7> 



THE SKELETOX 



The BASE OF TiiF. SKULL is Very invjiular, and extends from the ineisor teeth to the 

 occipital {)rotuhcrance. Laterally it is limited liy the zygomatic arches. Anteriorly 

 it presents the hard i)alate. \Mien the skull is inverted, the hard j^alate stands at 

 a higher level than the rest; it is bounded anteriorly and laterally l)y the alveolar 

 ridges containing the teeth. The bones appearing in the intermediate space 

 are the premaxillary and palatine portions of the maxillae, and the horizontal 

 plates of the i^alate "bones. The bone is rough for the attachment of the muco- 

 perio.^teum. The following points are readily recognised (fig. 81): — 



The meso-palatine suture commences at the alveolar point, traverses the 

 anterior ]>alatinc fossa, and terminates at the posterior nasal spine. 



The transverse palatine suture between the palate bones and palatine processes 

 of the maxillai. 



In young skulls the maxillo-premaxillary sutures, and behind the incisor 

 teeth four small openings known as the gubernacular canals. 



The anterior palatine fossa containing the termination of four canals: two 

 small orifices, foramina of Scarpa, situated one l)ehind the other in the meso- 

 palatine suture; and two larger openings, the foramina of Stenson. Scarpa's 

 foramina transmit the naso-palatine nerves; Stenson' s are in relation with Jacob- 

 son's organs. 



At the posterior angles of the hard palate are the posterior palatine foramina, 



Fig. 81.— Hard Palate of a Child Five Years Old. 



GUBERNACULAR CANALS 



ANTERIOR PALATINE FOSSA 

 MAXILLO-PREMAXILLARY SUTURE 



PALATE PROCESS OF MAXILLA 



.-- POSTERIOR PALATINE FORAMEN 

 - ACCESSORY PALATINE CANALS 



through which the posterior palatine vessels and the anterior i)alatino nerves 

 emerge on to the palate; a thin lip of bone separates them from the accessory 

 palatine foramina for the posterior palatine nerves. The accessory foramina are 

 ill tlic tulxTdsity of the ])alate bone. 



The hamular process of the internal pterygoid plate is the most posterior limit 

 of the hard palate 



At the ])osterior extremity of each alveolar ridge is the tuberosity of the maxilla. 

 Between the tuberosities of the maxilla and the palate bone are a few minute 

 foramina (varia])le in number and not always present), the external palatine 

 canals for tin; external palatine nerves. 



Behind the hard ])alatc are the posterior nares, se]:)arated from each other liy 

 the vomer. Eacli is bounded externally by the internal pterygoid plate; below by 

 the horizontal ])late. of thc^ palate bone"; above by the under surface of the body 

 of the sphenoid, with the ala of the vomer and a'i)ortion of the sphenoidal process 

 of the ])alate bone. 



E.xternal to the nares there is on each side a vertical fossa lying betwcnui the 

 pterygoid plates. It extends u])wards to the under surface of the greater wings of 

 the spluMioid; it is completed anteriorly by the coalescence of the pterygoid i)lates, 

 and below l)y th(^ tul)erosity of the palate bone. It contains the following points 

 of interest : — 



