2. ENVELOPE OF MOTION
Dr ulf posselt’s in 1952 first described a 3D concept
of mandibular movements
It was a Combination of border movements in all 3
planes:
a) Sagittal
b) Horizontal
c) Frontal
The envelope differs from person to person but it
has the same characteristic shape
3. ENVELOPE OF MOTION
The superior surface of the envelope is
determined by the tooth contacts
The other borders are primarily
determined by the TMJ anatomy and the
ligaments
5. WHAT IS
TEMPOROMANDIBULAR
JOINT??
It is the area where the mandible articulates
with the cranium.
It is described as a complex , multiaxial
,synovial , condylar and ginglimoarthroidal
joint.
Tmj is also known as CRANIOMANDIBULAR
JOINT.
6.
7.
8. Cranial component
It is also known as mandibular/glenoid fossa.
Mandibular component
The articular part of the mandible is an Ovoid
condylar process.
Tmj capsule
It is a thin sleeve fibrous tissue investing
joint completely.
Inside fibrous tissue capsule, a synovial
membrane is present.
9. Ligaments:
Following are the ligaments associated with
TEMPOROMANDIBULAR JOINT
The lateral or temporomandibular ligament
Sphenomandibular ligament
Stylomandibular ligament
14. CENTRIC RELATION
The position of the mandible in which the condyles
are in the most superior and anterior position in the
articular fossae, resting against the posterior slopes
of the articular eminences with the articular discs
interposed.
17. Maximal Intercuspal Position
or Maximum Intercuspation
This is a position in which the maxillary and
mandibular teeth make maximum surface contact
with each other. The mandible is elevated as
superiorly as possible in the sagittal plane.
20. MAXIMUM INTERCUSPATION
In MIP the condyle-disc assembly is anterior
and inferior and/or medial or lateral or a
combination of the above compared to their
position in CR.
Usually the condyle-disc assemblies are
ANTERIOR and INFERIOR.
21.
22. POSTURAL POSITION
(PP)
Is the habitual position of the mandible
when the patient is resting comfortably in
the upright position and the condyles are
in a neutral unstrained position in the
glenoid fossae.
In this position there is an equilibrium
between the forces acting on the
mandible.
23. POSTURAL POSITION
In the POSTURAL POSITION the muscles are
not totally relaxed. There is a degree of
electromyographic activity.
This position is determined by the muscles and
the forces of gravity.
24. POSTURAL POSITION
The condyles are usually anteriorly and
inferiorly compared to their CR position.
This position can be sustained and it is
comfortable for the patient.
25. POSTURAL POSITION
In this position, the teeth are apart and there
is a wedge space between the teeth.
The wedge shaped space is called the
INTEROCCLUSAL SPACE and is usually 2-
3mm between the incisors, 2mm between the
premolars, and 0.75-1mm between the
molars.
29. WHEN THE MANDIBLE IS IN CENTRIC RELATION
THE CONDYLES CAN ROTATE AROUND A
HORIZONTAL AXIS UP TO AN OPENING OF 20-
25 MM MEASURED AT THE CENTRAL
INCISORS.
31. IF OPENING OF THE MANDIBLE CONTINUES
BEYOND 20-25 MM THEN TRANSLATION OF
THE MANDIBLE OCCURS.
32. ROTATIONAL MOVEMENT
Movement of a body around an axis
• Pure rotational movement occurs minimally in
the mandible
• This pure rotational movement is also
referred to as hinge movement and the axis is
referred to as terminal hinge axis
34. LATERAL MOVEMENTS
(RIGHT AND LEFT DIRECTION)
1) The side to which the mandible is moving is called the
WORKING SIDE
2) The side that is opposite to the working side is called
BALANCING OR NON WORKING SIDE
3) The condyle on the working side is called the
WORKING OR ROTATING CONDYLE
4) The non-working condyle is called THE BALANCING
OR THE ORBITING CONDYLE
35. MANDIBULAR LATERAL TRANSLATION
The first part of the lateral movement of the mandible, depicted when the
medial pole of non-working condyle starts to travel down the slope of the
articular eminence. The movement is exhibited as a measurement of the
distance between the medial pole of the non-working condyle and the medial
wall of the glenoid fossa.
Also known as Bennett Movement and Immediate Sideshift
Non-Working Side
0.3
mm
36. FUNCTIONAL MOVEMENTS
(OCCUR WITHIN BORDER
MOVEMENTS)
Occur during functional activity of the
mandible
Are confined within the Border Movements
Begin and end in the maximum intercuspation
position.
37. FUNCTIONAL
MOVEMENTS
The chewing stroke starts at the MIP and
drops downwards and forwards to the
position of desire opening.
It returns in a straighter pathway slightly
posterior.
38. BORDER MOVEMENTS
The mandibular movements are limited by
ligaments, the articular surfaces of the TMJ,
and the morphology and alignment of the
teeth. The outer range of movement is
reproducible and called border movements.
39. PANTOGRAPH APPARATUS
The device has a stylus that marks on special
paper placed in all 3 planes of reference at the
same time. Distinct markings are produced that
are transferable to a fully adjustable articulator.
Recording Paper
40. PANTOGRAPHIC TRACING TRANSFER
TO FULLY ADJUSTABLE ARTICULATOR
Tracing plates
receive markings on
paper during
movements of the
mandible. The
articulator is set by
“tracing” the
movement recorded
46. BORDER MOVEMENTS IN SAGITTAL PLANE
Items of interest:
>Centric Relation
>Hinge axis movement
>Maximum
Intercuspation
>Edge-to-edge incisal
>Maximum Protrusion
>Maximum Opening
47. BORDER MOVEMENTS IN SAGITTAL
PLANE
CRC (Centric Relation Contact) will see the condyles in the
glenoid fossa and closure of the mandible along the hinge
axis, until first tooth contact is made (many times this is in
the molar region).
48. BORDER MOVEMENTS IN SAGITTAL
PLANE
CO (Centric Occlusion), or Maximum Intercuspation
(MI), is achieved when the patient is told to get their
maxillary and mandibular teeth together in a
comfortable, contacting position.
49. BORDER MOVEMENTS IN SAGITTAL
PLANE
The mandible will
open along the hinge
axis, with the condyles
rotating within the
glenoid fossa. The
rotational movement
will terminate at the
Terminal Hinge Axis
Position.
50. BORDER MOVEMENTS IN SAGITTAL
PLANE
The Terminal Hinge Axis
is the rotational
movement that occurs
from CR to the Terminal
Hinge Axis position.
The condyles are rotating
completely within the
glenoid fossa. It is a
reproducible and
consistent movement.
51. BORDER MOVEMENTS IN SAGITTAL
PLANE
Maximum Opening
displays the most
inferior position of
the mandible, after
the patient is
instructed to open
their mouth as wide
as they can.
52. BORDER MOVEMENTS IN SAGITTAL
PLANE
Maximum Protrusion
depicts complete
contact with the teeth
as the mandible is
completely protruded,
anteriorly. It is the
most anterior of the
positions, when
viewed from the
sagittal plane.
53. BORDER MOVEMENTS IN SAGITTAL
PLANE
Edge-to-Edge
contact of
Maxillary and
Mandibular
Incisors.
Mandible is
protruded forward
from MI, maintaining
some type of tooth
contact throughout.
54. BORDER MOVEMENTS IN SAGITTAL
PLANE
Protruded contact of
Maxillary and
Mandibular Incisors.
Mandible is continuing
to protrude forward
from Edge-to-Edge
Incisal, maintaining
some type of tooth
contact throughout.
55. BORDER MOVEMENTS IN SAGITTAL
PLANE
Maximum
Protrusion position.
The teeth are in some
degree of contact
(usually in Premolar-
Canine area) and
mandible is pushed
forward as far as
possible.
56. Border Movements in Sagittal
Plane
Mandibular Opening.
Going from
Maximum Protrusion
to Maximum
Opening.
57. Border Movements in Sagittal
Plane
CR
MI
E-T-E
MP
MOA
MO
HA
HAT
HA-MO
Legend:
CR = Centric Relation
MI = Maximum Intercuspation
E-T-E = Edge to Edge Incisal
MP = Maximum Protrusion Point
MOA = Maximum Opening Arc
MO = Maximum Opening Point
HA-MO = Hinge Axis to Maximum
Opening
HAT = Hinge Axis Terminating
Point
HA = Hinge Axis Arc
CL
RP
RP = Rest Position or Postural
Position of the Mandible
CL = Chewing Loop
67. Border Movements in Horizontal
Plane
Legend:
CR = Centric Relation
MI = Maximum Intercuspation
E-T-E = Edge to Edge Incisal
MP = Maximum Protrusion
ERL = Extreme Right Lateral
ELL = Extreme Left Lateral
RP = Rest Position
VCA = Vertical Chewing Arc
HCA = Horizontal Chewing Arc
LLB = Left Lateral Border
RLB = Right Lateral Border
ELL-MPB = Extreme Left Lateral
to Maximum Protrusion Border
ERL-MPB = Extreme Right Lateral
to Maximum Protrusion Border
CR
MI
VCA
HCA LLB
ELL
ELL-MPB
E-T-E
MP
ERL-MPBERL
RLB
RP
68. FUNCTIONAL RANGE IN HORIZONTAL
BORDER
As the mandible opens, the
size of the horizontal plane
border decreases until it
reaches a “point” at the
maximum opening position.
75. Border Movements in Frontal
Plane
Maximum Opening
of the mandible in
the Frontal Plane.
This is the most
inferior position.
76. BORDER MOVEMENTS IN FRONTAL
PLANE
Postural position
of the mandible
when viewed in
the Frontal Plane.
77. BORDER MOVEMENTS IN FRONTAL
PLANE
MO
RP
ELLMI
ERL
CL
Legend:
MI = Maximum Intercuspation
ELL = Extreme Left Lateral
MO = Maximum Opening
CL = Chewing Loop
RP = Rest Position
ERL = Extreme Right Lateral
