CH. V.J 



THE TEETH. 



From this formula it will be seen that the two bicuspid or pre- 

 molar teeth in the adult are the successors of the two deciduous 

 molars in the child. They differ from them, however, in some 

 respects, the temporary molars having a stronger likeness to the 

 permanent than to their immediate descendants the so-called 

 bicuspids, besides occupying more space in the jaws. 



The temporary incisors and canines differ from their successors 

 but little except in their smaller size and the abrupt manner in 

 which their enamel terminates at the necks of the teeth, forming 

 a ridge or thick edge. Their colour is more of a bluish white 

 than of a yellowish shade. 



The following tables show the average times of eruption of the 

 Temporary and Permanent teeth. In both cases the eruption of 

 any given tooth of the lower precedes, as a rule, that of the 

 corresponding tooth of the upper jaw 



Temporary or Milk Teeth. 



The figures indicate in months the age at which each tooth appears. 



Permanent Teeth. 

 The age at which each tooth is cut is indicated in this table in years. 



The times of eruption given in the above tables are only 

 approximate : the limits of normal variation are tolerably wide. 

 Certain diseases affecting the bony skeleton, e.g., Rickets, retard 

 the eruptive period considerably. 



It is important to notice that it is a molar which is the first 

 tooth to be cut in the permanent dentition, not an incisor as in 

 the case of the temporary set, and also that it appears behind the 

 last deciduous molar on each side. 



The third molars, often called Wisdoms, are sometimes unerupted 

 through life from want of sufficient jaw space and the presence of 



