WITH THE ALVEOLUS. 67 



and the lady and teeth conveyed as quickly as 

 possible to town ; the ter was renewed at each 

 stage, to keep up the temperature of the teeth, 

 and on arriving at Mr. Parkinson's, they were 

 replaced by him, and remained firmly in their 

 positions. Mr. Parkinson saw them twenty years 

 afterwards, when they were still good serviceable 

 teeth, and only sHghtly darker than their neigh- 

 bours. 



The operation of turning the centrals of chil- 

 dren, which I described a few evenings since, 

 depends for its success upon the perfect reunion 

 of the dental periosteum with the alveolar. So uni- 

 formly does this take place, that such cases may 

 be cited as the most perfect illustrations of re- 

 union to be met with ; the conditions are, however, 

 most favourable to that end ; for, although the 

 tooth is completely detached from the alveolar 

 process, it is not removed from it ; the operation 

 also being performed before the end of the root 

 is fully developed, the danger of rupturing the 

 vessels supplying the pulp is avoided, and thus 

 circulation is kept up throughout the tooth, while 

 that of the periosteum is for a time suspended. 



Although the imperfection of the root contri- 

 butes materially to the successful re-union in 

 cases of torsion, the replacement of such teeth 

 which have been entirely dislocated, is generally 

 unsuccessful ; for, the pulp-vessels being ruptured, 

 the ossification of the dentine cannot be com-* 



F 2 



