Orthodontia, or malposition of the human teeth; its prevention and remedy

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1893 Excerpt: ...of the plate apart sufficiently to slightly increase the space between them. When the wire is heavy, as is necessary where great force is to be exerted, it can be best formed into shape and afterwards altered as required by means of _the ordinary clasp-bending pliers. The construction of the lower plate is substantially the same, but the wires lie against the plate in a continuous smooth curve, instead of being corrugated. Figs. 46 and 47 represent an upper and lower expansion Fm 46_ plate as described. For cases where expansion is not needed, but simply the moving of one or more teeth, Mr. Coffin uses a solid rubber plate with wires so placed as Fm. 4_7. to produce the desired movements. T h e construction of this form of plate is the same as those just described, with the exception of the shape and arrangement of the wires and the non-separation of the plate. A single long piece of wire, bent at right angles near one end and flattened at the other, is embedded at its flattened end into the plate, while the other end, and a long portion besides is free and lies in close contact with the plate. Before the wire is attached to the wax base-plate, the plaster tooth representing the one to be moved should be cut away Cotfin's Expansion Plates. close to its neck and the bent end of the wire laid upon it so as to cover the entire diameter of the stub tooth. In this position it is vulcanized to the plate. When the plate is introduced, the_ wire will have to be drawn back with an instrument or string before the plate will go into position. Once in place and the wire released continuous pressure will be exerted on the malposed tooth. After the tension of the wire has been lessened by the moving of the tooth, it may be increased either by bending the wire where...