Transcript CD_files/15. Set Posterior Teeth Ling & Monopl

Setting Posterior Teeth
Set for Function
Philosophies of Denture Occlusion
 Many philosophies of arranging
denture occlusion
 No definitive scientific studies
prove one occlusal scheme clearly
superior
Rationale for Dalhousie Approach
 Principals to choose an occlusal scheme
 Based on clinical experience
 Dalhousie: two occlusal schemes :
• Lingualized Occlusion
• Monoplane Occlusion
Occlusal Schemes
Attempts to Stabilize Dentures
 Lingualized Occlusion:
Contacts on centered on
mandibular ridge minimizes
movement
 Monoplane Occlusion:
Lack of cusps minimizes
lateral forces on denture
Lingualized Occlusion
 Centric contacts are
maxillary lingual cusp to
central fossa / marginal
ridge
Based on the UCLA/IVOCLAR/ACP Series
Lingualized
Occlusion
 Anatomic teeth used in maxilla
 Better esthetics than
Monoplane
 Shallow cusped mandibular
teeth
 Forces centered over
mandibular ridge
Lingualized Occlusion
 No overbite
 May or may not have balancing
contacts in excursions
 Anterior teeth - must make at
least grazing contacts in
excursions
Lingualized Occlusion
 Maxillary anatomic (33°)
 Mandibular Teeth
 Steep Condylar Guidance
 Shallow cusped (Anatoline)
 Shallow Condylar Guidance
 Non-anatomic (Portrait 0°)
Denture Occlusion Options
Semi-anatomic
Non-anatomic
(balancing ramp)
Lingualized
(lingual contact)
Anatomic
Nonanatomic
Occlusal plane
Set mandibular premolars &
1st molar :
• Level with occl plane
• Centered over ridge
Line indicating the crest of the ridge
Balanced
Lingualized Occlusion
Maxillary anatomic opposing
Mandibular shallow cusp
If using a lingualized posterior
tooth form (Dentsply Anatoline)
• little or no Curve of Wilson
• lingual and buccal cusps of
level with plane of occlusion
15 degrees
Second molar elevated by ~ 15 ° from the occlusal
plane
Max. lingual cusps
contact central
fossae/marginal ridge
~ 1mm space
between buccal
cusps
Maxillary lingual cusps firmly contact
bilaterally simultaneously
Centric Position
Verify centric
No max. buccal cusp contacts in:
• Centric
• Lateral excursions
Working Excursions
Verify excursive contacts
Anterior teeth are in contact
during lateral excursions
Balancing Excursions
Note the balancing contacts
Effect of Mandible Moving
Downward During Excursions
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Maintaining Balancing
Contacts
 Change occlusal plane angle
 Increase compensating curves
 Increase cusp angles
Achieving Balance
• Condylar angulation
 Recorded with protrusive record
• Cusp angle
 Selected by dentist
Achieving Balance
• Occlusal Plane
 Determined by dentist with wax rims
• Curve of Spee & Curve of Wilson
 Controlled by inclination of teeth
Checking for Balance
Feels Smooooooth in
excursions
- Fingers on Maxillary Canines
- On Articulator
Assessing Balance
• Jumps or bumps are due to cusp tips
moving over other cusp tips, inclines,
marginal ridges
Occlusal Refinement
Occlusal Adjustment, Selective Grinding
 Set teeth as close to:
 Maximum intercuspation
 Balance
 All setups will need some adjustment
‘IIF’ Rule
IIF you have contacts on the Inner Inclines of
Functional cusps they are balancing contacts
B
L
B
Working
Contacts
L
Inner Inclines (inside of cusp)
Outer Inclines(outside of cusp)
Find the Balancing
Contact
Find the Balancing
Contact
What type of Contact?
What type of Contact?
What type of Contacts?
What type of Contact?
Assess
Contacts
 Centric Stops
 Excursions
Non-Balanced
Lingualized Occlusion
Maxillary anatomic opposing
mandibular non-anatomic
Mortar & pestle occlusion without maxillary
buccal cusp contact
Lack of mandibular cusp angles and no
attempt to balance the occlusion
No compensating curves
No overbite
No overbite
Magnitude of Overjet
Class I
More for Class II
patients
Class II
Magnitude of Horizontal Overlap
Class III
Class III patients
Little or no overjet
Setting the posterior teeth
• Teeth should end prior to the ascending
ramus
• Maxillary lingual
cusps contact central
groove/marginal ridge
of the opposing teeth
The horizontal
overlap
should be
ideal and
should be
sufficient to
prevent biting
of the cheek
and corner of
the mouth
Horizontal
overlap
• All maxillary teeth, with the exception of the lateral
incisors and cuspids, should be on the plane of
occlusion
Monoplane Occlusion
Monoplane Occlusion
 Cuspless teeth (0°) on a flat
plane with 1.5-2.0 mm overjet
 No cusp to fossa relationship
 No anterior contacts in
centric position
Monoplane Occlusion
 Eliminate cusps
 lateral forces reduced
 improves stability
 Simplifies tooth arrangement
Monoplane Occlusion
 No overbite
(would cause
tilting)
 Overjet of 2 mm is
used to create an
illusion of overbite
Monoplane Occlusion
 Excursions - may or may
not contact on balancing
sides
 Depends on condylar
inclination and other
aspects of the tooth
arrangement
Monoplane Occlusion
 Anterior teeth make contact
in excursions
 Modifications have been
proposed to minimize the
tilting potential:
 Balancing ramps
 Compensating curves
Monoplane Occlusion
without condylar influence
Monoplane Occlusion
Monoplane Occlusion
Advantages
• Technically easier to achieve
• Use when:
– Difficulty obtaining repeatable centric
records (muscle incoordination)
– Skeletal malocclusion (Class II, III)
– Severe residual ridge resorption
– Reduces horizontal forces
Monoplane
Occlusion
Disadvantages
• Poorer appearance
• Can be unstable if condylar
guidance is steep (posterior
teeth separate, leaving only
the anteriors in contact)
Monoplane Occlusion
 Clinical remount on an articulator
 Practice doing a clinical remount
Adjusting Monoplane
Occlusion
 Main adjustment is flat
 If heavy prematurity near
fossa, slightly shallow
fossa