4. INTRODUCTION
• A highly mobile muscular organ situated in the
floor of mouth.
• Associated with functions of stomato-gnathic
system like taste, speech, mastication and
deglutition.
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7. STRUCTURE
The human tongue is
divided into two parts:
I. an oral part at the front
II. a pharyngeal part
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8. • DIVIDED INTO TWO PARTS
• SUPERIOR (DORSAL)
• INFERIOR (VENTRAL)
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9. • TIP
• BODY
• ROOT
E
X
T
E
R
N
A
L
F
E
A
T
U
R
E
S
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10. The four types of
papilla are :
• FILIFORM
• FUNGIFORM
• FOLIATE
• CIRCUMVALLATE
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11. • 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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12. • Vallate papillae The largest of
the papillae ,
• blunt-ended cylindrical papillae .
• only about 8 to 12 in number.
• Foliate papillae are linear folds of
mucosa on the sides of the
tongue near the terminal sulcus.
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13. MUSCLES OF TONGUE
DIVIDED INTO TWO GROUPS:
• EXTRINSIC GROUP - originate from structures outside the
tongue and insert into the tongue. These muscles
protrude, retract, depress, and elevate the tongue.
• INTRINSIC GROUP - 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
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15. INTRINSIC MUSCLES
• Superior longitudinal: It shortens the tongue and makes
the dorsum concave.
• Inferior longitudinal: It shortens the tongue and makes the
dorsum convex.
• Transverse: It helps in narrowing and elongation of tongue
(increase in height of tongue).
• Vertical: It broadens the tongue and causes flattening of
tongue.
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16. EXTRINSIC MUSCLES
The extrinsic musculature consists of four pairs of muscles,
namely
• Genioglossus
• Hyoglossus
• Styloglossus
• Palatoglossus.
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17. GENIOGLOSSUS
• 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 centre of tongue
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18. HYOGLOSSUS
• Thin quadrangular muscles
• Origin: Greater horn and
adjacent part of body of hyoid
bone
• Insertion: Lateral surface of
tongue
• Function: Depresses tongue
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19. STYLOGLOSSUS
• Origin: Styloid process of
temporal bone
• Insertion: Lateral surface of
tongue
• Function: Elevates and
retracts tongue
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20. PALATOGLOSSUS
• Origin: Inferior surface of
palatine aponeurosis
• Insertion: Lateral margin of
tongue
• Function: Depresses soft
palate and elevates back of
the tongue.
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21. CONSIDERATIONS
• 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.
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22. considerations
• 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.
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23. considerations
•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. Dr. Bhupendra
27. TASTE BUDS
• 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 pore
like opening.
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28. Taste bud are involved in detecting
the five elements of taste
perception:
• salty
• sour
• bitter
• sweet
• Umami
• Taste buds have a life span of
about 10-12 days.
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29. DEVELOPMENTAL ANOMALIES OF TONGUE
• Macroglossia
• Microglossia
• Ankyloglossia
• Bifid tongue
• Fissured tongue
• Median rhomboid glossitis
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34. FUNCTIONS OF TONGUE
• It is a necessary part of the instrument of
articulate speech.
• It acts like a reed in a wood-wind instrument to
effect variations of sound qualities.
• It moistens lips to facilitate speech. This is an
important, yet frequently overlook observation.
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35. functions contd.
• 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.
• It also aids as a vehicle to direct the masticated bolus
to the oropharynx.
• It helps control and guide the fluid intake to the
pharynx.
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36. functions contd.
• It contains the greatest number of the taste organs
and mucin-secreting gland.
• 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.
• It aids in depressing the soft palate to eliminate
mucous, sinus, and lacrimal secretions.
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37. function contd.
•It aids in the retention of ill-fitting dentures.
•It helps block the trachea in deglutition to
keep food out of the bronchial tract.
•It effects displacement and compression of
air, thereby helping create suction in
swallowing.
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39. CHANGES ASSOCIATED WITH PARTIAL & COMPLETE
EDENTULISM
• Tongue size and position.
• If patient has been without teeth or prostheses for a long
time or has worn maxillary denture against lower anterior
teeth only, then the tongue can become enlarged and
powerful causing instability of dentures.
Dr. Bhupendra
40. CLASSIFICATION OF TONGUE
M. M House classification of tongue form(1958):
• Class 1: Normal in size, development and function.
Sufficient teeth are present to maintain normal form and
function.
• Class2: Teeth have been absent long enough to permit a
change in the form and function of the tongue.
• Class3: Excessively large tongue. All teeth have been
absent for an extended period of time, allowing for
abnormal development of the size of tongue.
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41. C. R Wright classification of 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.
• Class 2 – The tip is in a normal position but the tongue is
broadened and flattened.
• 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.
Class I Class II Class III
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42. ROLE OF TONGUE DURING FABRICATION AND
SUCCESS OF PROSTHESIS
• Small tongue = easy impression making but
compromised lingual seal.
• Relatively large tongue = hindrance while making
impression, but a good lingual seal is always expected
out of it.
• Tongue position is important to the prognosis of
mandibular denture.
Dr. Bhupendra
43. INFLUENCE AND ACTION OF FLOOR OF THE
MOUTH
• Suprahyoid muscles are the digastric, stylohyoid,
mylohyoid and the geniohyoid. Accessory muscles of
mastication.
• The mylohyoid and geniohyoid may influence the borders
of the mandibular denture.
• The right and left mylohyoid muscles together form the
floor of the mouth.
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44. • If the denture flange is extended below and under the
mylohyoid line, it will impinge on mylohyoid muscle and the
action of the muscle can unseat the denture.
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45. • The distal-lingual
extension should extend
over the retro-molar pad
and about 3 mm below
the mylohyoid ridge.
• The mylohyoid muscle
affects mid & ant. Portion
of the inferior border of
lingual flange.
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46. ALVEOLO-LINGUAL SULCUS
• The space between the residual ridge and the tongue
which extends from lingual frenum to the retro-mylohyoid
curtain.
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49. 2. MIDDLE REGION
• Extends from the Pre-mylohyoid fossa to the distal end of
mylohyoid ridge curving medially from body of the
mandible. The curvature is caused by prominence of
mylohyoid ridge.
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50. 3. POSTERIOR PART
• This part is the retro mylohyoid space or fossa. Also
known as Lateral throat form.
• It extends from the end of the mylohyoid ridge to the
retro-mylohyoid curtain ( glossopalatine and superior
constrictor muscles ).
• The denture border should extend posteriorly to contact
the retro-mylohyoid curtain ( the posterior limit of
alveololingual sulcus ).
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51. • The distal end of the lingual flange
turns buccally to fill the
retromylohyoid fossa.
• When the lingual flange is developed
in this manner the border has a
typical ‘s’ shaped curve.
• If the floor is too low, so the dentist
tends to over extend the denture
flange, which leads to loss of
retention because the denture flange
impinges on the tissues.
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52. TONGUE SPACE
• Artificial teeth must be arranged in neutral zone.
• If tongue is cramped by denture
• lateral pressure exerted
Producing
• instability in denture when tongue moves
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53. EFFECT OF TONGUE ON SPEECH
Linguo-Dental sounds (th)
• Tip of tongue slightly bw upper & lower anterior teeth.
• 3mm space – Normal
• <3mm - Anterior teeth too far forward - Excessive vertical
overlap
• >6mm -Anterior teeth too far lingual
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54. • Linguo-Alveolar Sounds (t, d, n, s, z)
• Contact of tip of tongue with the anterior most
part of palate.
• ‘t’ ‘d’ if teeth far lingual
• ‘d’ ‘t’ if teeth far anterior
Dr. Bhupendra
56. POST-INSERTION SPEECH ADAPTATION
• New prosthesis Difficulty in learning new motor
acts Obstruct adaptation.
• Speech adaptation to new Prosthesis 2-4 weeks
post-insertion.
• Old dentures act as a guidance.
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57. • Bilabial, labio-dental, linguo-dental & linguo-
alveolar sounds most affected.
• Lingual flange of the mandibular denture too thick
in anterior region, faulty S sound.
• Patient must practice opening & closing while the
tongue assumes a normal position.
Dr. Bhupendra
58. OCCLUSAL PLANE
• According to Fenn, to obtain
maximum stability of lower denture,
the occlusal plane of the lower
teeth should be very slightly below
the bulk of tongue, so that tongue
performs the majority of its
movements above the denture and
thus keep the denture down.
Dr. Bhupendra
59. NEUTRAL ZONE
• The soft tissue that form internal
and external boundaries of
denture base influences the
denture stability. It is to
understand and determine the
peripheral borders, tooth position
and external contours of denture.
Dr. Bhupendra
60. EFFECT OF LINGUAL FRENUM
• In case of hypertrophic frenum: lingual frenectomy is done.
• In case ankyloglossia exist with a heavy alveolar attachment,
then detachment of fibers may be necessary to ensure
clearance.
• In patients of lingual frenectomy, the denture should be made
before the surgery, to prevent relapse, as this denture acts as a
stent.
• Careful clearance is needed, as lingual frenum is attached to
tongue and inadequate clearance may result in LOSS OF SEAL
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61. PROSTHETIC RECONSTRUCTION OF MANDIBULAR
TONGUE
• A total glossectomy or laryngectomy results in
loss of basic vital functions and loss of speech.
• In these patients fabrication of a mandibular
tongue prosthesis can be done.
Dr. Bhupendra
62. 1. Edentulous maxilla. 2. Edentulous mandible, floor of mouth, surgical defect. 3. Final impressions using impression wax. 4.
Mandibular denture showing elliptical acrylic retention button and posterior platforms for posterior support of the tongue
prosthesis. 5. Final tongue prosthesis with mandibular denture. 6. Tongue prosthesis attached to mandibular denture. 7. Prosthesis
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63. • The tongue prosthesis is not mobile, but articulation is
improved by the fact that the prosthesis takes up space, thus
changing resonance of the oral cavity with certain sounds.
• Besides improving speech, the patient is able to crush food
against the palate, aiding mastication.
• The posterior channeled shape of the tongue assists in
deglutition.
• In this case, the patient was highly motivated, which helped
prognosis considerably.MAURICE W. BELSKY: Prosthetic reconstruction of mandibular Tongue prosthesis: J. Prosthet Dent , Vol 1, No. 2
December: 1992: p 171-173
Dr. Bhupendra
65. SUMMARY AND 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 prosthesis.
• So we can conclude that a proper diagnose of tongue is must
before proceeding and planning any type of dental
procedures.
Dr. Bhupendra
66. REFERENCES
• ZARB-BOLENDER Prosthodontics Treatment For Edentulous Patients 12th edition, Elsevier.
• BERNARD LEVIN Impressions for Complete Dentures, Quintessence Publishing Company
• SHELDON WINKLER Essentials of Complete Denture Prosthodontics 3rd edition, A.I.T.B.S
Publishers
• INDERBIR SINGH, Textbook of Human Embryology, 6th edition.1996, Macmillan India ltd.
• ORBAN’S, Oral Histology & Embryology, 10th edition, C.B.S Publishers & Distributors
• MAURICE W. BELSKY: Prosthetic reconstruction of mandibular Tongue prosthesis: J. Prosthet
Dent , Vol 1, No. 2 December: 1992: p 171-173
• An analysis of tongue factor and its functioning areas in dental prosthesis. Kessler JPD,1955
• JPD 1963,,VOL 13,857-865, by Philip Rinaladi
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Notas del editor
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.
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.
A second median swelling, the copula, or hypobranchial eminence, is formed by 2nd , 3rd , and part of the 4th arch.
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.
Further lateral lingual swellings increases in size, they cover the tuberculum impar and merge, forming anterior 2/3rd (body) of tongue.
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
It is a “lingual fixing muscle of the lower denture”
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.
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
Tips drain bilaterally to submental nodes
Anterior 2/3rd drains unilaterally into right and left Submandibular nodes.
Posterior 1/3rd drains bilaterally to Juguloomohyoid nodes
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
proper designing of the lingual flange at the wax up stage helps increase the stability of mandibular denture
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
