1380 



SUKFACE AND SUEGICAL ANATOMY. 



Nasal septum 



Inferior concha 



Anterior cranial fos 



Nasal cavity ^H 



*. Crystalline lens 



of the eyeball 



Buccal cavity ~<&|fc-~ 

 \ 



Mandible. 

 Meckel's cartilage 



* -$-- Palatine process 



JMMtfL Dental lamina 



^-.Tongue 

 - Dental lamina 



FIG. 1080.- 



-FRONTAL SECTION THROUGH THE FACE OF A HUMAN EMBRYO 

 AT THE SEVENTH WEEK. 



not extend forwards into the hard palate. The cleft in the latter is spoken of as single 

 or double according to whether the palatal processes have failed to unite with the lower 

 edge of the nasal septum on one, or on both, sides. When the cleft extends forwards 



through the alveolar 

 process to become 

 continuous with a 

 cleft of the lip, the 

 medial (premaxillary) 

 edge of the cleft is 

 usually projected for- 

 wards in advance of 

 the lateral (maxillary) 

 edge. Before pro- 

 ceeding to repair the 

 cleft in the lip, the 

 projecting premaxil- 

 lary edge is forced 

 back into line with 

 the maxillary edge. 



In what is known 

 as a complete double 

 cleft palate, the pala- 

 tine processes fail to 



join the nasal septum and the premaxillse on both sides ; the result is a wide median cleft 

 which communicates with both nasal cavities. The free inferior border of the vomer 

 extends along the middle of the cleft to be continuous anteriorly with the rounded pre- 

 maxillary mass ; 

 the latter, along 

 with the central 

 portiqn of the up- 

 per lip, is projected 

 forwards between 

 the two labial 

 clefts, often to such 

 an extent that it 

 appears to spring 

 from the tip of the 

 nose (Fig. 1081). 



In Operating O11 inferior concha "I 



Such a double hare- Central portion of 



lip the first step is upperlip 



to get rid of the 

 premaxillary pro- 

 jection. This is 

 done, not by re- 

 moving it alto- 

 gether, but by 

 removing a trian- 

 gular portion of 

 the septum of the 

 nose behind it, so 

 as to allow of its 

 being bent back 

 into line with the 

 alveolar processes 

 of the maxillae. 

 The base of the 

 triangular piece of 

 bone should not be 

 taken from the 



constricted portion of neck of the premaxillary projection, but should consist of the olive- 

 shaped thickening situated immediately behind the neck. This thickening is crossed 

 by the transverse suture uniting the premaxilla with the anterior extremity of the 



Ala nasi 

 Anterior extremity of 



Premaxilla - 



Left nasal cavity - 



Lateral edge of left 

 labial cleft 

 Right nasal cavity - 

 Nasal septum--' 

 Palatine process^, . 

 of right maxilla^ 



Tongue- 

 Lower lip- 



FIG. 1081. FROM A PHOTOGRAPH SHOWING DOUBLE COMPLETE HARE-LIP 

 AND CLEFT PALATE. 



