A text-book of dental pathology and therapeutics for students and practitioners

Front matter

mm

Class.

Book

Preface To Fifth Edition

This volume was originally designed as a text-book of the principles and practice of dental medicine for the use of students, and as a reference work on applied special pathology and therapeutics for the use of dentists. Accepting the dictum of the advanced teachers of the day, it was considered that an entirely rational system of dental medicine could have but one basis — namely, the same principles which underlie general medical and surgical practice. The book represents, therefore, an attempt at formulating, from data obtained from every available source, a system of dental pathology and therapeutics of which the several parts shall be in harmony with one another and also with the several collateral sciences involved. The impulse prompting the work was no desire to multiply books, but arose from a conviction expressed by many teachers, that such a volume was needed by students, practitioners, and teachers.

In revising the work for this new edition, the Editor has endeavored to maintain the original idea of a text-book furnishing a description of each dental disease and its treatment in such manner that teachers may find it a useful adjunct in the presentation of dental pathology and therapeutics to their students. The development in this branch of dental science during the last few years has necessitated many changes in the text to reflect the present advanced position of the entire subject. Many new illustrations have been added to increase its value for didactic purposes.

In place of the original section on Pharmacology, which was necessarily limited in scope, the various remedies and drugs mentioned are fully indexed in order that their various uses as applied to the therapy of the pathological conditions discussed may be studied .

The thanks of the Editor are due to those who have kindly loaned valuable illustrations. In no instance has a request been denied.

The Editor also takes this opportunity to express his warm appreciation of the continued favor bestowed on this work by professors and teachers of the subject throughout this Continent and in Europe.

0. E. Inglis.

1524 Chestxut Street, Philadelphia, 1915.

Chapter I. General Principles

General pathology {pathos, disease, and logos, a discourse) is that branch of science which treats of the modifications in function and changes in structure occurring in disease. It embraces all pathological processes occurring in the human body, and as many of these occur in and about the teeth, modified only by the peculiar anatomy of the parts, Dental Pathology may be said to be that branch of dental science which treats of modifications in function and changes in structure occurring in the diseases of the teeth and associate parts.

This being true, it follows that the study of dental pathology must be preceded by a study of the general disease processes which affect the tissues of the body, and such of these as are applicable to the study are known as the General Principles.

The word Therapeutics is derived from the Greek therapeuin, to take care of, meaning the measures adopted to remedy or remove the changes induced by pathological processes.

The study of the pathology of a part begins with a study of its anatomy and histology, then naturally follows a study of its physiology and embryology. These form the basis from which degrees of abnormal function and altered structure may be judged by comparison with similar processes occurring in other parts of the body.

The body is composed of cells held together by intercellular substance. These cells are the essential functionating parts of the organism; each cell is composed of a small mass of protoplasm containing in nearly all cases a nucleus, and has a form adapted to 2 (17)

its environment and function. The exact chemical composition of protoplasm is unknown and efforts at analysis destroy its peculiar property as a substance exhibiting a sequence of phenomena called life. It is a viscid substance composed physically of a network, the spongioplasm, containing a slightly more fluid substance, the hyaloplasm. 1 Chemically it is 70 per cent, water containing a collection of proteids, and differs as to these in the different classes of cells. Proteids are but imperfectly understood, but are known to consist essentially of carbon, hydrogen, oxygen, and nitrogen, combined with sulphur and other varying elements in enormous molecules

approximately represented by the formula FlG - * C400H310O120N50S. 2 This formula represents

merely the quantities of these elements, which are probably combined into various chemical compounds in the cell, including in some proteids one or more carbohydrate radicals, and each having its peculiar chemical affinity for food materials, and even irritating or poisonous materials, capacity for energy or function, and reduc- Changes of form in an tion to waste or use i ess ce n material. The

ameba: PP, pseudopodia; .

v, vesicle; N, nucleus. study oi the properties or cell protoplasm

may be made by observing in situ the action of living cells under normal conditions, and when subjected to artificial stimuli, and by observing the action of free single cells, such as an ameba, under like conditions.

If a drop of water be taken from the sides or bottom of an aquarium, placed on a slide and covered with a cover-glass, and then placed under a microscope with, first, a \" objective, there will be noted at some portion of the fluid a small transparent mass having the appearance of a colorless fragment of jelly; this is an ameba. The outline of the mass may have almost any form. At some portion there will be a defined and easily distinguished spot, the nucleus ; at another point a vesicle is seen; the body of the ameba appears to contain numbers of fine granules. The nucleus appears more markedly granular than the body of the ameba. If kept under observation, the ameba will be seen to change its outlines; at one or more and it may be in several places, projections like blunt arms or feet are seen to be extending from the ameba (Fig. 1). On account of their appearance they are called by the physiologist pseudopodia, from pseudo, false, and pons, a foot — false feet. These changes of

1 Kirke's Physiology. 2 Schofield, Elementary Physiology.

PROPERTIES OF CELLS form arc much varied (Fig. 2). The cell has, therefore, the property of altering its form — ?'. e., it has mobility and contractility; as by means of these motions it changes its location, it has the property of locomotion.

Fig. 2

%w p

Ameboid movement of a white blood corpuscle of man; various phases of movement.

(Klein.)

When certain solid substances contained in the water come in contact with the ameba, the latter is seen to flow around and engulf them ; as is shown in Figs. 3 and 4, where the analogue of an ameba, a leukocyte, has taken in bacteria (phagocytosis). After a time the ingested body is found to have disappeared; it has been digested. Evidently the cell must produce a substance capable of dissolving some foreign substances — i. e., it has the function of secretion. This is due to a digestive enzyme analogous to trypsin, which has been experimentally isolated from the ameba. 1 More than this, the

Fig. 3

Fig. 4

Leukocyte of a frog from the neighborhood of a piece of the lung of a mouse infected with anthrax, about forty-two hours after the piece of lung had been placed under the skin of the frog's back. The leukocyte is in the act of eating up an anthrax bacillus. (Brunton, after Metchnikoff.)

The same leukocyte a few minutes later, after it has completely enveloped the bacillus. (Brunton, after Metchnikoff.)

ameba does not take in substances indiscriminately; some it rejects. All cells change the chemical nature of the media in which they grow, both by exhausting the nutritive supply and ejecting their excreta.

If the temperature of the slide be raised the movements of the cell become more rapid, and if raised to a temperature of 55° C. the cell contracts in a round lump; it responds to stimuli, and has therefore the property of irritability.

If the stage be cooled, the movements of the protoplasm are

1 Hiss and Zinsser, Text-book of Bacteriology.

lessened, and when foreign substances come in contact with the cell it fails to encompass them — its irritability and contractility are lessened.

It is noted that some simple cells are attracted and stimulated by light; others are repelled by it.

If a mild induction (interrupted) current be passed through the water in which the ameba is, the movements of the cells are checked ; if a strong current be passed, the cell contracts sharply. If a galvanic (constant) current be passed, movement at first ceases, but pseudopodia are extruded toward the cathode and the cell crawls toward that pole. 1

Fig. 5

Forms assumed by a nucleus in dividing: a, resting nucleus; b, skein-form, open stage; c, wreath-form; d, aster, or star-form; e, equatorial stage of division; /, separation more advanced; g and h, star and wreath forms of daughter nuclei. (Reduced from Flemming's drawings in the Arch. f. Mik. Anat.)

The cell responds to mechanical stimuli, such as violent shaking, by contraction. 2

If substances such as ether or chloroform are added to the fluid, the irritability of the cell is so lessened that it does not respond to stimuli. It is either chilled by evaporation or actually anesthetized.

If the supply of oxygen be cut off, or if carbon dioxid be admitted to the fluid, movement ceases and the cell remains contracted.

If the observations are continued, it will be noticed that changes occur in the nucleus of the cell. A series of alterations in its figure are noted, as shown in Fig. 5. Two nuclei are formed, and soon the body of the cell divides and two cells appear — the ameba has reproduced itself.

These observations serve to show that protoplasm as shown by the behavior of cells containing it has the properties of irritability, contractility, motion, selection, secretion, and excretion (i. e., met-

1 O. Hertwig, The Cell.

2 Ibid.

PROPERTIES OE ('ELLS 21

abolism or cell digestion) and reproduction, and that it responds to stimuli of physical and chemical nature, and that its functions may be altered by substances which are brought in contact with it. Upon these facts depends the practice of therapeutics, in which stimulation, sedation or alteration of nutritive function of the cells by means of the various drugs or remedies available is the aim of the therapeutist.

A living organism, it will be seen, has a certain degree of action and function. The general average of its action and functions is spoken of as a condition of health. When from any cause the functions are raised or lowered or in any way chemically altered from the general average, a condition of disease exists.

Stimulation. — Certain agencies applied to the cell increase its activity; this is called stimulation. The movements of the cell become more rapid, food particles are taken in more rapidly and disappear more quickly; irritability, contractility, and secretion are increased. The cell subdivides, or reproduces more quickly. Increase the stimulation, and the vital activity becomes fretful; in some cases cell division is incomplete — the nucleus divides, but not the cell body. Increase the stimulation beyond this degree, and the wearied cell ceases its movements — refuses to respond; is paralyzed in the body by overwork. It has also been shown that the cell loses its essential substance in overwork and that sometimes the products of its activity are held about it, causing cessation of function. This may be restored, if not carried too far, by rest and nutrition or by rest and the removal of the waste product.

Sedation. — If the conditions be reversed; if, instead of applying a stimulus to the cell, an opposite influence be introduced, the phenomena are reversed.

If the temperature be reduced, the movements of the cell become sluggish ; the body changes its form more slowly and less extensively — i. e., contractility is lessened; particles taken into the cell remain apparently unchanged; irritability, secretion, and excretion are lessened; and, furthermore, reproduction does not occur nearly so rapidly — that is, the cell in contact with sedative influences has all of its activities lessened. This leads to paralysis and death of the cell — it is starved to death.

Alteration. — It is to be understood that the cell is a microscopic laboratory conducting complex chemical processes which may be altered by an infinite number of influences of subtle nature. This modification may possibly occur in a manner not referable to simple stimulation or sedation, as, for example, by retention of waste, or depositon of matter extraneous to the cell. Such changes may fittingly be spoken of as alterations, especially in view of the behavior of cells when subjected to the influence of that class of drugs known as alteratives or such influences as sunlight or the psychological remedies. While such alterations also probably occur as the result of stimulation and sedation, the fact that the beneficial action of certain classes of therapy is not understood warrants this third classification even if for explanatory reasons only. The term malnutrition is synonymous with alteration as here described.

Every cell has a range of resistance to these influences which tend to destroy it, which is fitly termed the resistance of vitality. Disease itself is some alteration in the cell chemistry controlling any one or more of these several cell properties, of irritability, contractility, growth, secretion, maintenance, or reproduction. If any one of these properties is not exhibited, it is said that the cell is diseased.

The cell lives its cycle and reproduces, and the parent is no more, the life being, continued in the offspring.

The life and properties of this small mass of protoplasm represent in miniature the primitive functions and life of the highest animals.

The contractility is represented in the motive apparatus of the higher animals.

The reception, engulfing, and dissolving, or casting out, of bodies with which the ameba is brought in contact correspond in the higher animals to the digestive apparatus and process and the excretory function.

The highly evolved irritability is represented in the nervous system of the higher animals.

The movements occurring in and about the vacuole are the progenitors of the circulatory apparatus and all of its adjunct organs.

If the irritability of a simple cell be increased or diminished, it corresponds to a disease of the nervous system, and so with the other functions.

In the human body certain collections of cells are found in which one function is active, the others in abeyance; thus, large colonies of cells exist in which contractility is the dominant property noted; these are muscle cells. Others have but the property of irritability; these are nerve cells. Still others develop peculiar chemical functions, and become glandular or secretory cells. Such collections of cells are known as tissues. These special cell colonies or tissues are built together into defined masses for the performance of their specialized functions. In the development of these masses, means of holding and maintaining the cells in definite mass forms and provisions for their food supply and waste-removing apparatus are provided in what are called the connective tissues, binding the

NUTRITION 23

colls iii definite forms and transmitting their vascular supply (foodand waste-carrier). When thus hound together the tissues are said to form organs.

While all tissues are capable of analysis into cells and intercellular substance, a more practical view may resolve the tissues into (1) functional cells; (2) a supporting intercellular substance; (3) intercellular spaces in which flows the lymph derived from the blood; (4) the channels of circulation and conductors of nervous impulses — i. e., arteries, capillaries, veins, lymphatics, and nerves. The arteries bring to the tissues the blood freighted with oxygen and nutrient material. As it passes through the capillaries a portion of the blood plasma, under arterial pressure and osmotic force, passes into the intercellular spaces into contact with the cells. This exuded fluid is now called lymph.

Stated in general terms, the food materials contained in arterial blood and furnished to the tissues by way of the lymph are water, some proteid, and the constituent to make proteid, amino-acids and polypeptids, 1 glucose and fats or their elements, inorganic salts, and oxygen. From this store the cells take what they require, and within themselves they elaborate chemically substances essential to their growth and maintenance as masses of functionating protoplasm (anabolism). As the protoplasm is of more complex composition than the majority of food elements, they are said to form from simple compounds substances of a higher degree of complexity. Having performed its functions, or in the act of such performance, this protoplasm is chemically altered into waste products of less complex chemical composition (catabolism) and such " products of catabolism" are thrown out from the cell into the lymph in the intercellular (lymph) spaces. This process may be spoken of as cell elimination and the substances themselves as cell ejecta. The total process is termed metabolism.

While the exact nature of the chemical change occurring in cells is not known, the present thought is that much of the process of cell metabolism is conducted wathin the cell through the action of one or more enzymes which have the power of catalytically effecting prompt and smooth chemical changes at low temperature, which can at times be produced in the laboratory only by complicated experiments not at all comparable with the action of cells.

Various organs of the body evidently prepare the food material absorbed by the intestines for the use of the cells — for example, glycogen is formed from the absorbed glucose by the ferment of liver

1 Howell, Text-book of Physiology, 1911, p. 877.

cells, and when needed again is transformed into glucose. As a proteid example the fibrinogen of the blood is supposed to be produced in the liver. 1 The proteid as built into complete form in the body juice and tissues is very complex and may contain all or a portion of fourteen or more monoamino-acids or four or more diamino-basic bodies, which shows the tremendous problem of the chemical study of metabolism, which is as yet imperfect. 2

Ehrlich's side-chain theory for immunity (which see) presupposes the presence of atom groups of protoplasm surrounding a complex group of atom groups, the nucleus, each atom group having affinity for a particular form of substance presented to it. These he terms receptors, and each is supposed to possess a combining or prehending group of atoms called an haptophorous group and a ferment group capable of altering the chemistry of the food element to suit its needs or that of the cell as a whole; this latter group is termed a zymophorous group. This obviously is merely stating in a scientific manner that the cell receives and digests food materials. The carbohydrates and fats are in the main the producers of energy, and are, lastly, resolved into glucose and fat or their elements for the consumption of the cells, and by them appropriated into their protoplasm, whence, by catabolic changes, they are started upon their retrogressive course to the final products CO2 and water. The proteids are mainly useful for the building of the cell protoplasm and its maintenance, and when catabolized end in products which in other organs are transformed into urea and uric acid.

There is evidence that changes occur in the cell waste either in the blood or in various organs of the body. While, then, the bodily ejecta contain substances fairly constant in composition, they are held to represent elaborations of cell waste rather than actual cell ejecta. For example, urea is pretty certainly derived from muscular tissue, yet is nearly absent in muscle and is supposed to be due to the dehydration of ammonium carbonate in the liver. 3 Lactic acid and ammonium carbonate have been experimentally shown to be probably combined into uric acid in the liver. The cell waste is carried by the lymph into the lymphatics connecting with the intercellular spaces. Thence it is delivered by way of the venous system to the circulation, for further elaboration and elimination from the body. Any interference with such elaboration or elimination must of necessity result in a retention of waste products within the system, probably leading to irritation and disturbance of metabolism in all cells.

Cell metabolism is a chemical change and is therefore accompanied

1 Howell, Text-book of Physiology, 1911, p. 444. 2 Ibid., p. 986.

3 Kirke's Physiology.

NUTRITION 25

by heat production. Energy is stored up in the cell as latent force existing in actual cell substance and is capable of liberation under stimulus, which force is expressed in various forms of functional activity — /'. e. } contractility in muscular tissue, irritability and mentality in nervous tissue, secretion in the various secretory glands, eliminative selection in the various excretory organs, etc. Experimental evidence has shown that after energy has been liberated to the point of fatigue, there is an actual loss of substance by the cells, in consequence of which they become smaller and of different histological appearance. It is evident, therefore, that any condition which will produce an expenditure of energy without a compensating restoration of cell material must result in a malnutritional process. Oils after a period of activity undergo degenerative processes, and are removed or are reproduced bv the process of mitosis (Fig. 5).

The life conditions of cells are necessarily those under wdiich they best perform these functions without exhaustion, and are the following: (1) a proper food supply, including water and oxygen; (2) a proper removal of waste products; (3) proper physical conditions, including a proper temperature; (4) possibly a proper innervation. 1 Any interference with these conditions, which may be termed the normal physiological conditions, results in a morbid process of physiology or pathology in its limited sense. With such interference disease may be said to begin. The definition of disease as an alteration of nutrition is therefore appropriate. For this reason the proximate exciting causes of disease are classed as (1) abnormal food supply; (2) abnormal waste removal; (3) abnormal physical conditions; (4) abnormal nerve supply.

The morbid physiology results in morbid products or in retained normal products and an altered cell function. When pronounced this is spoken of as Functional Disease, although it may be said to be in existence even if discomfort be not produced. Sooner or later an abnormal change in the histological characteristics of the cells or intercellular substance may occur, which has been referred to as Morbid Histology or Pathological Histology. As definite microscopic and often macroscopic appearances are associated with certain diseased conditions, these are referred to as the Morbid Anatomy of a disease or Pathological Anatomy. The phemonena associated with a disease are called its Semeiology (semeion, a mark or sign) or Symp-

1 While this conception is practical, experiments at the Rockefeller Institute have shown that, kept in a proper aseptic nutritive fluid at a low temperature various organs and tissues may be preserved for a considerable time and even shipped, thus being available for surgery. This shows that cells possess a life only dependent upon the body as a whole for their source of nutritive supply.

tomatology, and are either described by the patient as sensations or pains of varied character or situation (Subjective Symptoms), or may be noted by normal or aided vision, by physical examination, chemical analysis or positive reactions to certain biological tests (as in the Wassermann reaction for syphilis) (Objective Symptoms). That which excites a disease or promotes the action of the excitation is called a Disease Cause. The study of disease causes is Etiology (aetios, a cause, and logos). It is noted that diseases having a fairly defined pathology and morbid anatomy have from their beginning to ending tolerably constant phenomena; they have each a natural history; this is called the Clinical History of a disease.

The study of the origin and development of a disease together is known as its Pathogenesis (pathos, disease; gennao, I produce). Through the study of the characteristic symptoms of diseases, as well as those common to several diseases, a particular disease may be distinguished. This is called Diagnosis (dia, through; gignosko, I know) — Direct Diagnosis when there is no question as to the symptoms, Differential Diagnosis when several diseases are possible and the characteristics of one are considered as more pronounced. Under certain circumstances a disease may be inferred to be present by excluding all other possible conditions (Diagnosis by Exclusion). A fourth method of diagnosis is by the therapeutic test (see below) . In the course of a disease experience has shown that certain signs and symptoms are apt to be followed by good or ill results, as the case may be. By these signs and symptoms it may be foretold with some degree of assurance what will be the probable outcome of the disease. The inference based upon these symptoms is known as the Prognosis (pro, before, and gignosko, I know). The care of or treatment of a disease is its Therapeutics. This involves a knowledge of remedies applicable, known as the Materia Medica. When applied upon the basis of a scientific study of the pathogenesis, clinical history, and prognosis of disease and a parallel knowledge of the physiological action of drugs and of other remedies, the treatment is known as Rational Therapeutics. When the treatment is based upon the known good effects of a remedy in a certain disease, and not upon its physiological action, it is known as Empirical Therapeutics. Diagnosis may not always be clear, but upon a basis of previous experience of association of symptoms a given therapeutics may be applied with more or less rationality. Whether good results follow or not the method is known as "the therapeutic test."

The pathogenesis of a disease being known, intelligent efforts may be exerted for its prevention. The causes may be removed or neutralized before they have an opportunity to act; this is Prophylaxis.

NUTRITIOX 27

The science of prevention of disease upon the broad basis of a knowledge of disease causes and observance of laws of health is Hygiene.

It will be seen that a knowledge of special pathology can only be obtained from (1) a knowledge of pathology in general or at least of those principles of general pathology which underlie all disease processes; (2) a knowledge of the local anatomy and histology; (3) a knowledge of local embryology and physiology ; (4) a study of local pathology and morbid anatomy. To this must be added a study of materia medica and special therapeutics.

Chapter II. Causes Of Disease, General And Local

A disease cause may be defined as any influence of whatsoever nature which is capable of disturbing the nutritive balance of any portion of the body. The branch of study which deals with the causes of disease is called Etiology.

The causes of disease are classed as Exciting (or Determining) and Predisposing. These are each divisible into Extrinsic, originating from without, and Intrinsic, originating within the body.

EXCITING CAUSES OF DISEASE.

These are influences, either extrinsic or intrinsic, which are competent to suddenly or gradually interfere with the nutrition of the cells of a part or with the general nutrition of cells. These influences are very numerous, but may be grouped according to their action under a few convenient headings: (1) Abnormal Food Supply. (2) Abnormal Waste Removal. (3) Abnormal Physical Conditions. (4) Abnormal Nerve Supply.

These are termed the Proximate Exciting Causes, as their effects are immediately exerted upon the cells. Other causes may be back of these and are spoken of as Primary (or Contributory) Causes — e. g., tuberculosis of the lung (primary) may cause insufficient oxygenation of the blood which constitutes an abnormal food supply (proximate).

Abnormal Food Supply. — By abnormal food supply is meant an altered quantity or quality of nutritive elements delivered to the cells either of a part or of the entire body. The primary causes of this may exist as disturbances or faults in any of the food-elaborating organs, the lungs, the eliminating organs, or the oxygen carriers of the blood may exist in lessened numbers. In the first case the quality or quantity of nutritive material is impaired, in the second and fourth cases oxygenation is insufficient, and in the third case materials injurious to cells are retained in the body and are again presented as food to the cells, acting as poisons. Poisonous or even non-poisonous drugs, and the products of bacterial action, whether absorbed from the intestines or from foci of infection, have all more or less deleters)

EXCITING CAUSES OF DISEASE 29

rious action upon cell protoplasm, violent if entering the blood in large quantity, chronic if entering continuously in small quantities.

Faults in the circulatory apparatus, interfering with the circulation generally, cause an interference with general nutrition, while local disturbances of the circulation from any cause disturb the relations of the blood supply to the nutrition of a part. Thus the fresh blood supply (food supply) to a particular location may be excessive, as in arterial hyperemia, or deficient, as in venous hyperemia and inflammation.

Abnormal Waste Removal. — Abnormal waste removal is ordinarily included under the heading of abnormal food supply, and it is evident that retention of waste in the blood causes the presentation to cells of an abnormal food or poison. In local conditions, such as venous hyperemia and inflammation, the stasis causing waste retention prevents the access of a fresh food supply as well. In kidney disease the substances ordinarily physiologically eliminated by the kidneys are retained in the blood and act as poisons to cell protoplasm generally. Insufficient circulation of lymph about cells means a relative retention of waste products about the cells with its effects upon them.

Abnormal Physical Conditions. — This class of disease causes includes all injuries due to any of the physical or chemical forces: Traumatic injuries, such as cuts, bruises, surgical openings, etc. Mechanical causes, such as compressions, obstructions to ducts or the natural outlets of the body, faults in the circulatory mechanism, stoppages in the arteries or veins. Chemical causes, such as the action of abnormal temperatures, burns, freezing, or irritations of various sorts, such as those due to mustard, arsenic, acids, or caustics, and the local effects of microorganisms may all be classified under this heading. The disturbance is due to either a direct destruction of the life of the cells or an interference with the circulation in a part.