PHONETICS IN PROSTHODONTICS

2. Dr . SHARI.S.R
MDS IIYR
DEPT OF PROSTHODONTICS
GDC TVM

3. CONTENTS
 INTRODUCTION
 DEFINITION
 MECHANISM OF SOUND PRODUCTION
 CLASSIFICATION OF SPEECH
 ‘S’ SOUND AND THEIR PROSTHODONTIC CONSIDERATION
 DIFFERENT ASPECTS OF COMPLETE DENTURE
FABRICATION AND THEIR INFLUENCE ON SPEECH
 SPEECH TEST
 SPEECH ANALYSIS
 REVIEW OF LITERATURE
 CONCLUSION

4. INTRODUCTION
 “Speech is the use of systematized vocalization to
express verbal symbols or words.” (Sheridan:
1964).
 A good speech is a reflection of education,
careless speech is an indication of irresponsibility,
and faulty speech is a handicap proportionate to
degree of speech incapability.
 Speech is a very sophisticated autonomous and
unconscious activity, expressing thoughts,feelings
or perception by the articulation of words.

5. Why speech is important in dentistry?
 Most of the articulations take place in the oral cavity. Any
alteration in these structures will affect the speech
 High percentage of sound are produced by contact of tongue to
palate and teeth. Since these areas are covered or replaced by
complete denture ,speech rehabilitation becomes an important
task to a prosthodontist.
 So we require a fundamental knowledge about phonetics.

6. PHONETICS
 Derived from latin word Phoneticus.
 Phonetics is defined as the branch of linguistics
dealing with the sounds of speech ,the production,
combination and representation by written symbols.

7. Normal speech depends on five essential
mechanism(Rothman JPD 1961)
INTIATOR –Neurologic integration
(MOTOR AREA OF THE BRAIN)
MOTOR -Respiration
(LUNGS ASSSOCIATED MUSCLES THAT SUPPLY AIR)
VIBRATOR-Phonation
(VOCAL CORD-PITCH AND THE TONE)
RESONATOR
(ORAL ,NASAL ,PHARYNGEAL -INTENSIFY AND
ENRICH THE SOUND)
ENUCIATOR-Articulation
(LIP,TONGUE,PALATE,TEETH) DISTINCTNESS

8. INTIATOR
(MOTOR AREA OF THE BRAIN)
 1. Broca’s area
 2. Wernicke’s area
ARCUATE FASCICULUS
ANGULAR GYRUS
WERNICKE’S AREA

9. Cranial nerves involved in
speech production
 1. V th Cranial Nerve –Trigeminal nerve .
 2. VIIth Cranial Nerve – Facial nerve .
 3. X th Cranial Nerve – Vagus nerve .
 4. XII th Cranial Nerve – Hypoglossal nerve .
Nerve Supply of the larynx –Internal laryngeal
Recurrent laryngeal

10. MOTOR
(LUNGS ASSSOCIATED MUSCLES THAT
SUPPLY AIR)
 Expiration of air from lungs

11. VIBRATOR
(VOCAL CORD-PITCH AND THE
TONE)
 The expired air from lungs flows through trachea, larynx
and vibrates the soft lining inside the vocal folds to
produce the sound
 Minimum subglottal Pressure (pressure below the v f)for
vibration of vocal folds is 7cm of Water
 Pitch of the voice is depended on rate of vibration

12. RESONATOR
(ORAL ,NASAL ,PHARYNGEAL -
INTENSIFY AND
ENRICH THE SOUND)
 The air column between the vocal cords, pharynx, oral cavity
and the nasal cavity acts as the resonators
 The raw sound produced passes through the closed chamber
and it is then amplified and filtered.
 The velo pharyngeal sphincter controls the contraction of the
soft palate and helps in resonance of the voice.

13. ENUCIATOR
(LIP,TONGUE,PALATE,TEETH)
(ARTICULATORS)
 The sound produced in the vocal folds after filteration
and amplification is modified by the action of the
articulators in the oral cavity.
 Active articulators - Tongue, lips, soft palate,
mandible.
 Passive articulators – They support the active
articulators. Anterior teeth, alveolar ridge, hard palate.

14. CLASSIFICATION OF SOUNDS
 According to sonority(SHARRY)
• Voiceless sounds, made by friction
• Produced by separation of vocal cord
• Eg:s,sh,z,zh
SURDES
• Voiced sound
• Produced by vibration of vocal
cord.eg:a,e,i,o,u
SONANTS
• Articulated speech
• The airstream is modified at proper
time,place for producing these
sounds.eg:l,m,n,p
CONSONANTS

16. CONSONANTS - BASED ON MANNER
OF ARTICULATION
• Plosives or stops
• Fricatives
• Affricatives
• Nasals
• Liquids
• Glides

17. PLOSIVES/STOP
 Are characterized by stoppage and sudden
release of air stream and require
complete occlusion of the articulators
involved;
Eg:
 Bilabial- p,b
 Tongue and hard palate-t & d
 Tongue and soft palate-k

18. FRICATIVES/SIBILANTS
When air is forced through loosely closed articulator or
narrow passage ways ,eg:s,z,f,v,th,sh,zh.
eg :
 Labiodental f & v – lip articulate with max. ant.
 Linguodental ‘th’ – incomplete articulation of tongue tip
and max . Incisors
 Sibilants ‘s’, ‘z’, ‘sh’, ‘zh’ – tongue blade with lateral
aspect of hard palate

19. AFFRICATIVE
 Produced by combination of stop and
fricative and accomplished by articulation
of tongue and hard palate.eg: j,ch
jar,chin

20. NASAL OR DIVERSION
 Characterized by stoppage at one point to permit
escape at another.
 Eg : nasal n , nasal m, ng
LIQUIDS
 The body of the tongue is raised and air flows to the
right or left of the tongue
 Eg : l,R

22. GLIDES
 Produced by gradually changing the articulator
shape.eg:w,y(YOU)

23. CLASSIFICATION BASED ON PLACE OF
THEIR PRODUCTION-BOUCHER
LINGUOPALATAL
LINGUODENTAL
LINGUOALVEOLAR
BILABIAL
LINGUOVELAR
LABIO DENTAL

24. BILABIAL SOUND
 P,B,M
 Formed by stream of air coming from the lung with no resistance
along with entire path until it reaches the lip.
 The sound M is produced in a similar manner except that the air
escapes in part through the nose as a nasal sound.
 B,P- plosives, m-nasal
.

25. CLINICAL SIGNIFICANCE
1) TO ASESS THE CORRECT INTERARCH SPACE
 If the interarch distance is excessive, the patient
cannot close the lips comfortably to form the air
seal,
 while when deficient interarch distance exists,
the lips contact prematurely.
 Either of these two errors leads to a distortion of
the bilabial sounds.

26. 2)TO ASESS CORRECT LABIOLINGUAL POSTIONING OF ANTERIOR
TEETH
 Teeth too far labially, the lips do not meet comfortably.
 Lingual placement - the lips meet prematurely.
3)TO DETERMINE VERTICAL DIMENSION OF OCCLUSION
 The pronunciation of the bilabial sounds should be used to
check the vertical jaw relation and to make sure that the
lips meet comfortably without premature contact of the
occlusion rims.

27. LABIODENTAL SOUNDS
 ‘F’ and ‘V’- FRICATIVES
 Formed by raising the lower lip into contact with
the incisal edge of the maxillary anterior teeth.
 Incisal edge contacts the labiolingual center to the
posterior third of lower lip
 A correct labiodental sound depends upon the
labiolingual and superoinferior position (occlusal
plane) of the maxillary anterior teeth.

28.  TO DETERMINE THE ANTERIOR POSTERIOR POSITION OF INCISORS
 If the maxillary anterior teeth too far lingually with reference to
the lower lip ,muffles the sound f by allowing the lower lip to
slide over the labial surfaces of the upper teeth.
 Distortion of f also occurs when the maxillary anterior teeth are
placed too far labially, which allows the lower lip to slip up
under the incisors.

29. TO DETERMINE SUPERIO-INFERIOR POSITION OF MAXILLARY
ANTERIOR TEETH.
 If upper anterior teeth are too short (set too high),the
‘v’ sound will be more like ‘f’ f
v
 If they are too long (set too low),the ‘f’ will sound like
‘v’ f
v

30. LINGUODENTAL SOUND
 Example:th
 The tip of the tongue is grasped between the incisal edges
of the upper and lower incisor teeth. Air is forced into the
channel formed by the palate and the dorsum of the
tongue, then the tip of the tongue is retracted into the oral
cavity. As the air escapes through the space created by the
retraction of the tongue, the sound th is formed.
 eg:this,there,that.

31.  CLINICAL SIGNIFICANCE
Inadequate
interocclusal distance -
sensation of tongue
biting when th is
articulated. The
patient may tend to
place the tip of the
tongue behind the
anterior teeth instead
of between them.
Anterior teeth are set
too far lingually. The
tongue becomes
pressed against the
lingual surfaces of
the upper and lower
teeth and against the
linguogingival margin
of the upper anterior
teeth.
‘th’ will be pronounced ‘t’

32. LINGUOALVEOLAR SOUNDS
 Words include sibilants /Fricatives-s,z
 PLOSIVES-t,d
 Nasals-n
 The valve formed by contact of the tip of the tongue with most
anterior part of palate(alveolus) or the lingual side of the anterior
teeth.

34. CLINICAL SIGNIFICANCE
• TO DETERMINE THE HORIZONTAL AND VERTICAL
RELATIONS OF ANTERIOR TEETH.
Ask to say ‘s’,the incisal edges of upper and lower
anterior teeth should approach end to end but not
touch.
• TO DETERMINE THE LABIO-LINGUAL POSITION OF
ANTERIOR TEETH
Ask to say TEND ,if teeth are too lingual the ‘T’
will sound like ‘D’ T D
If they are too far anterior ‘D’ will sound like ‘T’
T D

35.  T,D,N
 Rugae is important for production of these sounds.
 Produced when the tongue is placed firmly against
the anterior part of the hard palate.

36.  excessive thickness - premature contact of the
tongue with the denture base when the sounds t,
d, n, and l are pronounced.
 Where no loss of tissue has occurred, as on the
palatal surface, the denture should be thin so
tongue space will be reduced as little as possible

37. LINGUOPALATAL SOUNDS
 TONGUE AND HARDPALATE
 Tongue contact the portion of hard palate just posterior
to the area which is contacted while pronouncing
linguoalveolar sounds.
 Sh(fricatives)-More broader grooves on tongue than
‘s’and ‘z’ sounds
 Ch,j(affricatives)
 R(rose),y(glides)

38. LINGUOVELAR SOUNDS
 k,ng & g.
 Produced by raising the back of the tongue to occlude
with the soft palate and suddenly depressing the middle
portion of the back of the tongue releasing the air in a
puff.
 Significance – In overextension ‘k’ sounded as ‘ch’.

39. TO DETERMINE THE THICKNESS AND POSTERIOR EXTENSION OF DENTURE
 Thick base in the post dam or edge is square
instead of tapering ------Distortion of velar sounds
 If posterior border extend too back on the soft
palate when velar sounds like ‘K’, ‘H’ are
pronounced denture may loose its PPS seal.

41. Articulatory characteristics
 “S” is formed by a hiss of air as it escapes from the
median groove of the tongue when the tongue is behind
the upper central incisor. The sides of the tongue are in
contact with the upper posterior teeth and alveolar
ridges, and this contact may extend as far forward as
the region of the lateral incisors.

42.  Groove has a cross section of about 10mm² .
 If the depth of groove is decreased---- ‘s’ is
softened toward sh
 If groove is further decreased ,toward sh as
lisp
 If the groove is too deep-----whistle when
making sound S

43. POSITION OF THE ANTERIOR TEETH
About one third of patients make s sound with tip of the tongue
contacting lingual side of anterior part of lower denture.
 When the lower incisors are set further back, ‘s’ is softened
toward the lisp because the tongue is crowded posteriorly, causing
the groove in the tongue to become more shallow.
 lower incisors too far labially, the ‘s’ will whistle the tongue will
be overextended anteriorly and cause the groove in the tongue to
deepen.

44. CLINICAL SIGNIFICANCE OF ‘S’
SOUNDS IN PROSTHODONTICS
1)TO DETERMINE THE THICKNESS OF DENTURE.
 If artificial rugae over contoured or denture base too
thick ----when producing ‘s’ sounds—sh or lisping.
 Whistling occurs---- insufficient denture base area.
2) TO DETERMINE VERTICAL DIMENSION OF OCCLUSION.
During ‘s’ sound pronounciation there should be 1-1.5mm
interincisal seperation(silverman closest speaking space).
Increased VD ---clicking of teeth while pronouncing ‘s’
sound

45.  TO DETERMINE THE ANTERIOR POSTERIOR POSITION OF TEETH.
• If anterior teeth placed too far back ----LISP.
• If anterior teeth placed too far labially---WHISTLE.
 TO DETERMINE THE WIDTH OF DENTAL ARCH.
 TO DETERMINE THE RELATIONSHIP OF UPPER TEETH TO THE
LOWER TEETH BY S-POSITION.
• The position in which there is approximately 1mm of space
between the incisal edges of upper and lower anterior
teeth,when s sound is pronounced

46. FACTORS IN DENTURE DESIGN
AFFECTING SPEECH
 Keuebeker(1984) investigated speech problem
that occurred after fitting the dentures and
listed the factors affecting
TOOTH POSITION
VERTICAL DIMENSION
OCCLUSAL PLANE
ARCH WIDTH
RELATION OF UPPER AND LOWER ANTERIOR TEETH
DENTURE THICKNESS
POST DAM AREA

47. 1.TOOTH POSITIONING
 Speech is influenced by the positioning of the teeth
 As briefed by Robinson, when a patient is pronouncing
“5”, “55”, “F” and “V” sounds, the incisal edges of
maxillary central incisors should contact to vermillion
border of lower lip at the junction of moist and dry
mucosa and this position is referred as “F” position.
 Anteroposterior positioning of the anterior teeth
determine the effect of production of sounds like f,v
set too anteriorly v-f
set too posteriorly f-v

48. Meyer M.Silverman The whistle and swish
sound in denture patients JPD
1967;17(2):144-48
 Anteroposterior, positioning of the anterior teeth affect
the pronunciation of “s”
 This article describes causes of abnormal sounds ,such
as whistle and swish sounds.
 Too lingual placement of teeth-reduced tongue space-
lack of space to allow narrow stream of air to pass over
the tip of the tongue- the air pressed in a wider stream
causing “s” to resemble “sh”
 Too anterior placement of the teeth–excess tongue
space- excess air ejected into a narrow stream–s
resemble as whistling “s”

49. 3mm of tongue not visible – anterior teeth are set
too far forward or excessive vertical overlap is
present
If >6mm – too far lingual anteriors
While pronouncing ‘th’

50.  The position of tongue and its relation with teeth are
also crucial at this stage when the patient pronounces
“3” and “33” , there should be enough space present
for the tip of the tongue to protrude between the
anterior teeth
Too far lingual t sounds d
Too far labial d sounds t

51. 2.VERTICAL DIMENSION
 Sounds having influence in the vertical dimension are S,B,P
,M
 Ribner (1965) Correctly trimmed occlusal rims have a uniform
space of 1mm in pronouncing “s”
 In excessive VD words affected are “B,P,M”- Premature contact of
the rims causing clicking in the trial

52. Ronald J.Hammond .Increased vertical
dimension and speech articulation
errors JPD 1984;52(2)
 This study indicates that most frequently
misarticulated were Fricatives /s/& /sh/
 The second most consistently made error after
increased VD were Affricatives /th/.
 Thirdly it was Plosives /t/

53. 3.OCCLUSAL PLANE
 If the occlusal plane is set too high the exact
positioning of lower lip may be difficult. On the
other hand, if the plane is too low, lip will overlap
labial surfaces of upper teeth to a greater extent
than is required for normal phonation and the
sounds produced might be affected.
set too high v-f
set too low f-v

54. 4.DENTAL ARCH
Narrow arch
Tongue will be cramped
Faulty phonation
Eg: linguo alveolars -T,D,N
linguo palatals –
Hence artificial tooth shoud be placed previously
occupied by natural tooth

55. 5. POSTDAM AREA
 Phonetics is affected if it is thick or square edge instead
of tapering in the posterior region
 When this area is thick –irritates the base of the tongue
– affects palatolingual sounds k,g
 This area is important in singers who wear complete
dentures

56. 6.DENTURE THICKNESS
 One of the common reason for incorrect
articulation of speech is the decrease in air
volume and loss of tongue space resulting from
thick denture base .
 Mostly the denture covering the palate
 Lisping will occur with words like s,z,c.
 Thickening in the anterior palate affects the
linguoalveolar sounds like t,d

57.  ALLEN(1958) said that the thickness in the palatal
vault is critical to speech in the anterior region
from canine to canine, thickening in the anterior
region of the incisive papilla facilitates proper
enunciation.
 POUND suggested the s curve in the molar area is
important for proper pronunciation of the sounds

58.  Palmer (1979) indicated that some patients
develop speech problem after insertion of the cd
because of loss of tactile sensation.
So he recommends that the nonanatomic papilla
on the oral surface of denture to be placed
posterior to the location of incisive papilla to
foster normal speech.
STRUCTURAL CHANGES FOR SPEECH IMPROVEMENT IN
COMPLETE UPPER DENTURE FABRICATION PALMER JM ,JPD
1979

59. CUSTOMIZING PALATAL CONTOURS OF A DENTURE TO
IMPROVE SPEECH INTELLIGIBILITY KONG HJ ,JPD,2008
 Customizing palatal contours of a maxillary
complete denture can be accomplished by using
tissue –conditioning material,which provides
sufficient working time for a patient to pronounce
a series of sibilant sounds while recording dynamic
impression of tongue.

60. SPEECH TESTS
 Speech test is done during the try in stage of a
denture
 It is made after satisfactory esthetics,correct
centric relation, proper vertical dimension and
proper balanced occlusion have been attained.

61.  1 TEST OF RANDOM SPEECH
 Engage the patient in a conversation and obtaining
a subjective speech analysis
 By asking how he feels,how his speech sounds to
him,and what words seem most difficult to
pronounce.

62. 2.TEST OF SPECIFIC SPEECH SOUNDS
 Ask the patients to say 6-8 words containing specific
speech sounds and containing these words in a sentence

64. 3. TESTS OF READING A PARAGRAPH
 Make the patient to read a paragraph containing
abundance of s,sh,ch sounds
 If problems encountered in the tests conducted palatal
contouring is done using palatography

65. PALATOGRAPHY
 A palatogram is to study the normal contact of
tongue in pronouncing the various phonemes.
 HOW TO OBTAIN PALATOGRAMS?
 Uniformly thin artificial plate of MA is made
 Trial test
 Plate is dried and dusted with non-scented talcum
powder and carefully inserted in mouth,
 Asked to pronounce ,remove and examine
 Moist tongue removes the powder from the area of
contact leaving a clear tracing on artificial plate

66. Recording medium for
palatogram
 1. Impression waxes
 2. Gypsum products
 3. Talc powder (non scented)
 4. Pressure indicating media.

68.  “ Allen protocol,’” all consonants used in making the
palatograms were combined with the vowel “0”
The “0”sound was found to be the only vowel that
consistently had no palatal contact when pronounced.
Because pronunciation of the consonant sounds alone
involves two or more sounds, and therefore two or more
tongue positions, this prevented unwanted additional
palatal contacts. For example, when pronouncing the “T”
sound, the vowel sound “ee” is also made.
Having the patient say “~to” to register the “T ’sound , a
more accurate reproduction of the desired contact areas.

69. SPEECH ANALYSIS
1.PERCEPTUAL/ACOUSTIC
• Broad band Spectrogram
recorded by sonogram
• Objective opinion of
performance
KINEMATIC MOVEMENT
ANALYSIS
• Ultrasonics
• Xray maping
• Cineradiography
• Electropalatography
• Optoelectronic
articulatory movement
tracking

70. Electropalatography

71. REVIEW OF LITERATURES
 Joseph G.Agnello etal , A Study of phonetics in
edentulous pts following complete denture
treatment JPD -1972
 They compared the words in edentulous state with
words in different stages of denture wear
 Analysis revealed the s,sh,t showed improvement
 The voiced th sound did not show any general
improvement

72. Phonetics and tongue position to improve mandibular denture
retention: A clinical report David M. Bohnenkamp, J Prosthet Dent
2007;98:344-347)
 The production of the sound “e”, as in the word “knee”, helped to
train the patient to use the tongue and buccinator muscles to
retain and stabilize a new mandibular denture in highly resorbed
mandibular ridge with retruded tongue position.

73. AN INVIVO STUDY TO COMPARE THE DIFFERENCE IN
SPEECH SOUNDS OBSERVED WITH CONVENTIONAL
AND CUSTOMISED PALATAL CONTOUR JIOH 2017
 Customised palatal contour dentures are better
for enunciation ofmiddle ch,intial j,middle
sh,initial s,middle t,initial d,middlen,initial I
phenomes
 Conventional dentures are better for enunciation
of middle j,initial sh,middle s,initial t phenomes
 It can be concluded that customised denture
prove to be better when compared to
conventional dentures.

74. Conclusion
 Speech problem after oral rehabilitation is a transient
problem
 When encounterd it cannot be easily solved so every
efforts should be made to avoid them by use of
pretreatment records or assessment of speech and
patients should be informed about initial changes in
speech
 Thus the treatment objective of every dentist should be
to make dentures which are not only mechanically
functional,esthetically pleasing,but also phonetically
accurate.

75. REFERENCES
 Prosthodontic treatment for edentulous patients- boucher edition
13
 Complete denture prosthodontics -sharry
 Improved phonetics in denture construction leslie r. Allen,j. Pros.
Den.Sept..Oct., 1958
 Phonetics and tongue position to improve mandibular denture
retention: A clinical reportdavid M. Bohnenkamp(j prosthet dent
2007;98:344-347)
 Palatogram assessment of maxillary complete dentures david W.
Farlt, DDS J prosthod 1998;7:84-90.
 Phonetic consideration in denture prosthesis robert rothman,
D.D.S. Jpd 1961