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Phonetics in denture construction
Phonetics in denture construction Howard. E. Kessler, D .D .S ., C leveland
T h e phonetic aspect o f denture construc tion is o f utmost im portance; yet it is not always given the detailed attention that is usually given to appearance and fit. Speech has always been the most im portant m edium for the com m unication o f ideas and, dow n through the centuries, has been one o f the ch ief forces behind .hum an progress. T h e m outh is the in strument for speech, and the dentist is the specialist o f the m outh. T hat den tistry, and all its specialties, plays a lead ing role both in maintaining normal speech and in helping to correct certain speech defects has been established previously.1 In recent years it has been asserted that the hum an voice has becom e a slave to m echanization. M any television and m otion picture actors and actresses have becom e so used to w orking with the m icrophone that they are afraid to take part in a stage presentation because they will then be forced to use and project their “ naked” voices w ithout mechanical help from the m icrophone. T h e m odern sound engineer can work wonders with the hum an voice. W hile sitting at his control board, he can create a strong, colorful, pow erful voice out o f a thin, drab, weak voice. W hereas the m icrophone can change the quality o f the voice and make it possible fo r weak or p oor voices to “ get by,” by the same token it intensifies the types o f speech defects that can be associated with the wearing o f dentures. T hu s the present-
day widespread use o f the m icrophone makes the role o f the dentist even more important. T h e m ajority o f denture wearers do not have any trouble with their speaking procedures. O f this enormous num ber o f satisfied denture wearers, a certain per centage have dentures w hich are phoneti cally correct fo r them and the remaining percentage o f the total have been able to com pensate with their tongues or lips for the phonetic shortcomings o f their dentures. O f this second group o f p a tients, the m ajority com pensate almost automatically because o f the amazingly high degree o f adaptive behavior o f the hum an tongue. U SE OF TAPE RECORDER
A tape recorder is an im portant part of the prosthodontist’ s equipment. A high frequency m odel with a m ileage-type in dex counter is preferred, so that when the voices o f m any denture patients are recorded on one large tape, the dentist is able to note their index numbers and know exactly where a patient’ s recording begins and ends. It is easy then to look on the patient’s file card fo r the number o f the patient’s before-extraction record-
D e n to fa c ia l speech consu ltan t, C le v e la n d school sys te m o f th e C le v e la n d Board o f E d u c a tio n ; m em b er, b o a rd o f trustees, C le v e la n d hea ring and speech center o f W estern Reserve U n iversity, and le c tu re r, School o f D entistry, W estern Reserve U n iversity. I. Kessler, H o w a rd E. R e lationship o f d e n tis try to speech. J .A .D .A . 48:44 J a n . I9S4.
347
348 • TH E JO U R N A L O F TH E A M ER IC A N DENTAL A SSO C IA TIO N
ing (if one was secured at that tim e), his w ax try-in recording, his practice re cordings and final recording. Since the index counter has taken guesswork out o f the tape selection, the dentist can now play back any o f these recordings im m e diately without the patient’ s having to hear other patients’ voices whose record ings are adjacent o n the tape. A com pact single knob control m od el is simple for the dentist to use. A great num ber o f patients can be recorded on a single 1,200 fo o t roll o f tape. T h e tape recorder is m ore accurate and m ore versatile than cither the wire or the disk recorder, in the writer’ s opinion. Silverman2 states: It is now possible by the use o f the speaking m ethod to measure a patient’s vertical dim en sion before the loss o f the rem aining natural teeth, and to record this in terms o f m illi meters, and to reprodu ce this measurement in full dentures at a later date.
This is a g ood procedure, but, in addi tion to this, it is helpful to tape record the patient’s voice at this time. T his p ro cedure is valuable because it gives the patient a little needed ear training and some understanding o f where his tongue touches, while he still has his natural oral sensation. It is a know n physiologic and psycho logic fact that individuals d o n ot hear their ow n voices as others hear them. W hen one has his voice played back to him , he usually says, “ T h a t doesn’ t sound like m e. T h a t isn’ t m y voice, is it?” T h e only patients w h o d o not react like this are those from the television and theatrical w orld w h o are used to hearing their voices played back to them. T hey too, however, need this procedure when they com e to have dentures made. As far as the ordinary patient is con cerned, to hear a recording o f his voice shows him h ow he himself really sounds to other people, and usually will give him some know ledge on the subject, so that he will better understand the dentist
when the subject o f speech production is discussed after (and during) the den ture construction. T H E DENTURE AND SPEECH
It used to be thought that the use o f artificial rugae helped the patient to feel “ natural” in speaking when he gets his new dentures. A fter experimentation, the author has changed his m ind on this point. Som e artificial rugae on acrylic resin upper dentures are a hindrance to tongue placem ent and also make the region too thick. T h e naturally contoured rugae now being used in the metal dentures, h ow ever, seem to be all right, probably be cause they are thinner and m ore ac curate. If the upper denture is too thick in this region just lingual to the anterior teeth, phonetic difficulties can be caused. In English, a T or a D (they are the same except that the D is v o ice d ) is produced with the tip o f the tongue touching the region just posterior to the upper anterior teeth. N ow , if the tongue should meet a foreign material without surface sensation about a fourth inch sooner (o r a half inch, as was seen with one phonetically incorrect denture) than was the case before the denture was in serted, this is bound to create some diffi culty. C orrect centric relation and vertical dimension are, o f course, im portant for the patient’s speech. T h e vertical d i mension is particularly im portant be cause it tends to control or regulate the am ount o f space in w hich the tongue has to work. I f com pensatory tongue m ove ments are necessary fo r norm al speech with a given denture, the compensation is m ade easier if the freew ay space is ade quate or m ore than adequate. I f an error is m ade in the vertical dimension o f a set
2. S ilverm an, M e y e r M . Speaking m eth od in m easur in g v e rtic a l d im e n s io n . J. Pros. Den. 3:193 M a rc h 1953.
KESSLER . . . VO LUM E 54, M ARCH 1957 • 349
o f dentures, it is better, fo r g ood speech production, to err on the side o f too much freeway space. H earing loss seems to have a lot to d o with the degree o f adaptive ability to learn to speak well with dentures. Per sons w h o have im paired hearing are sometimes never able to get rid o f their newly acquired speech defect by com p en sating for their phonetically incorrect dentures. A ge seems to have a lot to do with this problem also. Elderly patients often have a great deal o f trouble co m pensating fo r their first set o f dentures because their speaking patterns have been established fo r such a great length o f time. A situation w hich sometimes arises is a speech defect from a denture in which the upper anterior teeth are set in a crooked, staggered fashion to make them look m ore natural. T h e teeth usually look nice and natural in these instances, but they will sometimes make the wearer lisp by altering the air-rushing space used for the production o f sibilants. M any people w ith this problem can be helped by a speech therapist w ho will teach the p a tient to com pensate with tongue or lips for dimensional increase or change in aperture. M an y patients, however, do not want to receive speech therapy, so the next best thing is fo r the dentist to remove the anterior teeth and set them in a straight, conventional manner. It is peculiar that some patients w ho lisp with their dentures did not have any speech defect before, even though their natural dentition was m ade up o f teeth in the same crooked positions. Certain brands o f acrylic resin are phonetically superior for dentures in some instances because the cingula can be blended better into the base material. Som e porcelain anterior teeth have prom inent cingula and, thereby, cause possible phonetic difficulties. T h e author is now engaged in a research project in volving putting anterior teeth o f many different brands o f material, one after
another, in the mouths o f m any different patients and recording the patients’ voices each time on the tape. In this way, inform ation can be obtained concerning exactly which materials are best p h o netically for various types o f patients. Each tape recording must be played back to the investigator many times and in different reversed orders because it is often difficult to be com pletely objective in ju d gin g normal and defective speak ing voices. Some, unfortunately, must be judged subjectively. T h e construction o f a partial denture can sometimes take as m uch care, p h o netically, as the making o f a full denture. Sometimes, a television actress will be upset at the loss o f three or fou r upper teeth because her livelihood depends so heavily on normal, flexible speech and she is afraid o f possible tongue inter ference from an upper partial denture. O f course, some o f these patients are best helped by the use o f fixed bridgework. T here are some instances, however, where rem ovable bridgework fo r some reason or other is the .treatment o f choice. In some o f these instances it is advisable to use the pow dered plate m ethod. A n alginate upper impression is taken and a stone m odel is poured. A thin, dark vulcanite palate piece is made. If the dark vulcanite is not fou n d easily, it is possible to simplify the procedure by using a burnished heavy foil palate piece. T h e dark vulcanite will show u p better by contrast, but either can be used. This palate piece is covered with a talc and put in the patient’ s m outh. T he wearer is instructed to produ ce all the consonant sounds and later to read a pas sage containing all the sounds in English. A ll tongue placements are evidenced by the rubbing o ff o f pow der. T h e palate piece is put back on the stone upper m odel and the design o f the upper partial denture can be m odified to circumvent all definite tongue placem ent areas. For such a reading test the follow ing passage has been found adequate because
350 • TH E JO U R N A L O F TH E A M ER IC A N DENTAL A SSO C IA TIO N
sat and w atched the others hurry away. That night there was a great storm. D ow n came roof, beams, the w hole barn. In the foggy m orning some men came to see what damage had been done. W hen one o f them m oved a board, he foun d a young rat, quite dead, half in and half out o f his hole. Thus the shirker got his due.
This passage may be used fo r full den ture recording also. Just about every dentist has used the w ord “ Mississippi,” w hich is good. T he follow ing has often been used fo r a check on S and Z sounds: I rough out my thoughts in talk as an artist models in clay. Spoken language is so plastic— you can pat and coax, and spread and shave, and rub out, and fill up, and stick on so easily, when you work that soft material, that there is nothing like it for m odeling. O ut o f it come the shapes w hich you turn into m arble or bronze in your immortal books if you happen to write such.
ENGLISH
LINÔUADENTALS TH M e ch an ics o f speech production
it is supposed to contain all the sounds o f the English language: A R TH U R T H E RAT
O n ce there was a young rat named Arthur w ho never could make up his m ind. W henever the other rats asked him if he w ould like to go out with them, he w ouldn’ t say yes or no either. H e w ould always shirk making a choice. O ne rainy day there was a great noise in the loft where the rats lived. T h e beams were all rotten so that the barn was rather unsafe. At last one o f the rafters gave way and fell to the ground. “ This w on ’ t d o,” said the Captain Rat. “ I ’ll send out scouts to search for a new hom e.” A t last the scouts cam e back and said they had foun d a house where there was room and board for them all. T h e rats all scampered to make ready to leave the old barn; but not Arthur. “ Y ou are com ing, o f course,” the Captain R at asked Arthur. “ I ’m not sure,” said Arthur undaunted, “ the ro o f may not com e dow n yet.” So Arthur
For a selection to drill T , D and N, the author uses L in coln ’ s “ Fourscore and seven . . .” as far as the sentence “ It is altogether fitting and proper. . . . ” D enture patients from the theater usually will have favorite passages o f their ow n with w hich they are fam iliar and which they want to read. For instances in w hich the patient’s speech was defective before the denture was constructed, the dentist should make the denture as phonetically correct as possible; but such patients also need the professional assistance o f a speech therapist. DENTURES AND LANGUAGE DIFFERENCES
Patients w ho speak a language other than English have less trouble phonetically with their dentures, and there is a definite mechanical reason for this (see illustra tion) . In most languages N , L , T , D , S and Z are linguadentals (S and Z are sibi lants) . N is a nasal but as for actual tongue placem ent it is an alveololingual
KESSLER . . . V O L U M E 54, M A R C H 1957 • 351
or linguadental, depending on the language spoken, because it is articulated by contact o f the tongue on the teeth or alveolar ridge. Patients w h o speak a language other than English usually let the tongue lie on the floor o f the m outh with the tip behind the lower anterior teeth. T hey sound their dental consonants by lifting the mandible so that the blade o f the tongue touches the upper teeth. T h e m ovem ent is m uch like biting. In the English language, however, the true linguadentals are the T h ’ s— sounds which d o not occu r at all in many languages. In English the N , L , T , D , S and Z sounds are m ore properly referred to as alveololinguals because they are articulated on the alveolar ridge near the point o f the lingual surface o f the upper anterior teeth. I f a denture is m ade fo r a foreign language-speaking patient o r an English-speaking patient w ho uses his foreign language-speaking pattern, the patient will not have too m uch difficulty with his biting type o f tongue sound a c tions because he is using the incisal edges o f the upper anterior teeth m ainly fo r his contact. It can be understood easily that, no m atter how the upper denture is co n structed, these incisal edge positions can not be too far from the natural dentition position. In contrast to this, the English-speaking patient has m ore use fo r the area just lingual to the upper anterior teeth for tongue touching. For obvious reasons, it is m ore difficult fo r the dentist to get this area contoured to the most natural d e gree for a patient. Also, the fa ctor o f material without surface sensation enters
into the picture. T h e contour o f the upper denture is less im portant p h o netically fo r foreign language-speaking patients. DISCUSSION
Since the city o f Cleveland has a very large foreign-born population, the author has had a grand opportunity to make these observations. T h e statement can be m ade that in denture w ork care with phonetics is most im portant with patients w ho speak g ood English. In some isolated instances the dentist is fortunate enough to have a speech therapist’s cooperation while making a denture. In the m ajority o f instances, however, the dentist is w orking alone. Consequently, the largest share o f re sponsibility fo r the denture wearer’s speaking voice rests on the dentist. T h e patient bears part o f the responsi bility fo r his ow n speech. E ffort on the part o f the patient in learning to use the dentures fo r speech is just as im portant and difficult as it is fo r mastication. I f a patient requires tw o weeks to learn to masticate properly with his new dentures, he should allow a similar period fo r re learning correct speaking procedures. T h e dentist can fulfill his responsibility for the speech o f his denture patients by making all dentures as correct p h o netically as possible and by taking the time to give each patient as m uch educa tion in phonetics as is needed fo r utiliz ing his new dentures in norm al, in telligible speech. 304 Park Building
Science and the Citizen • There is no greater necessity in the w orld o f today than a closer understanding by politicians and citizens o f the motives and methods of science, and by the scientist o f the inevitability o f politics and the responsibilities o f citizenship. Sir R ob ert W atsonW att.
T h e phonetic aspect o f denture construc tion is o f utmost im portance; yet it is not always given the detailed attention that is usually given to appearance and fit. Speech has always been the most im portant m edium for the com m unication o f ideas and, dow n through the centuries, has been one o f the ch ief forces behind .hum an progress. T h e m outh is the in strument for speech, and the dentist is the specialist o f the m outh. T hat den tistry, and all its specialties, plays a lead ing role both in maintaining normal speech and in helping to correct certain speech defects has been established previously.1 In recent years it has been asserted that the hum an voice has becom e a slave to m echanization. M any television and m otion picture actors and actresses have becom e so used to w orking with the m icrophone that they are afraid to take part in a stage presentation because they will then be forced to use and project their “ naked” voices w ithout mechanical help from the m icrophone. T h e m odern sound engineer can work wonders with the hum an voice. W hile sitting at his control board, he can create a strong, colorful, pow erful voice out o f a thin, drab, weak voice. W hereas the m icrophone can change the quality o f the voice and make it possible fo r weak or p oor voices to “ get by,” by the same token it intensifies the types o f speech defects that can be associated with the wearing o f dentures. T hu s the present-
day widespread use o f the m icrophone makes the role o f the dentist even more important. T h e m ajority o f denture wearers do not have any trouble with their speaking procedures. O f this enormous num ber o f satisfied denture wearers, a certain per centage have dentures w hich are phoneti cally correct fo r them and the remaining percentage o f the total have been able to com pensate with their tongues or lips for the phonetic shortcomings o f their dentures. O f this second group o f p a tients, the m ajority com pensate almost automatically because o f the amazingly high degree o f adaptive behavior o f the hum an tongue. U SE OF TAPE RECORDER
A tape recorder is an im portant part of the prosthodontist’ s equipment. A high frequency m odel with a m ileage-type in dex counter is preferred, so that when the voices o f m any denture patients are recorded on one large tape, the dentist is able to note their index numbers and know exactly where a patient’ s recording begins and ends. It is easy then to look on the patient’s file card fo r the number o f the patient’s before-extraction record-
D e n to fa c ia l speech consu ltan t, C le v e la n d school sys te m o f th e C le v e la n d Board o f E d u c a tio n ; m em b er, b o a rd o f trustees, C le v e la n d hea ring and speech center o f W estern Reserve U n iversity, and le c tu re r, School o f D entistry, W estern Reserve U n iversity. I. Kessler, H o w a rd E. R e lationship o f d e n tis try to speech. J .A .D .A . 48:44 J a n . I9S4.
347
348 • TH E JO U R N A L O F TH E A M ER IC A N DENTAL A SSO C IA TIO N
ing (if one was secured at that tim e), his w ax try-in recording, his practice re cordings and final recording. Since the index counter has taken guesswork out o f the tape selection, the dentist can now play back any o f these recordings im m e diately without the patient’ s having to hear other patients’ voices whose record ings are adjacent o n the tape. A com pact single knob control m od el is simple for the dentist to use. A great num ber o f patients can be recorded on a single 1,200 fo o t roll o f tape. T h e tape recorder is m ore accurate and m ore versatile than cither the wire or the disk recorder, in the writer’ s opinion. Silverman2 states: It is now possible by the use o f the speaking m ethod to measure a patient’s vertical dim en sion before the loss o f the rem aining natural teeth, and to record this in terms o f m illi meters, and to reprodu ce this measurement in full dentures at a later date.
This is a g ood procedure, but, in addi tion to this, it is helpful to tape record the patient’s voice at this time. T his p ro cedure is valuable because it gives the patient a little needed ear training and some understanding o f where his tongue touches, while he still has his natural oral sensation. It is a know n physiologic and psycho logic fact that individuals d o n ot hear their ow n voices as others hear them. W hen one has his voice played back to him , he usually says, “ T h a t doesn’ t sound like m e. T h a t isn’ t m y voice, is it?” T h e only patients w h o d o not react like this are those from the television and theatrical w orld w h o are used to hearing their voices played back to them. T hey too, however, need this procedure when they com e to have dentures made. As far as the ordinary patient is con cerned, to hear a recording o f his voice shows him h ow he himself really sounds to other people, and usually will give him some know ledge on the subject, so that he will better understand the dentist
when the subject o f speech production is discussed after (and during) the den ture construction. T H E DENTURE AND SPEECH
It used to be thought that the use o f artificial rugae helped the patient to feel “ natural” in speaking when he gets his new dentures. A fter experimentation, the author has changed his m ind on this point. Som e artificial rugae on acrylic resin upper dentures are a hindrance to tongue placem ent and also make the region too thick. T h e naturally contoured rugae now being used in the metal dentures, h ow ever, seem to be all right, probably be cause they are thinner and m ore ac curate. If the upper denture is too thick in this region just lingual to the anterior teeth, phonetic difficulties can be caused. In English, a T or a D (they are the same except that the D is v o ice d ) is produced with the tip o f the tongue touching the region just posterior to the upper anterior teeth. N ow , if the tongue should meet a foreign material without surface sensation about a fourth inch sooner (o r a half inch, as was seen with one phonetically incorrect denture) than was the case before the denture was in serted, this is bound to create some diffi culty. C orrect centric relation and vertical dimension are, o f course, im portant for the patient’s speech. T h e vertical d i mension is particularly im portant be cause it tends to control or regulate the am ount o f space in w hich the tongue has to work. I f com pensatory tongue m ove ments are necessary fo r norm al speech with a given denture, the compensation is m ade easier if the freew ay space is ade quate or m ore than adequate. I f an error is m ade in the vertical dimension o f a set
2. S ilverm an, M e y e r M . Speaking m eth od in m easur in g v e rtic a l d im e n s io n . J. Pros. Den. 3:193 M a rc h 1953.
KESSLER . . . VO LUM E 54, M ARCH 1957 • 349
o f dentures, it is better, fo r g ood speech production, to err on the side o f too much freeway space. H earing loss seems to have a lot to d o with the degree o f adaptive ability to learn to speak well with dentures. Per sons w h o have im paired hearing are sometimes never able to get rid o f their newly acquired speech defect by com p en sating for their phonetically incorrect dentures. A ge seems to have a lot to do with this problem also. Elderly patients often have a great deal o f trouble co m pensating fo r their first set o f dentures because their speaking patterns have been established fo r such a great length o f time. A situation w hich sometimes arises is a speech defect from a denture in which the upper anterior teeth are set in a crooked, staggered fashion to make them look m ore natural. T h e teeth usually look nice and natural in these instances, but they will sometimes make the wearer lisp by altering the air-rushing space used for the production o f sibilants. M any people w ith this problem can be helped by a speech therapist w ho will teach the p a tient to com pensate with tongue or lips for dimensional increase or change in aperture. M an y patients, however, do not want to receive speech therapy, so the next best thing is fo r the dentist to remove the anterior teeth and set them in a straight, conventional manner. It is peculiar that some patients w ho lisp with their dentures did not have any speech defect before, even though their natural dentition was m ade up o f teeth in the same crooked positions. Certain brands o f acrylic resin are phonetically superior for dentures in some instances because the cingula can be blended better into the base material. Som e porcelain anterior teeth have prom inent cingula and, thereby, cause possible phonetic difficulties. T h e author is now engaged in a research project in volving putting anterior teeth o f many different brands o f material, one after
another, in the mouths o f m any different patients and recording the patients’ voices each time on the tape. In this way, inform ation can be obtained concerning exactly which materials are best p h o netically for various types o f patients. Each tape recording must be played back to the investigator many times and in different reversed orders because it is often difficult to be com pletely objective in ju d gin g normal and defective speak ing voices. Some, unfortunately, must be judged subjectively. T h e construction o f a partial denture can sometimes take as m uch care, p h o netically, as the making o f a full denture. Sometimes, a television actress will be upset at the loss o f three or fou r upper teeth because her livelihood depends so heavily on normal, flexible speech and she is afraid o f possible tongue inter ference from an upper partial denture. O f course, some o f these patients are best helped by the use o f fixed bridgework. T here are some instances, however, where rem ovable bridgework fo r some reason or other is the .treatment o f choice. In some o f these instances it is advisable to use the pow dered plate m ethod. A n alginate upper impression is taken and a stone m odel is poured. A thin, dark vulcanite palate piece is made. If the dark vulcanite is not fou n d easily, it is possible to simplify the procedure by using a burnished heavy foil palate piece. T h e dark vulcanite will show u p better by contrast, but either can be used. This palate piece is covered with a talc and put in the patient’ s m outh. T he wearer is instructed to produ ce all the consonant sounds and later to read a pas sage containing all the sounds in English. A ll tongue placements are evidenced by the rubbing o ff o f pow der. T h e palate piece is put back on the stone upper m odel and the design o f the upper partial denture can be m odified to circumvent all definite tongue placem ent areas. For such a reading test the follow ing passage has been found adequate because
350 • TH E JO U R N A L O F TH E A M ER IC A N DENTAL A SSO C IA TIO N
sat and w atched the others hurry away. That night there was a great storm. D ow n came roof, beams, the w hole barn. In the foggy m orning some men came to see what damage had been done. W hen one o f them m oved a board, he foun d a young rat, quite dead, half in and half out o f his hole. Thus the shirker got his due.
This passage may be used fo r full den ture recording also. Just about every dentist has used the w ord “ Mississippi,” w hich is good. T he follow ing has often been used fo r a check on S and Z sounds: I rough out my thoughts in talk as an artist models in clay. Spoken language is so plastic— you can pat and coax, and spread and shave, and rub out, and fill up, and stick on so easily, when you work that soft material, that there is nothing like it for m odeling. O ut o f it come the shapes w hich you turn into m arble or bronze in your immortal books if you happen to write such.
ENGLISH
LINÔUADENTALS TH M e ch an ics o f speech production
it is supposed to contain all the sounds o f the English language: A R TH U R T H E RAT
O n ce there was a young rat named Arthur w ho never could make up his m ind. W henever the other rats asked him if he w ould like to go out with them, he w ouldn’ t say yes or no either. H e w ould always shirk making a choice. O ne rainy day there was a great noise in the loft where the rats lived. T h e beams were all rotten so that the barn was rather unsafe. At last one o f the rafters gave way and fell to the ground. “ This w on ’ t d o,” said the Captain Rat. “ I ’ll send out scouts to search for a new hom e.” A t last the scouts cam e back and said they had foun d a house where there was room and board for them all. T h e rats all scampered to make ready to leave the old barn; but not Arthur. “ Y ou are com ing, o f course,” the Captain R at asked Arthur. “ I ’m not sure,” said Arthur undaunted, “ the ro o f may not com e dow n yet.” So Arthur
For a selection to drill T , D and N, the author uses L in coln ’ s “ Fourscore and seven . . .” as far as the sentence “ It is altogether fitting and proper. . . . ” D enture patients from the theater usually will have favorite passages o f their ow n with w hich they are fam iliar and which they want to read. For instances in w hich the patient’s speech was defective before the denture was constructed, the dentist should make the denture as phonetically correct as possible; but such patients also need the professional assistance o f a speech therapist. DENTURES AND LANGUAGE DIFFERENCES
Patients w ho speak a language other than English have less trouble phonetically with their dentures, and there is a definite mechanical reason for this (see illustra tion) . In most languages N , L , T , D , S and Z are linguadentals (S and Z are sibi lants) . N is a nasal but as for actual tongue placem ent it is an alveololingual
KESSLER . . . V O L U M E 54, M A R C H 1957 • 351
or linguadental, depending on the language spoken, because it is articulated by contact o f the tongue on the teeth or alveolar ridge. Patients w h o speak a language other than English usually let the tongue lie on the floor o f the m outh with the tip behind the lower anterior teeth. T hey sound their dental consonants by lifting the mandible so that the blade o f the tongue touches the upper teeth. T h e m ovem ent is m uch like biting. In the English language, however, the true linguadentals are the T h ’ s— sounds which d o not occu r at all in many languages. In English the N , L , T , D , S and Z sounds are m ore properly referred to as alveololinguals because they are articulated on the alveolar ridge near the point o f the lingual surface o f the upper anterior teeth. I f a denture is m ade fo r a foreign language-speaking patient o r an English-speaking patient w ho uses his foreign language-speaking pattern, the patient will not have too m uch difficulty with his biting type o f tongue sound a c tions because he is using the incisal edges o f the upper anterior teeth m ainly fo r his contact. It can be understood easily that, no m atter how the upper denture is co n structed, these incisal edge positions can not be too far from the natural dentition position. In contrast to this, the English-speaking patient has m ore use fo r the area just lingual to the upper anterior teeth for tongue touching. For obvious reasons, it is m ore difficult fo r the dentist to get this area contoured to the most natural d e gree for a patient. Also, the fa ctor o f material without surface sensation enters
into the picture. T h e contour o f the upper denture is less im portant p h o netically fo r foreign language-speaking patients. DISCUSSION
Since the city o f Cleveland has a very large foreign-born population, the author has had a grand opportunity to make these observations. T h e statement can be m ade that in denture w ork care with phonetics is most im portant with patients w ho speak g ood English. In some isolated instances the dentist is fortunate enough to have a speech therapist’s cooperation while making a denture. In the m ajority o f instances, however, the dentist is w orking alone. Consequently, the largest share o f re sponsibility fo r the denture wearer’s speaking voice rests on the dentist. T h e patient bears part o f the responsi bility fo r his ow n speech. E ffort on the part o f the patient in learning to use the dentures fo r speech is just as im portant and difficult as it is fo r mastication. I f a patient requires tw o weeks to learn to masticate properly with his new dentures, he should allow a similar period fo r re learning correct speaking procedures. T h e dentist can fulfill his responsibility for the speech o f his denture patients by making all dentures as correct p h o netically as possible and by taking the time to give each patient as m uch educa tion in phonetics as is needed fo r utiliz ing his new dentures in norm al, in telligible speech. 304 Park Building
Science and the Citizen • There is no greater necessity in the w orld o f today than a closer understanding by politicians and citizens o f the motives and methods of science, and by the scientist o f the inevitability o f politics and the responsibilities o f citizenship. Sir R ob ert W atsonW att.