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A MANUAL OF ANATOMY 



Upper 



Lower 



Incisors 



Upper 



Canines 



I^owet 



Upper 



Lower 



BiCUSJ'iDS 



Upper 



Lower 



Pig g2. — The Permanent Teeth 

 OF THE Left Side. 



The Permanent Teeth. — Pro-, 

 ceeding from the median line in a 

 direction outwards and backwards, 

 the permanent teeth are as fol- 

 lows: mesial incisor, lateral in- 

 cisor, canine, first bicuspid, second 

 bicuspid, and first, second, and 

 third molars. The third molar is 

 known as the dens sapientics or 

 wisdom tooth. Each tooth is 

 composed of the following parts: 

 the crown, which is the part above 

 the gum; the root, which is the 

 part embedded in the alveolus; 

 and the neck, which lies between 

 the crown and root. The surface 

 of a tooth which looks towards the 

 lip is called labial, and that look- 

 ing towards the tongue lingual, 

 whilst of the opposed surfaces one 

 is called mesial or proximal, and 

 the other lateral or distal. 



The Incisors. — There are eight 

 incisor teeth — two in each upper 

 jaw, and two in each half of the 

 lower jaw. In each case the two 

 incisors are known as mesial and 

 lateral respectively, and they are 

 called ' incisor ' because their 

 crowns are so formed as to be 

 adapted for the division of food. 

 The cutting edges of the crowns 

 of the upper incisors are bevelled 

 behind, and those of the lower 

 incisors in front. 



The upper mesial incisor is larger 

 than the lateral, and it gradually 

 tapers from the cutting edge of 

 the crown to the root. The length 

 of the crown exceeds its breadth. 

 The labial surface is slightly con- 

 vex, whilst the lingual surface 

 is concave. The Ungual surface 

 Molars prcscuts near the gum a ridge, 

 called the basal ridge, or cingulum. 

 The mesial angle of the cutting 

 edge of the crown is longer or more 

 projecting than the lateral angle. 

 The root is long, tapering, 

 conical, and slightly flattened on 

 either side. 



