304 



I. REICIIBORN-KJENNERUD 



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Fig. 4. Osteoclasts (vertical arrow) and osteoblasts (horizontal arrow) in 

 the same bone marrow space as that shown in the marginal part of the septum 

 in Fig. 3. On the top of the septum, osteoid lined by osteoblasts can be seen. 

 (X 150.) 



very little or no loss of alveolar bone in adults who have had a 

 chronic gingivitis for a long time. This has been reported by Peder- 

 sen ( 1937, 1939 ) and Hilming and Pedersen ( 1940 ) , who also found 

 that gingivitis in the Eskimos on the west coast of Greenland is 

 followed by the same breakdown of alveolar bone that Europeans 

 have in cases of gingivitis. These Eskimos live together with the 

 white population and eat their type of food. The lack of alveolar 



