Occlusion for the Partially Edentulous Patient Flashcards
What is another name for mutualy protected occlusion?
OPTIMAL FUNCTIONAL OCCLUSION
What is mutually protected occlusion?
- Multiple, even, bilateral, simultaneous occlusal contacts of the posterior teeth in MIP with the mandible is CR position
- The anterior teeth exhibit lighter occlusal contacts as compared to posterior teeth in MIP
- Posterior teeth are axially loaded in MIP
- In excursive movements there is canine guidance and anterior guidance
The __________ teeth withstand the majority of the load in MIP, protecting the _________ teeth from high loads.
posterior
anterior
The anterior teeth disclude the posterior teeth in excursive movements, thereby protecting the posterior teeth from…
off-axis loading
The anterior teeth exhibit _________ occlusal contacts as compared to posterior teeth in MIP
lighter
Posterior teeth are _______ loaded in MIP
axially
In excursive movements there is __________ guidance and _________ guidance
canine
anterior
What are the occlusal schemes during excursive movement?
1) Canine guidance - Anterior guidance
2) Group function (unilateral balance)
3) Balanced occlusion (bilateral balance)
Where do you begin when evaluating a patient’s detition for a partial?
-The current condition (teeth, supporting structure, intra-oral and peri-oral tissues)
-Occlusion
What are the ways to evaluate occlusion?
Intraorally and on Articulated Diagnostic casts
What is canine guidance?
the canines on the working side guide the movement when the mandible moves laterally causing all other teeth to disclude
What is anterior guidance?
the anterior teeth disclude the posterior teeth when the mandible moves in protrusion
The canines, central and lateral incisors disclude the posterior teeth, when the mandible moves in ____________.
protrusion
Contacts between the posterior teeth during excursive movements
are considered…
interferences that can create damaging effects on teeth and periodontium
Why is Canine Guidance/Anterior Guidance the optimal occlusal scheme?
- Mandible - Class III lever
- The more anterior (away from the fulcrum), the resistance (load) occurs, the lesser the impact (magnitude)
- The canine(s) has the longest root, and best bone support (canine eminence)
What lever is it when canine guidance on mandibular?
Class III lever
What are the anterior controlling factors?
- ANTERIOR TEETH
- ANTERIOR GUIDANCE
Anterior guidance is controlled by ______________________ of anterior teeth
position and contours
Anterior guidance is altered by…
- RESTORATIONS
- ORTHODONTICS
- EXTRACTIONS
- CARIES
- HABITS
- TOOTH WEAR
Is anterior guidance is fixed factor or a variable?
a variable
What is the anterior guidance angle?
the angle formed by the intersection of the horizontal plane and the disclusive pathway of the anterior teeth
What influences the anterior guidance angle?
- vertical overlap (VO)
- horizontal overlap (HO)
With increased VO overlap the anterior guidance angle…
increases
With increased HO overlap the anterior guidance angle…
decreases
What does an increased anterior guidance angle do?
- Allows steeper cusps on posterior teeth
- Decreases the likelihood for Occlusal Interferences
What is group function?
When the mandible moves laterally, the outer inclines of the mandibular buccal cusps, on the working side, slide along the inner inclines of the buccal cusps of the maxillary posterior teeth, guiding the movement.
What is balance occlusion?
*Simultaneous contacts on both sides (working and non-working) during lateral excursive movements (working side contacts and balancing side contacts)
*Contacts between the posterior and anterior teeth during protrusive movement
Is balanced occlusion acceptable for dentate patients?
NO
What are the cons of balanced occlusion?
*not acceptable for dentate pts *promotes tooth wear on natural teeth
* non-working side contacts are extremely destructive and must be avoided
Balanced occlusion can be an acceptable form of occlusion for…
removable prostheses
What does malocclusion lead to?
*Lack of posterior occlusion
*Significant wear of maxillary and mandibular anterior teeth
*Mandibular anterior teeth are supraerupted
*Posterior teeth are supraerupted
What is the plane of occlusion?
an imaginary surface that touches the incisal edges of the incisors and cusp tips of the occluding surfaces of the posterior teeth
What is the shape of the plane of occlusion?
It is not flat(teeth are positioned in the arches at varying degrees of inclination)
* Concave on the mandible and Convex on the maxilla
What is an occlusal interference?
any unwanted or premature interocclusal contact
What are examples of occlusal interferences?
⚫Centric Interferences
⚫Working side Interferences
⚫Non-Working side Interferences
⚫Protrusive Interferences
What can happen with protrusive interferences?
*Potentially destructive
*Interfere with the patient’s ability to incise properly
*Involve mesial inclines of mandibular posterior teeth and distal inclines of maxillary posterior teeth
*Disruption of normal muscle function
What can happen with working interferences?
*Posterior teeth
*Same side as the direction that the mand moves (working)
*Disclude anterior teeth = an interference
*Involve maxillary buccal cusps and mandibular buccal cusps and/or
maxillary lingual cusps and mandibular lingual cusps
What are working interferences?
*Posterior teeth
*Same side as the direction that the mand moves (working)
What can happen with non-working interferences?
*Opposite to direction of movement
*Particularly destructive in nature
*Potential for damage attributed to:
1.changes in the mandibular leverage
2.forces outside the long axes of the teeth
3.disruption of normal muscle function
*Involve maxillary lingual cusps and mandibular buccal cusps
What is important to know about occlusion when fabricating an RPD?
- Ensure adequate interarch/interocclusal space with a suitable occlusal plane
- Establish, when possible, favorable occlusal schemes using sound occlusal principals (anterior guidance, canine guidance, eliminate occlusal interferences)
- For most situations, maintain the existing occlusal vertical dimension