225 



when the vital powers of the matrix begin to flag, that this is 

 more abundantly formed, and often the remnant of the pulp is 

 converted into it, and thus tills up the cavity of the contracting 

 fano;. 



A most remarkable development of this substance is exhibited 

 in the specimen alluded to in the beginning as presented by Mr. 

 Foljrer. Here we see a longitudinal section of an enormous 

 tumor connected with the base of the tooth. This mass is com- 

 posed of large nodules or lobular conglomerations of osteo-deniine, 

 divided in the centre by numerous fissures once filled with pulp, 

 which in time would have been closed up by fresh deposit. The 

 exterior is of an irregular lobulated shape, covered with innumer- 

 able warty excrescences and sharp spicula. Laterally and pos- 

 teriorly the tumor is covered by a bulging plate of the true den- 

 tine and cement, by extension from the normal matrices of the 

 posterior portion of the pulp. A few nodules of the same growth 

 are found on the exterior surface of the tooth, and situated high 

 up within the dentinal tissue of the interior ; not more, however, 

 than is often met with. 



The normal or upper part of the tooth is of the following 

 dimensions. Breadth of surface of an antero-posterior longitu- 

 dinal section at base, 3 in. Circumference at same part, 8 in. 

 Length of central axis, 5 in. Greatest thickness of cement, 8 

 lines. Originally the tooth was a very large one, but is now 

 much worn at the tip. On the posterior surface the cement ex- 

 tends downward 6 in. 8 lines, whereas on the" anterior or dis- 

 eased side it is only 4 in. 8 lines in length. Its growth in front 

 was at first checked by an undue development of the dentine ma- 

 trix, and then entirely obliterated by conversion of the same into 

 this enormous mass of osteo-dentine, which extends 6 in. in a per- 

 pendicular direction below the termination of the cement, and for 

 the same distance antero-posteriorly. It measures around the 

 circumference 17 in., and is almost wholly confined to the anterior 

 side of a line drawn parallel to the axis of the tooth. 



This great outgrowth must of course have produced an absorp- 

 tion of the alveolar process in the direction of its increase, and 

 caused trouble to its neighbor in front. The axis of the tooth 

 must have been changed from the normal, for the lateral portion 

 of its summit has been worn away fiat, produced undoubtedly by 



PROCEEDINGS B. S. N. H. VOL. VII. 15 MARCH, 1860. 



