Week 6 - Optimal Occlusion Flashcards
Orthopedically Stable Joint Position
The articular surfaces and tissues of the joints are aligned such that forces applied by the musculature do not create any damage
How is optimal joint relationship achieved?
When the articular discs are properly interposed between the condyles and the articular fossae
More teeth contacts provide…
More stabilization of the mandible and decreases the forces to each tooth
Cusp-fossa occlusion
tooth-to-tooth
Cusp-marginal ridge occlussion
Tooth to two teeth
Is cups-fossa or cusp-marginal ridge more ideal?
Cusp-fossa, because cusp-marginal ridge can push teeth apart or lodge food into the embrassure
Axial loading
Cusp-tip to a flat surface
What type of lever do occlusal forces act as?
Class 3 - the effort is in between the force and the fulcrum
It’s not super efficient - that’s why we crush things on the posterior teeth
How do posterior teeth protect occlusion?
In maximum intercuspation, posterior teeth come into contact and act as stops to minimize horizontal load on anterior teeth
How do anterior teeth protect occlusion?
The anterior teeth guide excursive movements of the mandible so no posterior teeth contacts occur during lateral or protrusive excursion
What are some offects of tooth loss?
Supraeruption Tilting Loss of contact Loss of posterior tooth support Loss of vertical dimension Flaring of anterior teeth Non-working interferences
What are occlusal treatment goals?
- To direct occlusal forces along the long axes of the teeth
- To make sure all mandibular teeth contact their maxillary opponents at the same time and with the same intensity
- To furnish a smooth protrusive path guided by the anterior teeth without any interference from occlusal contacts between the posterior teeth (Posterior disclusion)
- Working contacts should no be prevented
What are the pairs of equilibration procedures
- Reduction of all contacting tooth surfaces that interfere with centric relation
- Selective reduction of tooth structure that interferes lateral excursions
- Elimination of all posterior tooth structure that interferes with protrusive excursions
- Harmonization of anterior guidance
What is responsible for most failures of equilibration?
Improper manipulation of the mandible
How do you locate occlusal interference?
Have the patient feel the first contact, and then squeeze to determine the direction and degree of the slide from CR
What are the two centric interferences
Interference of the arc of closure
Interference to the line of closure
Interference of the arc of closure
Any tooth structure tht interferes with the closing arc (CR) has the effect of displacing the mandible forward of the interference to reach MI
What is the grinding rule to correct anterior slide?
MUDL - mesial inclines of upper and/or distal inclines of lower teeth
Interference to the line of closure
Interferences that cause the mandible to deviate right or left from the initial contact point to MI
Grinding rule if the mandible deviates toward the cheek
BULL - buccal incline of uppers and/or lingual incline of lower
Grinding rule if the mandible deviates toward the tongue
LUBL - lingual incline of uppers and/or lingual incline of the lower
What are the two divisions of lateral interferences
Non-working side interferences
Working side interferences
What can happen when you start to relieve non-working side inclines
You can start to have working side interferences, and will have to start relieving them. Which can cause interferences on the non-working side.
So you usually have to adjust both together
Which teeth should touch during protrusive movements
Only anterior teeth
What is the grinding rule for protrusive interferences?
DUML - distal inclines of uppers and/or mesial inclines of lowers
With steep anterior guidance, correction of protrusive interferences is usually…
Minimal
With flat anterior guidance, correction of protrusive interferences is usually…
More extensive
