Fluoroscopy and nasoendoscopy in designing palatal lift prostheses

Fluoroscopy prostheses G. E. Turner, I;niver+il>-

and nasoendoscopy DMD,

MSD,B

and W. N. Williams,

trf Flor da. College of Dentistry,

Gainesville.

in designing

palatal

lift

PhDb

Fl;+

Prosthodontists frequently provide prostheses for the management of speech disorders related to palatopharyngeal dysfunction. Optimal prosthetic management of the palatopharyngeal port requires close interaction between the prosthodontist and speech pathologist in the use of videofluoroscopy and videonasoendoscopy for design, placement, and modification of the prosthesis. Function of the palatopharyngeal port during production of controlled samples of connected speech can be observed from multiview fluoroscopy, including lateral and frontal projections. Like fluoroscopy, nasoendoscopy can be used to observe and record function of the palatopharyngeal port during speech. This article provides an overview of the procedures suggested for diagnosing palatopharyngeal disorders. A method for designing and placing a prosthesis to aid in obturating the nasopharynx is also suggest,ed. Cd PROSTHET DENT 1991;66:63-71.)

P

rosthodontiscs frequently provide prostheses for management of speech disorders related to palatopharyngeal dysfunction. Patients with neurogenic disorders that affect oropharyngeal function are most often referred to the prosthodontist by the speech-language pathologist. However, patients with acquired defects of the palatopharyngeal port that are due to disease, trauma, or ablative surgery are most often seen ini.cially by the prosthodontist. The prosthodontist must decide if speech or swallowing function is impaired. For optimal prosthetic management of the palatopharyngeal port, a close interaction between the prosthodontist and speech pathtllogist is required. Written referrals between the prosthodontist and speech pathologist may result in less eficienr or perhaps inappropriate management than if the two specialists can interact in the same clinic. Written referrals may increase the number of patient visits becausch of a trial-and-error approach. For example, for patients suffering from neurogenic impairment of the palatopharyngeal port, function must be assessed with both videofluoroscopy and videonasoendoscopy as well as with the oral examination and chairside measures of speech production. It is also important to recognize that some with speech disorders related to neurologic impairment may have functional palatopharyngeal ports and are not suitable candidates for prosthetic management. A complete ,issessment of palatopharyngeal function while the patient is speaking can best be made by thp

-Presented in part at the American Academy of Maxillofacial Prosthetics meeting, San Diego, Calif., and presented at the Academy of Dentur+ Prosthetics meeting, Corpus Christi. Texas. aAssociate Professor and DIrector of Maxillofacial Pr0sthetic.s. hAssociate Prc.fessor arzti Dir&oof the Craniofacial Center IO/l/23201

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combined use of multiview videofluoroscopy, nasoendoscopy, and measures of oronasal air Hou and pressure. This article will discuss procedures for diagnosis of palatopharyngeal disorders. In additi:m, a method for prosthetic management of palatopharvngeal disorders will be described.

NORMAL FUNCTION

PALATOPHARYNGEAL FOR SPEECH

When neurogenic impairment of the palatopharyngeal port is present, speech is typically characterized by excessive nasal resonance (hypernasality), inappropriate audible nasal air emission, and a decrease ir: intraoral air pressure during the production of oral speech sounds. Given the simultaneous occurrence of severe lingL.al and labial articulation errors, which are often part of the sequelae of neurologic impairment, speech may be only partially intelligible. An understanding of normal palatopharyngeal physiology for speech is a prerequisite to adequately assess the palatopharyngeal port, which may or may not be functioning and subsequently may or may not be contributing to speech intelligibility. At rest, the sofl; palate drapes from the posterior border of the hard palate, leaving an opening from the back of the oral cavity through the nasopharynx (and into the nasal cavity. During normal nasal breathing clnd humming with the mouth closed, the respiratory air flow and vocalized sound are directed through this passageway. However, complete closure of the palatopharyngllal port is required for mouth breathing, for the production of normal oral (nonnasal) speech sounds, or for other oral activities such as swallowing, blowing, sucking, and whistling. This closure pattern is basically sphincteric and is comprised of three distinct but integrated activities’: I 1) the upward and backward movement of the soft palate as it makes contact, with the posterior pharyngeal wall; !2) the mesial movement of the lateral pharyngeal walls {primarily the

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1. Primary components of palatopharyngeal function, including palatal elevation, medial movement of lateral walls, and anterior movement of posterior wall. Fig.

\

I;

\1’\\

l’I - \\I I /

\

‘J

I I I I

fl

ti LATERAL

FRONTAL

Fig. 2. Tracing of videofluoroscopic image from lateral and frontal views of palatopharyngeal port during rest and function for speech.

palatopharyngeus and salpingopharyngeus) as they make contact with the lateral margins of the soft palate; and (3) the anterior displacement of the posterior pharyngeal wall as it makes contact with the elevated soft palate (Figs. 1 and 2). Although not all normal speakers necessarily use all three of these components to achieve palatopharyngeal closure, a failure of the port to close can usually be attributed to one or more of these factors.

DIAGNOSTIC

ASSESSMENT

To define the severity of the dysfunction and to identify the most appropriate treatment plan, the pattern(s) of speech production and the physiology of the palatopharyngeal port are evaluated by the speech pathologist. The evaluation includes (1) an oral assessment, (2) speech assessment (resonance and speech articulation), (3) oronasal air flow measures, (4) videofluorographic assessment, and (5) videonasoendoscopic assessment.

64

Fig. 3. Drawing illustrates limitation of visual inspection of palatopharyngeal closure.

Oral assessment Whereas an oral evaluation is made to identify possible problems related to the structural anatomy, an assessment of palatopharyngeal function for speech cannot be made from an oral assessment. It has been shown that the middle third of the soft palate typically makes contact with the posterior pharyngeal wall in the individual with normal speech. The lower one third of the soft palate, which includes the uvula, drapes inferiorly and may angle anteriorly, thus blocking visual inspection of the site of closure (Fig. 3).

Speech assessment The primary objective of the speech assessment is to determine (1) whether the palatopharyngeal dysfunction is consistent or intermittent and (2) the degree to which this dysfunction is contributing to the overall impairment of speech. Measures of several dimensions of speech are made, including an assessment of oronasal resonance, inappropriateness of nasal air flow during oral consonant production, speech articulation, and overall speech intelligibility.

MULTIVIEW

VIDEOFLUOROSCOPY

If the speech assessment reveals consistent palatopharyngeal insufficiency, a multiview videofluoroscopic evaluation is made. Although the lateral cephalometric x-ray technique continues to be used in some clinics to assessthe palatopharyngeal port, information from cephalometric films is limited to the production of isolated, sustained sounds. This technique does not permit an assessment of the functional characteristics of the palatal port while connected speech is produced. 2*3 Many individuals with normal speech do not completely close the palatopharyngeal

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Fig. 4. I,ateral videc~fluoroscopic view of palatopharynseal port durin:: patient’s best attempt to achieve closure.

Fig. 5. Frontal cideofluoroscopic view illustrates medial displacement of lateral pharvngeal walls cl\iring best attempt to achieve closure.

port while producing sustained vowels or consonants.3-” Therefore palatophar\ngeal function during production of an isolated. sustained sound may not be predictive of how the port functions during connected speech. Function of the palatopharyngeal port while controlled samples of connected speech are produced can be evaluated from multiview tluoroscopy, including both lateral and frontal projections.’ ” The lateral view shows 111)soft palate mobility and elevation, (‘!I soft palate movement patterns relative to the speech sample. and (3) the linear dimension 01 the residual palatopharyngeal inadequacy (Fig. -1). The frontal view sl;ou-s ( I) ,.he symmetry of soft palate elevation, (2) the sym:netry, position, and extent of medial movement of the late:al pharyngeal walls, and (13)the ver tical position where t!re maximum medial excursion occurs relative to the point of attempted soft palate--posterior pharyngeal wall cant tct (Fig. T,i.

completely closed and other phrases tha: would require the palatal port to close, open, and close again. Our usual speech sample consists of several sentences, including “In the evening, Connie watches TV with me.“ This sentence is routinely analyzed because normative data on soft palatal function to produce this sentence have been obtained on 100 normal speakers. in addition, palatal function during the production of this sentence has been analyzed for several hundred (clinical patients whi) had palatophargnpeal dysfunction.” This sentence contains 10 oral consonants and six nasal consonants requiring the rapid openink and closing of the palatopharvngeal port for normal sentence production (Fig. 6). As illustrated b> Fip. 6, time is plotted along the abscissa and palatopharvngeal opening (as measured in millimeters from the lateral projection )tf the fluoroscopic image) is plotted along the ordinate. The patterns of open ing and closing of’ the palatophar?ngeaJ port in the 100 normal speakers who produced this sentence were essentially identical. The palatal port opened t’our times for the nasal consonants c/n/ of In, ;n/ anti /nk;/ 01’evening, /ni of Connie, and /m/ol’_me). Iniddition. the-e were three points of closure that were associated with the oral consonants. The proximity of the /n/ and /ng/ in t h- word eveninu and -a the twso ins in the word C’onnie rr mdividuals with SUSpetted palatopharyngeal dysfumt i, ,!I ‘,

Speech

sample

For the production of normal propositional English speech. the palatopllaryngeal port is completely closed. except during the prc!duction of three nasal sounds. /m/, 1’ n/, and /ng/. These tlnee nasal sounds are produced by direct ing t.he localizes’ sound and air stream through the opened palatopharynaeal port and out of the nose. All other sounds in English arc defined as oral and are produced by c,losing the palatopharyngeal port and directing the vocalized breath stream o;it of the mouth. The selection of a ‘clinical speech sample should include phrases that wouid nnmally require the palatal port to he

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achieve closure.

Tracings

from videofluoroscopy

In addition to the analysis of palatal port function, stopframing the videofluoroscopic film during the best attempt at achieving palatopharyngeal closure (lateral view) allows for detailed tracing of the palatal port on acetate paper directly from the television monitor (Fig. 7). This tracing provides a “blueprint” that will aid the prosthodontist in defining the initial length, configuration, and position of the prosthesis (Fig. 8). This blueprint provides the basis on which the best estimate of the initial length, shape, and position of the palatal lift can be made. Fig. 9 illustrates the initial configuration and length of a palatal lift prosthesis for a male patient. The lift component was extended posteriorly 20 mm beyond the posterior border of the hard palate. It was estimated that this length would leave a gap of approximately 5 mm between the elevated soft palate and the posterior pharyngeal wall. This initial design was chosen to provide a significant reduction 66

in the overall size of the open portal but not to totally obturate the nasopharynx. The angle of the lift was constructed approximately 20 degrees relative to the palatal plane. This angle was not arbitrarily determined since McKerns and Bzoch’O showed that in men the typical relationship of the soft palate to the posterior pharyngeal wall is at a point above the palatal plane (Fig. 10). For women with normal speech, McKerns and Bzoch’O found that soft palate-pharyngeal wall contact occurs at and below the palatal plane (Fig. 11).

VIDEONASOENDOSCOPY Like videofluoroscopy, the value of nasoendoscopy is that the palatopharyngeal port can be observed and recorded (both the visual image and simultaneous sound recording) during speech. Unlike fluoroscopy, nasoendoscopy does not use radiation and thus it can be used as long and often as needed.”

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Fig. 9. Initial

configuration

Videonasoendoscoi)y permits visual scanning of the palatophargngeal port from a point above that of at tempted closure. In contrast to oral endoscopy, nasoen~ doscopy does not interfere with the oral structures (lips, tongue, and mandible,) involved in the production of speech (Figs. 12 and 13). The view obtained from nasoendoscopy permits assess ment of symmetry of soft palxde elevation and an appraisal of the shape of the rtasidual opening. In addition. symmetry and contribution (afthe lateral and posterior pharyngeai walls can be assesserl. Howe\,er, because of the inherent distortion of the image by the ,nide-angle lens. quantifiabk linear measurement+ are not possible. The speech sampi:, to be used during the nasopharyn

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goacopy evaluation should include the same controlled sentences used during the videoilu(,ro~,cc,I,?: examination. However, because nasoendoscopy doc+snot carry the danger of radiation exposure inherent in t-iuoroscopy, the examiner c.nn spend as much time as nrctssary in evaluating the function of the port during the production of multiple speech samples.

PROCEDURAL GUIDELINE8 PATIENT MANAGEMENT

IN

‘l‘he following guidelines provide an example interaction between the prosthodontist and the thologist in the identific;itic)n of candidates for prosthestAs and (:!j the sequential st t’i)s that are

of (1) speech palatal used in

the palift de-

TURNER

Fig. 10. Line drawing illustrates typical configuration of palatal closure for men with normal speech.

Fig.

PATIENT

VISIT

1. Speech is assessedto confirm or deny the existence of palatopharyngeal incompetency. Patients with speech/ resonance disorders not related to palatopharyngeal incompetency are not candidates for a palatal lift prosthesis and are referred for speech therapy only. 2. With the confirmation of palatopharyngeal incompe-

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11. Line drawing illustrates typical configuration of palatal closure for women with normal speech.

Fig.

12. Flexible nasoendoscopy is used to assesspalatopharyngeal port,

signing the configuration, position, and extension of the lift.

FIRST

AND

tency, a videofluoroscopic assessment is conducted. The primary purpose of the videofluoroscopic assessment is to identify the degree of soft palate elevation and lateral pharyngeal wall movement. From this fluoroscopic assessment, the segment of film illustrating the maximal soft palate elevation during production of connected speech is stopframed. A tracing of the palatal port structures is made from this segment (Figs. 7 and 8). 3. The palatal lift is constructed to the tracing of the palatal port at rest (Fig. 9). To allow adaptation to

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Fig. 13. Closure of palatopharyngeal nasoendoscope.

visit

(a:pproximately

6 to 8

1. The progress rrport from the speech pathologist is reviewed. 2. Speech is assessed to determine whether any change has occurred in palattjpharynpeal function. Some patients might develop adequate soft palate function from the stimulation of t,he initial palatal lift combined with the speech therapy so that. no further modification is needed at this time. However, fclr most patients who are still demonstrating palatopharyngeal incompetency, additional modification of the lift is required. 3. Videonasoendoscopy is used to identify the size and shape of the residual opening in the palatal port, with the prosthesis in place. The prosthesis is then modified and extended or widened to further reduce the palatopharyngeal incompetency without completely closing the palatal port. To achieve the optimal configuration, thermal plastic material is added to the lift while the nasoendoscope is left in position. As note
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midline

extension

of palatal lift.

port seen through

the prosthesis. the full posterior extension of the lift component is left a few millimeters short at this first visit. 4. The patient is referred t.,) his or her speech pathologist with a request tt) begin speech therapy two to three times a week for 6 weeks. Because of the nature of some speech disorders and because of the likelihood of learned compensatory but abnormal speech habits (resulting from the palatopharyngeai dysfunction), extensive but short term speech therap! is often needed to maximize the benefit that can be obtained by the palatal lift prosthesis.

Second patient weeks)

14. Initial

Fig. 15. Lateral extensions added to palatal lift to correct progressive neurologic disorder.

therefore multipl’e attempts during thit stage of modification are usually necessary. 4. The patient continues with speech therapy.

Third patient weeks)

visit

(approximately

6 to 8

1. The progress report provided by t le local speech pathologist is reviewed. 2. Speech is assessed to confirm reported progress. :3. If additional modification of the prosthesis is indicated, the use of nasoendoscopy will again be required. .4. Future visits will be determined by the nature of the disorder. For those disorders that might improve over time, the expected trea.tment plan would be te) reduce the size of the lift as palatopharyngeal funct.ion improves. Conversely, the expected treatment plan for progressive disorders is to increase the size of the lift as function diminishes. 5. The need for additional speech therapy, additional return visits, or a determination of t,he lack of any benefit being derived from the prosthesis is reviewed at this time.

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Fig. 17. Superior view of prosthesis for patient with unilateral palatopharyngeal dysfunction.

Fig. 16. Drawing illustrates unilateral dysfunction of palatopharyngeal port. Note that top illustration does not reveal defect because of superimposition of the contacting side as seen with lateral fluoroscopy. HP, Hard palate; PNS, posterior nasal spine; PPW, posterior pharyngeal wall; SP, soft palate.

TREATMENT The application of the previously described guidelines will require modifications, depending on the needs of the patient. For example, a patient with Lou Gehrig disease (amyotrophic lateral sclerosis), a progressive disorder, was evaluated to determine his candidacy for a palatal lift prosthesis. The sequence of guidelines was followed, and significant improvement was initially realized in the reduction of hypernasality and improved intraoral pressure for clearer production of oral consonants. The initial prosthesis design was primarily a midline extension of the lift (Fig. 14). As the disease progressed over the next 18 months, regular assessments with nasoendoscopy revealed openings in the palatal port lateral to the midline. With the nasoendoscope in place, lateral additions to the prosthesis were made and the midline extension was reduced (Fig. 15). In addition, because of asymmetry in palatal function, the right side of the lift required slightly more extension than the left. Although these modifications provided initial improvement in speech over an l&month period, the progression of the disease eventually rendered the prosthesis useless even with additional speech therapy. Another patient with Guillain-Barr6 syndrome, a nonprogressive disorder, was evaluated. In following the de70

scribed sequence of guidelines, a normal pattern of palatopharyngeal function was seen on lateral and frontal videofluoroscopy. However, speech was characterized by marked hypernasality and inappropriate nasal air emission, indicating that complete palatopharyngeal closure was not being achieved. Therefore the guidelines were modified to include nasoendoscopy on the first visit. The assessment revealed normal function and closure of the palatal port from the midline across the right side but incomplete closure on the left side (Fig. 16). The design of the palatai lift was unilateral to the side of the defect (Fig. 17). This design permitted complete closure of the palatal port. Over time, speech improved to a nonnasal quality for short periods without the lift. Although the prosthesis continues to be of value when the patient speaks for extended periods, speech therapy is no longer necessary. SUMMARY Palatopharyngeal dysfunction during speech can be diagnosed by general chairside measures. A specific treatment plan, surgery, speech therapy, and/or prosthodontic treatment can best be determined by multiview fluoroscopy and nasoendoscopy. Whereas most patients with palatopharyngeal incompetency are treated with operations or speech therapy or both, there are individuals who may benefit most from a palatal lift prosthesis than from other treatment. To achieve maximal benefit of a palatal lift prosthesis, the prosthodontist and speech pathologist together must use the technology of fluoroscopy and nasoendoscopy in the design, placement, and modification of the prosthesis.

REFERENCES 1. Skolnick ML. Videofluoroscopic examination of the velopharyngeal portal during phonation in lateral and base projections-a new technique for studying the mechanics of closure. Cleft Palate J 1970;7:80316. JULY

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2. (ilaser ER. Skolnick Ml,, McWilliams BJ, Shprintzen Rd. The dynamics of Passavant’s ridge in subjects with and without velopharyngeal insufficiency -a multi-vir-w videofluwoscopic study. Cleft Palate .J 1979. 16:24-44. i. Williams 12N. Eisenhxh CR. Assessing VP function: the lateral \tili technique vs cinefluorugraphy. Cleft Palate J 1981;18:45-50. 4. Mall KL. \ elopharynp-al closure ~111vowrls. .I Speech Hear Rrs 1962 .~::m;. i. Shelton RI,. Brookx Al;, Youngbtrom KA. Articulation and patterns (11 palatopharyngeal closr~! e. .J Speeclr Hear Disord 1964;29:990-408. 6. Benson D. J
Availability

9. Williams WN. Radiographic assessment of velJpharyngea1 function for speech. In: Bzoch KR, ed. Communicative disorders related to cleft lip and palate. 3rd ed. Boston: Little, Brown ana Co, 1989:195-210. 10 hlcKerns I~, Bzoch KR. Variations in velopharyngral valvmg: the factor of sex. Cleft Palate .J 1969:i:652-62. I I. Shprmtzen R.J. Nasopharyngoscopy. In: Bzoch KR, ed. Communicative disorders related to cleft lip and palate. 3rd el. Boston: Little, Brown and (‘c). 19X9:21 I-29.

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