Appraisal Of Speech Defects In DentalAnomalies With Reference ToSpeech Improvement *JOHN S. RATHBONE, D.D.S. andJOHN C. SNIDECOR, Ph.D.Santa Barbara, Cal.In the summer of 1952, Rathbone5initiated a study to ascertain the relativeeffectiveness of the orthodontist in ap-praising the speech defects of his pa-tients prior to orthodontic treatment.Dr. John Snidecor, Professor of Speechat the University of California, SantaBarbara College, cooperated in devis-ing, testing, and recording techniqupand served as criterion judge for thisexperiment. As this study took form,it was expanded to include the predic-tion of speech defects from modelsalone, the relation of the severity ofthe malocclusion to the severity of thespeech der"ecct, and the reappraisai oithe speech defect following all ortho-dontic treatment with no speech cor-rection. It is, therefore, the purpose ofthis paper to review the results of theoriginal study and to present the re-sults of the reappraisal of the speechdefect following all orthodontic treat-ment with reference to speech improve-ment. This is a report of a clinical studywhich was done with a limited popula-tion and with the resources that werereadily available.In the original study ten cases werepicked which before orthodontic treat-ment had various types of malocclusionsand definite speech defects. The sampleis small, but both authors feel that theseten cases are indicative of what one canexpect.Read before the Angle Society of Ortho-dontia, Washington, D. C., October, 1957.Our method of testing was by usingtest sentences devised by Snidecor. Theprocedure followed was to have theorthodontist rate the severity of themalocclusion, the models were thenexamined by the speech therapist todetermine what dental sounds he wouldpredict as defective and the degree ofpredicted deviation. Each patient wasthen asked to read the test sentencesand all defects were noted and gradedby each examiner. All procedures oftesting were done independently byeach examiner. The above testing wasdone prior to orthodontic treatment.Of the ten subjects in the originalstudy, four presented very markedmalocclusions, four had marked mal-occlusions and two had slight maloc-clusions. All subjects presented normalhearing and intelligence. Orthodonticcorrection was oriented toward ef-fective structures for speech as well astoward the more traditional goals of theorthodontist.. Pound` and others havepointed out clearly the need for suchconsiderations.The test sentences used in the originalstudy and in the reappraisal are stateddirectly below:TEST SENTENCES1. Post-dental (tongue back of theanterior teeth) n, t, d, r, 1, s, sh, z,n - Her name was Ann and shelived near Dan.4 Y-54 vol. 29, No. 1 Speech Defects 55t - Terry counted the kittens andtook three for his sister.d - Donald did not have the dollor the dog, but he did have anold radio.r - Roy watched the rabbit runaround the chair.I - The lad lit the lamp and didhi5 school work.s - The six sisters in red dressessang school songs.sh - She washed the dishes andput them on the shelf at the shop.t - The boys were surprised atthe zebra in the zoo.zh - Their father hid the tele-vision set in the garage.y - The young girl was amusedby the three yards of yellow yarnwhich she found in the yard.2. Lingua-Dental (tongue and teethsounds) th (unvoiced) th (voic-ed).th (unvoiced) - The thin thiefstole the three thimbles, but couldfind nothing else.th (voiced) - That lathe belongsto my father and brother.3. Labio-dental (lip and teethsounds) f, u.f - His father found the loaf ofbread and coffee on the sofa.u - He has seven vests, one forevery suit.4. Post-dental Combinations (tongueback of anterior teeth, each soundis a combination of two sounds)ch, j.ch - The teacher told the childrento chew the cherries carefully.j - Jack ate the jam and drankhis orange juice.Stated very briefly the major con-clusions from the first study were asfollows :1. The nature and history of theproblem were presented.2. The use of simple test sentencesas a means of diagnosing speechdefects proved to be a reliableguide for the orthodontist. Thisassumption is based on the per-centage agreement, 91.4%, reach-ed by the orthodontist with thespeech therapist in regard to themore common dental fricativesounds, s, sh, E and rh. When alldental sounds were considered ourpercentage agreement was only51.3%, a figure which could beexpected as a result of the lack ofspeech training on the part of theorthodontist.3. There is no one-to-one relationshipbetween the severity of the mal-occlusion and the severity of thespeech defect. This is in keepingwith the findings of Kessler3 whohas pointed out that many in-dividuals with malocclusions havesatisfactory speech by virtue oftheir ability to compensate in pro-ducing sounds. The previousworks of Bruggemanl and Fymbo*support this view. For the samereason models alone in judgingdefective sounds were found to beinsufficient in accuracy for theprediction of faulty dental sounds.FOUR YEAR RE-EVALUATION, WITHREFERENCE TO SPEECH IMPROVEMENTAfter a period of four years, eightof the ten original subjects were avail-able and re-examined with the samespeech test stated above. In view ofthe fact that the speech correctionistwas a more critical judge than theorthodontist, only his test results wereutilized. It was also thought that thecontinuous contact with the subjectsmight cause an unintentional and un-predictable bias on the part of theorthodontist.Conditions established for the re-evaluation were as follows:1. At the time of the first test andthe beginning of orthodontictreatment public school speechtherapists and parents were re- 56Rathbone and Snidecor January, 1959quested not to institute speechtherapy until dental correctionwas completed.2. The speech re-test was completedwithout reference to the resultsof the test administered four yearsbefore.3. Prior to re-test all orthodontictreatment had been completed,both active and retentive.Upon original examination all of thesubjects presented highly noticeable de-fective speech. Of the sixteen dentalsounds tested a mean of 6.4 soundswere found defective for all ten sub-jects, and a mean of 6.4 for the eightsubjects here reported. One subjectpresented only three faulty sounds inthe original test, whereas another sub-ject had twelve faulty sounds.When all subjects are considered,one finds that all dental sounds werefaulty, but that errors tended to con-centrate on the dental fricatives, s, z,sh. zh, and th.I" the seccn.1 test the szme %I?-centration of errors in a milder degreeoccurred in these fricatives with fewererrors in the other dental sounds. Care-ful study of the final casts indicatedfew, if any, residual organic and struc-tural reasons for residual defectivesounds. If the speech therapist hadjudged faulty sounds from the castsalone, as he did in the first study, few,if any, sounds would have been pre-dicted as faulty.Despite residual errors in all casesthe spontaneous improvement in speecharticulation following orthodontic cor-rection was dramatic. Without speechcorrection faulty sounds dropped froma mean of 6.4 to a mean of 1.5. In otherwords, for eight cases and from six-teen sounds tested a mean of 6.4 soundswas found defective before ortho-dontic treatment, and a mean of 1.5sounds was found faulty four yearslater when re-tested using the sametest sentences. The residual speech er-rors noted on re-testing were observedonly in the highly noticeable fricativesounds.Because all of the subjects presentednormal intelligence, normal hearing,and now present excellent to goodocclusion, it can readily be predictedthat speech therapy should be highlyproductive at this time and wouldprobably eliminate all noticeable errorsin the articulation of the remainingfaulty fricative dental sounds.The following case, which is demon-strated in Figure 1 left, was selected asan example because of the severity ofthe malocclusion and the various dentalconditions present which could contri-bute to defective speech.This subject was a female eighteenyears of age who had a very markedClass I malocclusion. This case present-ed the following dental conditions per-taining to speech: 1) high palate, 2)narrow maxillary width due to crossbiteon the right side, 3) severe maxillaryspaces, 5) thick maxillary anterior al-veolar ridge, and 6) a mild maxillaryprotrusion. About the only dental con-dition missing was an openbite and inthis case the bite is slightly closed.The treatment of this case involvedthe extraction of the four permanentfirst bicuspids and the placement ofedgewise bands on all mandibular andmaxillary teeth including second molars.Active treatment with a series of arch-wires and the employment of elasticstook a period of approximately twenty-two months. At this time all bands wereremoved and a removable maxillaryHawley plate with a fixed mandibularcuspid to cuspid retainer were placed.The retention period covered eighteenmonths during which the maxillary re-tainer was worn continuously for twelvemonths and at night only for the lastsix months. This subject was continuedunder observation following retentionand the case has maintained itself in2fitpr-c: :etaticfir,, 4) rr.zxi!!zrv antprinrI --- Vol. 29. No. 1Speech Defects57excellent condition, as shown in were most gratifying.Figure 1 right. Considering the age SUMMARYof this patient, the results achievedBased on a study of subjects prior toFig. 1 Left, before treatment with defective sounds t, d, r, 8, 1, sh, z, zh, th, ch, and f.Right, following treatment with residual defective sounds 8, 2, and th. The high palate ISstill present and a mild overbite; .these two factors could cause residual speech errors in:hat the combination of the two could affect correct tongue placement for maximumresults. Slight maxillary anterior spaces not shown in the photographs are contributingfactors. 58 Rathbone and Snidecor January, 1959orthodontic treatment and a re-study of provement resulting, in part,them four years later following all from orthodontic correction.orthodontic correction, the conclusions In considering the testing and evalu-stated below appear tenable: ation of defective sounds, it must beOrthodox treatment withoutspeech correction reduced thenumber of faulty dental soundsfrom a mean of 6.4 to a mean of1.5. Subjects were intelligent andhad normal hearing.Despite orthodontic treatment,residual speech errors were observ-ed in the highly noticeable frica-tives s, z, sh, zh, and th, but to alesser degree both qualitativelyand quantitatively. Other dentalsounds had improved to the pointwhere errors were not detectable.A careful study of the final castsindicate few, if any, reasons forthese errors and point to the needfor speech therapy with an op-timistic view for perfect or nearperfect speech.Generally speaking, this study sup-ports the view that improvedstructural factors predict improve-ments in speech with residualerrors that can be reduced oreliminated through speech ther-apy._.PRACTICAL APPLICATION OF SPEECH IN AN ORTHODONTIC OFFICEUsing this study in conjunction withthe work of Bruggeman' and others,we believe there are definite applica-tions of speech testing and recommendthat these can be followed in the ortho-dontist's office. These recommendationsconcern three factors which should bediscussed with the parents:1. Testing and evaluation of de-fective sounds by use of test sen-tences previously outlined.2. General development of speechsounds, especially the dentalsounds.3. Dental anomalies associated withspeech defects, and predicted im-simple and require little time, as speechis only a small part of an orthodonticdiagnosis. Such testing by the ortho-dontist has been shown to be valid andcan be done by simple test sentencesor words selected from such sentenceswhen reading skill is limited. By actualtesting, the orthodontist is in a positionto confirm whether the patient has aspeech defect or not.The next step is to explain thegeneral development of speech. Thiscan be stated simply that speech sounds,except the very simple vowels, developin a normal child gradually and pro-gressively until the seventh year andthat most, if not all, of the sounds willbe articulated correctly. Speech is alearned process, and a child will assumethe speech standards that exist in hisenvironment. One simple way of grad-ing the difficu!ty cf speech s=unds '.VQSshown by Wellmad, Case, Mengertand Bradbury, in which they consideredthe age at which the sounds in questionare made correctly by 75% of the chil-dren tested. The following is theirreference table for dental sounds adapt-ed from Spaech Sounds of Young Chil-dren :1. 75% at 2 years of age - n, t, d.2. 75% at 3 years of age - f, z.3. 75% at 4 years of age - v, T, 1,4. 75% at 5 years of age - th (voic-ed), th (unvoiced), s, sh, zh(measure) .Perfection in their production formost children need not be expecteduntil about their seventh birthday. Theparents should now have an idea onhow speech sounds develop and whytheir child of six to eight years withspaces or unerupted laterals should hisswhen making an s sound. Group foursounds are all friction sounds and de-Y (you), 4 i, (judge). VOL 29, No. 1 Speech Defects 59pend to a marked degree on effectivestructure and function of the articula-tory mechanism.The next step which should be dis-cussed is that of the dental anomalieswhich are associated with speech de-fects. For this purpose, the graduatethesis of Bruggeman' was used, utilizingonly the results of the female group,becauze females are able to producebetter speech where the abnormal oc-clusion is the same.The following dental anomalies areassociated with speech. The sounds ex-pected to be found faulty are listed witheach dental anomaly.Spaces - all dental sounds exceptn and y especially s, sh, z, zh arefriction sounds.High palate - dental sounds s, z, th,r and 1.Width of arch - dental sounds s, z,Open bite - dental sounds s, sh, z,zh, th, and, occasionally, t and d.Degree of Protrusion - dentalsounds s, sh, z, zhother friction sounds and, occasion-ally, other dental sounds.Thickness of alveolar ridge in upperanterior region - dental soundss, sh, z, the friction sounds.Severity of rotated teeth - same asspaces.The orthodontist is now in a positionto point out what dental conditionsexist in the malocclusion that couldcontribute to the child's speech defect.As previously shown, a child or personhas the ability to compensate for de-fective structure in the production ofsound, and for this reason one cannotpredict that a definite dental conditionwill cause a definite speech defect. Suchdental conditions can only be a guidein the consideration of any speech de-fect.After consideration of all these fac-tors, and where the malocclusion issevere and can be a factor in defectiveth.speech, it is frequently our recom-mendation that speech therapy shouldbe delayed until orthodontic treatmentis completed or well under way. Like-wise, defective speech can be a factoras to the time to institute orthodontictreatment in order that the child mayhave a better oral mechanism withwhich to articulate the dental sounds.The recognition of speech defects isanother service that orthodontists canrender their patients in consideringany malocclusion. Such recognitioncould be the deciding factor in thedetermination of when to start treat-ment. Improvement in speech can bepredicted with improved structuralfactors and any residual errors can bereduced or eliminated by the processof learning.Therefore, the orthodontist's respon-sibility to speech disorders is, first, tobe able to recognize defective soundsand to recognize the importance thedental structure has in relation to theproduction and articulation of speechsounds. Second, it is his responsibilityto place the oral structure in the mostnormal possible relationship so that re-habilitation of speech can be accom-plished.1808 State St.~ BIBLIOGRAPHY1. Bruggenian, Carl F.: A Study of theRelation of Malocclusion of Teeth andOral Deformities to Articulatory Defectsof Speech in Children, Unpublishedthesis, University of Iowa, 1934.2. Fymbo, Floyd H.: The Relation of Mal-occlusion of the Teeth to Defects ofSpeech, Arch. of Speech, 1: 204-216, 1936.3. Kessler,' Howard E.: The Speech ofYour Young Dental Patients, DentalSurvey, August 1951.4. Pound, Earl: Esthetic Dentures andTheir Phonetic Value, J. of ProstheticDentistry, 1: 98-111, 1951.5. Rathbone, John S.: Appraisal of SpeechDefects in Dental Anomalies, The Angle6. Wellman, B. L.; Case, I. M.; Mengert,I. G.; Bradbury, D. E.: Speech Soundsof Young Children, published by theUniversity of Iowa, Iowa City, 1931.Ortho., 25: 42-48, 1955.