part is made up of a wire cable enclosed in a flexible thread tube. When put in motion, this wire cable is capable of making five thousand revolutions to the minute. The termination of the cable is in a handpiece, or carrier. Fig. 2 shows the handpiece; B is a support to instruments to be used with it; C is a slot for fixation; E is a turn-clamp. The piece standing alone marked A is a bur; it represents, in its

A

shank, any and
every instru-
ment used with

the engine.

FIG. 1.-The dental engine.

ties of carious teeth preliminary to the process known as filling. When dental caries extends to close proximity with the pulp of a tooth, the necessity for the lightest possible touch is paramount; the difference of a hair's breadth is oftentimes all-important to prevent the exposure of that organ. In the majority of instances, such manipulation has to be accomplished unaided by the sense of sight. The engine works with such absolute certainty that the requirements are met without effort or concern on the part of him who directs and controls the lightning-like speed of the point that cuts.

The Removal of Teeth.-It not infrequently occurs that teeth require to be extracted where the relation with a dense alveolar process so nearly approaches the character of a true anchylosis that the force required to break the connection is beyond the ability of the operator to exert or the strength of the jaw of the patient to withCases of this kind afford signal A dental engine, being pos- triumph to this engine: through its aid the sessed of but limited power, has writer has succeeded, after a moment of alits office confined to the treat- most painless manipulation, in removing ment of dental lesions and with the greatest possible ease teeth which to the lighter operations praccould not have been extracted after the iced in oral surgery. In its ordinary manner. To remove a tooth, usplace, this engine affords an ing the engine, one of the five-sided bits, expeditious and a happy means of accomplishing a variety of performances. A surgeon, finding it convenient to own one, will be well compensated for his outlay. The dental engine, surgically considered, will disappoint the practitioner, unaccustomed to it suse, if undue demand be made on it; the cable will break, or, what is more common, refuse to revolve the instrument in the grasp of the hand-piece.

preferably the smallest, shown in Fig. 3, is placed in the carrier, and, while held closely against the organ to be removed, is reFIG. 3.-Five-sided bits. volved until it cuts its way between tooth and socket; this done, the finger forceps not infrequently suffices to lift it from the alveolus. The drill is to possess three or five sharp sides, continued its whole length; thus provided, it cuts from point to base, as the operator

Illustrations in use.-Being carries it around the tooth. invention in dentistry Treatment of an Absorbing Alveolar Pro4, a bur; B, proper, the present common cess.-Loosening of the teeth, arising

hand piece of the an

dental engine.

instrument; C, use of this particular machine out of absorption of

the support to the

slot for fixation;

their alveoli,

their

E, the turn-clamp is the preparation of the cavi- is a condition met admirably through the

aid of the engine. Frequently it is found glance at Fig. 5 will make plain to the that the origin of the bone disease, as well surgeon the usefulness of the instrument

FIG. 4.-Su

and

as the falling away of the gum from the in the treatment of osseous caries. As neck of the tooth, has explanation in the operations on the maxillæ are concerned, presence of common tartar. The indica- the help afforded by it is simply invaluable. tions in such cases are twofold-1st, to re- By its aid the surgeon feels himself able to move all calculus; 2d, to freshen the cir- do almost anything, and to do what is to cular edge of the absorbing bone. To be done without effort to himself accomplish the first of these indiwith the minimum of discomIcations, sugar-loaf drills, as por fort to a patient. On a number of occatrayed in Fig. 4, are to be used-sions the writer has performed what the smaller the better. One of were really quite extensive operations, while these being placed in the mandrel the patient, without an anesthetic of any is carried, while in rapid revolu- kind, was unconscious that the removal of tion, around the neck and root bone was being effected. Extreme as is gar-loaf drills. of the tooth; the scaling effected the assertion in seeming, it is really the by it is very complete, while at the same case that a whole diseased jaw can be cut time just enough abrasion is produced in | from its bed withont any particular evithe surrounding soft parts to excite the re- dence being afforded to the bystander that quired reaction, which changes to a healthy an operation of consequence is in progress. surface a suppurating one. A sinus big enough to admit a rose drill is all the external wound required. The pain connected with this means of operating can only be trifling. It is the very nervous alone that think ether necessary. The rose drills used in the operation are to be obtained of all sizes. Those shown in the cut are well adapted to the work.

To accomplish the second of the indications-namely, the freshening of the bone-the writer employs the rose drill shown in Fig. 5-smaller, however, than the smallest of these. Resting a drill of this kind against the diseased bone, the circumference is easily removed by means of the slightest pressure made on the revolving instrument. It may not be amiss to allude to the necessity for washing away the detritus by means of a syringe. Through such double operation the writer has found himself able to restore many loose teeth to a fair degree of health. True, the same ends are to be reached by different means; but no other kind of instrument so easily, readily, and painlessly The Surgical Engine.-Fig. 8 represents accomplishes the work as those here sug- the surgical engine; the best of these magested. chines known to the writer is that made by Treatment of Caries of Bone.-A| Bonwill, of Philadelphia. In the cut, B

Figs. 6 and 7 show modifications on the straight hand-piece used with the engine. In Fig. 6 is shown a small circular saw placed at an obtuse angle. Fig. 7 exhibits a bur placed in a like position. To operate a dental engine, the foot is used precisely as in any pedal lathe. Instrumentation is directed as a pen is carried, through means of its holder.

FIG. 5.-Rose drills.

36

T

OVEMBER 2.1875
PATENTED

ESWHITE

FIG. 6.--Hand

piece with

cir

cular saw at an

obtuse angle.

THE SURGICAL ENGINE.

well as the general simplicity of the insidework. These are but a few of the instruments used.

The circular saws (R) are three-quarter inch, one and one-half inch, and three inches in diameter, and extremely thin. But, with these shown in cut of various sizes, quite every operation can be performed.

A surgical engine differs from the dental in the replacement of the wire cable by a steel arm. This arm is made to represent

the upper extremity of man, and is complete in its variety of movements.

The im

The pedal

mediate revolving power of the mandril lies in the cord seen in the cut. is replaced by a crank which is worked by an assistant. The number of revolutions attainable is fifteen thousand to the minute. The momentum is next to irresistible. The cost of the machine, independent of the operating instruments, is fifty dollars. The cutting instruments used by the writer have: cost him, perhaps, as many more dollars. A surgical engine can be used for all indicates the tripod, or base, supporting light operations. Many dentists give the the driving wheel with cog-gear and crank. machine the preference for their particular Above this is an upright standard, upon sphere of work. The cable arm in the which is placed the fiexible arm (A), which dental instrument commends it, however is a duplication of the human arm, with to the writer for the simple and most easilyOn the other pulleys at the shoulder and elbow joints for performed manipulations. carrying the hand to the hand-piece (H). hand, facility in the use of this last-named Tis an arm pivoted near V, and at the op- engine enables a surgeon to accomplish posite end, bearing against the spiral spring more important ends with it. The illus(S), which keeps the arm at any easy, flex-trative performances following were first ible position desired. A screw keeps the done with a dental engine, this being the arm at any angle. V is a sliding tube with only machine in the market at the date of a heavy spiral spring inside, with the base the operations for which the particular It is to be understood of arm (4) resting thereon; and, by raising cuts were made. the tube, the band can be always kept so that, at the present time, a thought of tight as to prevent its slipping on the pul- employing it in similar operations would leys. The thumb screw (U) secures the only be entertained in the absence of the tube. At the extreme right of the engine power lying in the surgical machine. is a sectional view of hand-piece (H), as seen on the wrist end of arm (4), for imparting rotary motion to the drills (); the saws (R), and the bur (7). It shows the cone bearings (C and c1) which insure per fect centering of the tools, with a universal chuck for absolutely holding the same, as

Instruments used with the surgical engine are drills, burs of different forms and sizes, circular saws of diameters varying from one to six inches, reciprocating (resembling the common metacarpal) saws, the length being from ten to four inches, and special tools.

Fig. 9 is a reciprocating saw (S) which at O by a screw, with a threaded end from moves three-eighths of an inch and cut-C to D for screwing into bones to hold ting both ways for resections and amputa-them firmly while being cut.

A and B

FIG 9.-The Reciprocating Saw. a hole in the bone, as just described for certain cases of re-section. P is the end to be placed on the arm (A) of engine, by removing hand-piece (H).

FIG. 10.-Elevator for Fractures of the Skull.

bur in the engine, and the line of fracture
follwed and it only removed. The eleva-
tor, even here, is of value to extract the
piece or to hold it up while the sawing is
being done.

To use it, first take a nearly flat-pointed
spear drill (), the diameter of the hook
(C) on screw (4), and place it in the en-
gine, and cut about two-thirds through the
plate of fractured bone, which, with the
high speed of the engine and a sharp drill,.
can be done with but slight pressure. Then,
with a drill the size of the neck of bur (1),
drill two holes on one side of the first large
hole thus Ooo, and afterwards insert bur (1)
in the larger opening and let it under-cut
where the smaller holes were made, as
shown in section F. This will permit the
hook (C) to pass under and be held in po-
sition, while the feet (E) of the arch (D)
rests on either side of the fracture on solid
structure. The thumb screw (H) is now
turned by degrees until the part is in situ,
or even higher, that no pressure be permit-
ted on the inflamed parts. Any number of
sections can be elevated one after another;
or, by making the hole on the lines of frac-
ture, several sections at once.

Special tools are devices to meet special ends an example of a special tool is a drill of sufficient length to reach the human bladder, encased in a canula for convenence of passing, and for protection of the urethral passage. A second illustration may be instanced in a bur fitted for cutting into dust the carious head of a femur in hipjoint disease. Dr. Bonwill's elevator for fractures of the skull, shown in Fig. 10, is tanoher. It is intended to obviate the necessity of trephining. Can be done only by the assistance of the surgical engine. Should There need be no apprehension of the a case arise demanding the thorough remo- drill passing abruptly through the plate val of the section, it can be effected far of bone, as the surgeon should know well more perfectly than by the old round treph- the average thickness of the part. When ining saw by the use of a circular saw or a great accuracy is needed, a gauge or guide

T