Opening
Opening
Opening
Opening
Posselt’s Figure
Posselt’s Investigations
Posselt’s Investigations
Posselt’s Figure
MP
MO
ICPRCP
HA
MP = Maximal protrusionICP = Intercuspal positionRCP= Retruded Contact position HA = Hinge axisMO = Maximum opening
Posselt’s Figure
Posselt’s Figure – top edge
RCP
ICP
IG
EE
MP
Definitions
Articulators– A mechanical representation of the jaws and
temporo-mandibular joints
Articulators– A mechanical representation of the jaws and
temporo-mandibular joints
Use of articulators
Diagnosis• slides and occlusal relationships
Treatment planning • Diagnostic wax - up• Occlusal adjustment
Fabrication of Splint / Prostheses
Diagnosis• slides and occlusal relationships
Treatment planning • Diagnostic wax - up• Occlusal adjustment
Fabrication of Splint / Prostheses
Articulators
Types
– Simple Hinge– Average Value– Semi-adjustable– Fully adjustable
Types
– Simple Hinge– Average Value– Semi-adjustable– Fully adjustable
Articulators
Cast Holder
Cast Holder
Average Value
Articulators
4”
4”
BONWILL 1854
Articulators
Average ValueAverage Value
4”
4”
Articulators
Average ValueAverage Value
Articulators
Denar II - Arcon
Dentatus
Non ArconNon Arcon
Denar II
Adjustable Condylar Angle, ISS & PSSAdjustable Condylar Angle, ISS & PSS
Articulators
Semi-adjustable
Can alter;• TMJ to Incisor
distance• Bennett Angle• Condylor Guidance
Angle• Incisal guidance plate
Articulators
• Needs Facebow recording
• Ideally should be used for complete denture cases
Facebow recording
For semi adjustable articulator
Fully adustable: Denar 5
Posterior wall
Superior wall
Medial wall
Inclination of superior wall
Condylar angle
Intercondylar (& glenoid fossa) distance
ISS
Posterior wall
Superior wall
Medial wall
Inclination of superior wall
Condylar angle
Intercondylar (& glenoid fossa) distance
ISS
Denar 5a
Pantographic recording
For fully adjustable articulator
Difficultyofuse
HandHeld
AvValue
S-A FullyAdjustable
lots
none
HandHeld
AvValue
S-A FullyAdjustable
Amount of adjustment
lots
none
lots
Cost
HandHeld
AvValue
S-A FullyAdjustable
none
Articulator use vs time vs cost
lots
Difficultyofuse
Cost
HandHeld
AvValue
S-A FullyAdjustable
Amount of adjustment
none
lots
none
What if patient doesn’t match articulator?
Articulator
Patient
Articulators
ArticulatorsTherefore the distance from the condyle to the teeth is crucial
We obtain a measurement of this distance with a facebow
Facebow
Interocclusal recordUsed to locate the lower model to the upper
If lots of good stable occlusal contacts then no IOR needed
If need an RCP record, then we need an IOR that is thick and strong enough to obtain a record with the teeth separated and in terminal hinge axis e.g. Moyco Extra Hard Beauty wax
For routine ICP records when carrying out multiple crowns / bridgework, Blu-mousse just over the tooth preps is usually sufficient
Used to locate the lower model to the upper
If lots of good stable occlusal contacts then no IOR needed
If need an RCP record, then we need an IOR that is thick and strong enough to obtain a record with the teeth separated and in terminal hinge axis e.g. Moyco Extra Hard Beauty wax
For routine ICP records when carrying out multiple crowns / bridgework, Blu-mousse just over the tooth preps is usually sufficient
Aids to obtaining THA
Bimanual manipulation
Cotton wool rolls
Anterior “jig”
Splint therapy
Chin-point guidance
Bimanual manipulation
Cotton wool rolls
Anterior “jig”
Splint therapy
Chin-point guidance
Anterior jig
Cold-cure acrylic (Duralay/Trim)
Greenstick
Cold-cure acrylic (Duralay/Trim)
Greenstick
Anterior jig (trimmed)
Provides inclined planeProvides inclined plane
Separation of posterior teethAllows the use of easy flowingocclusal recording mediasuch as Blu-Mousse
Anterior Jig
From Howatt, Capp & Barrett
Clinically useful settings for articulator
Condylar angle 25°
Immediate side shift 0.3mm
Progressive side shift 6°
Condylar angle 25°
Immediate side shift 0.3mm
Progressive side shift 6°
Incisal guidance table
Allows shape of palatal to be reproduced
Allows length of incisors to be maintained
Allows shape of palatal to be reproduced
Allows length of incisors to be maintained
Tooth to be prepped
Shape created isthe inverse of Posselt’s figure
Following tooth prep
Tooth form reconstructed
Summary
The choice of articulator depends upon such factors as;
– Intended use - Skill of the technician– Availability of equipment - Expense– Patient's occlusion - Skill of the operator
– The more closely the articulator matches the patients anatomy, usually the better the outcome and the less adjustment is required at chairside on fitting prostheses.
The choice of articulator depends upon such factors as;
– Intended use - Skill of the technician– Availability of equipment - Expense– Patient's occlusion - Skill of the operator
– The more closely the articulator matches the patients anatomy, usually the better the outcome and the less adjustment is required at chairside on fitting prostheses.