EFFECT OF HIBERNATION ON TEETH ^95 



crobial activit\' dnriiicr hibernation l:)ecause the factors of moisture 



o 



and temperature during hibernation are inimical to growth of micro- 

 organisms. 



Hunt et ill. (1957) cited work which conckided that endocrine 

 secretions are a factor in dental caries, but here again Mayer and 

 Bernick ( 1959 ) have indicated a general involution of the endocrine 

 system during hibernation. Two points in Hunt's paper may point 

 the way to a possible explanation of the extensive dental caries in 

 captive Arctic ground squirrels. One involves dietarv factors, which 

 have an evident effect on caries. The other is that a desalivated 

 animal, in which conditions similar to those of an animal in hiberna- 

 tion are simulated, is not able to wash food awav from its teeth as 

 well as the animal with active salivary secretions. The resulting 

 prolonged contact of food with teeth, regardless of lowered tempera- 

 ture, may contribute greatly to the accelerated development of caries 

 in hibernating animals. 



Summary and Conclusions 



The observations reported in this paper underscore the lability of 

 bone minerals during hibernation, when both teeth and bone are 

 called upon to contribute calcium to the metabolism of the hiber- 

 nator. 



Hibernation results in deficient dentinogenesis, a reduction and 

 osteoporosis of both interseptal and interradicular bone, and de- 

 generation of alveolar bone, as well as a downgrowth of surface 

 epithelium, and pocket formation on mesial and distal surfaces of 

 adjacent teeth. There is also a disorganization of attachment fibers 

 and the presence of calculus on the cementum, together with ce- 

 mental tears. Carious lesions and pulpal and apical abscesses are 

 also aggravated in the teeth of hibernating animals. 



The process of hibernation can thus be seen to have severe effects 

 on the metabolism of the hibernating animal. During hibernation 

 there is a severe drain on mineral resources within the body. This 

 drain increases with time and gives one pause in postulating hiberna- 

 tion as an effective mechanism for meeting severe environmental 

 stress, for the process itself is an exceptionally stressful one. 



