What is occlusion?

Question 1

what can occlusion be defined as

Answer 1

contacts between teeth

Question 2

how can the definition of occlusion be refined

Answer 2

defining those contacts between the teeth when the mandible is closed and stationary as the static occlusion, and those contacts between teeth when the mandible is moving relative to the maxilla as the dynamic occlusion

Question 3

what are other names for centric occlusion

Answer 3

intercuspation position, bite of convenience or habitual bite

Question 4

what is centric occlusion

Answer 4

is the occlusion the patient makes when they fit their teeth together in maximum intercuspation

Question 5

what is centric relation

Answer 5

jaw relationship and describes a conceptual relationship between the maxilla and mandible

Question 6

how can centric relation be described anatomically

Answer 6

It can be described as the position of the mandible to the maxilla with the intra-articular disc in place, when the head of the condyle is against the most superior part of the distal facing incline of the glenoid fossa.

Question 7

what is the terminal hinge axis

Answer 7

two terminal hinge points are connected by an imaginary line called the terminal hinge axis

Question 8

describes how the mandible opens

Answer 8

The mandible opens by firstly a rotation of the condyle and then a translation which is downwards and forwards

Question 9

what is the terminal closure of the mandible

Answer 9

purely rotational

Question 10

what is freedom in centric

Answer 10

another aspect of the static occlusion and it is the freedom in centric occlusion which occurs when the mandible is able to move anteriorly for a short distance in the same horizontal and sagittal plane while maintaining tooth contact

Question 11

when will there not be freedom in centric

Answer 11

There will be no freedom in centric occlusion if either the front teeth or the posterior occlusion do not allow this horizontl movement

Question 12

what is dynamic occlusion

Answer 12

refers to the occlusal contacts that are made whilst the mandible is moving relative to the maxilla.

Question 13

what is the mandible moved away by

Answer 13

he muscles of mastication and the pathways along which it moves are determined not only by these muscles but also by two guidance systems

Question 14

what is the posterior guidance system of the mandible provided by

Answer 14

TMJ

Question 15

what is the guidance pathway determined by

Answer 15

the intra-articular disc and the articulatory surfaces of the glenoid fossa, all of which are enclosed in the joint capsule.

Question 16

what is guidance

Answer 16

If teeth are touching during a protrusive or lateral movement of the mandible then those (touching) teeth are also providing guidance to mandibular movement.

Question 17

what is canine guidance

Answer 17

refers to a dynamic occlusion that occurs on the canines during a lateral excursion of the mandible. A canine protected occlusion refers to the fact that the canine guidance is the only dynamic occlusal contact during this excursive movement

Question 18

what is group function

Answer 18

contacts are shared between several teeth on the working side during a lateral excursion. The working side is the side of the mandible towards which the mandible is moving.

Question 19

what is needed to qualify for group function

Answer 19

the contacts would need to be towards the front of the mouth and the most anterior needs to have the earliest and hardest contacts

Question 20

what is working side interference

Answer 20

Working side interference means a heavy or early occlusal contact towards the back of the mouth during an excursive movement

Question 21

what is non working side interference

Answer 21

is an anterior guidance on the back teeth on the non working side during lateral excursion

Question 22

what is posterior interference

Answer 22

osterior interference are therefore considered to be a less ideal type of dynamic occlusion and the term ideal relates to whether or not it is ideal for another part of the articulatory system, the TMJ

Question 23

what is the definition of ideal occlusion

Answer 23

• The coincidence of centric occlusion in centric relation (CO=CR), when there is freedom for the mandible to move slightly forward from that occlusion in the same sagittal and horizontal plane (freedom in centric occlusion)
  
  • When the mandible moves there is immediate and lasting posterior disclusion (anterior guidance on front teeth)