The essentials of bandaging /

by Berkeley Hill

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.

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.

The next thing is to take a mould of the lower jaw in wax softened by heat, holding the wax in an ordinary dentist’s tray. From this mould a plaster cast of the jaw is made. If the line of teeth be uneven in the cast, it is to be sawn through, the pieces raised to the right level, and cast again. In this cast a vulcanite plate is made exactly fitting the teeth (see fig. 24). The margins of the mould or splint should be carried down below the line of the gums, to grasp the jaw beyond the alveolar border; and when the fracture takes place behind the teeth, its outer side should be prolonged backwards as far as the muscles will allow, to prevent the displacement of the anterior fragment outwards which muscular action produces in these fractures. Holes should be made in the top of the splint, to permit a stream of water to be sent between the splint and the teeth daily, for cleanliness. Also, in difficult cases, a hole should be cut opposite a tooth in each fragment, for ascertaining from time to time that each part continues in its proper position while the splint is worn.

Metal is used for the plate by English dentists, instead of vulcanite. It can be made thinner, and is less brittle than the latter.

The perfect fit thus secured suffices, in simple fracture, to keep the parts in close apposition; while the movements of eating and speaking are very little interfered with.