CHAPTER VIII 



EFFECTS ON THE TEETH 



Like the skeleton, the teeth appear very resistant to inanition in general, 

 though especially susceptible to rickets and scurvy. After a brief summary, the 

 effects of inanition upon the teeth will be considered under (.4) total inanition, 

 or on water only ; and (B) partial inanition. 



Summary of Effects on the Teeth 



In total inanition, or on water alone, the teeth in adults show no appreciable 

 change in weight or structure, but there are slight changes in chemical composi- 

 tion, especially in chronic (incomplete) inanition. In the young, such inanition 

 may delay the process of dentition, but persistent growth and development of 

 the teeth (as of the skeleton) occur in young rats held at constant body weight 

 by underfeeding. 



The effects of partial inanition have been studied chiefly in rickets and 

 scurvy. In both human and animal rickets there is delayed and abnormal 

 dentition. Both enamel and dentine may be defective and imperfectly calci- 

 fied. Caries and lesions of the peridental membrane are frequent; but the dental 

 defects are not closely correlated with the skeletal lesions, and are exceedingly 

 variable in both human and animal rickets. 



In scurvy, the gums are markedly congested and swollen in about 80 per cent 

 of the adult human cases, but apparently in a much smaller proportion of guinea 

 pigs. The alveolar bone and peridental membrane undergo necrosis, with 

 consequent loosening of the teeth, and ulcerations or pyorrhea may occur 

 (more rarely in animals). Congestion and hemorrhage appear very early in 

 the dental pulp (guinea pig), with consequent pulpar degeneration and fibrosis, 

 and possibly osteodentine formation. Scorbutic changes may affect the teeth 

 before eruption, even in the fetus. Recovery of normal structure in the teeth 

 is possible upon antiscorbutic diet, unless extreme degeneration has occurred. 



(A) Effects of Total Inanition or on Water Alone 



Comparatively few observations have been made upon the teeth during 

 simple inanition. Weiske ('97) noted that in 4 adult rabbits 7-1 1 days on 

 distilled water alone, with loss of 35-41 per cent in body weight, there is a slight 

 decrease in the organic content of the teeth, with corresponding relative increase 

 in the inorganic content. Trowbridge, Moulton and Haigh ('18), in connection 

 with an elaborate study of the changes in seven yearling steers subjected to 

 various planes of prolonged underfeeding, found an apparent increase in the 

 weight of the teeth, even with stationary or decreasing body weight. The 



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