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.
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).
Verticalis: It broadens the tongue and causes
flattening of tongue.
16.
17. EXTRINSIC GROUP
The extrinsic musculature consists of four pairs of
muscles, namely
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus.
18.
19. BLOOD SUPPLY OF TONGUE
ARTERIAL SUPPLY:
from lingual artery, which is branch of External
Carotid Artery.
22. LYMPHATIC DRAINAGE:
Tips drain bilaterally to submental nodes
Anterior 2/3rd drains unilaterally into right and left
Submandibular nodes.
Posterior 1/3rd drains bilaterally to Jugulo omohyoid
nodes
23.
24. .Lymphatics do not accompany the blood vessels.
Tip of the tongue presents richest lymph drainage. A
cancer affecting the tip spreads to all cervical lymph
nodes of both sides.
27. TASTE BUDS
Distributed in
Inner wall of trough surrounding vallate papillae
Folds of foliate papillae
Posterior surface of fungiform papillae
Tip and lateral borders of tongue.
31. APPLIED ANATOMY
CHANGES ASSOCIATED WITH PARTIAL AND
COMPLETE EDENTULISM
CLASSIFICATION OF TONGUE
TONGUE AND STABILITY OF COMPLETE
DENTURES
NEUTRAL ZONE
TONGUE PROSTHESIS
32. 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.
33. CLASSIFICATION OF TONGUE
According to House classification:
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. Inefficient dentures sometimes can lead to
the development of class3 tongue
34. According to Wright's classification:
Class1 : The tongue lies in the floor of mouth with tip
forward and slightly below the incisal edges of the
mandibular anterior teeth
Class2 : The tongue is flattened and broadened, but the tip
is in normal position.
Class3 : The tongue is retracted and depressed into the
floor of mouth with the tip curled upwards, downwards or
assimilated into body of tongue.
35. ROLE OF TONGUE DURING
FABRICATION AND SUCCESS OF
PROSTHESIS
36. 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.
37. Tongue position is important to the prognosis of
mandibular denture.
38. 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.
INFLUENCE AND ACTION OF FLOOR OF THE MOUTH
39. The mylohyoid muscle
• Origin:
From the whole length of mylohyoid line.
• Insertion:
Posterior fibers to the body of the hyoid bone.
Middle and anterior fibers to the median raphae.
• Nerve supply: mylohyoid nerve.
• Actions :
Elevates the floor of the mouth during swallowing.
Depress the mandible and elevate the hyoid bone.
40. 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.
41. 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.
42. Alveololingual sulcus
The space between the residual ridge and the tongue which
extends from lingual frenum to the retro-mylohyoid curtain.
45. The 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.
47. A slope of the lingual flange towards the tongue in the
molar region allows the mylohyoid muscle to contract
and raise the floor of the mouth without displacing the
denture.
48. The posterior region
This part is the retromylohyoid 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).
49. The denture border should extend posteriorly to contact the
retro-mylohyoid curtain (the posterior limit of alveololingual sulcus).
50. 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
51. 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.
56. Effect of Dental prosthesis on Taste
perception( J. Pros Dent Jan.1952 vol.2 No.01)
The sense of taste may be interrupted by the
interjection of an outside stimulus such as a denture.
Thickness of denture, lack of rugae, insulation against
heat & cold.
Irritation, pressure or substance on the surface of
lower denture
57. 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
58. How to check lack of tongue space
Ask patient to raise tongue
If cramped
Denture rise immediately, as tongue moves
But in lingual flange overextension
Denture movement occurs, as tongue rises
some distance
59. 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
60.
61. 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
62. 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.
63. 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.
64. 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.
65. 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.
66. 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.
67. Careful clearance is needed, as lingual frenum is attached
to tongue and inadequate clearance may result in LOSS OF
SEAL and a loose UNSTABLE denture.
68. USE OF TONGUE FOR RECORDING CENTRIC
RELATION IN EDENTULOUS PATIENTS
J Prosthet Dent 1999; 82: 369-70.
70. 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.
71. 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 inserted. 8. Dentures in occlusion.
Journal of Prosthodontic , Vol 1, No. 2 (December: 1992: p 171-173
72. 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.
74. 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.
75. REFRENCES
CUNNINGHAM’S manual of practical anatomy, Oxford.
INDERBIR SINGH, Textbook of Human Embryology, 6th edition.1996,
Macmillan India ltd.
ORBAN’S, Oral Histology & Embryology, 10th edition, C.B.S Publishers
& Distributors.
JOHN J. SHARRY Complete Denture Prosthodontics 3rd edition, Mc
Graw Hill Book Company.
ZARB-BOLENDER Prosthodontics Treatment For Edentulous Patients
12th edition, Elsevier.
76. BERNARD LEVIN Impressions for Complete Dentures, Quintessence
Publishing Company.
SHELDON WINKLER Essentials of Complete Denture Prosthodontics 3rd
edition, A.I.T.B.S Publishers
FENN, LIDDELOW & GIMSON’S Clinical Dental Prosthetics. Mosby.
JOHN BEUMER, Maxillofacial rehabilitation. Mosby
JEROME C. STRAIN: Complete Dentures & taste perception,
J.Prosthet Dent: vol.2 No. 01, Jan 1952
MAJID BISSASU: Use of tongue for recording centric relation for
edentulous patients: J.Prosthet Dent 82:369-70, 1999.
MAURICE W. BELSKY: Prosthetic reconstruction of mandibular Tongue
prosthesis: J. Prosthet Dent , Vol 1, No. 2 December: 1992: p 171-173
Voice principally produced—larynx, while tongue by constantly changing its shape & position of contact with teeth, alveolar process—gives its sound form & its qualities