CSA Intro to occlusion

Question 1

What is occlussion?

Answer 1

Relationship of maxillary to mandibular teeth at rest and in function

Question 2

What is TMJ?

Answer 2

joint(s) which articulate mandible to skull

Question 3

What is central occlusion \or ICP (intercuspal position)

Answer 3

Position of mandible with mandibular and maxillary teeth cusps are maximally interdigitated regardless of condylar position

Question 4

What is occluso vertical dimension ?

Answer 4

Vertical relationship between maxilla and mandible when teeth = in ICP

Question 5

What decreases the occluso vertical dimension ?

Answer 5

tooth wear or missing teeth

- can be compensated by over eruption of teeth

Question 6

What is resting vertical dimension ?

Answer 6

Vertical relationship between maxilla and mandible when resting comfortably in upright position with relaxed facial musculature

Question 7

What measurement is resting vertical dimension? RVD

Answer 7

Arbitrary from chosen point on maxilla to one on mandible when mandible = in resting position

Question 8

What is freeway space?

Answer 8

Space between maxillary and mandibular teeth at rest (usually 2-4mm)

Question 9

How is freeway space calculated?

Answer 9

Calculated by vertical difference between RVD and OVD

Question 10

How is RVD achieved?

Answer 10

• Achieved after swallowing/yawning

Question 11

What is retruded contact position RCP or centric relation (CR)

Answer 11

Mandibular position occurring at very first contact between maxillary and mandibular teeth when condyle = in most superior and rotating around it’s terminal hinge axis

Question 12

When is the most retruded position of mandible?

Answer 12

when initial intercuspal contact

Question 13

What do condylar heads rotate around?

Answer 13

rearmost within their glenoid fossa and rotate around their terminal hinge axis

Question 14

What is the glenoid fossa?

Answer 14

depression in temporal bone that articulates with mandible

Question 15

What is protrusion ?

Answer 15

Anterior movement of mandible when teeth = in occlusion

Question 16

What is terminal hinge axis?

Answer 16

Point where condyle rotates during rotary phase of opening mouth

Question 17

When does terminal hinge axis only occurs?

Answer 17

when mandible = in most retruded position

Question 18

What is opening of mouth?

Answer 18

involves 2 concurrent processes that = occur in the TMJ

Question 19

What does the condyle do movement wise?

Answer 19

rotates and translates

Question 20

What is rotation ?

Answer 20

condyle rotates around terminal hinge axis when in retruded position

Question 21

What is translation?

Answer 21

Forwards/Downwards movement of condyle down articular eminence of TMJ = wider opening of jaw

Question 22

What happens to condyle during translation ?

Answer 22

pulled forwards by lateral pterygoid muscle (a little bit by temporalis)

Question 23

What is condylar guidance?

Answer 23

Effect of shape of articular eminence on protrusive movements of mandible

Question 24

What is the result of condylar guidance?

Answer 24

lowering of the angle of mandible as condyle = slides down articular eminence

Question 25

What are lateral excursions?

Answer 25

Occlusal relationship between teeth when mandible = shifted horizontally to right or left

Question 26

What is the working side during lateral excursions

Answer 26

Side to which the mandible has moved:

Question 27

What does working side occur?

Answer 27

during mastication depending on which side you position food with your tongue

Question 28

What is the non working side?

Answer 28

Side away from which mandible has moved (pulled by the lateral pterygoid muscle)

Question 29

What is horizontal movement guided by?

Answer 29

working side

Question 30

What is canine guidance?

Answer 30

During lateral excursions, all teeth = disclude except canines on working side

Question 31

What does canine guidance prevent ?

Answer 31

• Prevents molars/premolars from wearing/fracturing during lateral movements

Question 32

What is group function ?

Answer 32

During lateral movements 2 or more teeth = stay in contact

Question 33

When do ppl get group functions?

Answer 33

as they age

Question 34

What is disclusion ?

Answer 34

Separation of teeth due to prominent tooth on tooth contact

Question 35

How can disclusion occur?

Answer 35

* natural e.g. prominent canines/canine guidance | * unintentionally created by dentist >restoration = too ‘high’ in bite

Question 36

What are parafunctions?

Answer 36

Tooth contacts = X involved in normal functioning of jaws i.e. mastication and speech

Question 37

What is parafunction caused by

Answer 37

attrition (bruxism) or abrasion e.g. chewing nails/pencils, holding lip/tongue/cheek piercing in between teeth

Question 38

What is bruxism ?

Answer 38

Subconscious, non-functional grinding of maxillary and mandibular teeth

Question 39

When does bruxism occur?

Answer 39

night (pain in jaws in morning) stressful time •Toothwear, fracturing and pain in masseters/headache

Question 40

How to treat bruxism?

Answer 40

• Treatment: Pt. education and splints (mouth guards)

Question 41

What is conformative treatement?

Answer 41

Treatment = aimed to fit in pts. existing occlusion

Question 42

What is reorganised treatment?

Answer 42

Treatment = aimed to change pt. occlusion

Question 43

What is interference?

Answer 43

Any tooth that causes premature contacts causing other teeth to disclude on lateral and protrusive excursions

Question 44

What causes interference ?

Answer 44

. ‘High’ filling X bite properly | • Could get ‘shiny spots’ on amalgam if pt. prematurely bites down on it

Question 45

What is a result of shiny spots on amalgam?

Answer 45

teeth to ‘jolt’ - PDL on opposing tooth = could inflame and widen so incr. mobility - Pt. may complain of sensitivity so check occlusion

Question 46

What is fremitus ?

Answer 46

Palpable vibration or slight movement of teeth when occluded

Question 47

What is overjet?

Answer 47

Horizontal distance between maxillary and mandibular incisal edges in ICP

Question 48

What is overbite ?

Answer 48

Vertical distance between maxillary and mandibular incisors in ICP

Question 49

What is articulating paper?

Answer 49

Inked paper = placed between maxillary and mandibular teeth (bitten down on)

Question 50

What does articulating paper indicate?

Answer 50

position of tooth contacts

Question 51

What is an articulator ?

Answer 51

Mechanical device = recreates pts. jaw- can see relationship between maxillary and mandibular teeth

Question 52

What types of articulators are used by technicians ?

Answer 52

1. Simple hinge: 2. Average value: 3. Semi adjustable: 4. Fully adjustable

Question 53

What is axiographic recording ?

Answer 53

Mechanical device that records condylar movements and TMJ movements etc.

Question 54

What does overloading teeth mean?

Answer 54

- Premature contacts - Lateral forces on posterior teeth - Excessive (masticatory) forces due to parafunction > MOM = working harder than normal

Question 55

What does bruxism cause?

Answer 55

- incr. wear, incr. RO fracture or rests. and teeth, - incr. muscle/MOM pain and micro cracks in enamel - masseteric hypertrophy in severe cases

Question 56

How to avoid occlusal problems with rests?

Answer 56

should conform to pts. existing occlusion: - ‘bite’ feel same after rest. as did b4 started - Use articulating paper and ask pt. “does it feel normal?” to see if rest. = high on bite

Question 57

What is the effect of high rests?

Answer 57

- Pain > incr. in MOM and tooth | - Mechanical failure > fractured rests, incr. wear

Question 58

How to extraorally examine patients on clinic?

Answer 58

- MOM palpitation (masseter/temporalis) > tender where muscles originate/insert? - TMJ during open/close of mouth - TMJ clicking/grinding