ACROMEGALY 831 



extent show a tendency to become thinner in their platee. Osborne also 

 comments on the enlargement of all crests, tuberosities and eminences in 

 the direction of muscular action and finds this due to part of the tendons 

 becoming coossified with the bones rather than to a reaching out of the peri- 

 osteal bone formation. On the whole, the description by Osborne is very 

 similar to that given of the skeleton of our own case. . (Figs. 7, 15.) He, 

 too, found, osteophytes in the joints and roughened articular surfaces. 

 Furnivall also described bone deposits at the attachment of muscles and 

 ligaments and at the margins or articulations, but in his case the joints 

 themselves were not affected. The joints were also normal in Israel's case. 



The Skull. We will not enter into details regarding other bones, but 

 the changes in the skull, on which depend the earliest and most reliable 

 diagnostic signs of the disease, deserve especial mention. They have been 

 analyzed in a most lucid and original manner by Keith. 



Availing himself of all the acromegalic skeletons to be found in Lon- 

 don, Keith attempted a an exact inquiry into the nature of the growth 

 changes of the skeleton, particularly of the skull." 



Growth Changes in the Palate. "By the palatal area is meant the 

 space bounded anteriorly and at the sides by the outer alveolar margin and 

 behind by a base line drawn from one side of the palate to the other behind 

 the last molar tooth. This area is actually diminished in the acromegalic, 

 especially that of the lower dental arcade." "Besides the reduction in the 

 size of the lower alveolar area there are also certain constant and well 

 marked growth changes in the alveolar part of the lower jaw of the acro- 

 megalic : 



"1. The width between the last lower molars is increased in the mean 

 by nearly ten mm. so that the right and left lower molars, in place of being 

 nearer together than the upper are wider apart and project beyond the 

 upper dental arcade. 



"2. The canines are advanced so as to come more nearly into a trans- 

 verse line with the incisors. 



"3. Porous vascular bone is heaped upon the alveolar margin elevat- 

 ing the dental sockets. The vault of the hard palate is thus increased ; the 

 mean height of the alveolar margin measured from the hard palate oppo- 

 site the second molar tooth is 17.5 mm. in the acromegalic and 12.5 in 

 English students. Similarly, the lower alveolar margin of the mandible is 

 raised, the tooth sockets being elevated at the same time. The separation 

 of the teeth which occurs in acromegaly is due to the alveolar or socket 

 elevation, not to a linear increase of the alveolar margin. The growth at 

 the alveolar margins and the elevation of the dental sockets are supposed 

 to be stimulated by the pressure brought to bear on those parts during mas- 

 tication. Pressure cannot influence the linear dimensions of the alveolar 

 arch ; that depends on the number and size of the teeth." 



Growth Changes in the Mandible. "As regards the body of the jaw, 



