DENTISTRY during tliis period, when publications upon dentfetr? were frequently appearing in , that the manufacture of artificial teeth if porcelain was introduced; and in 1821 a work upon this suhjcet was published by Audi- l.ran. entitled Iwii hi*tori'i ue (t /tnitiqite aur . /,.< incnri'iiiitibl,*. l>y this thai Fain-hard in 17'J* proposed i .nufa.-turc ; and that in 177t'. Duehateau, ..;' St. (.ei-main-en-Layo, attempted ilu-in, and finally succeeded with . of Dul.ois, a dentist of note in Paris. Tin- latter imitated the colors of the natural ml gums by thy use of mineral oxides,
- aiii'-l royal letters patent for the in-
vention. Denti-try was introduced into the 1'nited Stat^> l.y he Mair, of the French forces which joined our army during the revolution-
Englishman named Whitlock
also commenced the practice soon after the arrival of !. Mair. About 1788 John Green- . -tablished himself in New York, the Mierican of this profession. In 1790, and again in 17'.t5, he carved in ivory an entire
- . -etli for (ion. Washington. They were
1 by spiral springs, and the neatness and ingenuity of the work was considered equal to any executed at that period abroad. Other dentists soon appeared in New York, 1'hiladelphia, and Baltimore. Their work in- cluded the extracting of teeth, filing and (leaning them, and replacing the natural teeth when ht with artificial ones, commonly made of ivory. Dr. Hudson, formerly of Dublin, who had settled in Philadelphia, first directed his attention particularly to the cure of the diseases of the teeth, and to arresting the pro-
- dental caries. In 1820 the number of
practitioners in the United States was probably little more than 100. Ten years afterward
ere about 300, of whom probably not
more than one sixth were well instructed. Hut the increase in their numbers was after- ward very rapid. In 1842 they were believed to number about l,4i>i, and in 1872 about An important event in the history of dental sur-ery in this country was the estab- lishment of the "American Journal and Li- "t Dental Science " in Baltimore, in The society of dental surgeons was soon after formed, and at its second annual nieetinL' the ".Journal" was made the property and or^an of the association. Maryland found- ed l.y it> le-:Mat:uv. a f.-w months previous to the ..r-Miii/utii.n of the x.ciety above named, a college of dental Misery, with four professor- ship-. de-L'ned f..r in-tnictioii in the principles and mechanical practice of the art. Two years .rd another s..r'u-ty of dentists, like that 'f Hultim..: abed at Richmond, Va., and in August, 1844, a third s as formed at Cincinnati. Ohio, styh-,1 the ' Mississippi Valley .ition of Dental Sur-eon-." , college -ablished in Phila- delphia and ari-.th.-r in < incinnati, and state .il dental societies in various parts of lelp and the country. In August, 1855, the national convention of dentists was organized through the active exertions of Dr. Elisha Townsend of Philadelphia, and its first annual meeting was held in that city. Dr. John B. Rich of New York was its first president. Besides the reports of these societies, which have disseminated a knowledge of the discoveries and improvements made in the science, many very valuable works of a practical nature have been published by American authors. The means of preventing the diseases to which the teeth are subject, is a branch of dental science quite as important as that relating to the arrest and cure of these diseases. These means consist, first, in giving what assistance nature requires to bring the teeth of second dentition into a regular arrangement ; and sec- ondly, in the care of the -individual himself in preserving the teeth uniformly clean. As the temporary or first set of teeth drop out, which as a general rule they should be allowed to do, by their roots being absorbed, the sec- ond set already formed succeed and take their places. Of the temporary teeth there are but 20, and these are of small size. The teeth of the second dentition are 32 in number, with one or two exceptions are of larger size than their predecessors, and consequently occupy a greater space. Yet these, appearing one by one, take their places, and should occupy in the harmonious process of the growth of all the parts the same room apparently that was filled by the 20 deciduous teeth. This is accom- plished by the elongation forward of the jaw, the arch gradually assuming the form of a semi-ellipse in place of that of a semi-circle. Teeth irregularly arranged, interfering with each other, or as in some cases with the lips, or pointing inward so as to be removed from the healthy action of mastication, or twisted in their sockets, are not only disfiguring, but are particularly liable to disease and decay. From their first appearance to the age of 16 of the individual, they may be treated by various me- chanical applications attached to the other teeth and bearing suitably upon those to be brought into place, so that without violence the work of nature is gently assisted, and a per- fect set is gradually formed. It is the opinion of dentists that when the teeth are kept per- fectly clean they will not be affected by caries. As the secretions of the mouth are, however, liable to be vitiated by constitutional disorders, the keeping them clean requires great vigilance. When caries occurs it should be immediately removed by the use of the file. The surface of the bone from which the enamel is removed should be left smooth and polished, and if proper care be afterward taken in keeping it clean, the disease may not return. If the decay has ex- tended into the bony substance of the tooth, the filing is then only preparatory to the com- plete removal of the diseased portion by exca- vating with suitable instruments, and filling the cavity with some proper material. Much
