Treating velopharyngeal inadequacies with a palatal lift prosthesis

Maxillofacial prosthetics

Treating

velopharyngeal

a palatal

lift

inadequacies

with

prosthesis

Leo J. Kipfmueller,

Ph.D.,*

and

Brien

R. Lang,

D.D.S.,

M.S.**

Central Michigan University, Mt. Pleasant, Mich., and The University Michigan, School of Dentistry, Ann Arbor, Mich.

of

lh e construction of the palatal lift and modified palatal lift restoration was reported by Gibbons and Bloomer,l Lang,2 and Lang and Kipfmueller.3 This report describes the speech and velopharyngeal function of eighteen patients treated with a palatal lift or modified palatal lift prosthesis. REVIEW

OF LITERATURE

Prosthetic treatment with fixed speech prosthesis for patients with velopharyngeal inadequacy has been reported by several authors. 4-11 This prosthesis has an acrylic resin pharyngeal section on a palatal extension section which projects downward and then upward behind the residual palate into the pharyngeal cavity. The pharyngeal section is molded to assist velopharyngeal closure by contact through muscle action of the posterior and lateral pharyngeal wall. Subtelny, Sakuda, and Subtelnyll reported that a group of patients who could not speak successfully had restorations with pharyngeal sections that extended below the palatal plane. Contact between the palatal extension section and the dorsum of the tongue was observed during function which may have contributed to defective speech.6r I1 Prosthetic treatment with a palatal lift prosthesis was first reported by Gibbons and B1oomer.l In one form, the restoration merely lifts the palatal tissue and may be likened to a broad, straight, and comparatively flat palatal extension. When the This research was supported in part by a Research Fellowship Grant Rehabilitation Administration, U. S. Department of Health, Education, article is based in part on a doctoral dissertation directed by Dr. T. David at the University of Michigan. *Associate **Associate

Professor, Professor

Speech Pathology, Department of Speech and Chairman, Department of Prosthodontics.

and

from the Vocational and Welfare. This Prins and completed Dramatic

Arts.

63

64

Kipfmueller

and Lang

length of the palatal tissues is insufficient to contact the posterior pharynyeal wxli. the prosthesis is modified by the addition of ;I small acrylic resin pharynccal ../ section to close the remaining space.?, 3 The advantage of both restorations for treating lx~tients with palatopharyngeal inadequacy is that tile space for producing oral sountizis increased. In addition, the size of the pharyngeal section is greatly lcduc-tkd from the dimension which would be required if ;I fixed tvpe of cleft palate prosthesis \\ (‘1C’ used.:’ The palatal lift and modified palatal lift speech aids as a means of velopharyn,geal obturation have received limited study and reporting. l-3 Our study was concernc~d with a detailed speech analysis of patients fitted lvith a palatal lift or modified lifl of the residual speech aid prosthesis. The cephalometric tracings, measuremrnts lumen, with and without the restorations in place, and photographs of thcx n:str 11;I. tions have been reported elsewhere.” OBJECTIVES The objectives of this study were achievt%d by comparing each subject with himself in two experimental conditions, with and without the restorations in the mouth. The specific objectives were (1) to evaluate the effects of the palatal lift and modified palatal lift speech aids on speech intelligibility and nasality as shown h\ responses of untrained and trained listeners to word lists and recorded speech samples, respectively, and (2) to evaluate the effects of the prostheses on velopharyngraf valve function as shown by radiographic cephalometric analysis. EXPERIMENTAL

SUBJECTS

AND

FITTING

OF RESTORATIONS

Eighteen patients fitted with a palatal lift or modified palatal lift speech aid wcw used as subjects for this study. Eight patients had velopharyngeal incompetency a11ci ten patients had velopharyngeal insufficiency as determined by clinical evaluation at the University of Michigan School of Dentistry, Department of Prosthodontics The patients ranged from 12 to 43 years of age with a mean age of 25 years and 7 months. The group was composed of 7 women and 11 men. VelopharyngeaZ incompetency group. The velopharyngeal structures of the eight patients with velopharyngeal incompetency were anatomically capable of creating closure but physiologically unable to achieve adequate closure.*“, I’ Thr ran:;c in unobturated velopharyngeal lumen size while phonating “i” was 13.5 to 0.0 mt~i. ,4 palatal lift speech aid with a palatal extension was constructed for each paticot to merely lift the palatal tissues. Velopharyngeal insufkiency group. The velopharyngeal structures of the WI patients with velopharyngeal insufficiency were anatomically incapable of producing closure.14-15 Insufficiency was due to inadequate soft palate length and/or tissue of the soft palate for the following reasons: ( 1) an aftermath of surgical closure of a congenital cleft palate, or (2) a congenitally short soft palate without an overt clef{. In this group, the unobturated lumen size of the velopharyngeal port while phonating i ranged from 22 to 3.5 mm. as determined by direct caliper measurement on radiographs. The inadequate tissue length necessitated a modification of the palatal lift speech aid by the addition of an acrylic resin pharyngeal section on the end of the

Volume Number

27 1

Treating

palatal lift.2, 3 The exact size was determined prosthesis and met the criteria for a palatal maintained.

uelopharyngeal

inadequacies

65

clinically during construction of the lift speech aid.3 A patent airway was

RADIOGRAPHIC CEPHALOMETRIC DATA Lateral skull cephalograms were made while the patient phonated i at his habitual pitch level with and without the prosthetic speech aid in the mouth. These cephalograms were measured directly with a caliper to determine the degree of velopharyngeal port change resulting from the placement of the restoration. The dimension of the velopharyngeal port was determined for the incompetency group from the point of closest approximation between the posterior aspect of the velum and the anterior margin of the posterior pharyngeal wall.

SPEECH TESTS Recordings of the Fairbanks Rhyme TestI were used to provide material from which to measure intelligibility of pronunciation of consonants and nasality of the patients by untrained listeners. This test consists of 5 lists of 50 stimulus words matched in phonemic distribution and word familiarity. From the reservoir of 250 words, an unlimited number of test lists can be composed by the use of a table of random numbers. For evaluating intelligibility of consonants, this test has been shown to be of value in studying pathologic speakers,171 I8 and it permits a definitive evaluation of specific consonant changes. lo, ‘O In addition, the Fairbanks Rhyme Test renders an operational definition of nasality resulting from misidentification by untrained listeners of oral consonant as nasal consonant classes.17, I8 In our study, we inserted additional phonemes ts, s, and S since other researchers have indicated that the fricatives provided a sensitive index for evaluating patients with cleft palates.21-26 The Sentence Test devised by Van DemarkZ7 was used for ratings of articulation and nasality by trained listeners. This test consists of 13 sentences which provided a pseudomodel of connected speech which the entire experimental group could read and insured the uniformity of the speech stimulus. All speech recordings were made in a sound treated room with a Shure microphone (Model 5%)) Ampex Tape Recorder (Model 35I ) , and a VU meter monitored to peak between -3 and 0.

SPEECH EVALUATION AND ANALYSIS All listening sessions were conducted in a sound-treated room. No session exceeded one hour. Twenty-five listeners untrained in speech pathology or phonetics were employed to write on score sheets the first letter or letters as they heard them spoken with the word stem provided; that is, -en, -ot, -un, etc.,16 for the entire 50 words. All untrained listeners received an audiometric screening test to preclude hearing deficits. The data received from this group permitted a mean percentage difference and actual consonant error difference to be calculated with and without the restoration in the mouth. In addition, this permitted a tabulation of the nasaloral consonant confusions as an index for nasality by using the operational definition of nasality as presented by Prins and Bloomer.17p I8 Eight trained listeners used the method of pair comparisons for judging differ-

66

Kipfmueller

J. Prosthet. January,

and Lang

Table I. Rank order differences in mean percentage and differences in actual without and with restorations in the mouth by untrained listeners responding modified Fairbanks Rhyme Test

Dent. 1972

(lrrors to the --

we/w

Percentage” Patient

w/o*

R. L. B. T. P. L. K. w. P. D. C. F. C.

68.88 75.68 85.20 81.92 86.48 87.76 88.80 92.48 84.96 91.96 91.76 85.68 96.32

St H. T.+ M.? K.t J. B. s. M.-) G.t J. B.t B.t

1

J. G.t

92.72

G. M. R. B.f s. v. C. F.

97.36 83.12 65.36

Total

95.36 initial

consonant

W” 94.88 92.00 96.64 93.28 96.32 96.48 97.28 98.24 90.16 98.80 95.28 88.56 98.48 94.80 98.48 84.00 62.96 86.08

Difference 26.00 16.32 11.44 11.36 9.84 8.72 8.48 5.76 5.20 3.84 3.52 2.88 2.16 2.08 1.12 .88 -2.40 -9.28

errors

-

Total 389 304 185 226 169 153 140 94 188 63 103 179 46 91 34 211 433 58

3,066

Errors

-

64 100 42 84 46 44 34 22 123 15 59 143 19 65 19 200 463 174

__ Difference 325 204 143 142 1 i<’:1 109 106 72 65 48 44 36 27 26 15 11 - 30 -116

Restoration worn (yr.j 12 14 ti 4

1,716

*This is the average percentage of consonants in each patient’s word list correctly identified by the listener group. Total errors for each patient are based on the number of errors made by all listeners. This resulted from 1,250 judgments for each patient, W/O without restoration; W with restoration. tSubjects

classified

as having

velopharyngeal

insufficiency.

encq in articulation and nasality on a 5 point scale. Six sentence pairs were randomly selected and dubbed on a master tape so that each sentence was matched in both conditions with and without the restoration in the mouth. RESULTS

AND

DISCUSSION

A tabulation of the identification errors as determined by untrained listeners is presented in Table I. The total number of identification errors for the combined groups was reduced from 3,066 to 1,716 when the restorations were in the mouth for an over-all total reduction in error of 44 per cent. Four of the first five patients with greatest improvement in mean percentage of accurate consonant identification were from the insufficient group and had restorations with a modified palatal lift. Two patients who showed a decrease in identification improvement of consonants with the restoration in the mouth were from the incompetent group. Inspection of individual patients indicates that the range of change in accurate identification of consonants within the insufficient group was from 26 to 0.88 per cent. Within tbt incompetent group, the range of mean improvement was from 16.32 to -9.28 per cent. More improvement was noted for the patients who had worn the restorations longest. When the length of time the restoration had been worn was correlated with

ic%c,er :’

Treating

Table II. Improvement in initial velopharyngeal incompetency

L. H. 100 98 96 94 92 90 $ 88 - 86 884

1

L. J.

consonant

1 K. B.

velopharyngeal

production

Patient W.S.

C. J.

inadequacies

for patients

with

G. M.

S. V.

67

C. F.

0 X 0”

;=” cd X

: 2

.g 582 80 ‘d 78 $ 2 8 &j

76

74 72 70 68 66 64 62 \

X

\ 0

“0, With prosthesis; X, without prosthesis.

the rank order of improvement, a rho of 0.54 was obtained which is significant at the 0.05 level. During this period, the adaptation of the patient to the restoration and modifications of the restoration may have been of importance to improved speech production. The improvement in initial consonant production for patients with velopharyngeal incompetency is seen in Table II and for patients with velopharyngeal insufficiency in Table III. An analysis of distribution and type of error was undertaken to determine if the prosthetic speech aid restorations had a significant effect on the accurate identification of all phonetic categories or if a differential effect was imposed by the restorations (Table IV). In looking for the types of errors contributing to these results (with the exception of the nasal consonants), listener confusion errors with restorations in the mouth occurred more often within the phonetic class. For example, for plosives without the restorations in the mouth, 39 per cent of the error resulted from plosive confusions. With the restoration in the mouth, 45 per cent of plosive errors were plosive confusions. This shift to within-class error may be noted in the fricative class for fricative confusions changed from 51 to 65 per cent and vocalics from 57 to 80 per cent when the restoration was in the mouth. The restorations not only

68

Kipfmueller

and

Lang

Table III. Improvement in initial velopharyngeal insufficiency

consonant

R. S.

2 ; s8 2 5 e, 2 2 8k3 P4

for patients

with

Patient

I-~. 100 98 96 94 92 90 88 86 84 82 80 78 76 74 72 70 68

production

B. T.

T. M.

1

1 P. K.

/ P. M.

D. G.

j F. B.

j C. B. i J. 6.

j lx!. B.

0

g

0 Fz oi X

x

0 gi

i s

0 “0,

With

prosthesis;

X, without

prosthesis.

increased the correct identification of consonants, but they also caused the listenerserrors to be closer in approximation to the intended sound. The restorations appeared to be most effective in allowing the patients to improve the clarity of vocalic production while the clarity of nasal consonants appeared to be somewhat impaired. However, with the restorations in the mouth, of the. 218 nasal errors, 143 were made by one patient (C. F.) and of the 171 vocalic errors, 125 were made by three patients (T. M., R. S., and S. V.). The results from the 5 point rating scale used by the 8 trained listeners are prrsented in Table V. Trained listeners evaluated 6 pairs of sentences matched in botlr conditions. If all listeners rated a great difference with and without the restorations, the median score would be 30; if all listeners rated no difference, the median score would be 6. No patient received a median score representing no difference when the two experimental conditions were compared. Five patients were above the inferred midpoint median of the scale (18) indicating the degree of change was in the direction of great change (Table V) . Seven of the patients in the insufficient group were in the first ten ranks based on the responses of trained listeners. The intergroup correlation between untrained and trained listeners resulted in a rho of 0.78, which is significant at the 0.01 level. An attempt to quantitatively measure nasality resulted in a lack of a substantive measure. The operational definition of nasality reported by Prins and Bloomertl-, Js that is the degree to which untrained listeners misidentify oral consonant phoneme

~l;lm&

u

Treating

;1

Table IV. The effects of the restoration

uelopharyngeal

inadequacies

69

on type of error*

With

Consonant class

restoration

No.$

( Per

Without

restoration

No.$

cents

1 Per

centS

Plosives (9,025t)-p, Plosives Fricatives Nasals Vocalics

b, t, d, k, g

926 421 215 221 69

10 45 23 24 7

1729 690 547 344 148

19 39 32 20 9

Fricatives (5,500)-s, Plosives Fricatives Nasals Vocalics

z, f, v, h, s, 0, 6

367 90 240 24 13

7 25 65 7 4

617 191 321 85 20

11 31 51 14 3

218 114 48 32 24

8 52 22 15 11

214 14 3 148 49

8 7 69 23

171 16 5 14 136

4 9

469 43 20 137 269

10 9 4 29 57

Nasals (2,625)-m, Plosives Fricatives Nasals Vocalics

n

Vocalics (4,800)-l, Plosives Fricatives Nasals Vocalics

r, w, j

*Error tNumbers

scores in

below

3 per cent

parentheses

8 80

not shown.

indicate

the

number

of judgments

available

for

the

consonant

class. small

$“No.” indicates the number of errors proportion of occurrence and recorded

§“Per cent” indicates percentage classes for 25 untrained listeners.

within a consonant errors.

distributions

of error

and

class;

affricates

type

of error

excluded across

due to consonant

as nasal phoneme classes, was not evident in this study. One third of the patients had no nasal-oral consonant confusions with the restoration in the mouth, while, without the restoration, all had some nasal-oral confusions (range from 1 to 39 per cent). Nasal-oral confusions were reduced for 8 patients by 10 per cent or more and to the degree that nasality might be measured by nasal-oral confusion reduction, this group might be said to have decreased nasality with the restoration in the mouth. When the rank order of median difference ratings of hypernasality by trained listeners were correlated with the rank order of nasal-oral consonant reduction by untrained listeners, a rho of 0.06 was obtained. The lack of correlation between the two procedures suggests that these techniques did not measure the same dimensions of speech. This focuses upon the problem of defining nasality and obtaining a quantitative measure of it.

RADIOGRAPHIC CEPHALOMETRIC ANALYSIS The radiographic analysis was concerned lumen of the velopharyngeal closure achieved

with the decrement in the residual while phonating i following the in-

70

Kipfmueller

Table V. Median of sentence-pair patient as rated by trained listeners Patient

L. H. R. S.” B. T.” P. K.” P. M.” D. G.* C. J. T. M.” F. B.” w. s. L. J. s. v. G. M. C. F. C. B.” K. B. J. G.* R. B.*

.I. Prosthet. ,January.

and Lang scores for the articulation

Rank order 1

*Subjects classified as having velopharyngeal

difference

Median

Dent. 1972

of each

score 27

insufficiency.

sertion of the prosthetic speech aids. The range of decrease in residual lumens was from 0.0 to 22 mm. When the rank order of reduction of lumens was correlated with reduction of error based on consonant identification, a rho of 0.52 was obtained. The median of difference in articulation as scaled by trained listeners correlated with reduction in lumens at 0.48. These results were significant at the 0.05 level. Similar results were found when relating increased intelligibility of speech to reduction in residual lumen size. No significant relationship was obtained when reduction of lumen was correlated with nasality measures, nasal-oral consonant confusion, and medians of the ratings of trained listeners. Inasmuch as the size of the lumen and nasality should be theoretically related, the validity of the operational definition of nasality based on confusion of nasal-oral consonants is questioned. In addition, the scaling method does not appear to be highly related to the anatomic data in the assessment of nasality. These results add further to the notion that nasality is a multidimension phenomenon, apparently dependent upon factors more complex than the size of the velopharyngeal port. SUMMARY The palatal lift and modified palatal lift speech restorations have a marked effect on intelligibility of speech as shown by reduction in errors of consonant identification by untrained listeners and judgments of improvement in skill of articulation by trained listeners. The effects of the restorations on improved identification of consonants was most uniformly beneficial for those patients with insufficient velothe restorations had a differential effect on the pharyngeal closure. In addition, type of error so that misidentifications of consonants with the restoration in the mouth were often consonants of the same class as those recorded.

Treating

velopharyngeal

inadequacies

71

CONCLUSIONS The palatal lift and modified palatal lift speech prostheses were effective in assisting with obturation of insufficient and incompetent velopharyngeal mechanisms. In 12 patients, the lumen size decreased to 0.0 mm. while phonating i, and in all but two patients, the residual lumens were less than 2.0 mm.

References 1.

Gibbons,

P., and

Bloomer,

H.

H.: The Palatal Lift; a Supportive-Type 1958. of the Palatal Lift Speech Aid, J. PROSTHET.

Speech

Aid,

J.

PROSTHET. DENT. 8: 362-369, 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

21. 22.

Lang, B. R.: Modification DENT. 17: 620-626, 1967. Lang, B. R., and Kipfmueller, L. J.: Treating Velopharyngeal Inadequacy With the Palatal Lift Concept, Plast. Reconstr. Surg. 43: 467-477, 1969. Blakeley, R. W.: The Complementary Use of Speech Prostheses and Pharyngeal Flaps in Palatal Insufficiency, Cleft Palate J. 1: 194-198, 1964. Curtis, T. A., and Chierici, G.: Prosthetics as a Diagnostic Aid in Pharyngeal Flap Surgery, Cleft Palate J. 1: 95-98, 1964. Falter, Jane W., and Shelton, R. L. Jr.: Bulb Fitting and Placement in Prosthetic Treatment of Cleft Palate, Cleft Palate J. 1: 441-447, 1964. Fletcher, S. G., Haskins, R. C., and Bosma, J. F.: A Movable Bulb Appliance to Assist in Palatopharyngeal Closure, J. Speech Hearing Dis. 25: 249-258, 1960. Hardy, J. Cl., Netsell, R., Schweiger, J. W., and Morris, H. L.: Management of Velopharyngeal Dysfunction in Cerebral Palsy, J. Speech Hearing Dis. 34: 123-137, 1969. Harkins, C. S., Harkins, W. R., and Harkins, J. F.: Principles of Cleft Palate Prosthesis. New York, 1960, Columbia University Press. Mazaheri, M., and Millard, R. T.: Changes in Nasal Resonance Related to Differences in Location and Dimension of Speech Bulbs, Cleft Palate J. 2: 167-175, 1965. Subtelny, J. D., Sakuda, M., and Subtelny, J. D.: Prosthetic Treatment for Palatopharyngeal Incompetence: Research and Clinical Implications, Cleft Palate J. 4: 130-158, 1966. Calnan, J. S.: Diagnosis, Prognosis and Treatment of Palat-Pharyngeal Incompetence With Special Reference to Radiographic Investigations, Br. J. Plast. Surg. 8: 265-282, 1956. Randall, P., Bakes, F. P., and Kennedy, C.: Cleft Palate-Type Speech in the Absence of Cleft Palate, Plast. Reconstr. Surg. 25: 484-494, 1960. Kelley, A. B.: Congenital Insufficiency of the Palate, J. Laryngol. Rhinol. Otol. 25: 281300, 1910. Vaughan, H.: Congenital Cleft Lip, Cleft Palate, and Associated Nasal Deformities, Philadelphia, 1940, Lea & Febiger, Publishers. Fairbanks, G.: Test of Phonemic Differentiation: the Rhyme Test, J. Acoust. Sot. Am. 30: 596-600, 1958. Prins, D., and Bloomer, H. H.: A Word Intelligibility Approach to the Study of Speech Change in Oral Cleft Patients, Cleft Palate J. 2: 357-368, 1965. Prins, D., and Bloomer, H. H.: Consonant Intelligibility: a Procedure for Evaluating Speech in Oral Cleft Subjects, J. Speech Hearing Res. 11: 128-137, 1968. Clarke, F. R., Nixon, J. C., and Stuntz, S. E.: Technique for Evaluation of Speech Systems, Stanford Research Institute, Project 5090, Menlo Park, Calif. Hirsh, I. J.: Information Processing in Input Channels for Speech and Language: The Significance of Serial Order of Stimuli, in Millikan, C. L., and Darley, F. L., editors: Brain Mechanisms Underlying Speech and Language, 1967, Grune & Stratton, Inc., pp. 21-38. Counihan, D. T.: Articulation Skills of Adolescents and Adults With Cleft Palates, J. Speech Hearing Dis. 25: 181-187, 1960. McWilliams, B. J.: Articulation Problems of a Group of Cleft Palate Adults, J. Speech Hearing Res. 1: 68-74, 1958.

72 23. 24. 25. 26. 27.

Kipfmueller

and Lang

J. Prosthei.

January.

Dent. 1972

Morris, H., Spriestersbach, D., and Darley, F.: An Articulation Test for Assessing Comprtency of Velopharyngeal Closure, J. Speech Hearing Dis. 27: 218-226, 1962. Spriestersbach, D., Darley, F., and Rouse, V.: Articulation of a Group of Children Wit11 Cleft Lip and Palate, J. Speech Hearing Dis. 21: 436-445, 1956. Spriestersbach, D., Mall, K., and Morris, H.: Subject Classification and Articulatioh t;t Speakers With Cleft Palates, J. Speech Hearing Res. 4: 362-372, 1961. Subtelny, Joanne D., and Subtelny, J. D.: Intelligibility and Associated Physiological Factors of Cleft Palate Speakers, J. Speech Hearing Res. 2: 352-360, 1959. Van Demark, D.: Misarticulations and Listener Judgments of the Speech of Individuals With Cleft Palates, Cleft Palate J. 1: 232-245, 1964. DR. KIPFMUELLER SPEECH DEPARTMENT CENTRAL MICHIGAN UNIVERSITY MOUNT PLEASANT, MICH. 48858 DR. LANG UNIVERSITY OF MICHIGAN SCHOOL OF DENTISTRY ANN ARBOR, MICH. 48104