try in phase Flashcards
How is the occlusal balance maintained?
Via two compensation curves-
An antero-posterior curve
A lateral curve
What is a balanced occlusion?
The first point of contact in centric relation
As many teeth as possible should be in contact evenly
Intercuspal positon=retruded contact position
What is balanced articulation?
Desirable to have multiple contacts during movement
Stops dentures from tipping
What are the two compensating curves?
Curve of Spee
Curve of Monson
What is the Curve of Spee?
Antero-posterior compensating curve
Maintains mesio-distal contact when mandible is protruded
What is the Curve of Monson?
Lateral compensating curve
As many contacts as possible during right and left excursive movements
What do tooth characteristics involve?
Arrangement- degree of rotation, spacing, irregularities
Shade- overall, local
~age appropriate, lighter than normal etc.
Shape- overall, local
~oval, tapered and square
How might tooth arrangement be considered?
Midline diastema?
Retroclined central incisors?
Subtle diastema between central and lateral incisors?
How might gender relate to tooth shape?
Female- often oval
Male- often square
Both- tapered
How much tooth should be visible?
Older patients have a more lax musculature so less gingival exposure
Difficult to reproduce young look
Should be according to facial expressions
What shape should the upper incisors run?
They should curve and be parallel to the lower lip line
What if there’s an error in vertical jaw relations?
If small-
Adjust on articulator pin, + or - occlusal vertical dimension (OVD)
What if there’s an error in antero-posterior relationship?
Remove teeth and replace w wax before re-recording occlusal relationship
How do you re-record the registration?
Hold lower jaw firmly
~index fingers buccal to lower 456 region and thumbs under chin
Manipulate into centric relation and slowly close
How much of the lower teeth should be visible?
During speech and smiling should be able to see the tips
How can you check for overextensions?
Cheek traction
~press gently on occlusal surface whilst pulling on cheek, if moves, it’s overextended
What if there’s an error in the neutral zone?
Denture may be displaced
The lower anterior teeth need to be set ahead of the underlying ridge
What if the tongue is cramped?
There may be lingually inclined molars so the tongue can displace the denture
Where should the lower sevens be on the denture?
Should not be placed on the ascending ridge
If so, replace with retromolar pad acrylic
How should buccal fat pads be considered?
Sevens may be removed to prevent trauma during function
What is a post dam?
A raised ridge on the posterior border of the upper denture so there’s an air-tight seal anterior to the soft palate
Why is a post dam needed?
During packing and flasking there is a degree of polymerisation shrinkage
This affects the posterior border fit
Why is mapping the post dam key to retention?
Each patient is different
Compressibility is different in different areas
Bad post dam=bad seal
How do you mark the post dam?
Patient say aaaahh
See where vibrating line is
Mark w indelible pencil
Palpate w ball or pear burnisher to see which tissues are compressible
Mark more than one if retching or poor tolerance
Acrylic between two dams as thin as possible
How deep should the post dam be?
The more compressible the tissue, the deeper the dam
