The cephalometric analysis of the velopharyngeal function in terms of the shape and mobility permits quantitative assessment of velopharyngeal insufficiency, contributing to decision making of the therapeutic plan

Hanawa, Tomoko

Isshiki, Nobuhiko

Kawano, Michio

Matsumoto, Akiko

Nose, Kensuke

Sawada, Masaki

Kyoto University Research Information Repository

Title Cephalometric Analysis of the Velopharyngeal FunctionAuthor(s)Nose, Kensuke; Isshiki, Nobuhiko; Sawada, Masaki;Matsumoto, Akiko; Kawano, Michio; Hanawa, TomokoCitation音声科学研究 = Studia phonologica (1990), 24: 39-47Issue Date1990URL http://hdl.handle.net/2433/52481RightType Departmental Bulletin PaperTextversionpublisherKyoto UniversitySTUDIA PIIONOLOGICA XXIV (1990)Cephalometric Analysis of the Velopharyngeal FunctionKensuke NOSE, Nobuhiko ISSHIKI, Masaki SAWADA, Akiko K. MATSUMOTO,Michio KAWANO and Tomoko HANAWAINTRODUCTIONA number of methods we have applied so far for evaluation of the velopharyn-geal function include assessment of speech, oral inspection, rhinometric mirror,pneumotachography, velopharyngeal radiography, videofluorography, and naso-pharyngoscopy.l) However these are mostly qualitative examination.Among the radiographic examinations, lateral view of the velopharynx is easyto obtain, but it is not suitable for quantitative analysis, because it represents onlyunidirectional aspect.Videofluorography is suitable for evaluating the dynamic pattern of velopharyn-geal movement, providing the information not only on the velopharynx, but alsoon the other articulatory organs such as the tongue, pharynx and larynx.2,3) How-ever it is incapable of quantitative measurement because of the difficulty to fix thehead position.Cephalometric analysis, which has been found useful for evaluation of the bonytissue, can also be applied for assessing the velopharyngeal structure and function. 4 ,5)More specifically, velopharyngeal function in terms of its shape and mobility wasanalyzed quantitatively on the basis of cephalometric principle.METHODSStandard cephalogram was taken from two directions; lateral and axial views.A contrast medium (Barium sulfate) was used to obtain good contrast of the softtissue. (Fig. I and 2)The items measured are;I) Velum-velopharyngeal depth ratio (V-VD ratio, the length of the soft palateto the depth of the nasopharynx)2) Mobility of the soft palateKensuke NOSE (1l!Ymi~1l-): Department of Plastic Surgery, Ohtsu Red Cross HospitalNobuhiko ISSHIKI (-1.~~A~$'): Professor, Department of Plastic Surgery, Faculty of Medicine, KyotoUniversityMasaki SAWADA (11~H8iEm): Lecturer, as aboveAkiko K. MATSUMOTO (t.1t*~.::F-): Researcher, as aboveMichio KAWANO (J!l1l!YJm:X): Instructor, Department of Otorhinolayrngology, Faculty of Medicine,Kyoto UniversityTomoko HANAWA (tiWi M.::F-): Researcher, as above40 Kensukc );'OSE. Nobuhiko IssWKt, ~bsaki .\\\'AD,\, Akiko K. ~L\TSUMOTO,~\'fichio KAWAl"O and Tomoko HANAW,,-Fig. I. Lateral ccphalogram (above: at a rest. below: III)Fig. 2. Axial cephalogram (abon.": al resl. belo\\': /S/)Cephalometric Analysis of the Velopharyngeal Function 413) Mobility of the lateral pharyngeal wall1) Velum-velopharyngeal depth ratio (V-VD ratio)The depth of the nasopharynx was defined as the distance between PNS (pos-terior nasal spine) and PPW (posterior pharyngeal wall, the point where the lineANS-PNS crosses the posterior pharyngeal wall), while the length of the soft palatewas represented by the distance between PNS and U (uvula). The V-VD ratiowas derived from these figures by division; the length of the soft palate/ the depthof the velopharynx. A small number of this ratio means deep pharynx or/and shortvelum. (Fig. 3)2) Mobility of the soft palateIn Fig. 4, Vm means the middle point of the nasal surface of the soft palate atrest, and Vm' is the intersecting point of the line Vm-EAM (external auditory meatus)Fig. 3. Velum-velopharyngeal depth ratio (V-VD ratio)V: Vdum length VD: Velopharyngeal depth,V-VD ratio=V/VDMOBILITY OF THE SOFT PALATEFig. 4. Mobility of the soft palate is represented by theratio of velar displacement (Vm--Vm') to the velo-pharyngeal distance at rest (Vm__VmH). Mobilityf~te=(Vm--Vm')! (Vll1--VmH )42 Kensuke NOSE, Nobuhiko ISSHlKI, Masaki SAWADA, Akiko K. MATSUMOTO,Michio KAWANO and Tomoko HANAWAMOBILITY OF THE LATERALPHARYNGEAL WALL~~~~'LJFig. 5. Mobility of the lateral pharyngeal wall is re-presented by the ratio of displacements of the bilateralwall (LW-LW') to the original distance between thewalls at rest (LW). Mobility rate = (LW-LW')/LW.and the nasal surface of the soft palate while pronouncing a fricative Ifl. Vml! isthe intersection of the line Vm-EAM and posterior pharyngeal wall.3) Mobility of the lateral pharyngeal wallIn Fig. 5, LW stands for the width of the velopharynx at rest and LW' for thaton production of a fricative If /.PATIENTSTwenty seven patients are examined including 16 cleft lip and palate (postoper-ative), 8 cleft palate (postoperative), 1 submucous cleft palate and 2 congenital velo-pharyngeal insufficiency. The age and sex distribution of the patients are shownin Fig. 6.The veolpharyngeal function of the patients are divided into three groupsaccording to our criteria on over-all functional assessemnt: good, fair and poor.The "good" group numbered 10, "fair" 10, "poor" 7 respectively.105E2I: male0: femaleo-""-'----II--..&..:;",,:~~..L._-J..:::.,'-I-......J....::..a...._-5 6-10 11-15 16-20 21- (Y.o.)Fig. 6. Age and sex distribution of the patients.Cephalometric Analysis of the Velopharyngeal FunctionRESULTS43Velum-velopharyngeal depth ratio:The V-VD ratio was found statistically different each other among three groups.(Fig. 7)As shown in Fig. 7, the poor V-P function group demonstrated the V-VD ratioalways below 0.83, while the good group had the ratio always above 0.85, thus withthe two groups being separated without overlapping. The fair group showed some-what scattered values of the ratio, ranging from 1.04 to 0.76, from normal valueFig. 7. Velum-velopharyngeal depth ratio in three groups.to poor value in other words. This finding seems clinically extremely importantin treating fair and poor groups, suggesting the poor group may have structural de-fect such, as requires surgical treatment. Spreading of the ratio in the fair grouppartly into the normal and partly aslo into the poor range of the ratio may be inter-preted as meaning that some of them that lie in the normal range may have morefunctional problem and those in the poor range may have more structural basis forslight V-P insufficiency.Further studies are required particularly on the fair group; how they can beeffectively treated, what their prognosis are, and any difference in them dependingupon the V-VD ratio.Mobility of the velopharynx:Two dimensional graph of the relationship between the mobility of the velumand that of the lateral pharyngeal wall in three groups is shown in Fig. 8.••!----;,,-,-----:.'";---~75-----,!'OOMOBILITY OF THE SOFT PALATE (%)• 0 000• 0 0 r••xX.0X X•44 Kensukc NOSE, Nobuhiko ISSHIKI, Masaki SAWADA, Akiko K. MATSUMOTO.Michio KAWANO and Tomoko HANAWA~ 100,0-·-_-------------,!!! .... lairS ~ :POOl'-<o 75~-<I'"~ 50'"il~~ 2S~ x~ x~Fig. 8. Relationship between the mobility or the velumand the lateral pharyngeal wall.DISCUSSIONVclopharyngeal closure during speech production IS achieved mainly by twofactors; velar elevation and medial movement of tttC lateral pharyngeal wall. Eachcomponent was assessed by measurement on the cephalogram and the mobility wasexpressed in percentage by the ralio of the motion displacement to the originaldistance at rest.Supposing that the velopharyngeal aperture can be approximated by squareFig. 9. Fiberscopic finding or velopharynx (above: al rest,below, III).Cephalometric Analysis of the Velopharyngeal Function 45in shape (Fig. 9), and supposing the lateral wall moved X percent and the velumdid Y percent, the percentaeg of velopharyngeal areal change induced by the. twodimensional movements can approximately be expressed by the formula X+Y -XV.(Fig. 10) If the velum and lateral wall moved 50°1<> of their original distance for exam-ple, the area is said to be decreased by 75%: because calculation of the above formula! 1Vrn'-Vrn"Vm-Vm" i-----.J1Vrn-Vrn'LWLFig. 10. Velophryngeal closure approximated by square vari.ation Above: The area of insufficiency, below: ArealmobilityMobility rate of the lateral wall X=(LW-LW')/LWMobility rate of the velum Y=(Vm......Vm')/(Vm",-,Vm")Areal mobility=[VL-V(I-Y)L(I-X)]/VL=X+Y-XY.(%)100 ~93.8 A-t~ ~89.30 t80 t XX60·XX 48•240X20X0good fair poorFig. 11. Calculated a real mobility in three groups.46 Kensuke NOSE, Nobuhiko ISSHIKI, Masaki SAWADA, Akiko K. MATSUMOTO,Michio KAWANO and Tomoko HANAWAyields O.5+0.5-0.5xO.5=O.75. In other words, the areal mobility in this exam-ple is 75°1<>. The data collected from the cephalogram were all computed accord-ing to the formula to yield the areal mobolit),.The areal mobolity, which incorporates the mobilities of both the velum andthe lateral wall is shown in Fig. 11, as classified by the groups of velopharyngeal fun-ction; good, fair and poor.Fig. 11 clearly shows a disparity in the value between the good and poor groups.Disparity between the fair and poor groups is also distinct, indicating the usefulnessof this index to differentiate between the two groups.As described above, we could grade the velopharyngeal function of the patientusing our cephalometric analysis on two dimensional graph such as Fig. 12 in termsof shape and mobility. This analysis can be summarized as Fig. 13 with regard tothe relationship between the velopharyngeal function and its shape and mobility.There are some limitations of the cephalometric analysis. One is the age fac-tor of the patient. We can't apply this examination to young children. The youn-1.2 00Q 1.1 0~a::...J.0 .0~ 1.0.~ 0 0>-•a::c( • .00a: 0.99 • 0LLJ X>0.8 x x •X• •x x0.7 l--...L20--~40:----:6~0 ~~8~O-----';100AREAL MOBILITYFig. 12. Velum-ve1opharyengeal depth ratio vs.areal mobility.FUNCTION~ good00tID /wCL<CI(J) poor"t:lro.cpoor goodMOBILITYFig. 13. The ve10pharyngeal function expressedby its shape and mobility.Cephalometric Analysis of the Velopharyngeal Function 47gest patinet who underwent this examination was 5 years old. And the other limi-tation is that this examination reveals only one aspect of the velopharyngeal closure,that is during the production of a vowel or a fricative. In interpreting and clinical-ly applying these data, simplification of the velopharyngeal aperture as a squareand subsequent calculation may aslo be taken as a limitation.In spite of the limitations as above, this cephalometric analysis provides us withsome important information about the cause of the insufficiency. In the fair group,the analysis gives us the clue as to which factor causes the velopharyngeal insufficien-cy in a certain patient, the shape or mobility. If the insufficiency results mainly frompoor mobility, the speech therapy should be instituted first6). If the velum is ragard-ed as being short, operative therapy would be considered. In the poor or incompe-tent group, in addition to fiberscopic findings, this analysis provides informationon the depth of the nasopharynx and the width of the pharyngeal flap required forthe insufficiency.7,8,9)SUMMARYThe cephalometric analysis of the velopharyngeal function in terms of the shapeand mobility permits quantitative assessment of velopharyngeal insufficiency, con-tributing to decision making of the therapeutic plan.REFERENCES1) Taira, T. et al: Assessment ofvelopharyngeal function: Advantages and disadvantages of variousmethods. Practica Otolaryngol. 79: 907-914, 1986.2) Moll, K.L.: Cinefluorographic techniques in speech research. J. Speech Hear. Res. 3: 227-241,1960.3) Skolnick, M.L. et al: Patterns of velopharyngeal closure in subjects with repaired cleft palateand normal speech: A multiview videofluoroscopic analysis. Cleft Palate J. 12: 369-376, 1975.4) Mourino, A.P. & Weinberg, B.: A cephalometric study of velar stretch in 8 and lO-year oldchildren. Cleft PalateJ. 12: 417-435, 1975.5) Simpson, R.K. & Colton, J.: A cephalometric study of velar stretch in adolescent subjects.Cleft palate J. 17: 40-47, 1980.6) Kawano, M. et al: Treatment and result of slight velopharyngeal incompetence. Studia Phono-logica 17: 15-26, 1983.7) Isshiki, N. et al: Cineradiographic analysis of the movement of the lateral pharyngeal wall.Plast. Reconstr. Surg. 44: 357-363, 1969.8) Argamaso, R.V. et al:: The role oflateral pharyngeal wall movement in pharyngeal flap surgery.Plast. Reconstr. Surg, 66: 214-219, 1980.9) Isshiki, N. & Morimoto, M.: A new folded pharyngeal flap. Plast. Reconstr. Surg. 55: 461-465,1975.

Cephalometric Analysis of the Velopharyngeal Function

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Cephalometric Analysis of the Velopharyngeal Function

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