Articulators and Splints Flashcards
What are the four types?
Simple hinge
Average value
Semi adjustable
Fully adjustable
What is an articulator?
A mechanical hinge like device which stimulates movements of the mandible
Replication of the paths of movements of the TMJ
What is the simple hinge type of articulator?
Most basic type
Arbitrary arc of closure
Produces an even occlusal contact in a static position only
Cannot simulate excursions
What is the simple hinge articulator based upon?
Bonwills 4” equilateral triangle
What is an example of the average value articulator a?
Ash free plane 75 and dentatus ARS
What are the values for the average value?
Incisor : 10: horizontal plane
Condylance angle: 30: horizontal plane
Bennetts angle: 15: Sagittaal
What are the semi adjustable articulators?
Dentatus ARH non archon and Denark Mark 2 arcon
What are the angles measures in the semi adjustable?
Incisor: adjustable : horizontal
Condyla: set to patients protrusion wafer: Frankfort plane
Bennett: set to oateint later : Sagittaal
What is the fully adjustable type of articulator?
Denark D5A
Incisor: adjustable Condylar: set to pantographs Bennett: pantographs Inter condylar distance: adjustable width Pantographs: recordings transferable
What is the condylar guidance angle?
The angle created when the condylar path is compared to the Frankfort plane which is usually set at 30dgrees
What is the incisal guidance angle?
The angle formed with the horizontal plane by the line between the incisal edges of the maxillary and mandibular central incisors when the teeth are ICP set at 10 degrees
What is the Bennett angle?
This is the angle between the Sagittal plane and the path of the advancing condyle during lateral mandibular event as viewed along the horizontal plane
15degreees
What is arcon?
The condylar element on the lower member
Better for crown and bridge
What is non arcon?
The condylar element is on the upper member
More beneficial for denture construction
What are the advantages of Articulators?
Occlusal movements can be reproduced outside the mouth
Occlusal surfaces can be constructed out the mouth
Occlusion can be viewed from lingual aspects
Time saving
Convenient for patient
What are the uses of articulators?
Diagnosis Treatment planning Multiple crowns and bridge Reorganising the occlusion Occlusal splints eg Michigan
What can hand held casts do?
They can reproduce ICP
All excursions are governed by the teeth with no include of TMJ
But not accurate enough for multiple restorations
When are simple hinges useful?
For single crown but not popular
When are average values used?
In denture construction
T/F the semi adjustable articulators provide a better approximation to the retruded position
T
What articulator is used for fixed prosthesis ?
Semi adjustable articulators
When would you use ICP?
When only restoring a small segment of the arch and enough inter occlusal stops
When would you use RCP?
When having to restore larger parts of the occlusion
What is a Facebow? And when is it indicated?
An instrument used to record the relation of the maxilla to the hinge axis of the rotation of the mandible
Multiple crowns
Bridgework
Occasionally dentures
Reorganising occlusion
What do you use to set the condylar guidance angle on a semi adjustable articulator?
Inter occlusal Wafers
How thick are the wafers used to record the condylar guidance angle?
3-5mm thick
What happens with the wafers for the arcon vs non arcon?
When the wafer is removed and articulator is closed, the arcon articulator condylar guidance angle remains the same but non arcon the angle changes
T/F the fult adjustable articulators can reproduce a full range of movements?
T
What are used to record the mandibular borders in fully adjustable?
Pantographs paper or digital
What are thr two types of facebows?
Kinematic/hinge axis
Average
What are kinematic hinge axis facebows?
Facebow is attached to the mandible which is moved through the translational retruded arc
Ends of the bow have stylinwhich sit over the condylar head areas
Need a second now to record this transfer to the articulator
T/F the average axis Facebow is more commonly used?
T
Too time consuming for kinematic
What do the average facebows use for landmarks?
3 points
Anterior and posterior landmarks
How do you use the denar face bow?
- Mark 43mm dot from the incisal edge of upper right lateral
- Place hydro bite on to bite fork
- Centre bite fork in mouth and pt then bites
- Place the ear plugs into EAM and slide the the reference pin to number 2
- Then tighten screw
5.
What are Occlusal splints ?
Rigid or flexible appliances that overlay the occlusal surfaces of the teeth
When are splints used?
Tooth surface loss
- diagnosis
- prevention
- mangement
Bruxism
-control the noise but not a treatment
TMD
-not to be used for long term
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What are the functions of splints?
Alter occlusal forces Prevent wear and mobility of teeth Reduce bruxism and Parafunction Treat masticatory muscle pain and dysfunction Alter thr structural relationship of TMJ
What are the theories to how a splint works?
Clarke 1984 OMRTC -occlusal disengagement -maxilliomandibular realignment -restore vertical dimension -TMJ repositions -cognitive awareness
WHat is the occlusal disengagement theory?
Provide an ideal occlusion to reduce abnormal muscle activity
What is the maxilliomandibular realignments theory?
Assumes that ore existing mandibular positions were incorrect
What is the aim of the maxilla mandibular relaignemnt ?
Produce Neuronmuscular balance
What is the restored vertical dimension theory?
-Assumes patient has lost vertical height leading to abnormal muscle activity
What happens to the muscles in the restored vertical dimension theory?
Restored to correct length
What is the TMJ repositions theory?
Assumes condylar had needs to be repositioned in glenoid fossa
What adjunct is needed for the TMJ repositioning theory?
Need Radiograph to diagnose it
What is the cognitive awareness theory?
Having something in you mouth alters behaviour
PLACEBO
Which type of splint mechanism can be applied to all?
Cognitive awareness
What are the three groups of splints?
Relaxation
Repositions
Stabilisation
What are the types of relaxation splints?
Soft splint/POC
Localised interference splint
Anterior bite plane
Which type of splint is rarely used now?
Repositioning
What are Types of the stabilisation splint?
Michigan/stabilisation
Thermoform
What is the soft splint/POC made from?
Polyethene
Polyvinyl
VAccum formed
T/F there is no attempt to balance occlusion in the soft splint/POC ?
T
What can the soft splint/POC be used for and why?
First line splint and diagnostic aid in bruxism
Cheap and quick and easy
Simple alginate impression and no jaw reg needed
When are soft splint/POC usually worn?
At night
Which arch are soft splint/POC usually made?
Lower
But can be for either
What can happen in some peopl with soft splint/POC ?
May increase Parafunction so monitor
T/F soft splint/POC can be used over ful denture to increase face height?
T
What are LOIsplints used for?
Deliberately over load the proprioception fibres of four teeth and this provide neuromuscular feedback
May also remove posterior interferences as anterior teeth are separated
How do you make a LOIS?
Upper and lower alginate
Centric occlusion wax
Upper heat cured acyclic plate retained with Adams clasp or ball end clasp and then to occlusal ball end clasps on canine or premolar to interfere with Occluding
When would you use a LOIS?
Patient who bruxism or clench
Habit breakers
Short periods only
What is another name for ther anterior bite plane?
Lucia Jig
De programmer
What type of splint is the anterior bite plane, full or patprtial coverage?
Partial
Occlusal disengagement
T/F can make an anterior bite plane at chair side?
T can use autopolymersising acrylic
When are anterior bite planes used?
Acute muscle spasms
SHORT TERM
When shoud the anterior bite plane be used?
Not at night!!!!
How does the anterior reposition splint work?
Provides mandible
How do you make an anterior repositions splint?
Upper and lower alginate
Patient open wide until click heard
and then into protrusion no click heard
When In this protuding position no opening or closing clicks should be heard, at this point, record wax
When are anterior repositions splints used?
Patients that have internal dereangemtn
When should you not use an anterior reposition splint?
If the click does not disappear on protrusion
When shoud anterior repositions splints be worn?
Everyday
All day
Including eating
What should you advise with ant reporting splint?
Soft diet and review monthly
How long does it take for patient to become symptom free with anterior reposition splint?
6-12 weeks
Weaned off slowly
What is another name for a stabilisation splint?
Tanner
Michigan
Fox appliance
Centric relation appliance
What does the stabilisation splint provide?
Ideal occlusion
Anterior guidance which is free from posterior interference
RCP equals ICP
Which arch is the stabilisation splint made on?
The one with the most missing teeth
RECORD RJR/CR
How does the stabilisation splint retain itself?
Friction fit but can also be ball ended clasp
What should the stabilisation splint allow in centric occlusion?
Even contact with oppsing teeth
posterior balanced occlusion
What is the stabilisation splint useful for?
Determine the positi of centric relation in those that have deranged occluso
When should the stabilisation splint be made?
Night time
Review monthly
Weaned off
What are thermoformed splints?
Half way version between soft and hard splint
Made in hard polymer or laminate version
What are the determinant of occlusion?
Teeth
Left and right TMJ
Neuromuscular system
What is occlusion?
Any contact between opposing arches
It is static
What is another term for ICp?
Centric occlusion
Maximim intercuspation
What is ICP?
Position of the mandible when there is maximum intercuspation of oppsing teeth and fossa
Purely tooth related
Held on average for 17mins per day
What is another term for RCP?
Centric relation
Ligamentous position
What is RCP?
Position of the mandibl when tooth contact first occurs on retruded arc of closure
Where are the heads of the condyle in RCP?
Medically braced
Upper most
Unstrained
Where does RCP lie relative to ICP?
RCP is 1-1.5mm posterior to ICP
What is the working side?
Side to which mandibular movement is directed
What is non working side?
Side away from a mandible movement
The working side is also the ?
Bennett movement
What is anterior guidance ?
Path of guidance provided by the Palatal surfaces of the most anterior functional upper teeth during protrusion of mandible
What is canine guidance?
Path of guidance provided by Palatal surface of thr maxillary canoe teeth during lateral movement of mandible
What is disclusion?
Separation of anterior and posterior teeth during canine guidance
Separation of posterior teeth during anterior guidance
What is group function?
Articulation between posterior teeth On working side during lateral movement of the mandible
What is long centric?
Is a patient lacks anterior tooth contact in ICP they must protrude or move laterally before guidance teeth touch
If front teeth hit together as hard or harder than posterior teeth then there is no freedom in centric
Which patient have long centric?
Class 2/2 and crowns that are toot thick on plagal surfaces
What is an occlusal interference ?
Undesirable occlusal contact that May produce deviation of the mandible to and from ICP
What are centric interferences?
Premature contact that occurs when the mandible closes with the condyles in their optimum position in the glenoid fossa
What are working interferences?
Premature contact between the maxillary and mandibular posterior teeth on the same side of the arch as the direction of movement in lateral excursion
What are non working interferences?
Premature contact between the maxillary posterior teeth on the opposite side of the arches as the direction in which the mandible moves in lateral excursion
What are protrusive interferences?
Premature contact between the mesial aspects of mandibular pst teeth and distal aspect of maxillary teeth during protrusion
What is the optimum occlusion?
Condyles in Unstrained position in ICP
Molars in heavy contact in ICP
Anterior teeth in lighter contact in ICP
Occlusal forces dericted along long axis of teeth
In lateral movement working side guidance and no non working side interferences
In protrude movements anterior guidance and posterior disclusio
WHat is the confimratife approach?
Accepts ICP
What is the reorganised approach?
Makes ICP and RCP co incident
What are the features of a Michigan splint?
RCP equals ICP
Posterior disclusion
Canine protection
No non working side contacts
