ULSD Occlusion II

Where is the contact point for lingual cusps of premolars? (maxillary)

the distal fossa of the antagonist tooth

Where is the contact point mesiolingual cusp of molars? (maxillary)

the central fossa of the antagonist tooth

Where is the contact point distolingual cusp of molars? (maxillary)

the distal marginal ridge of antagonist and mesial marginal ridge of the distal tooth

(picture on slide 5 of ppt)

Where is the contact point buccal cusps of premolars and mesiobuccal cusps of molars? (mandibular)

the marginal ridges

Where is the contact point distobuccal cusps of molars? (mandibular)

the central fossa

(picture on slide 6 of ppt)

What is lateral movement?

mandible is moving to the side

What's another name for "working side"?

laterotrusive

What is a working side?

the side towards which the mandible is moving

Jaw moves right, the right side is the working side

What's another name for "nonworking side"?

mediotrusive/balancing

What is a nonworking side?

- the side opposite to the movement

- always moves towards the midline

What is working movement?

- the side toward which the mandible is moving laterally

- almost a straight lateral movement

What is nonworking movement?

- side that moves toward the median line

- more diagonal movement

- moves medial, anterior, down (or else it hits the temporal bone)

How does the condyle move during laterotrusive movement?

- mandible is depressed, dental arches separate, and jaw moves to the right and brings teeth to the right of centric occlusion in RIGHT working

- left non working side may or may not make contacts

- more diagonal movement (medial, anterior, and down)

What are other names for working cusps and what do they do?

- functional cusps (both)

- supporting cusps (support vertical arch)

- centric cusps (holds central occlusion)

* do the grinding of food

What cusps are the working cusps for mandibular and maxillary teeth?

- buccal cusps (posterior mandibular)

- lingual cusps (posterior maxillary)

How are working cusps shaped?

- broad and rounded or blunt

- blunt because it's constantly being used

What's another name for nonworking cusps?

- guiding cusp

- non-centric cusp

What cusps are the nonworking cusps for mandibular and maxillary teeth?

- lingual cusps (posterior mandibular)

- buccal cusps (posterior maxillary)

What's an acronym to remember the nonworking cusps?

BULL

Buccal Upper Lingual Lower

How are nonworking cusps shaped?

relatively sharp with definite tips

What do nonfunctional cusps protect?

cheek (buccal max) and tongue (lingual mand)

What are guiding inclines?

- the inner triangle ridges leading to nonworking cusps

- in contact movements, they guide the supporting cusps out of occlusion

What's protrusive movement?

mandible moving anteriorly/forward

What is functional tooth guidance?

dynamic contact relationships between the incisal, lingual, and occlusal surfaces of the maxillary and mandibular teeth during different mandibular movements

What are the three types of tooth guidance?

- canine guidance

- group function

- anterior guidance

What is canine guidance?

- ideal guidance --> prevent teeth from oversliding

- tooth furthest anterior in a position to take lateral load with straight lateral movement

**canines cause disclusion (separation of opposing teeth) of the posterior teeth on the working and nonworking side (slide 20)

Can molars and premolar cusps touch when canines are tip-to-tip?

no, molars/premolars are not touching. if they are touching, it's called interference

What is group function?

- the sliding contact between cusps of opposing canines, premolars, and molars on the working side

- disarticulates all teeth on the nonworking side

- acceptable alternative to canine function

When should group function be used as an alternative to canine guidance?

when the canine position or length does not allow canine guidance

What does more posterior teeth along with the canine on the working side promote in group function?

- it promotes the disclusion of the posterior teeth on the nonworking side

- it occurs when canine crown length does not allow for full guidance through out the lateral movement

What is anterior guidance aka incisal guidance?

- promotes disclusion of posterior teeth in mandibular protrusive movement through the maxillary central incisors and sometimes accompanied with the lateral

- basically when anteriors are on incisal edges, posterior teeth won't touch

What is mutually protected occlusion?

- canines protect posterior teeth by disengaging the posterior teeth by providing guidance during excursions allowing cusps of posterior teeth to disclude rather than strike one another

- posterior teeth protect anterior teeth by providing a stable vertical dimension of occlusion