Complete Denture 4- Maxillo-mandibular Relation Records Introduction and Definitions

3. Dr. Amal Fathy Kaddah
Professor of Prosthodontics
Faculty of Dentistry
Cairo University

4. the end
If it's not
okay, then
it's not the
end

5. • The stomatognathic system
• What 'occlusion' is and why it is important
• Definitions.
• The significance of 'ideal occlusion‘
• Difference between natural and artificial Occlusion.
• Mandibular Movements.
• Articulators and Facebows.
• Balanced Occlusion and Factors affecting Balanced Occlusion.
• Concepts of occlusion (Balanced and Non balanced Occlusion).
• Recording of Occlusion for removable prosthodontics.
• Occlusal correction for Removable Prosthesis.
• Occlusion and implant restorations (Loading protocols)
Occlusion Outline

6. Maxillomandibular
Relationship
Any spatial
relationship of the
maxilla to the
mandible
The Glossary of
Prosthodontic 2005
jaw Relation

7. Clinical significance
of jaw relation

8. • Re-establish the functional position of the
mandible
• Maintaining the stability of complete
dentures, with the least amount of trauma to
the supporting tissues.
• Esthetic and functional efficiency.
• Preservation of the remaining structure.
• Comfort

9. The stomatognathic
system

10. Stomatognathic System
• The movement of the jaw is
orchestrated OR organized by a very
complex set of muscles, which are in
turn controlled by the body's local
and central nervous system
Stoma = Mouth
Gnathion = jaws

11. The stomatognathic system
= the masticatory
system =
• Teeth
• Periodontium
• Jaws
• TMJ
• Associated muscles of
tongue & muscles of
the soft palate
• Investing tissues
• Neural control

12. Muscles of Mastication:
Neuro Muscular System
Masseter
Temporalis
Lateral Pterygoid
Medial Pterygoid
Tempromandibular
Sphenomandibular
Stylomandibular
TMJ and T M Capsule
Associated Ligaments

14. Bilateral joints permit the mandible to
move as one unit with two
functional patterns:
- Hinge (inferior
portion)
- Translation (superior
portion)

15. Translation
(superior portion)
Hinge
(inferior portion)

16. 1- The Condyles
2- Articular disc
3- The joint capsule
4- Articular Fossa
(surface of the temporal bone)
5- Temporomandibular ligament
6- Masticatory Muscles
The main components are

17.  Condyle: The rounded
articular surface at the
end of the mandible
(lower jaw).
 Glenoid fossa: A deep concavity in the
temporal bone at the root of the zygomatic arch
that receives the condyle of the mandible
 Tubercle: A slight elevation from the
surface of the bone giving attachment
to a muscle or ligament.

18. Articular disk is a thin, oval fibrous
connective tissue plate, non-vascular,
placed between the condyle of the
mandible and the mandibular fossa.
Its upper surface is concavo-convex
and Its under surface, is concave, to accommodate and
adapt itself to the form of the mandibular fossa and the
articular tubercle. Able to tolerate forces,
It divides the joint into two cavities, each is provided
with a synovial membrane.

19. Biconcave
articular disc
C.T. capsule
• Capsule: Dense fibrous connective tissue,
Provides protection to condyle and fossa during
movements
• Lacks blood vessels and nerves
• Able to tolerate forces without damage or pain
being produced

20. The Synovial fluid:
Consist of small amounts of a clear, straw-colored
viscous fluid. It is an infiltrate of the blood
diffused out from the rich capillary network of
the Synovial membrane.
Function:
1- Lubrication
2- Nutrition.
3- Clear the tissue debris.

21. TMJ LIGAMENTS AND CAPSULE
Yellow Stylomandibular Ligament
Red Pterygomandibular raphe
Green Sphenomanibular ligament

22. Muscles of Mastication:
Masseter
Temporalis
Lateral Pterygoid
Medial Pterygoid
Anterior belly of digastric
Mylohyoid muscle
Geniohyiod muscle
Accessory muscles of mastication

23. The mandible opens,
and while initiating
closing, there is a shift
slightly to the side of
the bolus, due to
the oblique orientation
In normal chewing
function
of the masseter and medial pterygoid.

24. The closure of the mandible does
not occur in a straight upward
movement but rather in a curve

25.  Elevation of mandible (closes the jaw)
Masseter
Temporalis
 Elevation of the mandible (closes the jaw)
 Assist in Retrusion of mandible
 Assist in protrusion of mandible
• Elevation of the mandible (closes the jaw)
• Minor contribution to protrusion of the mandible
• Right medial pterygoid with left lateral pterygoid
turn the chin to left side
Medial Pterygoid
Wikipedia

26. • Protrusion of the mandible: The primary function
of the lateral pterygoid muscle is to pull the head of the
condyle out of the mandibular fossa along the articular
eminence to protrude the mandible.
• Jaw opening (Depresses the mandible) it is
assisted by the digastric, mylohyoid and geniohyoid
muscles.
• SIDE TO SIDE movements GRINDING MOVEMENT
• Unilateral action of a lateral pterygoid produces contralateral
excursion (a form of mastication), usually performed in
concert with the medial pterygoids.
Lateral Pterygoid
Wikipedia

27. The primary function of the lateral pterygoid
muscle is to pull the head of the condyle out of
the mandibular fossa along the articular
eminence to protrude the mandible.
Protrusion of the mandible

28. the Digastric muscles is not a muscle of mastication
but it play an important role in mandibular function
The Lateral Pterygoid muscles open the mouth
(depressing the mandible), with the assistance
of the Digastric muscles

29. The Lateral Pterygoid muscles move the
condyles laterally (from side to side)

30. IF YOU CAN’T FEED
A HUNDRED PEOPLE
THEN JUST FEED ONE

32. 1. Orientation relations (Occlusal plane orientation)
2. Vertical relation, and
3. Antero - posterior relation
Three - dimensional record
Boucher classified jaw relations into three groups

33. 1- ORIENTATION RELATION
Orient the mandible to the cranium in
such a way that when the mandible is
kept in its most posterior position, the
mandible can rotate in a sagittal plane
around an imaginary transverse axis
passing through or near the condyles.
THE AXIS CAN BE LOCATED BY THE
FACEBOW.

34. • ORIENTATION OF MAXILLA IN RELATION
TO BASE OF SKULL
Plane of maxilla may be tilted in some
patients, in such cases plane of mandible
will not be altered since it articulates with
base of the skull. Hence, a maxillary tilt will
alter the relationship of maxilla to mandible
during different movements, also affect the
level of occlusal plane.

35. • Orientation of occlusal plane
• The occlusal plane is defined as “the
average plane established by the
incisal and occlusal surfaces of the
teeth".

36. • Importance of orientation of
occlusal plane
Anteriorly, occlusal plane mainly helps in
achieving esthetic & phonetic. posteriorly, it
forms a milling surface, where tongue &
buccinator muscle are able to position the
food bolus onto it , and hold it there during
mastication. Incorrect of occlusal plane would
hamper esthetics, phonetics, & mastication. It
may affect stability of complete denture &
ultimately result in alveolar bone resorption.

37. 1. Protrusive relation,
2. Right lateral relation, and
3. Left lateral relation

39. Recording
Jaw
Relations
Occlusal
plane &
Facial
Contour
Horizontal
Relation
Eccentric
jaw
relation
Vertical
Relation
Recording Jaw Relationships

40. When you realize you've made a mistake,
take immediate steps to correct it.

42. The STATIC relationship between the
incising or masticating surfaces of the
maxillary and mandibular teeth, or tooth
analogues.

43. The contact relationship
between the occlusal
surfaces of teeth during
function.
It is the DYNAMIC contacts relationship of
the teeth as the mandible moved to and from
eccentric relation.

44. Movement occurring when mandible
moves away from maximum
intercuspation
Undesirable contacts
occurring during
lateral movements

45. The side toward which the
mandible moves in a lateral
excursion
Working side

46. Non working (balancing) side
The side which the mandible moves
toward the median line in a lateral
excursion

47. The most retruded relation of the
mandible to the maxillae when the
condyles are in the most posterior
unstrained position in the glenoid fossae

48. The relation of the
mandible to the maxilla
with the mandible in its
most retruded position.
(GPT) 2005

49. Dawson has defined this position
as the rearmost, uppermost,
midmost (RUM) position of the
condyle in the fossa at which the
medial pole of the condyle disc
assembly is braced against the
bony wall of the eminentia.

50. Whatever is the definition of centric relation it is
reproducible, stable and functional position.
The rearmost, uppermost, midmost (RUM)
position of the condyle in the fossa
The most posterior unstrained position in
the glenoid fossae
The uppermost and rearmost
position in the glenoid fossae
The anterior-superior position
against the articular eminences

51. The mandible is in centric relation if four
criteria are fulfilled:
1.The disk is properly aligned on both condyles.
2.The condyle-disk assemblies are at the highest point possible
against the anterior slopes of' the eminentiae. (Uppermost)
3. The medial pole of each condyle-disk assembly is braced by
bone. (midmost)
4.The inferior lateral pterygoid muscles have released their
contraction and are passive (most posterior unstrained
position)

52. Is the only constant repeatable
position within the functional
limit to start constructing a
stable occlusion

53. Maximum Intercuspation:
The complete intercuspation of the opposing
teeth independent of condylar position

54. CENTRIC
OCCLUSION
The occlusion of opposing teeth when the
mandible is in centric relation, This may or
may not coincide with the centric relation in
natural dentition GPT 9

55. Centric Occlusion:
Static contact relationship that exist
after the jaw movement has stopped
and the tooth contact are identified

56. • In 90% of individuals with full
complement of natural teeth,
maximum intercuspation, does not
coincide with centric relation of the
jaws.
• In most patients centric occlusion is
located anterior to the centric
relation by 0.5-1.5 mm measured in
the horizontal plane.

57. In the edentulous patients, use the
posterior border position (CR)
Centric Occlusion made to coincide
with CR

58. Long centric or Freedom in centric
The occlusal surface of the teeth could be
altered to allow freedom of tooth movement in
harmony with the rotation of condyle. (from
hinge position to habitual intercuspal position).

59. Anterior Contacts in MI and posterior point
is the COR
Long centric or Freedom in centric

60. Centric occlusion with
teeth present is a tooth to
tooth relation whereas
centric relation, is a bone
to bone relation
(Static positions)

61. Eccentric Occlusion:
Static occlusion other than centric
occlusion: Protrusive occlusion and Lateral
occlusion

62. The vertical dimension of the face when
teeth are in maximal intercuspation.

63. • The distance measured between two selected
anatomic or marked points (usually one on the tip of
the nose and the other one on the chin) when
occluding members are in maximal intercuspation.
GPT 9

64. Occlusal vertical dimension
The distance measured between two points
when occluding members are in contact and
condyles are in centric relation.

65. Inter-alveolar distance
inter-ridge distance
• The vertical distance
between specified
positions on the maxillary
and
mandibular alveolar ridges at the
occlusal vertical dimension.

66. The vertical dimension of the face when
the mandible is in rest position.

67. • The space between the
maxillary and mandibular
occlusal surfaces when the
mandible is in the rest
position.
when the mandible is in a specified balanced
position, it ranges from 2-4 mm.

68. • Isometric contraction
It is contraction of muscle without shortening
Elevator muscles.
Contract
isometrically to keep
the mandible at rest
(tension without
shortening)
Ring of closing, opening and post
vertebral muscles.

69. V D R
V D O
= V D R - F W S
V D O
2 to 4 mm.

70. Hinge Axis
• A transverse axis about which the
mandible can rotate without
translatory movement of the condyles.
Hinge Movement
• An opening or closing movement of
the mandible about the hinge axis.

71. This relation exists when the
jaws are in centric relation and
the teeth are in centric occlusion
To obtain a centric relation record it is
necessary to determine the vertical
dimension of occlusion.

72. State of equilibrium of the denture bases
in relation to their supporting structure.
when the opposing teeth contact.

73. Balanced Occlusion
• Simultaneous contacts of the occluding surfaces
of the teeth in various jaw positions.
Free Articulation = Balanced Articulation
= Unobstructed Articulation
• Articulation that is unobstructed by cuspal
interference.
• Simultaneous contacts of the occluding surfaces
of the teeth during function
The Glossary of Prosthodontic 2005

74. Balanced
Occlusion/Articulation
•The Bilateral simultaneous
contact of the anterior and
posterior teeth in excursive
movements. (GPT 9)

75. Christensen’s phenomenon
• A gap occurring in the
natural dentition when
the mandible is
protruded. It can lead to
instability in full dentures
unless compensating
curves are incorporated
into the dentures.

76. Bonwill’s Triangle
The distance between the center of each
condyle and the contact point of the two lower
central incisors form an equilateral triangle
(4 inches=10 cm length)
which does not change
throughout life. This
triangle is established
as the Bonwill triangle.

77. • V ARIATIONS IN THE
SIZE of Bonwill’s
triangle influence the
cusp angulation for
complete dentures.
Bonwill’s Triangle
• He found that the dimensions of the teeth and other
cranial bones and even the whole body are in constant
relation to the length of the sides of this triangle.
• Construction of average articulators is generally in
accordance with Bonwill’s theory,

78. • As a result of his jaw measurements
Bonwill developed in 1864 the first
Bonwill articulator, a device for
simulating the temporomandibular
joint movements for
manufacturing dentures.
Bonwill’s Articulator

79. In Summary
1. What 'occlusion' is and why it is important
2. The stomatognathic system
3. Clinical significance of jaw relation
4. Retruded Jaw Relation, Centric Jaw Relation, Centric Relation
5. why occlusion is important
6. Denture Stability
7. The stomatognathic system
8. Centric and Eccentric occluding relation
9. Vertical dimension of occlusion
10.Vertical dimension of rest
11.Interridge distance
12.Free way space, inter occlusal distance
13.Balanced Occlusion and Free Articulation
14.Hinge Axis and Hinge Movement
15.Christensen’s phenomenon
16.Bonwill’s Triangle

80. ‫نـفــع‬ ‫إن‬ ‫بعلمي‬ ‫حـسبي‬
‫الطمــع‬ ‫في‬ ‫إال‬ ‫الــذل‬ ‫ما‬
‫من‬
‫رجــــع‬ ‫هللا‬ ‫راقـب‬ ..
‫وارتفــع‬ ‫طير‬ ‫طــار‬ ‫ما‬
‫وقــــع‬ ‫طـار‬ ‫كـما‬ ‫إال‬