THE FACE, MOUTH AND PHARYNX 199 



any possible sepsis from entering the orbit. Further, in this 

 way the origin of the inferior oblique muscle of the eye can be 

 preserved intact. The periosteum is elevated over the floor 

 of the orbit until the inferior orbital (spheno-maxillary) fissure 

 is reached. A Gigli saw is passed down into the fissure and 

 brought out again below the zygomatic bone, and the maxilla 

 is then divided. 



The attachment of the lateral nasal cartilage to the frontal 

 (nasal) process of the maxilla is divided, and the nose can then 

 be displaced to the opposite side. One blade of a pair of large 

 bone forceps is passed backwards into the upper part of the nasal 

 cavity, and the other blade into the orbit towards the medial 

 end of the inferior orbital fissure. When the blades are ap- 

 proximated, the frontal process of the maxilla, the lacrimal 

 bone, and the ethmoidal labyrinth (lateral mass) are divided, 

 and the naso-lacrimal duct is torn through. To detach the bone 

 from its attachments posteriorly, the flap must be well retracted, 

 so that a chisel may be inserted into the groove between the 

 maxilla and the pterygoid process (plates) of the sphenoid. A 

 slight blow will effect the separation. The maxilla is still held 

 in place by the hard palate, which has yet to be divided. The 

 mucous membrane is cut through from the original incision in 

 the lip backwards across the gum and along the inner border 

 of the alveolus, and it is continued round the last molar tooth 

 to join the incision along which it was previously split between 

 the cheek and the gum. The palatal aponeurosis and the velum 

 palatinum (soft palate) are freed from the posterior margin of 

 the hard palate, and a saw is passed through the anterior nares 

 and made to cut downwards into the mouth. The maxilla 

 may now be lifted out with the finger and thumb, as it is 

 only attached to a few fibres of the internal pterygoid and 

 the proximal part of the infra -orbital nerve. At this stage 

 severe haemorrhage will occur from the alveolar (dental) 

 branches of the internal maxillary artery if the preliminary 

 step of temporary occlusion of the external carotid has not 

 been adopted. 



The Zygomatic (Malar) Bone may be fractured by direct 

 violence and depressed inwards. It may be levered back into 

 position by a strong periosteum detacher, passed upwards 

 through an incision in the mucous membrane along the line 

 of its reflection from the cheek to the gum. This fracture may 

 be associated with fracture of the maxilla, in which case the 



