On emergency, when gutta-percha, leather, or pasteboard are not at hand, the jaw may be set, and then kept in position by a four-tail bandage, made from a pocket-handkerchief, until more complicated apparatus can be prepared. The apparatus must be worn five weeks before it is laid aside and mastication permitted. =Interdental Splints.=—In cases of unusual difficulty, interdental splints may be employed. To fashion some of these, the mechanical skill of a dentist is requisite, unless _Morel Lavallée’s plan_ is resorted to. He applied a mould or socket to the line of the teeth, and kept it in place by pressure underneath the jaw. He first brought the fragments into apposition by means of threads and wire. Then he took a piece of gutta-percha, about ⅓ inch thick and ½ inch broad, and long enough to extend, when bent along the lower jaw, from one wisdom molar to the other. This was softened in water, and pressed on the teeth; next a well-padded horse-shoe plate was placed under the chin, reaching from one angle of the jaw to the other, and two wires were passed through the side of this plate opposite the angle of the mouth; these were drawn through the plate by a screw nut; their upper ends being curved into hooks with sharpened points. The points catch into the gutta-percha; by screwing up the nuts, the chinplate was raised, and the teeth driven up and bedded into the splint. This method, however, has its disadvantages. If the fracture take place behind the first molar, the bearing on the upper fragment is too slight to keep it down in its place. In the _New York Medical Journal_ for September and October, 1866, Mr. Gunning, of that city, has published a mode of applying caps fitted to the teeth for fracture of the jaw-bone. External support is abandoned wherever it is possible. In simple fractures, the caps or interdental splints, being accurately fitted, require no fastening to the teeth. The jaw should be adjusted in its splint as quickly as possible after the accident. The fragments are first brought into their true position. Gaps through loss of teeth at the line of fracture, are filled by plugs of hard wood, and the fragments kept in place by wiring the teeth together tightly. Continued strain on the teeth causes much pain; hence all means for keeping the fragments in place while the splint is being fitted should be removed when that is accomplished, though ligatures used solely to support loosened teeth may be left, as there is no traction upon them. Stumps, and teeth loose before the accident are best taken out, if they interfere with the arrangement of the splint. [Illustration: Fig. 24.—Vulcanite Interdental Splint to fit the arch of the teeth of the lower jaw, seen upside down. The holes marked a pass through to the upper surface, to allow water to be injected between the splint and the teeth, while it is worn, for cleaning. ]