NASOFRONTAL REGION IN MAN 



141 



Witness, for example, the dissection represented in figui'e 1 1 . 

 Hei'e the sinus frontalis is very small. In fact, partly eth- 

 moidal in topoj2;ra]:)hy. The interesting thing about this case 

 is that the sinus frontalis was bilaterally very diminutive in size. 

 Its communication (fig. 11) with the recessus frontalis of the 

 meatus nasi medius is established by means of a large ostium 

 frontale in the same axis as the infundibulum ethmoidale. 



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. Sinusfronfalis 



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Fig. 11 Dissection from an adult. Recessus frontalis exposed. Note the 

 diminutive sinus frontalis and the absence of a ductus nasofrontalis. "The 

 views held on the presence and absence of the sinus frontalis are, doubtless, largely 

 due to differences of opinion as to what should be called a sinus frontalis, and how 

 far the development must have progressed into the frontal region before the cell 

 has reached the dignity of a sinus frontalis." (J. P. Schaeffer). 



The dissection shown in figure 9 likewise presents the sinus 

 frontalis in duplicate in which no ductus nasofrontalis is pres- 

 ent. Each sinus communicates with the recessus frontalis by 

 means of a large ostium frontale. On the other hand, one en- 

 counters specimens with true ductus nasofrontales. Some of 

 these ducts are straight and short (fig. 6), others straight and 

 long (figs. 12 and 13). Again, the ductus nasofrontalis may be 

 long and more or less serpentine. Witness, for example, the 

 specimen shown in figure 7. Here is a sinus frontalis with a long. 



