Occlusion and Articulators

Question 1

the most universally used impression material for diagnostic casts

Answer 1

alginate

Question 2

Alginate powder components:

Answer 2

• insoluble calcium alginate produced by a chemical reaction between salts
• setting rate controlled by trisodium phosphate

Question 3

(More/Less) volume = less dimensional change

Answer 3

More –> alginate should be thick enough to capture anatomy of patient’s teeth

Question 4

Remove tray from patient’s mouth _____ min after seating alginate in patient’s mouth.

Pour impression with stone within _____ min. Cast sets within ______ min.

Answer 4

2-3 min
15 min
30-60 min

Question 5

CR position

Answer 5

at the articulation between the condyles and the thinnest portion of the upper and lower discs in the most ANTERIOR-SUPERIOR position against the articular eminences

Question 6

complete interdigitation of teeth, sometimes referred to as centric occlusion (CO)

Answer 6

MIP

Question 7

the most reliable and reproducible jaw relationship in the mouth

Answer 7

CR

Question 8

method of positioning a patient in CR

Answer 8

bimanual manipulation

Question 9

Steps to bimanual manipulation:

Answer 9

1) With patient lying back, hold the posterior mandible with finger and the chin with the thumbs
2) Deprogram the jaw (patient relaxes as much as possible)
3) Recognize first CR tooth contact and repeat until a consistent first tooth contact is identified
4) Keep anterior teeth slightly apart in CR with acrylic resin jig
5) Lastly, measure an interocclusal record of posterior teeth with PVS

Question 10

aims to replicate the articulator relationship of maxillary arch to the skull and the mandible to the hinge axis of the TMJs of the pt

Answer 10

facebow record

Question 11

non-adjustable vs semi-adjustable vs fully adjustable articulators

Answer 11

Non-adjustable
- cannot entirely represent the movements of the mandible
- only opens and closes
- much shorter distance between hinge and teeth, thus can cause premature contacts

Semi-adjustable
- includes Bennett angle (15 degrees) and horizontal condylar inclination (30 degrees)

Fully adjustable
- pantograph (most complex articulator that is used to record mandibular border movements)

Question 12

most complex articulator that is used to record mandibular border movements

Answer 12

pantograph

Question 13

Casts made with alginate impressions are better mounted with __________.

Casts made with elastometric materials are better mounted with __________.

Answer 13

wax records / ZOE paste or elastomeric materials (PVS)

Question 14

describes how the teeth separate from one another in order to protect the teeth from wearing or receiving too much occlusal force

Answer 14

disoclusion

Question 15

• determines anterior occlusion
• occludes between incisal edges of lower incisors and lingual slopes of upper incisors
• shown by pin and guide table

Answer 15

incisal guidance

Question 16

• determines posterior occlusion
• slope of articular eminence
• shown by horizontal condylar inclination (HCI)

Answer 16

condylar guidance

Question 17

canine guidance

Answer 17

During lateral movements, posterior teeth disclude as contact is solely between upper and lower canines.

Question 18

involves both incisal and canine guidance

Answer 18

anterior guidance

Question 19

________ and _________ guidance may or may not work in harmony with each other.

Answer 19

Condylar and incisal guidance

Question 20

During protrusive movement, both the _______ and _______ guidance supply clearance for all posterior teeth.

Answer 20

incisal and condylar

Question 21

During lateral movement, __________ on the working side and __________ on the balancing side supply clearance for posterior teeth.

Answer 21

canines / condyle

Question 22

preferred guide tables, as they move in curves and can follow patients lingual anatomy

Answer 22

custom incisal guide tables (vs mechanical guide tables)

Question 23

guidance that should be protected during restorative treatment because they can modify the “guiding teeth”

Answer 23

anterior guidance

Question 24

front teeth preserve the back teeth, back teeth preserve the front teeth

Answer 24

mutual protection