While the results are not marked, the accelerated group varies more than the retarded group at first, but the relations are reversed at the end of this period. Considering the group as a whole, this means that physiological variation is greatest for all the boys when the rate of growth is greatest, and least when the rate is at a minimum.

Since the amount of variation depends on the rate of growth, we must expect to find that a truly pathological individual stands much closer to the average of his age-group when growth is slight than when growth is great. In other words, if we are to draw a line between the pathological and the normal, the line must vary in position from year to year, being closer to the average during the years of minimum growth, and farther from the average, measuring on the same scale, during the years of maximum growth.

Next we may ask whether the extreme variants at a particular age remain extreme types throughout the course of their development. An answer to this question will determine whether we are to consider a particular case of extreme variation as pathological, or whether we can expect more or less complete recovery to normal type.

While it is true that a close correlation exists between the development of the various parts of the body, nevertheless all organs do not develop at the same rate, so that when one organ has reached a particular stage in its development another may exhibit a certain amount of variability. From this point of view,

the increased variabilities in stature which we found in both accelerated and retarded groups may be an expression of a different rate of development from that of dentition, for if this is so, the greater the degree of acceleration or retardation of dental development the greater will be the variations in stature.

So it follows that what we have been calling the "physiological age," based on the stage of development of one particular organ, by no means represents the physiological development of the body as a whole. Nor can two individuals of the same "physiological age" be considered as physiologically identical, since they are identical in one characteristic only. Furthermore, and most important, chron ological age cannot be left out of the reckoning. It is not the same thing whether an individual is "physiologically" 10.8 years old when he is only 9 years chronologically or when he is 13. In the first case, as an accelerated individual he represents a stimulated condition; in the other he represents the depressed physiology of the retarded.

If we trace the course of growth in stature, for example, we find that the boys who grow rapidly before the interval 14-15 years grow slowly later on, while those who grow slowly before that time later grow rapidly. If this were not so, we should find the accelerated individuals continuing to grow rapidly into giant types, while the retarded would grow up pigmies, whereas we find that the ultimate variation in the adult is relatively small. Still, this recovery toward the normal type does not take place in the same way in all individuals. For example, if one group of children attains a certain status in the development of some particular feature at 10 years, while another group attains the same status at 14 years, the former will take longer than the latter to attain the full development, the rates of growth proceeding in entirely different

ways.

When acceleration of growth does begin late in life among the retarded, the whole energy is expended in a very short time, the rate of growth far exceeding that of normal individuals. But it seems

fairly clear that the recovery to normal type is not completed in this short period of rapid growth; excessively retarded individuals remain underdeveloped. Since the subsequent development of individuals of apparently the same physiological status proceeds variously, we cannot put a finger on the extreme variants at any particular age and say, "These are pathological," for while one. may continue growth as an extreme type, another may later revert to normal condition. We can say, however, that an individual extremely retarded in late childhood is much more likely to be a true pathological type than one retarded early in childhood. Whether, conversely, early acceleration has a beneficial influence we are in no position to say.

These cautions, then, prevent us from discriminating the pathological from the rormal on the basis of our data on dentition. As they stand, they are indicative but not of diagnostic value. Only by a more thorough study of dental development especially in relation with other body characters can such data be obtained.

nity to suggest what data orthodontists are now in a position to supply :

the

(1) Metrical observations on course of growth of the teeth in the population at large from the first development of the germ to the final states in both deciduous and permanent dentition.

(2) Parallel observations on the same individuals of the other parts of the body, such as palate measurements, stature, weight, strength, pubescence, ossification, etc., for the purposes of correlation.

(3) Observations of the same sort on the selected group which comes to the orthodontist for treatment, to show the types of variation which are found among avowedly extreme cases. Further, similar observations to show what variations can be effected by the various corrective practices.

In all these observations care must be exercised to separate the data by age, sex, nationality or race, and economic conditions.

77TH ST. AND CENTRAL PARK WEST.

T

HE infrequency with which dental appliances and the smaller instruments are by accident aspirated into the bronchi is most remarkable, when we consider the number of cases treated yearly by the dentist. The following case is, however, of peculiar interest to the dental profession:

Case No. Fbdy 653 was brought from a western city with the history of aspirating the band of a gold crown, which had slipped from the grasp of the dental [VOL. LX.-62]

operator. Some slight coughing immediately followed, but there was no dyspnea. Later in the evening the patient had a severe attack of coughing and expectorated a small amount of blood. Radiographs made on the evening of the day of the accident showed the presence of the gold band in the right main bronchus. The situation was considered an emergency, and an able surgeon made an attempt at removal by oral bronchoscopy in the sitting position, under local an

operation consumed six hours. The surgeon was able to grasp the foreign body, but on attempting its withdrawal

was taken to a hospital, where he remained one week. Great swelling of the neck tissues and tongue, marked dyspha

gia and odynphagia followed, and the temperature rose to 101.8° F. Patient suffered from frequent coughing attacks, and the voice became very husky, although there occurred no alarming dyspnea.

The patient arrived at Jefferson Hospital on the eleventh day following the accident, the tenth following the unsuccessful bronchoscopy. Condition on admission:

Eyes. Pupils equal. React to light and accommodation. No imbalance.

Throat. Tongue much swollen and motility greatly impaired. Pharynx injected.

Larynx. Intense laryngitis with the presence of exudate and granulation tissue. Motility of the arytenoids much impaired.

Neck. Considerable swelling of the cervical tissues. Few enlarged lymph glands. Thyroid not enlarged.

Thorax. Well formed. Rounded. Walls thick and muscular.

Lungs. Expansion somewhat limited over the upper left front. Percussion note impaired over the upper right and lower left fronts. Breath sounds blowing over the upper right front and in the left axilla. Vocal fremitus and vocal resonance seem unchanged. No râles or friction heard.

Heart. Area of dulness normal. Sounds clear and regular. No murmur, shock, or thrill.

The radiographic report of Dr. David R. Bowen reads as follows:

There is a metallic foreign body in the left lung, I believe at the bifurcation of the lower branch of the left bronchus. This is slightly in front of the anterior plane of the vertebral bodies. There is distinct evidence of considerable pathology in the right lung, particularly in the distribution of the lower bronchial branch, but hardly less marked in the distribution of the middle branch. There is very little evidence of any similar condition of the left lung. (See Fig. 1.)

Per-oral bronchoscopy in Jefferson Hospital with local anesthesia revealed an intense laryngitis and tracheitis with exudate and granulation tissue. The band

(Fig. 2) was found embedded in the left 1 wer lobe bronchus, at the orifice of the posterior branch, and was removed in one minute and forty-nine seconds. The

FIG. 2.

Band of a gold crown removed from the left bronchus.

patient experienced no discomfort and no rise of temperature following the bronchoscopy, and left for his home on the following day.

COMMENT.

The possibility of the aspiration of dental materials into the bronchi, in spite of the infrequency of its occurrence, should always be remembered. It should never be assumed that the foreign body has entered the alimentary tract until a radiograph has proved the fact. Of more particular interest to the medical profession, perhaps, is the view taken. with regard to the danger of the presence of the foreign body in the bronchus. From our extensive study of these cases the fact has evolved that if the stay of the intruder is prolonged for weeks or months, suppurative processes are set up in that portion of the lung distal to the foreign body. Signs and symptoms simulating with exactness those of pulmonary tuberculosis develop, and if the foreign body be not removed, a fatal ultimate result is almost certain. Certain organic substances set up a very active and violent inflammation of the bronchi and adjacent lung tissue in a very short time, often immediately after their aspiration, but the above-mentioned course of symptoms is the usual one taken in metallic foreign body cases. The pathologic lung changes are caused partly by interference with drainage of the parts below, and partly by the abrasions and the lessened resistance to infection

ANTISEPTICS OF THE HALOGEN GROUP.

Antiseptics of the halogen group are germicidal in inverse ratio to their atomic weights. Fluorin cannot be kept in solution, and is moreover extremely caustic to soft tissues. Chlorin is the most efficient of the group, but it is difficult to keep in solution without deterioration in strength. Bromin also has disadvantages which are difficult to overcome. Iodin has been probably even more widely used than any other of the halogen group. It is conceivable, therefere, that a combination of chlorin and iodin would produce the ideal antiseptic. This we have in trichlorid of iodin.*

CHEMICAL PROPERTIES OF TRICHLORID OF IODIN.

Trichlorid of iodin (IC) is, as the name indicates, an atomic compound of

*See Dental Items of Interest, March 1918, for test tables of this anesthetic.

chlorin and iodin having three atoms of chlorin to one of iodin. It is a heavy reddish brown fuming powder, acid in reaction.* It comes in hermetically sealed ounce glass vials, and is freely soluble in water. That it may be used in aqueous solutions is very important, as all antiseptics are most efficient when used in aqueous solutions. Being an atomic compound, it is, moreover, highly ionized in solution and therefore in a most active form.

PREPARING THE SOLUTION.

Certain precautions must be observed. in preparing the solution. After making a small opening in the glass vial and weighing out the required amount of powder, the vial must be immediately resealed. This may be very satisfactorily accomplished by melting over the opening a small quantity of paraffin wax. This is necessary because the ICl, powder keep it in its original form. No metal is deliquescent and it is much better to

should be used or touched in weighing out the trichlorid of iodin, as it attacks most metals energetically and is thereby rendered worthless for further use. As it will also attack the metal of the scales, it is necessary to first accurately balance on the scales a glass-stoppered bottle;

* Obtainable from Merck & Co., New York City.