Occlusion-N

Question 1

What is a joint/articulation?

Answer 1

What is the connection between two separate parts of the skeleton

Question 2

TMJ synonyms

Answer 2

Temporomandibular joint

Craniomandibular articulation

Question 3

What is TMJ?

Answer 3

It is the ARTICULATION between the MANDIBLE and the two bones on the base of the skull called the TEMPORAL bones

Question 4

Parts of TMJ

Answer 4

There are three parts on each half of the TMJ
1. MANDIBULAR CONDYLE —-the process of the mandible.

2. The ARTICULAR or the GLENOID FOSSA.— shallow, concavity on the base of the skull in the temporal bone

3 the ARTICULAR EMINENCE or RIDGE

4. The ARTICULAR DISCinterpose between these two bony parts 

These three parts are enclosed by a FIBROUS CONNECTIVE TISSUE CAPSULE

Question 5

The articular, or the glenoid fossa

Answer 5

It is a non-functional portion of the joint

Question 6

In the glenoid fossa, how many surfaces touch

Answer 6

Two surfaces touch

1. ANTERIOR SURFACE of the condyle and the posterior slope of the articular eminence contact.

2.MEDIAL WALL of the glenoid fossa.

Question 7

Articular disk

Answer 7

It is made up of FIBROCARTILAGE . It is a SYNOVIAL JOINT

The disc is a tough band of dense, fibrous, connective tissue that acts as a SHOCK ABSORBER between the mandibular condyle and the articular Fossa and the articular Eminence

It stabilizes the condyle by filling the space between the different contours of the condyle, and the articular, fossa and articular eminence

Question 8

This is a ginglymoarthroidal joint (sling like). How many compartments does it have?

Answer 8

2 compartments:

1. Superior(upper)—translation
   2 Inferior (lower.)— rotation 12 to 15 mm.

Question 9

Proprioceptive fibres in the disc

Answer 9

They help to REGULATE MOVEMENT of the condyle by UNCONSCIOUSLY determining the POSITION of MANDIBLE

Question 10

Posterior determinant of occlusion

Answer 10

Mandibular condyle

Protrusive movement and
lateral movement

Question 11

Anterior determinant of occlusion

Answer 11

Teeth
Protrusive movement—-anterior teeth
Lateral movement — canine and group function

Question 12

Mandibular movements

Answer 12

They can be

FUNCTIONAL—mastication,speech ,yawning

PARAFUNCTIONAL — clenching, tapping, grinding

Question 13

The movement of the mandible is by virtue of two factors

Answer 13

NEUROMUSCULAR CONTROL -it is the movement of the mandible which occurs with the help of muscles under the influence of nervous system

HARD TISSUE GUIDANCE —-TMJ—-posterior guidance

                                 ——-occlusal surface of TEETH——anterior guidance

Question 14

The planes of mandibular movement

Answer 14

Three planes:

1. frontal, coronal, or lateral plane
2. sagittal , longitudinal plane
   3.horizontal, axial, or transverse plane

See diagram pg 5- naresh- new

Question 15

Hinge Axis

Answer 15

Also called the Horizontal axis or the Axial axis

Question 16

Definition of hinge axis

Answer 16

It is the TRANSVERSE AXIS that runs horizontally from one side of the condyle to the other side of the condyle, or from one side to the other side of the mandible

Question 17

Important points, hinge axis

Answer 17

1. The axis VARIES during different phases of protrusive movement.
2. during INITIAL mouth opening, the axis is present at the head of the condyle.
3. During LATE stage of mouth opening the axis passes through the mandibular foramen
4. Rotation around its axis is seen during.:Protrusive movement
   Mouth opening movement

Question 18

The rotational mandibular movement

Answer 18

12 to 15 mm

Process of turning around an axis

The rotation occurs when the mouth opens and closes around a fixed point or access within condyle

The teeth can be separated, and then occluded with no positional change of the condyle

Question 19

Translational movement of mandible

Answer 19

The movement in which every point of moving object simultaneously has the same DIRECTION and VELOCITY

This occurs in MANDIBLE moves FORWARD as in protrusion

The teeth condyle, and rami —-all move in the SAME DIRECTION and SAME DEGREE

Question 20

Planes

Answer 20

Planes:

1. FRONTAL or CORONAL plane or LATERAL plane ——divides the body into front and back
2. HORIZONTAL PLANE or AXIAL plane or TRANSVERSE plane.—-divides the body into upper and lower parts
3. SAGGITAL PLANE or LONGITUDINAL plane.— divides the body into left and right sections
4. MEDIAL PLANE —-equals left and right sides.

5.PARASAGGITAL PLANE

6. OBLIQUE PLANE—-anything not parallel to these three

Question 21

Posselt’s envelop of motion

Answer 21

1. Sagittal plane and horizontal axis.— dagger
2. Frontal plane and saggital axis.—— shield
3. Horizontal plane and vertical axis—- diamond

Question 22

Sagittal axis

Answer 22

It is an imaginary access that runs along the mid sagittal plane
What is horizontal from front to rear at right angle to the frontal plane

The mandible around the axis shows little rotational movement

During movement, the mandible moves downwards and mediately along the slope of the Enteroglenoid process on the (nonworking side).
The other side of the condyle will move upward and laterally(working side)

Shield diagram

Frontal plane

Suggitalaxis

Question 23

Vertical axis/longitudinal axis

Answer 23

Axis that run through the condyle, and the posterior border of ramus

Passes from head to foot at the right angle, transverse plane, or horizontal plane

Rotational movement of mandible is sing-along, vertical axis

Diamond shape
Horizontal plane

When mandible moves in lateral excursions, the centre for rotation is a vertical axis, extending through the rotating, or the working side condyle

Question 24

Frontal plane is also called

Answer 24

Coronal plane or lateral plane

Question 25

Horizontal plane is also called

Answer 25

Axial plane or transverse plane

Question 26

Sagittal plane is also called

Answer 26

Longitudinal plane