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This and that
DEPARTMENT
DENTAL
AND
OI;
ORAL RADIOGRAPHY
E
zzE sE ss ==
=
Edited By Clarence 0. Simpson, M.D., D.D.S., F.A.C.D., and Howard R. Raper, D.D.S., F.A.C.D.
L
z s E 1z z= z
OOK at Fig. 1. Not such a bad-looking ratliogra~)h. pootl, in fact. in the bicuspid region. Sow look at Fig. 2. Sot, as good as k’ig. 1: do you t tiink :’ It is of the samr case. The root outlines arc not as distinct. 9ot) as good radiograph ! P,ut wait. 1Catttcr
il
Sctt,ing the xrtical angle is what. is cwlrmonly spoken oi’ HIS” tipI)ing t hta tube.” 110~ inneli shol~ld the tnbct 133 til)pctl ! For rrppcr tefd. tlw folkw“JlPt the angle Of lhe S-IXYS iW Sllrll il2 iug rule has long bren parrottcil: t,o strike, at right angles, a lille bisect irip tlir> angle Corinecl by thrb long axis of thr teeth and the plane of Ihe film in the month.” A good rule from a mathematical standpoint h~tt. impractical From a clirlical standpoint. I have long intended to c>xplain ant1 dissect this rule for the benefit of the readers of this Journal. I still intend IO, but not now. All I shall say nom is that probably not one t,o the thousa.nd of those who make dental radiographs ever took the bother to even understand the meaning of the rule. What has happened in practice is this: the operator. learning that a vertical angle which is too low results in elongation therupon shoots ‘~~11plenty :!Yfi
This and That
387
high. That is to say, he tips his tube a lot; he uses a high vertical angle. This causes foreshortening, but what of it, since the radiographs look pretty good (Fig. 1)) and one is sure of gettin, v the ends of the roots; and root outlines show even clearer ‘? The objection to this expedient of shooting ‘em plenty high is that. we do not get a good or true view of the parts. Abscess cavities may be superimposed on the end of the root and fail to show at all in the radiograph. The view of the alveolar crests and the proximal surfaces is hopelessly distorted. Even rather large pyorrhea pockets may escape detection in SLU~I negatives,
Fig.
3.
and, in the jumble of shadows, other desired information might escape as it escaped the operator who made Fig. 1. The folly of making observation from a high diagonal angle may be brought home more forcibly to my male readers if they will stop to consider what the view of our young ladies would be from say a window on the fifteenth floor. Viewed from such an angle one might suppose skirts came to the ankles. A view of the dental parts from a proportionally high x-ray angle is no more reliable. THE
OPEN
GATE
When I was a boy I had a dog. In those days people had front fences. My dog and I used to take walks together; we “went places.” Back of the front fences were other dogs. So the stage is set for a bark-fight. Back and forth, up and down t,he fence, the dogs raced barking viciously, villainously.
388
Howad
R. Raper
Now the odd and significant thing about these fights (% :‘! is tha.t t,here were gaps in the fence; palings were off in places and usually the gate stood wide open. The dogs might have gotten together at, these points and fought it out to t,he death, or arrived at some amicable agreement ~ Eut they didn’t. The> raced by the open places, ignoring them completel>-. Perhaps they were to0 enraged to see them; or, have it your way: perhaps t~hey liked 1.0 bark. TZe that as it may, we dentists, arguing the pulpless tooth question. remind mc of the dogs. Up and down the fence we rage ignoring the open gate, t.110 placao where w-e might get t,ogether and come to an understanding. Let me point, out this open gate, the common ground on which practically all denLists ma) meet and agree concerning the pulpless tooth: We can agree, can’t QY, that a tooth with a vital pulp is a more desirable cit,izen of the oral cavity i-han a pulpless one 1 I think we can. Xot,e, you friends and defenders of the pulpless tooth: that all I have said is that thcl tooth with the vital pulp is more desirable. If this were not true, there would be no objection t,o de&alizing teeth before placing a gold crown, and that, is a pract,ice abandoned by all. So let me repeat for the sake of emphasis! a tooth with a. vit,al pulp is more to be desired than a pulpless one. The next simple fact is that pulpless teeth ean he prevented. Very well then. if TW agree that pulplcss teeth are not. tlesirablc and that they can be ljrevented, then in the name of common sense why don’t. w make it our primary aim to prevent them? Why don’t we talk about the prevention of pulpless teeth more, ancl our methods of monkeying with ihem less. Or do we hase too much fun barking?
When George Washington had the toothache, he had t,he tooth extracted. That is the way dentist,ry was practiced in those days. Then came t,he period of “conservative dentistry. ” I’eople wcare taught to ha.ve their teeth extracted just because t,heg had ached. They were assured that such teeth could be made as good as new. Indeed they were even told that such teeth. could be made better than they lvere before, because “‘they would never ache a.gain. ” And this could be done for a trifling amount of money, say a dollar and a half. The people at large still believe t,hat they are perfectly safe in neglecting their teeth until pull) involvement and toothache occur, and that’ the treatment required after this is ctntirely satisfactory and within the reach of all. This, I believe, is absolutely contrary to the facts. Once a tooth has been neglected until toothache has occurred and pulp canal work becomes necessary. that tooth is never as good again no matter hoIv skillful the treatment. (And when it is unskillful-as it so often is--it amounts to nothing more than making the disease chronic, and so, rid of symptoms, letting it go at that.) As this is written dentistry hesitates, too timid to admit that it cannot make teeth t,hat have ached-teeth requiring pulpal and periapical treatment, I mean-“as good as ever.” There is a tendency, in fact, to pretend that of course dentistry can treat, such teeth with perfect success and satisfaction.
This and That This, of course, encourages neglect. Why should a person be so all-fired keen to prevent toothache if it can be cured and the tooth made as good as ever? Dentistry, it seems to me, is under the moral obligation of admitting its limitations. The profession as a whole has no more right to pose as being able And to do something it cannot do than has the individual in the profession. when the individual does this sort of thing we call him a quack. Not that I wish to imply that there is anything deliberately vicious in dentistry’s failure to admit its limitations in connection with the treatment of teeth. It is a combination of timidity and natural and entirely justifiable cautiousness. But it seems to me the admission must be made. Medicine does not hesitate to admit that it cannot treat cancer satisfactorily after it reaches a certain point. Indeed it widely proclaims the fact and organizes societies for the avowed purpose of keeping the disease from getting to the point where treatment becomes doubtful. Ditto tuberculosis. Dentistry is not discharging its obvious duty to the public until it makes similar admissions and takes similar action to prevent pulpless teeth. Not that I am proposing that the treatment of teeth be abandoned. It should not be and never will be. What I am proposing is to give up the silly defense of our treatment. To admit frankly that it is simply the best we can do under the circumstances, but that the circumstance of neglect to the point where such treatment becomes necessary makes entirely satisfactory results impossible. Was George Washington so far wrong? Answer me this, Mr. Dr. Dentist: a tooth of yours has ached (to your disgrace for allowing it to). Will you now have the tooth extracted, or treated by a dentist whom I shall select for you by shutting my eyes and pointin, e to a name in the classified list of dentists in the telephone book ? And, if you elect to have it treated, what will you have done with it later when you are sick with one or more of the degenerative diseases ? INTERPROXIMAL
X-RAY
EXAMINATION
TECHNIC
The technic for making the interproximal x-ray examination was first published in this Journal. That was over a year ago. Since then the Eastman Kodak Company have manufactured and placed on the market the bite-wing film packets necessary to the makin g of the complete five-film examination. These are, of course, a great improvement over the crude homemade packets I was using at the time I first described my technic. niore experience in the making of interproximal examination has resulted in the development of more exact methods. In brief, the technic for this examination is settling down, becoming simpler and more definite, easier to describe, understand and practice. What follows now may be considered supplementary to what has already been published in these pages. Some of it is in the nature of repetition for emphasis ; some of it is new. Position of the Head.-The same for all regions. A line drawn from the tragus of the ear to the ala of the nose should be horizontal. Angle of the X-rays.-The vertical angle should be about 8 degrees above (i.e., tip the tube about 8 degrees) for the posterior teeth. Slightly higher for the anterior teeth, say about ten degrees above.
390
Howard
R. Raper
When determining the horizontal x-ray angle, consider the upper teeth only. (See to it that you ge1 all the surfaces of tlica njq~t’r t ret11 and jwn will get the lowers incidentilll~.: ‘I’ll0 I~orizot~t;~l ;Ulplt5 I’i)!’ ;I fiVt,-filltl ~‘~iiIlliJI1~ tion arc as follows :
For the lateral incisor region, direct llle rays straight through tlie tIpper lateral incisor. If the angle is from too far arounti on the Gtl~~~~--thatis foe much l?le,sio-IinguallS---the result, may be fni lure 1-o gT1. Lhr (LiStill r4 tl\c Ill)per central and the mesial of the upper laicral incisor 011 the negal ivcl. For the posterior region, direct the parallel with 111(~IIiPSiAI SWface of the upper first molar. Tlie common niistakc will bc ric)t to tiirwt the rays cJisto-lingually enough. Placing fhc E’iha Packcfs ir7, the Xoutk.---il is v(ii*y great deal easier t 0 place the neat, manufactured bite-wing film packets in position in the mouth than it was to pla.ce t,he cruder, mow bunglesome, hoirit~ntatlc ones formerl\ used by the writ-w. Zt is? of course, no more difficult lo place bite\ying film packets in the mouth for interproximal exnminat,ioii than ii is t 0 place ordinary film packets for ordinary intraoral radiodontic worl<-but it is new and somewhat different and -there are certain points iI> teehuic -whic~h must be learnccl before it, cau bc donv \rith elitire cxase and tlispalcli. Y illustrates the several points iii technia which Poslf~+w Kc{jiow.--Fig. will make the placing of posterior film Ibackets simple and ea,sy. Before placing it in the montlt, bcllcl the ul)l)er front cornw to co1?~ptYisatP for th(‘ low paI+ Of tllc> palatat valdt in the irlll,el*io~ region. This bent1 can be seein clear])- jn Fig. :!. ;ZIso bwltl thp lower front corner sligbtl>- ; anti tbca othel This belitlirig oi’ ilre film corners may bc beni 01’ relieved slightly iC desired. packet is not :I rcqniremcut Iwculiar to bitt-wing !ilnr ~~;~PI;~~s;.rl’11~ \vvilclr bends ordinary film packets i’or ordinary dental s-ra~. work as I’OUIH~ nlw+ sary or expedient, which is 1o say, particularly in t11c incisor ant1 cwp.kl regions. ‘l’hc theory of the bending is to deliberately bend the film whrrcn bending is obviously ullayoitlablc anylloT\-. in c>rtlc~ to l)rcJ\-etjt unncwssar~ bending of the entire film and to render the placin, (f of the film easier for hot11 patient and operator. Plate tlica packet ~n2ctically in placr for llie lowrr t wtll---we Yig. 3. Don’t let it ride ou the tonplrr ; slide it down a.t the sitlc n-l’ the tongue. Let the front, cdgc of I he packet come forwrtl calear i1if-n the in&al region. (The conmlon mistake vrill be 11ot to c“Et it en0Ugh forward.) This leaves a space betwcwl the fact of the film anti lingual snrfacc nf the teet,h-except the molars. l)o not pull on 1 hc bile-wing ill a11 cfTor~- to rlos~ this space. TJct the> whole upper part of the paclwt slant inward towartl thv rt~rdinn line so that, when the patient closes the teet II onto ?hr bite-tving, it Tvill slicle easily into the palatal vault. rilyS
il
filr
1'11is u11rl l'h t
391
Use medium size Johnson and Johnson, readyeach side of the bite-wing. made cotton rolls cut a little shorter than the widt,h of the packet. Touch the cotton roll to water, then to Clorega or \Vwnet’s powder, t,hen apply to the The packet is now ready for packet firmly with a slight rubbing motion. use. While it is not absolutely necessary to use cotton rolls, the writer finds it such a great help that he never fails to do so. The- tend to keep the film from sliding too far lIpward or downward. With the cotton rolls in position, place rhe film packet practically in f)osition for the lower teeth. Eave the patient bite cwl to cwtl. Tf this forces the packet too far downward, bend the upper part of the film backward farther or, in some cases, change the technic to pnttin g the packet practically in place for the upper leet,h instead of the lower. IVhen the patient is biting on the bitrDo not pull on the bite-wing. wing and the film packet is in correct, position, only a very little of the bitrTying l)rotrudes labially beyond the teeth. The old homemade packets Ivitli sharp corners rc~qnircd a great deal of bending to avoid hurting the patient and to get them into correct position. With the neat packages with the rounded corners, non’ available, the matter of bending or relieving at the corners becomes more a matter of personal discussion and option; less a matter of necessity. Placing the Film Packet in the Lotox Incisor* Reyion.-The writer has lately developed a very simple method of getting the packet in the correct mesio-distal location for the lateral incisor region. Place the packet as though it were for the central incisor region and have the patient bite on the bite-wing, but not tightl>v. Now move the bite-wing to the side (distally) until the mesial edge of the bite-wing comes to the mesial of the upper central incisors. And now have the patient bite tightly. Ti?ne of Exposwc .-The t,ime of exposure for posterior bite-wing negafives is substant,ially the same as for ordinary posterior dental negatives. Only about one half the time is required for anterior interproximal negatives. For a time the writer made the mistake of overexposing anterior negatives.
DENTAL
AND
OI;
ORAL RADIOGRAPHY
E
zzE sE ss ==
=
Edited By Clarence 0. Simpson, M.D., D.D.S., F.A.C.D., and Howard R. Raper, D.D.S., F.A.C.D.
L
z s E 1z z= z
OOK at Fig. 1. Not such a bad-looking ratliogra~)h. pootl, in fact. in the bicuspid region. Sow look at Fig. 2. Sot, as good as k’ig. 1: do you t tiink :’ It is of the samr case. The root outlines arc not as distinct. 9ot) as good radiograph ! P,ut wait. 1Catttcr
il
Sctt,ing the xrtical angle is what. is cwlrmonly spoken oi’ HIS” tipI)ing t hta tube.” 110~ inneli shol~ld the tnbct 133 til)pctl ! For rrppcr tefd. tlw folkw“JlPt the angle Of lhe S-IXYS iW Sllrll il2 iug rule has long bren parrottcil: t,o strike, at right angles, a lille bisect irip tlir> angle Corinecl by thrb long axis of thr teeth and the plane of Ihe film in the month.” A good rule from a mathematical standpoint h~tt. impractical From a clirlical standpoint. I have long intended to c>xplain ant1 dissect this rule for the benefit of the readers of this Journal. I still intend IO, but not now. All I shall say nom is that probably not one t,o the thousa.nd of those who make dental radiographs ever took the bother to even understand the meaning of the rule. What has happened in practice is this: the operator. learning that a vertical angle which is too low results in elongation therupon shoots ‘~~11plenty :!Yfi
This and That
387
high. That is to say, he tips his tube a lot; he uses a high vertical angle. This causes foreshortening, but what of it, since the radiographs look pretty good (Fig. 1)) and one is sure of gettin, v the ends of the roots; and root outlines show even clearer ‘? The objection to this expedient of shooting ‘em plenty high is that. we do not get a good or true view of the parts. Abscess cavities may be superimposed on the end of the root and fail to show at all in the radiograph. The view of the alveolar crests and the proximal surfaces is hopelessly distorted. Even rather large pyorrhea pockets may escape detection in SLU~I negatives,
Fig.
3.
and, in the jumble of shadows, other desired information might escape as it escaped the operator who made Fig. 1. The folly of making observation from a high diagonal angle may be brought home more forcibly to my male readers if they will stop to consider what the view of our young ladies would be from say a window on the fifteenth floor. Viewed from such an angle one might suppose skirts came to the ankles. A view of the dental parts from a proportionally high x-ray angle is no more reliable. THE
OPEN
GATE
When I was a boy I had a dog. In those days people had front fences. My dog and I used to take walks together; we “went places.” Back of the front fences were other dogs. So the stage is set for a bark-fight. Back and forth, up and down t,he fence, the dogs raced barking viciously, villainously.
388
Howad
R. Raper
Now the odd and significant thing about these fights (% :‘! is tha.t t,here were gaps in the fence; palings were off in places and usually the gate stood wide open. The dogs might have gotten together at, these points and fought it out to t,he death, or arrived at some amicable agreement ~ Eut they didn’t. The> raced by the open places, ignoring them completel>-. Perhaps they were to0 enraged to see them; or, have it your way: perhaps t~hey liked 1.0 bark. TZe that as it may, we dentists, arguing the pulpless tooth question. remind mc of the dogs. Up and down the fence we rage ignoring the open gate, t.110 placao where w-e might get t,ogether and come to an understanding. Let me point, out this open gate, the common ground on which practically all denLists ma) meet and agree concerning the pulpless tooth: We can agree, can’t QY, that a tooth with a vital pulp is a more desirable cit,izen of the oral cavity i-han a pulpless one 1 I think we can. Xot,e, you friends and defenders of the pulpless tooth: that all I have said is that thcl tooth with the vital pulp is more desirable. If this were not true, there would be no objection t,o de&alizing teeth before placing a gold crown, and that, is a pract,ice abandoned by all. So let me repeat for the sake of emphasis! a tooth with a. vit,al pulp is more to be desired than a pulpless one. The next simple fact is that pulpless teeth ean he prevented. Very well then. if TW agree that pulplcss teeth are not. tlesirablc and that they can be ljrevented, then in the name of common sense why don’t. w make it our primary aim to prevent them? Why don’t we talk about the prevention of pulpless teeth more, ancl our methods of monkeying with ihem less. Or do we hase too much fun barking?
When George Washington had the toothache, he had t,he tooth extracted. That is the way dentist,ry was practiced in those days. Then came t,he period of “conservative dentistry. ” I’eople wcare taught to ha.ve their teeth extracted just because t,heg had ached. They were assured that such teeth could be made as good as new. Indeed they were even told that such teeth. could be made better than they lvere before, because “‘they would never ache a.gain. ” And this could be done for a trifling amount of money, say a dollar and a half. The people at large still believe t,hat they are perfectly safe in neglecting their teeth until pull) involvement and toothache occur, and that’ the treatment required after this is ctntirely satisfactory and within the reach of all. This, I believe, is absolutely contrary to the facts. Once a tooth has been neglected until toothache has occurred and pulp canal work becomes necessary. that tooth is never as good again no matter hoIv skillful the treatment. (And when it is unskillful-as it so often is--it amounts to nothing more than making the disease chronic, and so, rid of symptoms, letting it go at that.) As this is written dentistry hesitates, too timid to admit that it cannot make teeth t,hat have ached-teeth requiring pulpal and periapical treatment, I mean-“as good as ever.” There is a tendency, in fact, to pretend that of course dentistry can treat, such teeth with perfect success and satisfaction.
This and That This, of course, encourages neglect. Why should a person be so all-fired keen to prevent toothache if it can be cured and the tooth made as good as ever? Dentistry, it seems to me, is under the moral obligation of admitting its limitations. The profession as a whole has no more right to pose as being able And to do something it cannot do than has the individual in the profession. when the individual does this sort of thing we call him a quack. Not that I wish to imply that there is anything deliberately vicious in dentistry’s failure to admit its limitations in connection with the treatment of teeth. It is a combination of timidity and natural and entirely justifiable cautiousness. But it seems to me the admission must be made. Medicine does not hesitate to admit that it cannot treat cancer satisfactorily after it reaches a certain point. Indeed it widely proclaims the fact and organizes societies for the avowed purpose of keeping the disease from getting to the point where treatment becomes doubtful. Ditto tuberculosis. Dentistry is not discharging its obvious duty to the public until it makes similar admissions and takes similar action to prevent pulpless teeth. Not that I am proposing that the treatment of teeth be abandoned. It should not be and never will be. What I am proposing is to give up the silly defense of our treatment. To admit frankly that it is simply the best we can do under the circumstances, but that the circumstance of neglect to the point where such treatment becomes necessary makes entirely satisfactory results impossible. Was George Washington so far wrong? Answer me this, Mr. Dr. Dentist: a tooth of yours has ached (to your disgrace for allowing it to). Will you now have the tooth extracted, or treated by a dentist whom I shall select for you by shutting my eyes and pointin, e to a name in the classified list of dentists in the telephone book ? And, if you elect to have it treated, what will you have done with it later when you are sick with one or more of the degenerative diseases ? INTERPROXIMAL
X-RAY
EXAMINATION
TECHNIC
The technic for making the interproximal x-ray examination was first published in this Journal. That was over a year ago. Since then the Eastman Kodak Company have manufactured and placed on the market the bite-wing film packets necessary to the makin g of the complete five-film examination. These are, of course, a great improvement over the crude homemade packets I was using at the time I first described my technic. niore experience in the making of interproximal examination has resulted in the development of more exact methods. In brief, the technic for this examination is settling down, becoming simpler and more definite, easier to describe, understand and practice. What follows now may be considered supplementary to what has already been published in these pages. Some of it is in the nature of repetition for emphasis ; some of it is new. Position of the Head.-The same for all regions. A line drawn from the tragus of the ear to the ala of the nose should be horizontal. Angle of the X-rays.-The vertical angle should be about 8 degrees above (i.e., tip the tube about 8 degrees) for the posterior teeth. Slightly higher for the anterior teeth, say about ten degrees above.
390
Howard
R. Raper
When determining the horizontal x-ray angle, consider the upper teeth only. (See to it that you ge1 all the surfaces of tlica njq~t’r t ret11 and jwn will get the lowers incidentilll~.: ‘I’ll0 I~orizot~t;~l ;Ulplt5 I’i)!’ ;I fiVt,-filltl ~‘~iiIlliJI1~ tion arc as follows :
For the lateral incisor region, direct llle rays straight through tlie tIpper lateral incisor. If the angle is from too far arounti on the Gtl~~~~--thatis foe much l?le,sio-IinguallS---the result, may be fni lure 1-o gT1. Lhr (LiStill r4 tl\c Ill)per central and the mesial of the upper laicral incisor 011 the negal ivcl. For the posterior region, direct the parallel with 111(~IIiPSiAI SWface of the upper first molar. Tlie common niistakc will bc ric)t to tiirwt the rays cJisto-lingually enough. Placing fhc E’iha Packcfs ir7, the Xoutk.---il is v(ii*y great deal easier t 0 place the neat, manufactured bite-wing film packets in position in the mouth than it was to pla.ce t,he cruder, mow bunglesome, hoirit~ntatlc ones formerl\ used by the writ-w. Zt is? of course, no more difficult lo place bite\ying film packets in the mouth for interproximal exnminat,ioii than ii is t 0 place ordinary film packets for ordinary intraoral radiodontic worl<-but it is new and somewhat different and -there are certain points iI> teehuic -whic~h must be learnccl before it, cau bc donv \rith elitire cxase and tlispalcli. Y illustrates the several points iii technia which Poslf~+w Kc{jiow.--Fig. will make the placing of posterior film Ibackets simple and ea,sy. Before placing it in the montlt, bcllcl the ul)l)er front cornw to co1?~ptYisatP for th(‘ low paI+ Of tllc> palatat valdt in the irlll,el*io~ region. This bent1 can be seein clear])- jn Fig. :!. ;ZIso bwltl thp lower front corner sligbtl>- ; anti tbca othel This belitlirig oi’ ilre film corners may bc beni 01’ relieved slightly iC desired. packet is not :I rcqniremcut Iwculiar to bitt-wing !ilnr ~~;~PI;~~s;.rl’11~ \vvilclr bends ordinary film packets i’or ordinary dental s-ra~. work as I’OUIH~ nlw+ sary or expedient, which is 1o say, particularly in t11c incisor ant1 cwp.kl regions. ‘l’hc theory of the bending is to deliberately bend the film whrrcn bending is obviously ullayoitlablc anylloT\-. in c>rtlc~ to l)rcJ\-etjt unncwssar~ bending of the entire film and to render the placin, (f of the film easier for hot11 patient and operator. Plate tlica packet ~n2ctically in placr for llie lowrr t wtll---we Yig. 3. Don’t let it ride ou the tonplrr ; slide it down a.t the sitlc n-l’ the tongue. Let the front, cdgc of I he packet come forwrtl calear i1if-n the in&al region. (The conmlon mistake vrill be 11ot to c“Et it en0Ugh forward.) This leaves a space betwcwl the fact of the film anti lingual snrfacc nf the teet,h-except the molars. l)o not pull on 1 hc bile-wing ill a11 cfTor~- to rlos~ this space. TJct the> whole upper part of the paclwt slant inward towartl thv rt~rdinn line so that, when the patient closes the teet II onto ?hr bite-tving, it Tvill slicle easily into the palatal vault. rilyS
il
filr
1'11is u11rl l'h t
391
Use medium size Johnson and Johnson, readyeach side of the bite-wing. made cotton rolls cut a little shorter than the widt,h of the packet. Touch the cotton roll to water, then to Clorega or \Vwnet’s powder, t,hen apply to the The packet is now ready for packet firmly with a slight rubbing motion. use. While it is not absolutely necessary to use cotton rolls, the writer finds it such a great help that he never fails to do so. The- tend to keep the film from sliding too far lIpward or downward. With the cotton rolls in position, place rhe film packet practically in f)osition for the lower teeth. Eave the patient bite cwl to cwtl. Tf this forces the packet too far downward, bend the upper part of the film backward farther or, in some cases, change the technic to pnttin g the packet practically in place for the upper leet,h instead of the lower. IVhen the patient is biting on the bitrDo not pull on the bite-wing. wing and the film packet is in correct, position, only a very little of the bitrTying l)rotrudes labially beyond the teeth. The old homemade packets Ivitli sharp corners rc~qnircd a great deal of bending to avoid hurting the patient and to get them into correct position. With the neat packages with the rounded corners, non’ available, the matter of bending or relieving at the corners becomes more a matter of personal discussion and option; less a matter of necessity. Placing the Film Packet in the Lotox Incisor* Reyion.-The writer has lately developed a very simple method of getting the packet in the correct mesio-distal location for the lateral incisor region. Place the packet as though it were for the central incisor region and have the patient bite on the bite-wing, but not tightl>v. Now move the bite-wing to the side (distally) until the mesial edge of the bite-wing comes to the mesial of the upper central incisors. And now have the patient bite tightly. Ti?ne of Exposwc .-The t,ime of exposure for posterior bite-wing negafives is substant,ially the same as for ordinary posterior dental negatives. Only about one half the time is required for anterior interproximal negatives. For a time the writer made the mistake of overexposing anterior negatives.