BIOLOGY IN HUMAN AFFAIRS 



walls consist of a single layer of endothelial cells, break 

 down, allowing the blood to ooze out into the tissues. 

 Hemorrhage is therefore the most outstanding change 

 resulting from vitamin C deficiency; but another effect, 

 namely, rarifaction of the bones, is of great importance. 

 While scurvy is developing, the bones become rarified and 

 fragile. Rarifaction of the alveolar bone which forms the 

 sockets of the teeth is the cause of looseness of the teeth 

 seen in scurvy. 



Approximately forty days of total deprivation of vitamin 

 C causes the appearance of the clinical signs of scurvy. 

 Hojer made the interesting observation that in approxi- 

 mately half the time required to produce clinical scurvy 

 the odontoblastic layer in the teeth is affected. If approxi- 

 mately seven-tenths or eight-tenths of the minimum protec- 

 tive dose of vitamin C is given to guinea pigs for ten to 

 fourteen days, the odontoblastic membrane will show 

 abnormal structure, the cells being of unequal size. If but 

 half the minimum protective dose is given, the odonto- 

 blastic layer will have separated from the dentine, the 

 fibrils apparently having become detached. If but three- 

 tenths, or thereabouts, of the protective dose is given, 

 the odontoblastic layer will have broken up into islets 

 of distorted cells. This may be of great significance to 

 the health of human teeth, since doubtless many people, 

 at different times, have gone for more than twenty days 

 entirely without a supply of vitamin C. If changes compar- 

 able to those in the guinea pig take place in the human 

 teeth, it is not unreasonable to suppose that subsequent 

 death of the pulp would be the result of this type of specific 

 starvation. The frequent occurrence of lifeless pulps in 

 otherwise normal-appearing teeth demands an explanation 

 as to its etiology. The recent researches on animals showing 

 odontoblastic damage seem to account for the condition 

 seen in many human teeth. 



[372] 



