adult dentition period


  Eruption (6-21 years)
• Mixed dentition period


  Transitional stage between 6-12 years

  
• Cervical line or Cervix


  Line where enamel and cementum meet, also called cemento-enamel junction (CEJ), separates anatomical crown and root, found at the neck or cervix of tooth

  
• Clinical crown


  That portion of the tooth which is visible in the mouth

  
• Anatomical crown


  That portion of the tooth which is covered by enamel

  
• Anatomical root


  That portion of the tooth which is covered with cementum

  
• Clinical root


  That portion of the tooth which is not visible in the mouth

  
• Types of teeth vary depending on


  • Individual shape
  • Size
  • Location in the jaws
  • Function

  
• Dental arch


  The teeth in a jaw form collectively a dental arch, composed of upper dental arch (maxillary teeth) and lower dental arch (mandibular teeth)

  
• Anterior teeth


  Incisors and canines, occupy the anterior or front of the dental arch

  
• Posterior teeth


  Premolars and molars, occupy the back portion of the arch

  
• Succedaneous teeth


  Permanent teeth that replace or succeed the deciduous teeth e.g. incisors, canines and premolars

  
• Nonsuccedaneous teeth


  Permanent molars

  
• Incisors


  For biting, cutting foods, front teeth, single root, 2 types - central and lateral

  
• Canines (Cuspids)


  For holding, tearing, cutting of food, longest teeth in human dentition, single root, best anchored and most stable teeth

  
• Premolars (Bicuspids)


  Posterior teeth for tearing, holding and grinding, behind the canines and in front of molars, 2 types - 1st and 2nd premolars, have a chewing surface and one or two roots, absent in the deciduous/primary dentition

  
• Molars


  Posterior teeth for grinding, behind the premolars, 3 types - 1st, 2nd and 3rd molars, have a chewing surface and two or three roots

  
• Deciduous dentition


  • Each quadrant has 5 teeth: 2 incisors, 1 canine, 2 molars, one arch has 10 teeth, total in both arches is 20 teeth, dental formula is I 2 C 1 M 2 = 10 x 2 = 20

  
• Permanent teeth


  • Each quadrant has 8 teeth: 2 incisors, 1 canine, 2 premolars, 3 molars, one arch has 16 teeth, total in both arches is 32 teeth, dental formula is I 2 C 1 P 2 M 3 = 16 x 2 = 32