Occlusion Flashcards
definition of a stable occlusion
One in which occlusal contacts help to limit the possibility of tooth movement (drifting, tipping, over-eruption)
what is ICP
-describe this in terms of which teeth are contacting
The position of “best fit” between the maxillary and mandibular teeth (therefore, a position determined by the teeth)-The position which the mandible aims for at the end of the chewing cycle
-On posterior teeth, the lower buccal cusps and upper palatal cusps occlude against the fossae and marginal ridges of the opposing teeth
The lower incisal edges and canine tips occlude against the cingulum area of the opposing teeth
movement of working and non working sides
Working - Rotation
Non working - downward/forward/translation
name 3 forms of guidance and what teeth are involved
Anterior Guidance (Canines and Incisors)
Group Function (includes posterior teeth)
Balanced Articulation (complete dentures only)
describe anterior guidance
Anterior Guidance:
in excursions one or more anterior teeth contact and there is immediate “disclusion”of all the posterior teeth
describe group function
Group Function:
in excursions a number of teeth on the working side
contact and there is disclusion of teeth on the
non-working side
parafunction effect
Purposeless clenching and grinding of the teeth
Forces exerted are greater and of longer duration than during function
Contacts may occur in many positions of the mandible
Forces may be horizontally directed
Protective neuromuscular reflexes do not operate
Damage to the teeth, the periodontium, the muscles and joints may result
name some tooth positions
Retruded Contact Positon • Intercuspal Positon • Centric Occlusion • Edge to Edge • Protrusivecontact
name some jaw positions
Retruded Axis Posi:on • Maximum Opening • Centric Rela:on • Protrusion • Rest Posi:on
what is the rest position
Rela:onship of the mandible to the maxilla
when the patient is relaxed
and sitting upright
• Interocclusal clearance 2-3mm free way space
what is RCP
First tooth contact when the mandible is in
retruded axis positon
• Most superior anterior
positon of the condylar head in the glenoid fossa
what is a facebow and what does it record
Horizontal record of hinge axis of mandible
• A caliper-like instrument used to record the spacial relationship of the maxillary arch to some anatomic reference point or
points
• This relaConship is transferred to an articulator
• Facebow orients the maxillary cast in the same relationship
to the opening axis of the articulator
• Customarily the anatomic references are the mandibular
• condyles transverse horizontal axis and one other selected
anterior point
what measurement value for the reference plane locator
inferior orbital margin? - 43mm above lateral incisor
- how to mount an upper cast
- how to mount a lower cast
Upper cast - Facebow
Lower cast - registration
what to organise to:
Reorganised approach
Conform approach
Reorganised - RCP
Conform - ICP
when to use wax as a registration material
When there are enough teeth and the bite in ICP is obvious you don’t need wax. • If too much wax is used and the lower cast is mounted like this the OVD will be increased and the restoration will be high in the bite whenplaced. • When using wax you must ensure it is thin and cusp contact points are visible
when to use registration paste
When ICP wont be obvious to the technician • Silicone paste that sets quickly • A small amount is needed • Too thick and it will increase the OVD • Occlusal contacts must be visible through the material
acceptable articulator choices
semi adjustable
average value
what are the average values (of an average value articulator
- Sagittal Condylar Guidance Angle 30 degrees
- Bennet Angle 15 degrees
- Incisal Angle
What is the sagittal condylar guidance anlge
-what record is needed to set it
the angle at which the condyle descends down the glenoid fossaof the TMJ in the saggital plane
-protrusive record edge to edge
what is the bennett angle
angle decribed by orbiting angles during lateral protrusive movements
-distance the NW condyle moves medially measured in degrees compared to a straight path
what tooth/tooth contact occurs on the:
- NW side
- Working side
- NW - dissimilar cusps contact
- Working - similar cusps contact
what is centric occlusion
occlusion of opposing teeth, when mandible is in centric relation
what is centric relation
The maxillo-mandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disks with the complex in the anteriorsuperior position against the shapes of the articular eminencies. • This position is independent of tooth contact. • It is restricted to a purely rotary move- ment about the transverse horizontal axis
what is the retruded contact position
• That guided occlusal relationship occurring at the most retruded position of the condyles in the joint cavities. A position that may be more retruded than the centric relation position
what is the retruded axis position
The position the mandibular condyle adopts during the terminal hinge movement of opening or closing. See also hinge axis. • Anterior superior position of the condyle within the fossa
all dentures are made along what part of posselts
retruded arc of closure (Centric relation)
what aspects make up mutually protected occlusion
- canine guidance
- posterior disclusion in lateral excursion
- no NW/W side contact
- no protrusive interference
what are occlusal interferences
undesireable tooth contactsthat may produce mandibular deviationduring close to ICP/hinder smooth form to or from ICP
how to get patient into RCP
Bimanual manipulation of mandible into RAP
• Patient asked to slowly close together un first tooth contact (RCP)
• Bite registration taken in this position (RCP/CR record)
• Diagnostic wax up of normal anatomy of teeth in this position
• Vacuum form stent made on the wax up.
• Stent used as a template to try in planned changes with Protemp
