SURGICAL ANATOMY OF THE BONES OF THE FACE. 121 



and the tympanum and the membrana tympani be ruptured, as is frequently the case ; again, if 

 the fissure passes across the pituitary fossa and the muco-periosteum covering the under surface 

 of the body of the sphenoid is torn, blood will find its way into the pharynx and be swallowed, 

 and after a time vomiting of blood will result. Fractures of the anterior fossa, involving the 

 bones forming the roof of the orbit and nasal fossa, are generally the results of blows on the fore- 

 head ; but fracture of the cribriform plate of the ethmoid may be a complication of fracture of 

 the nasal bone. When the fracture implicates the roof of the orbit, the blood finds its way 

 into this cavity, and, travelling forward, appears as a subconjunctival ecchymosis. If the roof 

 of the nasal fossa be fractured, the blood escapes from the nose. In rare cases there may 

 be also escape of cerebro-spinal fluid from the nose where the dura mater and arachnoid have 

 been torn. In fractures of the posterior fossa extravasation of blood may appear at the nape of 

 the neck. 



The bones of the skull are frequently the seat of nodes, and not uncommonly necrosis 

 results from this cause, also from injury. Necrosis may involve the entire thickness of the 

 skull, but is usually confined to the external table. Necrosis of the internal table alone is rarely 

 met with. The bones of the skull are also frequently the seat of sarcomatous tumor. 



The skull in rickets is peculiar: the forehead is high, square, and projecting, and the 

 antero-posterior diameter of the skull is long in relation to the transverse diameter. The bones 

 of the face are small and ill-developed, and this gives the appearance of a larger head than 

 actually exists. The bones of the head are often thick, especially in the neighborhood of the 

 sutures, and the anterior fontanelle is late in closing, sometimes remaining unclosed till the 

 fourth year. The condition of craniotabes has by some been also believed to be the result 

 of rickets, by others is believed to be due to inherited syphilis. In all probability it is due 

 to both. In these cases the bone undergoes atrpphic changes in patches, so that it becomes 

 greatly thinned in places, generally where there is pressure, as from the pillow or nurse's arm. 

 It is. therefore, usually met with in the parietal bone and vertical plate of the occipital bone. 



In congenital syphilis deposits of porous bone are often found at the angles of the parietal 

 bones and two halves of the frontal bone which bound the anterior fontanelle. These deposits 

 are separated by the coronal and sagittal sutures, and give to the skull an appearance like a 

 "hot cross bun!" They are known as Parrot's nodes, and such a skull has received the name 

 of natiform, from its fancied resemblance to the buttocks. 



In connection with the bones of the face a common malformation is deft palate, owing to 

 the non-union of the palatal processes of the maxillary or pre-oral arch. This cleft may involve 

 the whole or only a portion of the hard palate, and usually involves the soft palate also. The 

 cleft is in the middle line, except it involves the alveolus in front, when it follows the suture 

 between the main portion of the bone and the pre-maxillary bone. Sometimes the cleft runs 

 on either side of the pre- maxillary bone, so that this bone is quite isolated from the maxillary 

 bones and hangs from the end of the vomer. The malformation is usually associated with 

 hare-lip, which, when single, is almost always on one side, corresponding to the position of the 

 suture between the lateral incisor and canine tooth. Some few cases of median hare-lip have 

 been described. In double hare-lip there is a cleft on each side of the middle_line. 



The bones of the face are sometimes fractured as the result of direct violence. The two 

 most commonly broken are the nasal bone and the inferior maxilla, and of these the latter is by 

 far the most frequently fractured of alK the bones of the face. Fracture of the nasal bone is 

 for the most part transverse, and takes place about half an inch from the free margin. The 

 broken portion may be displaced backward or more generally to one side by the force which 

 produced the lesion, as there are no muscles here which can cause displacement. The mala.r 

 bone is probably never broken alone ; that is to say, unconnected with a fracture of the other 

 bones of the face. The zygomatic arch is occasionally fractured, and when this occurs from 

 direct violence, as is usually the case, the fragments may be displaced inward. This lesion is 

 often attended with great difficulty or even inability to open and shut the mouth, and this has 

 been stated to be due to the depressed fragments perforating the temporal muscle, but would 

 appear rather to be caused by the injury done to the bony origin of the Masseter muscle. 

 Fractures of the superior maxilla may vary much in degree, from the chipping off' of a portion 

 of the alveolar arch, a frequent accident when the "old key" instrument was used for the 

 extraction of teeth, to an extensive comminution of the whole bone from severe violence, as the 

 kick of a horse. The most common situation for a fracture of the inferior maxillary bone is in 

 the neighborhood of the canine tooth, as at this spot the jaw is weakened by the deep socket for 

 the fang of this tooth ; it is. next most frequently fractured at the angle ; then at the symphysis, 

 and finally the neck of the condyle or the coronoid process may be broken. Occasionally a 

 double fracture may occur, one in either half of the bone. The fractures are usually compound, 

 from laceration of the mucous membrane covering the gums. The displacement is mainly the 

 result of the same violence as produced the injury, but may be further increased by the action 

 of the muscles passing from the neighborhood of the symphysis to the hyoid bone. 



The superior and inferior maxillary bones are both of them frequently the seat of necrosis, 

 though the disease affects the lower much more frequently than the upper jaw, probably on 

 account of the greater supply of blood to the latter. It may be the result of periostitis, from 

 tooth irritation, injury, or the action of some specific poison, as syphilis, or from salivation by 

 mercury ; it not unfrequently occurs in children after attacks of the exanthematous fevers, and 

 a special form occurs from the action of the fumes of phosphorus in persons engaged in the 

 manufacture of matches. 



