3. Introduction
The tongue is a muscular organ in the mouth of most
vertebrates that manipulates food for mastication, and is used
in the act of swallowing. It is of importance in the digestive
system and is the primary organ of taste in the gustatory
system.
A major function of the tongue is the enabling of speech in
humans and vocalization in other animals.
The average length of the human tongue from the oropharynx to
the tip is 10 cm. The average weight of the human tongue from
adult males is 70g and for adult females 60g.
Mujtaba Ashraf 3
4. Structure
The human tongue is divided into two
parts:
I. an oral part at the front
II. a pharyngeal part at the back.
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5. The left and right sides are also
separated along most of its length
by a vertical section of fibrous
tissue (the lingual septum) that
results in a groove, the median
sulcus on the tongue's surface.
Its anterior part is in the oral
cavity and is somewhat triangular
in shape with a blunt apex of the
tongue. The apex is directed
anteriorly and sits immediately
behind the incisor teeth. The root
of the tongue is attached to the
mandible and the hyoid bone.
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6. Mujtaba Ashraf 6
Tongue thrusting habit tend to displace mandibular
denture and sometimes maxillary denture also.
Measurement of the tongue force and fatigue
indicate that long span edentulous state effects
the musculature of the tongue. The tongue
becomes stronger and this increase in strength
must be considered.
JPD 1963,,VOL 13,857-865, by Philip Rinaladi
7. Mujtaba Ashraf 7
After the loss of teeth, tongue expands into the
space created by loss of teeth, known as
Proptosis Lingualis.
The enlarged tongue creates problem during
impression making, contributes to mandibular
denture instability, is crowded by denture base
resulting in difficulty in swallowing.
8. The crowded tongue always presses on the front
part of palate causing soreness and tenderness.
It also causes excessive pressure on the
mandibular denture which pushes it forward
and outward every time the mouth is opened.
9. Tongue Form
Class 1: Tongue is normal or ideal in
development, size, and function. A sufficient
number of natural or artificial teeth are
properly distributed to maintain the normal
form and function of the tongue.
Class 2: Natural teeth have been absent for a
sufficient period to permit a change in the
functional action and form of the tongue.
Mujtaba Ashraf 9
By M M House-1958
10. Mujtaba Ashraf 10
Class 3: Tongue is excessively large. All, or
practically all, of the teeth may have been
absent for an extended period of time, or there
may be an abnormal development of the size of
the tongue.
Inefficient dentures sometimes create a
Class 3 condition in the functional action and
form of the tongue.
11. Tongue Position
Class 1 – Tongue lies in
the floor of mouth with
the tip forward and
slightly below the incisal
edges of mandibular
anterior teeth.
It has the most favorable
prognosis as adequate
border seal can be
achieved because floor of
the mouth will be high
enough to cover the
lingual flange.
Mujtaba Ashraf
11
-By CR Wright
12. Mujtaba Ashraf 12
Class 2 – The tip is in a
normal position but the
tongue is broadened and
flattened.
13. Mujtaba Ashraf 13
Class 3 – The tongue is
retracted and depressed
into the floor of the mouth
with the tip curled upward,
downward or assimilated
into the body of tongue.
Its very unfavorable position
as an adequate border seal
can’t be achieved. An
attempt to extend the
flange to gain border seal
results in overextension
during tongue movements
that would dislodge the
denture
14. Tongue position and the degree of freedom
provided for tongue movements during border
molding procedures also play an important role
in positioning of the denture borders, design of
the denture flange thus influencing stability of
the mandibular denture.
Tongue Position and Occlusal plane
15. Tongue should be in resting position with the tip just
passively touching the lingual surface of the
mandibular anterior teeth and the lateral surface
touching the mandibular posterior teeth.
16. Muscles
The eight muscles of the human tongue are classified as either
intrinsic or extrinsic.
The four intrinsic muscles
superior longitudinal, inferior longitudinal,
transverse, and vertical muscles.
The intrinsic muscles of the tongue originate and insert
within the substance of the tongue and they alter the shape
of the tongue by:
• lengthening and shortening it,
• curling and uncurling its apex and edges, and
• flattening and rounding its surface.Mujtaba Ashraf 16
17. Extrinsic muscles of the tongue originate from
structures outside the tongue and insert into the
tongue.
the genioglossus, hyoglossus, styloglossus, and
palatoglossus.
These muscles protrude, retract, depress, and elevate the
tongue
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18. Genioglossus
Mujtaba Ashraf 18
Thick fan-shaped
Origin: superior mental spines on the posterior surface of
the mandibular symphysis
Insertion: Body of hyoid, entire length of tongue
Function: Protrudes tongue, depress center of tongue
19. It is a “lingual fixing muscle of the
lower denture”.
The movements of the tongue esp.
the contraction is in conjunction
with the lingual vertical and the
Genioglossus muscle that helps in
the drawing of the tongue
anteriorly towards the floor of the
muscle.
Hence, it increases the pressure
which the tip of the tongue can
exert on the floor of the oral
cavity and the alveolar process.
20. Hyoglossus
Mujtaba Ashraf 20
Thin quadrangular muscles
Origin: Greater horn and adjacent part of body of hyoid bone
Insertion: Lateral surface of tongue
Function: Depresses tongue
21. Styloglossus
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Origin: Styloid process of temporal bone
Insertion: Lateral surface of tongue
Function: Elevates and retracts tongue
22. Palatoglossus
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Origin: Inferior surface of
palatine aponeurosis
Insertion: Lateral margin of
tongue
Function: Depresses soft
palate and elevates back of
the tongue.
23. • It helps tongue to touch the palate, thus
preventing the bolus from coming out.
• It is also a lingual dislocating muscle.
• It is having the same action as that of the
styloglossus muscles.
24. Blood Supply
The tongue receives its blood
supply primarily from the lingual
artery, a branch of the external
carotid artery.
There is also a secondary blood
supply to the tongue from the
tonsillar branch of the facial
artery and the ascending
pharyngeal artery.
The tongue is drained by dorsal
lingual and deep lingual veins
Mujtaba Ashraf 24
25. Nerve Supply
Innervation of the tongue
consists of motor fibers,
special sensory fibers for
taste, and general sensory
fibers for sensation.
Taste and general
sensation from the
pharyngeal part of the
tongue are carried by the
glossopharyngeal nerve
[IX] .
Mujtaba Ashraf 25
26. Mujtaba Ashraf 26
General sensory
innervation from the
anterior two-thirds or
oral part of the tongue is
carried by the lingual
nerve, which is a major
branch of the
mandibular nerve [V 3] .
27. Papillae
The superior surface of the oral part of the tongue is covered
by hundreds of papillae.
The papillae in general increase the area of contact between
the surface of the tongue and the contents of the oral cavity.
Types:
Filiform
Fungiform
Vallate
Foliate
All except the filiform papillae have taste buds on their
surfaces.
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28. Filiform papillae are small
cone-shaped projections
Fungiform papillae are
rounder in shape and larger
than the filiform papillae, and
tend to be concentrated along
the margins of the tongue.
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29. Mujtaba Ashraf 29
Vallate papillae The largest of
the papillae are the, which are
blunt-ended cylindrical papillae
invaginations
only about 8 to 12 in number
Foliate papillae are linear
folds of mucosa on the sides of
the tongue near the terminal
sulcus of tongue.
29
30. Taste Bud
The taste buds are the sensory end
organs for gustation.
Each bud is flask-shaped, with a
wide base and a short neck opening
at the taste pore.
The apical ends of the taste cells
contain microvilli 2-3 μm in length
that connect with the luminal
surface through a porelike opening.
Taste buds have a life span of about
10-12 days.
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31. Mujtaba Ashraf 31
Taste bud are involved in detecting the
five elements of taste perception:
salty
sour
bitter
sweet
umami
32. A popular myth assigns these different
tastes to different regions of the
tongue; in reality these tastes can be
detected by any area of the tongue.
Via small opening i.e. taste pores, parts
of the food dissolved in saliva come
into contact with the taste receptors.
These are located on top of the taste
receptor cells that constitute the taste
buds. The taste receptor cells send
information detected by clusters of
various receptors and ion channels to
the gustatory areas of the brain via
nerve
Mujtaba Ashraf 32
33. Development
The tongue appears in embryo of approximately 4 weeks in the
form of two lateral lingual swellings and one medial swelling,
the tuberculum impar.
These 3 swelling originate from the first pharyngeal arch.
Mujtaba Ashraf 33
34. Development
A second median swelling, the copula, or hypobranchial
eminence, is formed by 2nd , 3rd , and part of the 4th arch.
Further lateral lingual swellings increases in size, they over the
tuberculum impar and merge, forming anterior 2/3rd (body) of
tongue.
Mujtaba Ashraf 34
35. Development
A third median swelling, formed by the posterior part of 4th
arch, marks development of epiglottis.
Immediately behind this swelling is laryngeal orifice, which is
flanked by the arytenoid swelling
Mujtaba Ashraf 35
36. Development
The posterior part, or root of the tongue originates from the
2nd, 3rd, and parts of the 4th pharyngeal arch.
The body of the tongue is separated from posterior 3rd by a ‘V’
shaped groove, the terminal sulcus.
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38. Macroglossia
too large tongue seen in
Downs syndrome &
Beckwith-Wiedemann syndrome
due to an over development of the
musculature
Enlargement due to lymphangioma gives
the tongue pebbly appearance with
multiple superficial dilated
lymphatic channels
Mujtaba Ashraf 38
39. In case of patients with large
sluggish tongue, proper designing
of the lingual flange at the wax up
stage helps increase the stability
of mandibular denture providing
adequate room for the tongue to
perform its function of distributing
the food during mastication and to
relax when the mouth is at rest
without disturbing the mandibular
denture.
Impression making In Macroglossia
40. This can be achieved by adding as little as wax
possible, behind the incisors in the anterior region
while behind the premolars, a flat or slightly concave
surface should be established
In the molar and retromolar region, the polished
surface is designed to be slightly concave facing
inwards, upwards and forwards.
Narrow posterior teeth should be selected for patients
with macroglossia
41. Microglossia
Due to the failure of lingual swellings of the first
arch to develop
the tongue which is present in the posterior most
part develops from the copula i.e. the
hypobranchial eminence of third arch only.
Mujtaba Ashraf 41
42. Impression making for Microglossia
Though impression making is easy microglossia
jeopardizes the lingual seal. In such cases, the
mandibular denture should be planned to be made
with thick lingual flanges with wider posterior teeth
while retaining its characteristic shape.
43. Ankyloglossia
The apical part of the tongue may be anchored to
the floor of the mouth by an overdeveloped
frenulum.
Tongue tie
Causes
speech disorders
deformities in dental occlusion
difficulties in swallowing
Mujtaba Ashraf 43
44. Cleft Tongue/Bifid Tongue
The tongue may be bifid because of non-fusion of
the two lingual swellings.
Mujtaba Ashraf 44
45. Fissured tongue
Its a malformation manifested clinically by numerous small
grooves on dorsal surface radiating out from central groove
along the midline of tongue
Down syndrome & Melkersson-Rosenthal syndrome
Mujtaba Ashraf 45
46. Median Rhomboid Glossitis
It is an asymptomatic
elongated erythematous
patch of atrophic mucosa on
the mid-dorsal surface of the
tongue
Presents in the posterior
midline of the dorsum of the
tongue ,just anterior to the
V-shaped grouping of the
circumvallate papilla. This is
due to failure of fusion of
lingual swellings with
tuberculum impar.
Mujtaba Ashraf 46
47. 1. It is a necessary part of the instrument of
articulate speech.
2. It acts like a reed in a wood-wind instrument to
effect variations of sound qualities.
3. It moistens lips to facilitate speech. This is an
important, yet frequently overlook observation.
Function Of Tongue
An analysis of tongue factor and its functioning areas in dental prosthesis;B. Kessler JPD,1955
48. 4. It acts as an improved conveyor belt to help complete
the process of mastication by gathering, holding, and
assisting food to the food table for complete mastication
before deglutition.
5. It also aids as a vehicle to direct the masticated bolus
to the oropharynx.
6. It helps control and guide the fluid intake to the
pharynx.
7. It contains the greatest number of the taste organs
and mucin-secreting gland.
An analysis of tongue factor and its functioning areas in dental prosthesis;B. Kessler
JPD,1955
49. 8. It is a contributing factor in aiding normal
positioning of erupting teeth in the dental arches as a
counter-pressure to the facial muscles on the labial
and buccal side of teeth.
9. It aids in depressing the soft palate to eliminate
mucous, sinus, and lacrymal secretions.
An analysis of tongue factor and its functioning areas in dental prosthesis;B. Kessler
JPD,1955
50. 10. It aids in the retention of ill-fitting dentures.
11. It helps block the trachea in deglutition to keep
food out of the bronchial tract.
12. It effects displacement and compression of air,
thereby helping create suction in swallowing.
51. Mastication:
The tongue an important accessory organ in the digestive
system.
The tongue is used for crushing food against the hard palate,
during mastication and manipulation of food for softening prior
to swallowing.
The epithelium on the tongue’s upper, or dorsal surface is
keratinized. Consequently, the tongue can grind against the hard
palate without being itself damaged or irritated.
Mujtaba Ashraf 51
52. Mujtaba Ashraf 52
Places food on occlusal table.
During mastication food after being adequately mixed with
saliva and chewed ,is converted into bolus and is placed on
tongue in its central depression, series of muscular waves
travelling posteriorly along the tongue, passes the food
over epiglottis into the oesophagus.
53. Speech
Speech is the mechanical process of producing audible
sounds to represent language.
The intrinsic muscles of the tongue enable the shaping of
the tongue which facilitates speech.
Voice is mainly produced in larynx and modified by
tongue by constantly altering its shape, position by
contacting lips, teeth, alveolar processes, hard palate
and soft palate.
Mujtaba Ashraf 53
54. Mechanism Of Speech Production
Normal speech depends on proper functioning of 5 essential
mechanism:
(1) The motor: consisting of the lungs and associated
musculature which supply the breath (air)
(2) The vibrator: consisting of the vocal cords which
give pitch to the tone
(3) The resonator: consisting of oral, nasal, and
pharyngeal cavities and paranasal sinuses which
create overtones peculiar to each individual
Mujtaba Ashraf 54
Robert Rothman; Phonetic consideration in denture prosthesis, J Prosthet Dent;1961;11:214-223)
55. Mujtaba Ashraf 55
(4) The enunciators or articulators: consisting of the lips,
tongue, soft palate, hard palate and teeth, which form
musculoskeletal valves to obstruct the passage of air,
breaking up the tones and producing the individual speech
sounds
(5) The initiator: consisting of the motor speech area of the
brain and the nerve pathways which convey the motor
speech impulses to the speech organs.
56. Articulation
Articulation, in phonetics, a configuration of the vocal
tract resulting from the positioning of the mobile organs
of the vocal tract (e.g., tongue) relative to other parts
of the vocal tract that may be rigid (e.g., hard palate).
This configuration modifies an airstream to produce the
sounds of speech.
Mujtaba Ashraf 56
57. Mujtaba Ashraf 57
The main articulators are:
tongue
upper lip & the lower lip
teeth
alveolar ridge
hard palate
velum (soft palate)
uvula
pharyngeal wall and
glottis (space between the
vocal cords)
58. The primary concern in phonetics is with the changes in
the stream of air as it passes through the oral cavity. Of
these, the tongue plays a major role.
The tongue is the principal articulator and changes
position and shape for the pronunciation of each of the
vowels and consonant.
In pronouncing, the tongue contacts a specific part of
the teeth, alveolar ridge, or hard palate.
Mujtaba Ashraf 58
59. Mujtaba Ashraf 59
Vowels are voiced sounds, that is, the vocal cords are
activated by vibration in their production.
They are the free emission of a speech sound through the
mouth and require subglottic pressure for the production.
vowels in English: a, e, i, o, u
Consonants are produced as a result of the airstream
being impeded, diverted, or interrupted before it is
released,
such as p, g, m, b, s, t, r, and z.
Consonants may be either voiced sounds or breathed
sounds, which are produced without vocal cord vibration.
Zarb- Bolender:Speech consideration with complete dentures ;Prosthodontic treatment For Edentulous Patients
CLASSIFICATION OF SPEECH
60. Mujtaba Ashraf 60
Consonants are divided into 6 groups:
(depending on their characteristic production and use of
different articulators and valves)
Plosives (Stops)
Fricatives
Affricatives
Nasals
Liquids
Glides
CLASSIFICATION OF CONSONANTS
Zarb- Bolender:Speech consideration with complete dentures ;Prosthodontic treatment For Edentulous Patients
61. Mujtaba Ashraf 61
Plosive consonants: These sounds are produced when
overpressure of the air has been built up by
consonants between the soft palate and pharyngeal
wall and released in an explosive way.
Ex: p, b, t, d
Fricatives: are also called sibilants and are characterized
by their sharp and whistling sound quality created
when air is squeezed through the nearly obstructed
articulators.
Ex: s, z
62. Mujtaba Ashraf 62
Affricative consonants: are a mix between plosive and
fricative ones.
Ex: c, j
Nasal consonants: are produced without oral exit of air.
Production involves the coupling of nasal cavity as
resonators.
Ex: m, n, ng
Liquid consonants(semi vowels): are , as the name
implies , produced with out friction.
Ex: r, l
Glides: that is sounds characterized by a gradually
changing articulator shape
Ex: w, y
63. Mujtaba Ashraf 63
CLASSIFICATION OF CONSONANTS BASED ON
THE PLACE OF THEIR PRODUCTION
Consonant sounds are most important from the dental point
of view. They may be classified according to the anatomic
parts involved in their formation:
(1) Palatolingual sounds: formed by tongue and hard or soft
palate
(2) Linguodental sounds: formed by the tongue and teeth
(3) Labiodental sounds: formed by the lips and teeth
(4) Bilabial sounds: formed by the lips.
Robert Rothman; Phonetic consideration in denture prosthesis, J Prosthet Dent;1961;11:214-223)
64. Mujtaba Ashraf 64
PALATOLINGUAL SOUNDS
formed by tongue and hard or soft palate
T, D, N, and L.
S- the sound ‘s’ as in sixty six- is formed by a hiss of air as it
escapes form the median groove of the tongue when the
tongue is behind the upper incisor.
65. Mujtaba Ashraf 65
The essential factor in the production of a correct s
is the proper grooving of the tongue.
As the depth of this groove is decreased, s is
softened toward sh, and as the groove is further
decreased, toward th as a lisp.
Excessive thickness of the denture base in the
anterior part of the palate is often the cause of
lisping.
66. Mujtaba Ashraf 66
T, D, N and L
Rugae area is very important for the
production of these sounds.
Tongue must be placed firmly against
the anterior part of the hard palate
for the production of these words.
If teeth too lingual – T will sound
like D
If teeth too forward - D will sound
like T
67. Mujtaba Ashraf 67
BILABIAL SOUNDS
Formed by contact of the lips.
b, p, and m
In b and p, air pressure is built up behind the
lips and released with or without a voice sound.
Insufficient support of the lips by the teeth or
the denture base can cause these sounds to be
defective.
Therefore the antero-posterior position of the
anterior teeth and thickness of the labial flange
can affect the production of these sounds.
Used to asses the correct inter-arch space
Labial fullness of the rims can be checked
68. Mujtaba Ashraf 68
LABIODENTAL SOUNDS
Formed between the upper incisors and the labiolingual
center to the posterior third of the lower lip.
f and v
Upper anterior teeth are too short (set too high up), V
sound will be more like an F.
If they are too long (set too far down), F will sound more
like a V.
69. Mujtaba Ashraf 69
LINGUODENTAL SOUNDS
Consonant Th is representative of the
linguodental group of sounds
Dental sounds are made with the tip of
the tongue extending slightly between
the upper and lower anterior teeth.
The words this, that, these, and those
will provide information as to the
labiolingual position of the anterior
teeth.
If about 3mm of the tip of the tongue is
not visible, the anterior teeth are
probably too far forward.
70. Mujtaba Ashraf 70
LINGUOALVEOLAR SOUNDS
Alveolar sounds (e.g., t, d, s, z, n, and l) are made with
the valve formed by contact of the tip of the tongue with
the most anterior part of the palate (the alveolus) or the
lingual side of the anterior teeth.
The sibilants (sharp sounds) s, z, sh, ch, and j (with ch and
j being affricatives) are alveolar sounds because the
tongue and alveolus form the controlling valve.
The important observation when these sounds are
produced is the relationship of the anterior teeth to each
other. The upper and lower incisors should approach end
to end but not touch.
Zarb- Bolender:Speech consideration with complete dentures ;Prosthodontic treatment For Edentulous Patients
71. Conclusion
Knowledge of anatomy, physiology and functions of
tongue is an essence to understand the complex
morphological and functional changes in the tongue with
aging or with complete and partial edentulism.
This knowledge will help us to reach optimal prosthetic
success, as tongue plays significant and perhaps the
dictating role in affecting stability and retention of
prostheses.
Mujtaba Ashraf 71
72. References
Langman’s medical embryology. — 12th ed. / T.W. Sadler.
Orban’s Oral Histology and Embryology, 11/e
Netter's head and neck anatomy for dentistry, 2nd ed.
Gray's Anatomy For Students, Third Edition
Zarb- Bolender:Speech consideration with complete dentures;
Prosthodontic treatment For Edentulous Patients 13th ed
Robert Rothman; Phonetic consideration in denture prosthesis, J
Prosthet Dent;1961;11:214-223)
Mujtaba Ashraf 72