112 



HISTOLOGY 



vessels and nerves which are branches of those about to enter the apical 

 foramen. Around the neck of the tooth, dense connective tissue forms the 

 circular ligament (Lig. circulare dentis). 



The gum (gingiva) is the part of the lining of the mouth which sur- 

 rounds the tooth. It is covered by the stratified oral epithelium, in which 



Dental sac. 



Outer layer. Inner layer. 



Outer enamel cells. 



Enamel pulp. 



Inner enamel cells. 



Enamel. 



Dentine 



Odontoblasts 



Dental papilla - 

 (future pulp) 



Blood vessel. 

 Bony trabecula of the lower jaw 



FIG. 102. LONGITUDINAL SECTION OF A DECIDUOUS TOOTH OF A NEWBORN DOG. X 42. 

 The white spaces between the inner enamel cells and the enamel are artificial, and due to shrinkage. 



intercellular bridges are well developed, and this epithelium rests on tall 

 connective tissue elevations or papillae. There are no glands in the gums. 

 When the tooth erupts it makes a hole through the epithelium, but the 

 margins of the aperture become inverted. Thus the epithelium extends 



