TEETH. 



61 



plantar ligaments ; those of the fourth and fifth by dorsal and plantar 

 ligaments with the cuboid. 



The heads of the metatarsal bones are united to each other by a 

 strong transverse ligament : and to the phalanges by two lateral, the 

 plantar, and an expansion of the extensor tendon. 



The phalanges. — Their ligaments are arranged similarly to those 

 of the hand. 



TEETH. 



The teeth are placed in the alveolar processes of the upper and 

 lower jaw, and are the hardest portion of the human body. The 

 permanent teeth are thirty-two in number, sixteen in each jaw; they 

 are divisible into four classes. On each side of each jaw there are 

 two incisors^ one cuspid, two bi-cuspid and three molars ; each 

 tooth consists of a body or crown, which is the part exposed above 

 the gum ; the neck, a narrow portion surrounded by the gum ,- and 

 a root or fang which is contained within the alveolus. The roots 

 are surrounded by a periosteum, and perforated at their extremities 

 by a foramen for the transmission of an artery and nerve. 



Fig. 49. 



Incisors, — Are next to the median line ; their edge is bevelled, 

 and in early life serrated ; the root is single and conoidal ; those of 

 the upper jaw are larger than those of the lower jaw. 



Cuspid, or Canine. — Is next to incisors. Its body is conoidal, 

 and it has the longest root. Those of the upper jaw are sometimes 

 called eye-teeth, those of the lower jaw stomach-teeth. 



Bi-cuspid. — Are next in size to the molars. The body has two 

 grinding points, of which the external is the larger. The root is 

 sometimes bifid and grooved upon either side. The anterior is the 

 smaller. 



Molars. — They have large quadrilateral bodies, with four or five 



a 



