VAN 221: Veterinary Splanchnology and Applied Anatomy (1+1)

Teeth

TEETH ( OX )

• The teeth are hard, white or yellowish-white structures implanted in the alveoli of the jaws
• They are organs of prehension, mastication and sometime of defence
• The domestic mammals have two sets of teeth
• The teeth of the first set appearing in the early life are known as the milk or deciduous teeth (temporary) and these are replaced later during the period of growth by permanent teeth
• According to their position they are classified as,
  • Incisors or cutting teeth are implanted, in front in the alveoli of the premaxilla and mandible
  • Canines which are situated a little backwards.
  • Premolars and molars (cheek teeth) - forming the sides of the dental arch.
• The complete dentition of an animal can be expressed in a condensed form in a dental formula
• In this formula letters indicate the kind of teeth and the figures above and below express the number of teeth in the upper and lower jaws on each side
• The individual teeth are designated numerically beginning from the midline as first, second and so on
• The canines are known as fangs or tusks. The vestigial first premolar is known as wolf tooth.
• The dental formula for the Ox is 2 (I –0/4 C – 0/0 PM – 3/3 M – 3/3) = 32

Parts of tooth

• Each tooth presents for description a part above the gums the crown, and a part inside the gums and embedded in the alveolus is known as the root or fang
• The line of union of the crown and root is the neck. The crown is made up of dentine covered over by enamel
• The root, which is embedded in the alveolus, consists of dentine and covered by cementum
• The surface of the tooth by which it is in contact with the tooth of the opposite jaw is the table or grinding surface
• The surface facing towards the lip is the labial surface, towards the tongue is the lingual surface and towards the cheek is the buccal surface
• Simple and complex teeth -  Simple tooth is one, the crown of which is covered by the enamel
• A complex tooth is one, where the enamel covering the crown forms one or more invaginations on the table.

Teeth are composed of 4 tissues from within outwards

• Pulp, dentine cement and enamel
  • The pulp of the tooth is a soft gelatinous tissue, which occupies the pulp cavity, in the centre of the tooth
  • The pulp is well supplied with blood vessels and nerves. In growing tooth, it is very extensive but decreases as age advances
  • The dentine is ivory like and forms the bulk of the tooth and covers the pulp
  • It is hard and yellowish white
  • The enamel is the hardest tissue in the body and covers the dentine of the crown
  • It is clear and bluish white in colour and forms the protective covering over the teeth
  • The cement or crusto petrosa covers the dentine of the root
  • The root of the tooth is firmly attached to the alveolus by a vascular layer of connective tissue the alveolar periosteum (Periodontal membrane)