Teeth of the Guinea-pig, irrodMced hy a Scorbutic Diet. 511 



corroborated the observations made on animals. This fact establishes beyond 

 doubt the identity of the disease in the three cases. 



In drawing from the above experiments conclusions bearing on human 

 subjects, one is fully alive to the fact that more work, both of an experi- 

 mental and statistical nature, will have to be done before definite conclusions 

 can be drawn. At present, no satisfactory explanation has been advanced 

 for the great prevalence of tooth decay amongst civilised communities. This 

 investigation suggests that deficiency in diet forms a reasonable working 

 hypothesis on which future research may be based. It is true that adult and 

 even infantile scurfy is more or less rare in most civilised countries, but this 

 appUes to the well declared form of the disease. Our animal experiments 

 show definitely that the scur^-y may be of an extremely mild form, and yet 

 produce very marked changes in the teeth. Hess (1917) shows how children 

 may suffer from " subacute " scurvy by no means easily recognised. He 

 further defines another type, which he calls " latent scurvy," which is a state 

 of malnutrition, and can only be diagnosed by the improvement in the state 

 after the administration of an antiscorbutic. It is evident that such transient 

 conditions of infantile scurvy may occur more often than is usually suspected, 

 and may reasonably be expected to influence dentition. It has already been 

 pointed out that it is not advisable to speculate too much at this stage. One 

 thing is certain, that the problem invites further investigation. Our know- 

 ledge of nutrition has advanced rapidly during the last decade. Besides the 

 antiscorbutic factor there are at least two other accessory factors which are 

 vital to our existence. One is the antineuritic, sometimes called the anti- 

 beri-beri " \itamine," and the other the " fat soluble " factor discovered by 

 McCollum and Davis (1914). That the polyneuritic condition known as 

 beri-beri is produced by the dietetic deficiency of the former is now almost 

 universally acknowledged. The actual pathological changes in human 

 subjects caused by the dietetic deficiency of the " fat soluble " factor have 

 not yet been defined, but that it is indispensable for rats has now been shown 

 beyond doubt. Other nutritional irregularities due to protein deficient in 

 certain amino-acids, or to certain inorganic constituents of the diet, are also of 

 supreme importance, and it would be of interest to study their effect on the 

 teetL 



An investigation, in which some of these factors are being studied for a 

 different purpose, is at present being carried on at the Lister Institute, and 

 it is hoped that the post-vimiem material may be utilised for further dental 

 investigations, with the object of throwing more light on the function of the 

 diet in dental hygiene. 



