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.