46 



SURGICAL ANATOMY OF 



spheno- maxillary; and of two fissures, the spheno-max- 

 illary and ptery go-maxillary. The relation of these 

 fissures and cavities to the body of the bone is of great 

 importance in the process of its removal. The apex of 

 the antrum corresponds on the face to its malar process; 

 the base of which looks inwards to the outer wall of the 

 nose; and its roof is formed by the orbital plate, and its 



FIG. 5. 



FIG. 6. 



FIG. 7. 



Fig. 5 shows the defective development of the superior maxillary bones, from 

 a frjetus seven months old; and Figs. 6, 7 show the central mass formed of two 

 portions. In these cases, particularly in Fig. 5, the fact of the central portion 

 being composed of two intermaxillary bones is well seen, the fissure being in the 

 mesial line exactly under the nostril. (FERGUSSON.) 



floor by the alveolar process. The walls of the antrum 

 are very thin, so that growths or collections of fluid 

 readily cause a bulging of its parietes and protrusions 

 into neighboring cavities or fissures. The fangs of the 

 first and second molar teeth project into its floor, hence 

 the importance of extracting one of these teeth and per- 



