196 OSTEOLOGY. 



In viewing the skeleton of the face the observer is struck with the large 

 proportionate size of the orbital and nasal apertures. The former are circular in 

 outline, with sharp crisp margins. Under cover of the zygomatic process of the 

 frontal bone the roof and lateral wall of the orbit is deeply recessed. The fossa 

 sacci lacrimalis is oftentimes directed more towards the facial aspect than towards 

 the orbital cavity. The superior and inferior orbital fissures are proportionately large, 

 and the latter, in the macerated skull, forms a wide channel of communication 

 with the fossa infratemporalis. The nasal aperture, apertura piriformis, is cordate 

 in form, and exhibits a greater proportionate width than is met with in the adult ; 

 its inferior margin is not far beneath the level of the inferior orbital margins. 

 The vertical depth of the maxillae is small, and as yet the processus alveolaris is 

 imperfectly developed, its inferior edge lying but little below the level of the 

 inferior border of the arcus zygomaticus. Sunk in the alveolar border at this 



Position of fonticulus frontalis 



Tuber parietale 



Position of 



-fonticulus 



occipitalis 



Cartilaginous 



nasal septum -0| ISfc^ ^^F Suture between 



TL . interparietal and 

 supra-occipital parts 

 of occipital bone 



Fonticulus mastoideus 



FIG. 183. LATERAL ASPECT OF THE SKULL AT BIRTH. 



stage may be seen the relatively large hollows in which the dental sacs are lodged. 

 Within the body of the maxilla the maxillary sinus is represented by a shallow 

 groove, disposed in relation to the middle meatus of the nose. For this reason the 

 space separating the orbital floor from the palatine surface of the bone is small, 

 but is later increased to its adult proportions by the enlargement of the maxillary 

 sinus and the consequent expansion of the body of the maxilla. 



Viewed from the inferior surface, the hard palate is shallow, owing to the poor 

 development of the alveolar border. The sutures between the ossa incisiva and 

 the processus palatini of the maxillae are readily recognisable, and the vertical 

 height of the choanse is seen to be relatively small, owing to the perpendicular parts 

 of the palate bones not having reached their adult proportions. 



The mandible consists of two parts united, in the median plane in front, by 

 fibrous tissue to form the symphysis. The alveolar border is deeply grooved for 

 the reception of the dental sacs, whilst the remaining substance of the body of 

 the bone is but slightly developed. The foramen mentale pierces the bone about 

 midway between its superior and inferior borders. 



