is doubt as to the importance of this mark in the relation of the salivary factor and dental caries. Furthermore, no constant points of difference can be found to correspond with the differences in salivary factors, and in Howe's and Keniston's work no substantial proof can be found to verify a relationship of the salivary factor to dental caries. This conclusion is in harmony with and confirms the findings of Gies and his collaborators.

[Journal of Cutanecus Diseases, Chicago, October 1917.]

Focal Infection in the Etiology of Skin Disease. BY E. D. CHIPMAN.

The aim of this paper is to report the observations in fifty consecutive cases belonging to those dermatoses which may be suspected of having a focal origin. For the most part it records only the incidence of focal infection in these cases. Chipman does not present this study as a protagonist. For him it is simply a preliminary survey of the field, which may later be found to be fertile or barren. The statistical method which he employs is justifiable for this purpose, and its results may be suggestive, but are never to be considered conclusive of a causal relationship between dental foci and cutaneous lesions.

A summary of this study shows that of six cases of alopecia areata five showed dental infection (long before the days of the doctrine of focal infection there was in the French dental literature abundant reference to the rôle of dental disease in the production of alopecia areata, and the earlier pages of the DENTAL COSMOS contain numerous notes on this subject); of two cases of chilblains each showed dental infection; of four cases of circumscribed eczema each showed dental infection; of two cases of erythema multiforme one showed dental infection; the one case of granuloma annulare encountered in this study showed dental infection; of two cases of herpes progenitalis one showed infection of the maxillary sinus; of two cases of herpes facialis each showed infection of the teeth; of four cases of lichen planus each showed dental infection; of two cases of lichen simplex of Vidal each showed dental infection; of seven cases of psoriasis five showed infection of the teeth, and one infection of both

teeth and tonsils; the single case of Raynaud's disease showed infection of teeth and tonsils; each of seven cases of rosacea showed dental infection; likewise for the two cases of urticaria, the three cases of vitiligo, and the two cases of zoster.

Out of the fifty cases, thirty-five showed infection of the teeth alone; four showed infection of both teeth and tonsils; one of teeth and appendix, and one of accessory nasal sinus (maxillary).

One circumstance observed in several cases of this series merits special remark, namely, the tendency to the development of symptoms on interference with an active focus. For example, in one case of rosacea a marked exacerbation followed active treatment of an apical abscess. This, however, soon subsided, and was followed by a corresponding improvement. In one of the cases of neuritic eczema in which two apical abscesses were treated, a slight exacerbation followed the interference with the teeth. This was followed by a month in which no progress was made, at the end of which interval the condition spontaneously resolved.

Another point worthy of emphasis is that it is not necessary to find the same microorganism in the skin lesion that is found in the original focus in order to suspect the latter of being in etiologic relationship with the former.

The above paragraph, together with the central thought (anaphylaxis) of the following quotation from Chipman's article “If we accept it as established that anaphylaxis results from focal infection we must consider it possible that the dermatoses caused by hypersensitiveness are ultimately due to focal infection"—is found in a developed form in Duke's "Oral Sepsis" (vide DENTAL COSMOS, July 1918, book review).

In the discussion which followed this paper, Sutton reported that in seventy-five of a series of one hundred cases of skin discases specifically studied, there was marked improvement or complete cure after removing the focus of infection, e.g. a case of lichen planus labialis was cured, sequent to the removal of several apical foci. Another case was that of a chronic eczema which failed to respond to any treatment until the mouth had been put in a healthy condition. Sutton and his colleagues, in cases where simple re

moval of focus failed in results, resorted to autogenous vaccines.

R. A. Davis reported an obstinate case of dermatitis herpetiformis. The patient was treated with emetin for pyorrhea alveolaris, and the skin lesion healed immediately. Since then he has had the same experience with six or eight similar cases.

Engman spoke of a case of superficial gangrene of the fingers and gangrenous spots on the penis with Raynaud's phenomena of both hands and feet. The patient disappeared. Nine years later he returned with toenails extracted and finger-nails scarred, still having some trouble. For twelve years he had had a constant virulent intermittent oral infection. This was cleaned up. Immediately all of his objective and subjective symptoms disappeared.

Morrow mentioned a case of eczema of face and neck of many years' duration. Radiographs showed many apical abscesses. A few hours after the extraction of the teeth the man felt much better. A few days later the rash had almost disappeared. In the course of a few weeks the eruption entirely vanished.

Heinmann reported a case of a man age sixty, with typical pityriasis rubra of the Hebra type. His teeth were in a very bad condition. These were extracted, and within two weeks the man was well and had been well since (three years from the time of the extraction).

A fibroma is in a way a rarity. It may resemble a cyst, but the chief difficulty which it presents is that of excluding sarcoma. Often this requires the utmost care, even in the study of microscopic sections.

Churchman's case here reported concerns a man, forty-four years of age. The growth

was first noticed two months before admission to the hospital. There were no unpleasant symptoms. The growth was removed by a wedge-shaped incision, done between stay sutures. Convalescence was uneventful; the tongue functions perfectly.

As regards the technique of operations on the tongue, experience has taught the author -(1) Never to touch the inside of the mouth with a knife. The entire resection of the tongue and floor of the mouth is done with a cautery. This, combined with the stay sutures, eliminates hemorrhage. And (2) Where malignance is suspected, to remove the tongue by the jaw-splitting operation, preferably two to three weeks after a complete and very radical dissection of the glands on both sides of the neck, and after these wounds have been allowed to heal.

[Surgery, Gynecology, and Obstetrics,
Chicago, July 1918.]

Mixed Tumors of the Salivary Glands: A Study Based on the Experimental Production of Neoplasm in the Submaxillary Gland of the Dog. BY ALEXANDER FRASER.

This is a broad and judicial consideration of the subject. There are a number of valuable illustrations, which are well reproduced.

Fraser describes briefly the principal theories of the origin of these growths, and then proceeds to report an experimental study of the morphological reaction of the salivary glands to injury, which was undertaken with the object of observing the regenerative changes on the part of the salivary epithelium, and whether the character of such changes would serve to establish any definite clue as to the origin of the mixed tumors.

Frazer summarizes and discusses this work as follows:

(1) The mixed tumors arise from the ducts of adult glands. No claim is made that true neoplasm has been experimentally produced, but the experimental results justify the con

clusion that the primary structures of the mixed tumors may easily arise from the ducts of the adult gland.

(2) The endothelial theory has no foundation in fact. All the so-called endothelial structures are easily explained as natural modifications of primary duct formations.

(3) Injury, such as localized or partial obstruction of ducts, probably plays a prominent part in the origin of these tumors.

(4) The cartilage is developed from the epithelium of the parenchyma of the tumor. This claim will undoubtedly meet with strong opposition.

Chinosol in Root-filling.-Root-canal fillings that are to be radiographed will have a denser outline if chinosol is incorporated with chloro-percha, and pumped into the canal before inserting the point. Chinosol being a good antiseptic is particularly indicated in canals that have been putrescent.-VICTOR H. FUQUA, Dental Review.

a

Method of Polishing Vulcanite or Metal Plates. After filing and scraping, use leather washer (the same as is used for the ordinary water tap) on the lathe in conjunction with equal parts pumice and emery powder (knife polish). This quickly takes out all scratches without the use of sandpaper. Proceed then with the brushes in the usual manner.-Oral Health.

To Obtain Smooth Finish on Palatal Surface of Vulcanite Dentures.-After the case has been invested, separated, and the wax boiled out, paint the cast with liquid silex. Allow to dry thoroughly before closing the flask. This eliminates the burnishing of tin foil, which tends to wrinkle and tear during the process, resulting in a rough and unsightly finish to that part of the denture.— LESTER N. ROUBERT, Dental Review.

Pulpless Teeth. The writer does not agree with the oral surgeon who radically condemns every pulpless tooth: on the contrary, he knows it is possible, if the patient will present in time, to remove the pulp and aseptically fill vital root-apices, in a large percentage of such teeth, with no post-operative periapical infection, a fact which can be established radiographically and by cultural tests; but he does not believe that an infected or abscessed root apex should be retained for a minute, nor would he spend that time on one, unless attempting apiectomy. CLARENCE J. GRIEVES, Journ, N. D. A.

Removing Silver Nitrate Stains.—Many times, even though one may be very careful. a little silver nitrate will fall on the hands of an operator and cause a great deal of discoloration and also discomfort in operating. When this happens, soak the hands for about fifteen minutes in water as hot as one can stand, and then very carefully rub the spots with pumice stone. The spots will be seen to disappear without any injury to the part treated. After the black color caused by the dead skin entirely disappears, soak the hands in almond cream. Very large spots may require a few treatments at short intervals before the black color entirely disappears.W. E. WHITTAKER, Dental Review.

Root Surgery.-To skilfully perform root surgery requires a perfect technique, plenty of time, and the utmost delicacy of touch in the use of the instrument, so that one may know by the feel of the blade just when the infected peridental membrane and outer layer of cementum has been removed. Our fingers must be our eyes, as we are working in the dark, but even so, there is no more need of mutilating a tooth with a plane than there is of mutilating it with a bur or any other instrument, and only the careless operator will do so. With this instrument the healing is accomplished by hyperemia, induced by the trauma of the operation, and no medicine is used. EDWARD A. ROYCE, Dental Review.

To Hold a Fractured Jaw for Impression and Adjustment. In all articles on fracture of the jaw. there seems not to have been given the most accurate way of taking a successful impression. Make rather loosefitting bands of regulating strip of about 36 gage or Liberty (née German) silver 38 to 40 gage to cover two teeth on each side of the fracture, solder each pair firmly together,

and then accurately align the edges of the teeth at the fracture with the bands slipped on; then hold the two sections of bands in line with sticky-wax, remove, solder them together, and cement into place for a permanent splint. This will allow you to take an impression or do any other work necessary, without pain to the patient, and with greater assurance of success than by sawing the model and trying to adjust fragments.-Dental Summary.

The Interproximal Contact Point.-The form of the contact point has much to do with comfortable mastication and the preservation of normal gum in the interproximal space. The contact point on normal human teeth is a small curved eminence on the proximal surface near the occlusal or incisal. From this small contact the proximal surface of enamel slopes away more or less abruptly, leaving the area in actual contact exceedingly small. This holds true of broad teeth like the molars as well as of narrow teeth like the incisors or cuspids. The philosophy of this narrow contact relates to the fact that when food is forced between the proximal surfaces of the teeth, as it will be at times, it is not retained there owing to the limited area. If the contact were broad, as we sometimes see it on fillings, food particles would be held between the teeth, leading to all the evils associated with this condition.-C. N. JOHNSON, Dental Review.

Cancer of the Mouth and Face.-Medical research has established the fact that cancer is a local disease at its beginning, and that every case might be cured if treatment (operation) were performed early enough. And what is true of cancer in general is especially true of cancer of the mouth and face. Bloodgood has shown by his experience that an early diagnosis and prompt radical treatment will cure eighty per cent. of such cases, and states that this number may be increased to one hundred per cent., if the diagnosis is made sufficiently early. As has been stated by Means and Foreman: “The operative technique of tumors of this region has reached a high state of perfection, and if further advance is to be made against cancer of the buccal cavity, it must be by the earlier recognition of the disease." There is, then, a grave responsibility placed upon the person first seeing these cases, and this person in the natural course of events is frequently the dentist.-ERNEST SCOTT, Dental Sum

mary.

[VOL. LX.-57]

Extracting Diseased Teeth.-It is the common practice among many to extract diseased roots, and leave the wound socket to nature to take care of. In the writer's experience this practice is not only non-surgical, but really of harmful result. When the pulp of a tooth-root becomes diseased, and is not treated properly, the bacterial toxins pass upward into the periapical space, and cause dissolution of those subdental tissues. The radiograph discloses in such cases marked radiopacity, representing cystic degeneration and carious destruction of the alveolar tissues. Obviously the removal of the diseased root or roots cannot remove this tissue. The apical granuloma and the subapical alveolar structure must be removed by surgical curetment, and the socket packed for some time in a series of post-operative visits. By this means alone can the oral surgeon hope to remove whatever vestiges of infected tissue may be remaining to pour their insidious toxins into the blood stream and into the lymphatics to attack the weakened and nonresisting tissues elsewhere in the economy, be they lymph nodes or glands, intestinal lining, or myocardium.-MILLEL H. FELDMAN, Dental Summary.

A New Method for Making a Porcelain Crown. The following described new method for making a porcelain crown will be found to be very practical for bicuspid and molar roots, and especially adapted for short-bite cases when a gold crown would not be desirable. Make a coping with one or two posts, according to the requirements of the case. Then, having the coping placed on the root, take an impression and a bite. Make models and adjust them in an articulator, then remove the coping from the model, and solder a strip of gold plate around the coping on three sides, namely, mesio-proximal, lingual, and disto-proximal, having the gold strip wide enough to reach to, or nearly to, the occlusal surface of the crown as it will be when finished. Then, having selected a facing of the proper shade and size, solder the pins of the facing to the post of the coping. Then make a mix of synthetic porcelain of a shade to match the facing and fill it in upon the coping, which, having three side walls of gold and the facing as a buccal wall, sustains the synthetic porcelain at every point. While the synthetic porcelain is soft carve it to an approximal occlusion with the antagonizing tooth in the articulator, and when fully hardened grind and polish the porcelain to a proper occlusion.-H. A. CROSS, Dental Review.

School Clinic at North Tonawanda, N. Y.-At the Payne Avenue school in North Tonawanda a free dental clinic has been opened in connection with the free dispensary which has been maintained at this school for a long time for the examination of school children and for operations on the nose and throat. The free dental clinic has been made possible by the donation of funds from some of the philanthropic people of North Tonawanda, and the Council has promised the Health department that if the clinic proves successful they will put a sufficient sum in the budget next year to continue it in operation. The dispensary has a capacity for four patients (beds), and many operations are done on the nose and throat, removing tonsils, adenoids, etc. The little patients are kept at the dispensary for one day and then taken to their homes. Mr. R. A. Searing, superintendent of education, has been largely instrumental in bringing about this much-needed institution.-Health News.

Taking a Bite for Crown or Bridge Work.-One of the most difficult items to contend with in operative dentistry is the taking of a satisfactory bite, particularly where the occlusions are close. When the wax or compound bite is removed it often breaks in two pieces, making it difficult to obtain a perfect cast for the occluding surfaces to be articulated to the crown or bridge about to be constructed, or it breaks when placed on the plaster model. Many ideas have been advanced for overcoming this, such as placing a piece of linen, cut about the length and width of the bite to be taken, then placing the wax above and below the piece of linen, taking the bite in the usual manner. linen holds the bite together and prevents biting clear through. A better and more rapid way of obtaining this result is the use of the Articu-bite, a little instrument in which all manner of hard, close, difficult articulations and bites can be obtained in two minutes' time without the possibility of a mistake.-W. E. BEACHLEY, Dental Review.

The

Dietetics and Oral Hygiene.-Associated with an appreciation of the true functions of the saliva and mucus there goes the important dietetic principle or precept that the physiologically correct type of meal is of such a nature or so arranged that it will leave the mouth physiologically clean. I have never as yet come across any physiologist or medical man who has dared to say that the meal should be of such a nature or so arranged

that the mouth and teeth will be left dirty. Yet their precepts and practices would rather indicate that they have a preference for such types of meals. It may be contended in the future that the types of food which we dentists indicate as leaving the mouth and teeth clean or otherwise are not correct in all details-possibly they may not be. Nevertheless we have established a most important principle which was overlooked in the past, and is not at present taught by physiologists. There was something pardonable for dentists in their old injunction to brush the teeth after every meal, for they knew that when the dictates of dietetic specialists were carried out, the mouth, as a very general rule, did require some artificial form of cleaning. It is relatively unpardonable for physiologists not to recognize or to have recognized that the mouth is naturally kept physiologically clean, and should not, under a proper dietetic régime, require the teeth of man to be brushed to keep them healthy.-J. SIM WALLACE, Dental Record.

The Clasp as an Anchorage for Partial Dentures. We have been using clasps ever since practically the advent of dentistry. It is one of the oldest types of means of retaining partial artificial dentures, and strange to say, today it is the most abused plan of supplying partial artificial dentures. It is one of the most universal means of anchoring partial dentures, and for that reason it should be better understood than any other system of anchoring partial dentures, but strange to say, as I have said, the least understood and the most abused system. If you have taken the pains to study these conditions, as possibly I have done more than some of you. if you will only go into the laboratories in the cities and study the impressions that come to these laboratories from the profession generally, with the request to make a partial artificial denture, you will be surprised. Beeswax impressions, beeswax combinations of bites are taken and sent to the laboratories with the request for a partial removable denture of some kind. Is it any wonder that we are receiving the bitterest condemnation of this work? Is it any wonder these appliances are the means of destruction of the natural teeth and their surrounding tissues? The wonder is that they do not cause more destruction than they do. The clasp, to my mind, is an attachment that can be used and should be used in the great majority of cases. As I have already said, there are many instances where these complicated pieces of work are possible, or no doubt indicated, and