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PETEE BASSOE 



growth is seen to have taken place (1) in the alveolar margin, (2) on the 

 mental eminence, (3) on the lower margin anterior to the groove for the 

 facial arterjr. The most remarkable changes are seen in the ramus; the 

 double process of deposition and absorption has completely altered the 

 character of the ramns. (Fig. 16.) It has become markedly narrower; 

 the region of the angle has been absorbed and hence the appearance of an 

 opening-out of the angle between the ramus and the body of the jaw in the 

 acromegalic. The ascending ramus has increased in height. Its average 

 height in the normal as measured from the lowest insertion of the masseter 

 to the upper surface of the condyle is 65 mm. while in three acromegalic 



Fig. 16. Drawings of lower jaw from cases of acromegaly contrasted with draw- 

 ings from normal English skull (indicated by heavy outline). The dotted areas are 

 those which are absorbed, the shaded those which are deposited. (After Arthur Keith, 

 Lancet, Lond., 1911.) 



skulls it measured 90, 92, and 95 mm. respectively. The growth has 

 taken place at the points of pressure ( temper o-maxillary joint) and 

 traction (coronoid process)." Another growth change is caused by 

 absorption of bone from the inner side of the ramus and deposition of 

 bone on its outer side so that the rami become more widely separated 

 which increases the width of the mouth and pharynx. 



Keith similarly compares the bone changes in the temporal, frontal 

 and occipital region of the skull of acromegalics with normal and gorilla 

 skulls. Thus he points out that the forward growth of the frontal bone 

 leads to a most remarkable transformation. "When viewed in absolute 

 profile the anterior part of the temporal ridge falls 15 to 20 mm. behind 

 the line of the frontal pole of the brain in normal crania but in acromegaly 

 this ridge may pass forward until it is in a line with the frontal pole or it 

 may even pass in front of it. We have here a key to the great growth of 

 the supraorbital ridges and expansion of the frontal sinuses in the aero- 





