MALOCCLUSION AND ITS FAR-REACHING EFFECTS

SAMUEL ADAMS COHEN, M.D.NEW YORK

When we consider from the standpoint of beautyand comfort the great blessing of a healthy oral cavity,we cannot but wonder why the medical profession hasonly at this late date come to stress its importance.It is in this area more than anywhere else in the humanbody that prevention\p=m-\theideal of the physician\p=m-\canbe exercised. It has already been pointed out1 thatcaries, the most frequent disorder of the oral cavity,can be at least greatly minimized by both prenatal andpostnatal influences; prenatally not only by giving par-ticular attention to the diet of the mother for theformation of teeth of her unborn child, but also bypreventing any disturbance in the mother's metabolismthat might interefere with the assimilation of food.Postnatally, the physician should advise for the childa diet which provides for continuation of adequatetooth formation, and which also aids in the develop-ment of proper functioning of the jaws so as to lessenthe probability of the occurrence of malocclusion.Malocclusion is one oral disorder that has not

received the attention it deserves. It is a great handi¬cap to the child physically and mentally. This isevident when the physician notes the frequency withwhich a diagnosis of mental retardation and physicalimpairment accompanies the diagnosis of malocclusion.Normal occlusion goes hand in hand with well formedjaws, sound teeth, proper mastication, correct breath¬ing, normal speech, normal brain development and thewell-being of the child.The oral cavity of the new-born is very shallow,

owing to the imperfect development of the alveolarprocess. The hard palate is flat. The teeth are formedfirst, and the bone develops around them for their sup¬port. A tooth grows by the multiplication of cells ofthe tooth germs, and the growth is comparable to theforces exerted on it by multiplication of cells as in anyother part of the body. The peculiar forces of themuscles of the face and the surrounding bone deter¬mine the extent of development. The lips, tongue,palate and other tissues exert pressure on the lingualsurfaces of the bone, through the periostium, which inturn stimulates its growth. This mechanical stimulusis necessary in addition to nutrition for growth.Animal experiments and clinical evidence show that

the muscular function acting through occlusion affectsthe development not only of the jaw but also of theentire skull. Any lack of harmony in the working ofthese muscular forces causes the teeth to occlude abnor¬mally after their eruption. Every pathologic occlusionhas a simple beginning in its deviation from the normaleither in structure or in function. Once this balanceor harmonious relation in the forces acting on the oraltissue is altered, there is a resulting disturbance in thedevelopment of the jaw. This improper developmentprogresses because the same forces that act in keepingthe teeth in their normal relation act equally in increas¬ing any disproportion that exists.If the child has proper oral care up to the age of 6,

the chances are that oral disorders in after life willbe avoided or at least greatly decreased. Assuming

From the Forsyth Dental Infirmary for Children.1. Cohen, S. A.: Oral Disorders in Pediatrics, Am. J. Dis. Child.

24:160 (Aug.) 1922.

that the child has inherited a normal oral cavity, themost effective means of preventing oral deformities areto (1) provide proper nutrition; (2) provide sufficientand proper exercise of the jaw; (3) avoid faultyoral habits, and (4) remove causes of mouth breathing.

MOUTH BREATHINGThe physical defects often seen accompanying mouth

breathing of long duration include poorly developedalae nasi with small nose and short upper lip, upperarch narrow and lengthened, deflected septum, andsometimes impaired hearing. The child's appetite isusually poor, and there is a great desire for fluids, totake away the constant dryness of the mouth andthroat. A history of anorexia and unsatisfied thirstis given by the mother as a consequence.The amount of discomfort and deformity that may

result from mouth breathing is difficult to estimate.Those who have a long, narrow face, with a shortenedmandible, are apparently the worst sufferers Anormal face, on the other hand, seems to show evi¬dences of comparatively little discomfort.One of the commonest causes of persistent mouth

breathing, especially in infancy, is adenoids. The causeof adenoids is often hard to explain, but their removalis comparatively simple. This course is urgentlyadvised, as soon as the diagnosis is established. Earlyage is no barrier to their removal. When adenoidsare responsible for mouth breathing, their removal isusually sufficient to restore nasal breathing; but nasalbreathing does not usually follow after the removal ofthe adenoids in early childhood unless proper instruc¬tion of muscle training is given and carried out.About 75 per cent, of the children seen at the Forsyth

Dental Infirmary are still mouth breathers from onemonth to three years after the removal of their tonsilsand adenoids. In a small percentage of these children,the condition may be traced to some further existingmechanical obstruction ; in others, mouth breathingexists either because of habit formation or because ofimproper development of the facial muscles. Byrepeatedly reminding these children to breathe withtheir mouths closed, and by the constant practice ofsimple special exercises which tend to develop thefacial muscles (as recommended by Dr. Alfred P.Rogers of Boston), a great many of them can be taughtto breathe properly.Nasal breathing is vital for correct oral development,and is one of the surest preventions of irregularityof temporary teeth. Fortunately, not all mouth

breathers develop material deformities of the dentalarches, maxilla or mandible.

FAULTY HABITS

Faulty habits may play some major or minor partin the causation of oral deformities. These habitsshould be prevented if possible; if formed, they shouldbe discontinued. A practice to be especially condemnedis the prolongation of feeding through the artificialnipple. Bottle feeding does not furnish the properdevelopment of the muscles of the jaw. It retards thechild in learning to masticate properly. The musclesof mastication should be put into function as early aspossible, and there is no valid excuse for allowing thechild to continue bottle feeding when it has sufficientstrength to be fed with a spoon.It is hardly necessary to comment on the fact that

the breast-fed baby is better nourished than the babywho is artificially fed. From the point of view ofnormal oral development, the breast-fed baby, by the

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very act of nursing, has the additional advantage ofdeveloping its mouth and jaw to a higher degree ofperfection than the baby who obtains its nourishmentthrough an artificial nipple. The breast-fed baby, byhis act of vigorous sucking with a great deal of force,causes the tongue to act as a wedge to the back partof the mouth, which in turn causes a widening of thenasal passages. The child nursing from a bottle doesnot go through the same performance of developingits jaw muscles ; the milk flows readily, and the softrubber nipple does not offer the same kind of resistanceas does the human nipple. A nipple of proper size isimportant if the baby nurses from a bottle. An idealnipple is one that is long and large enough so that thebaby can draw the fluid from the bottle only by work¬ing the jaw up and down; and pressing the nipplebetween the tongue and palate, and bringing into playthe muscles of the palate. It is worthy of note thatDrs. Hellman and Wenker have found that from 79to 81 per cent, of arrested jaw development occurredin babies who were artificially fed.2The pernicious habit of thumb or finger sucking is

often a problem to be met by the physician. Ordinarilyhe is consulted only after the usual treatments havefailed. An aluminum mitten or a large woolen glove,bound up to include the whole hand, or some, similardevice that makes the child's hand so bulky that it isimpossible to introduce it into the mouth, is sometimessufficient to break the child of the habit. Serious oralconsequences may result with the continuation of thishabit. A simple, satisfactory and ingenious methodwhich is occasionally used is that of employing someappliance which covers the child's palate and henceremoves the satisfaction derived from sucking.Another habit influencing malocclusion is the constant

biting of the lips, which causes continual pressure onthe front teeth. It is not so common as thumb suck¬ing, and, moreover, is one that is easily broken; butif this habit is allowed to continue, there is a pro¬truding of the front teeth, and also a receding of thelower distal arches.

NUTRITIONAL DISTURBANCES

Clinically, it has been found that nutritional dis¬turbances are one of the outstanding etiologic factorsof malocclusion. Because of improper nutrition, thereis frequently an asymetrical development which causesa disturbance in function, this, in turn, resulting in aninterference of the local nutrition, with subsequent lossof anatomic form.Rickets is one of the worst conditions in the causa¬

tion of malocclusion, and is also responsible for someof its severest forms. There is often a marked jawdeformity in cases of moderate rickets. Even mildcases of rickets clinically show some jaw deformity.The arrest in the development in the maxillary bonesin rickets usually causes some degree of malocclusion,although sometimes it may not be susceptible oftreatment.Deprivation of proper masticatory exercise inter¬

feres with the proper development of the face bonesand face muscles. This factor introduces the questionof the physical properties of food. The modernmethods of food preparation tend to cause disuse ofthe jaws and teeth. Soft, mushy food of the presentday diet is bound to cause a lack of vigorous mastica¬tion, which is so vital to proper jaw development.Vigorous mastication causes the masseter muscles to

2. Wenker, R. J.: Dental Item of Interest 41:619 (Aug. 19) 1919.

have a widening effect on the lower jaw, which tendsto widen the arch of the maxilla and the palate. Anormal nasopharynx and roomy nostrils result fromthis widening effect. If the child has been kept onbottle or soft food fifteen months or more, it is some¬times difficult for him to learn to masticate properly.

ABNORMALITIES AND DEFORMITIESWhen there is a lack of muscular action in parts of

the body other than that of the face, there results noconcomitant bony deformity. But not so with thebones of the face ; it has been pointed out previouslythat masticating action causes bone growth by a mecha¬nical stimulus, and that absence of or insufficiency ofhard food does not furnish the necessary muscularaction to cause the necessary mechanical stimulus.Chewing involves the use of the muscles of mastica¬

tion which are attached to the bones, and results ingrowth of the jaws, ample to accompany the teeth innormal occlusion. In looking over sample diets recom¬mended, one cannot help feeling that there is a lackof proper food from a physical and mechanical pointof view, to insure proper and ample functioning ofthe masticating muscles.Only normal mouths can perform normal functions.

Malocclusion always indicates abnormal functioning.Normal occlusion means the health of the teeth andtheir surrounding parts. Malocclusion implies a path¬ologic condition of the teeth and surrounding tissues.It is the experience at the Forsyth Dental Infirmarythat a well formed mouth rarely harbors any significantoral disorders. By a well formed mouth is meant onein which all the teeth in both arches are so situatedas to have the proper interrelation, with the portionsof the teeth in the arches in such a position as to giveone another, singly and collectively, the greatest pos¬sible support.3 Malocclusion may result from anycombination of one or two kinds of irregularities,that is, either the teeth all stand in line and the jawsare disproportional in size, or the jaws are proportionalin size, and the teeth are improperly placed in line.As there are no two faces alike, so there are no twodentures alike ; therefore there cannot be any criterionfor normal or abnormal occlusion.Children who are underdeveloped frequently have

dental arches which are too narrow. An indicationof lack of vigor is shown by the improper develop¬ment of the arches. Supernumerary teeth are usuallyan indication of malocclusion.Prognathism, a marked projection of either jaw, is

easily recognized. The diagnosis of severe or moderatedegrees of malocclusion is also comparatively simple.The upper arch is frequently narrow and lengthened,although there may be little or no crowding of theteeth. It remained for the late Dr. E. A. Bogue 4 ofNew York to interpret properly the diagnosis of mal-occlusion in its early stages. Temporary teeth aremuch smaller than permanent teeth. If before theeruption of the permanent teeth there is no spacingbetween the deciduous teeth, there will surely be insuffi¬cient space for the larger permanent teeth when theyerupt. Therefore, the presence of perfectly close,regular teeth after 5 years of age is an indication fortreatment, since Nature must be aided if there is tobe sufficient room for the permanent teeth to come.

Spreading apart of the baby's teeth begins to take placebefore the third year. At three and a half years the

3. Angle, E. A.: Treatment of Malocclusion of the Teeth, Philadel-phia, S. S. White Dental Manufacturing Company, 1907.

4. Bogue, E. A.: Internat. J. Orthodent. 7:242 (May) 1921.

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upper dental arch must measure at least 27 mm. in thelateral width between the temporary molar region. If at4 years the breadth is less than 28 mm., it is absolutelycertain that the child will not have a normal arch unlessit is aided artificially, for the child will not outgrowthe defect. This measurement is the distance betweenthe second deciduous molars and is taken by means ofa caliper; from 28 to 30 mm. is the variation of anormal width, and any measurement below 28 mm.should be considered abnormal. An abnormal measure¬ment is sufficiently reliable to warrant a diagnosis.The measurement of this width is simple enough toadvise that the use of the caliper be added to the everincreasing armamentarium of the physician.About two years before the permanent teeth erupt,

their growth within the tissues causes a distal enlarge¬ment of the dental arches. This widening causes thespacing between the temporary teeth which is normaland should be sought for between the ages of 4 and6 years. Frequently, in cases tending toward abnor¬mality, spacing is found only between the anteriorteeth. Spacing, however, should occur between all theteeth in the mouth. If the child's general developmentis slower than the average, the spacing occurs at a

correspondingly later age. This fact is one which isimportant to remember from the point of view ofdiagnosis and treatment.

TREATMENTOnce the diagnosis of malocclusion is made and

there is no further mechanical hindrance, the patientshould be turned over to the orthodontist for treat¬ment. Previous to this, the rhinologist should beconsulted to determine and treat any mechanicalinterference to breathing, so far as is practical. Thus,the physician, in conjunction with the rhinologist andthe orthodontist, is directly concerned in the treatmentof every case of malocclusion.As has already been stated, abnormal conditions will

not correct themselves, and the forces involved tendto maintain and exaggerate these abnormalities. Onthe other hand, there is a remarkable and promptresponse on the part of Nature to correct malocclu¬sion as soon as favorable conditions are established.The treatment of malocclusion should begin as earlyas possible, thirty months of age being considered themost favorable time. The younger the person, themore plastic the tissues. The longer the teeth remainin malocclusion, the more fixed and unyielding becomethe surrounding tissues. For this reason it is fareasier to move teeth about the socket of the alveolarprocess in younger than.in older children. As eachsucceeding and permanent tooth erupts, the chancesfor complete success are diminished, and the durationof treatment is lengthened. In early treatment, onlyslight force is necessary to direct each erupting toothto its proper position, as the growth and repair aremost rapid, and the tissues yield very easily. How¬ever, if treatment is postponed, the situation becomesmore complex as treatment involves the whole dentalapparatus ; the teeth are more firmly held in the socket,and the muscles are already altered to work in unisonwith malocclusion, as is evident by the firmly fixedlines.Treating the dental deformity before the sixth year

insures not only good mouth functioning but also cor¬rect breathing, since the width of the maxillary archdetermines whether or not there is room for normalnasal breathing. Narrowing of the nasal spaces is the

result of malocclusion because of a deflection of theseptum. Early treatment of the arches either preventsor relieves narrowing of the nasal spaces ; the width ofthe nasal floor is dependent on the width of the upperdental arch.In fact, the growth and development of the mouth

and tissues are so closely interwoven with the nasalspaces that any pathologic disturbance in one will causedisturbance in the other. Besides the nasal develop¬ment and function being corrected through the correc¬tion of malocclusion, there will also be an improvementin the usually accompanying faulty posture, curvatureof the spine, and abnormal development of the chest.Faulty and narrow jaw development causes the eusta-chian tubes to be so curved that the orifices close ortend to be closed. This naturally causes deafness orimpaired hearing. Improvement of the jaw, if it isthe cause of existing aural conditions, will aid thismaterially.5 Correct pronunciation is seriously inter¬fered with if the arches are in an abnormal position.This is especially true of the letters F and V, whichare enunciated by sudden escape of air between thelower lip and the upper front teeth. Faulty habits ofenunciation are corrected more easily in early than inlater childhood. It follows that the earlier the correc¬tion of the deformity is undertaken, the more likeli¬hood there is for proper enunciation and proper tone.Dr. Bogue states that the child's brain at 6 years is

within 40 gm. of its weight at 19 years of age; henceit is most important that all irregularities of the faceand teeth should be corrected before the sixth year,while growth is at its maximum. He asserts that thegrowth of brain tissue is retarded mechanically bypoor occlusion. For these reasons and many morethat can be enumerated, the physician should be on thelookout for normal arches in children between theages of 2% and 6 years. Doubtful cases should beclosely observed and treatment begun just as soon as

diagnosis is established.CONCLUSION

From the foregoing few facts, it is seen that thedental apparatus is not an organ with a single func¬tion which may be compared to the other organs, forexample, the eyes and ears, treatment or lack of treat¬ment affecting those alone. The impairment of thedental apparatus, because of its very complex structure,includes also the impairment of muscles of mastica¬tion, voice production and voice sound, teeth, dentalarches, facial expression and beauty of face. All ofthese functions are performed properly only if theyare developed properly, and if there is any impair¬ment in even a part of the dental structures, theresult is improper functioning of all the complex actsdescribed above, in addition to an unattractive counte¬nance. Not only is there a tendency on the part ofNature to cause these abnormal conditions to progress,but Nature will show herself at her best in maintainingand continuing to maintain the entire dental apparatusin proper condition, and therefore proper functioning,if the dental apparatus is in order or is guided to bein proper working order.The final responsibility of oral disorders rests with

the physician. It should be his particular care thatproper measures for prevention and treatment of mal-occlusion be introduced at the proper age, in orderthat the greatest amount of good may be accomplishedin the shortest time and at the least expense.

5. Wright, W. H.: J. Nat. Dent. A. 7:979 (Dec.) 1920.

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