Occlusal Considerations Flashcards
Optimal Functional Occlusion
baseline for evaluating patients occlusion: (4)
Teeth
TMJ
Musculature
EVALUATE THE ENTIRE MASTICATORY SYSTEM
Occlusion for Direct Restorations
Goals (4)
Minimize trauma to supporting structures and teeth
Preserve/maintain remaining structures including the existing
occlusal scheme
Promote longevity of the restoration
Restore mastication to a reasonable level
In most clinical situation: occlusal contacts on direct restorations
(amalgam alloy and composite resin restorations) are created to be
in
harmony with the existing occlusion (MIP & excursive movements)
Occlusion (definition)
The static relationship between the incising and masticating
surfaces of the maxillary and mandibular teeth or tooth analogues.
Articulation (definition)
The static and dynamic contact relationship between occlusal surfaces
of teeth during function.
Teeth relations in
OPTIMAL FUNCTIONAL OCCLUSION (2)
In stationary position
During excursive movements
TheTEETH
(foroptimalfunctionalocclusion)
Stationary Position
Posterior Teeth: (2)
Multiple, even, bilateral, and simultaneous
occlusal contactswith the mandible in the
CR position, are the most desirable.
The posterior teeth are loaded mainly along the long axis of the tooth (axial loading).
Axial Loading
Forces are directed over the long axes of teeth. Teeth and their periodontal
ligaments are best designed to absorb forces along the long axes.
Failure to achieve axial loading: (3)
Forces could eventually cause cracks, fractures, and wear on the teeth. Trauma to supporting structure: periodontal ligament and surrounding bone Possible trauma to the temporomandibular joints and TMD disorders
The TEETH
(for optimal functional occlusion)
Stationary Position
Anterior Teeth:
Anterior teeth should have LIGHTER occlusal
contacts when the posterior teeth are in occlusion.
Since the anterior teeth are not loaded axially,
they are not able to withstand high loads.
In Excursive Movements, optimal occlusal relationships are: (2)
Canine Guidance and
Anterior Guidance
Right Lateral Movement
LATEROTRUSIVE SIDE
The canines on this side guide the
movement (teeth with long roots and away
from the fulcrum area)
Right Lateral Movement
MEDIOTRUSIVE SIDE
No teeth should contact on this side (if they
did, they would have off-axis loading)
If in excursive movements, canine guidance and anterior guidance
are not present, then — are present.
OCCLUSAL INTEFERENCES
Occlusal Interference:
an unwanted (or premature) interocclusalcontact
Interocclusal Contacts
Two Philosophies
Cusp-Fossa contacts
Cusp-Marginal Ridge contacts
Each functional cusp occludes in a fossa
of the opposing tooth (2)
Tooth to tooth arrangement
Used when restoring both
opposing quadrants of teeth
Each Functional cusp contacts the marginal ridges
of opposing pair of teeth or fossae of opposing teeth (3)
A one tooth to two teeth arrangement
The majority ofnatural dentitions have this type
Commonly used for single restorations
The cusp-marginal ridge occlusal relationship allows for
some
cusps to occlude onto marginal ridges and some others to occlude
into fossae.
The cusp-fossa relationship allows only for
each cusp to occlude
into one fossa.
Four inclines are present on all cusps:
facial, lingual, mesial, and distal
Distal
Cusp
Ridges (2)
Outer (buccal) slope of
buccal cusp (buccal
contour ridge)
Outer (lingual) slope of
lingual cusp (lingual
contour ridge)
Mesial
Cusp
Ridges (2)
Inner (lingual) slope of buccal cusp (triangular ridge of buccal cusp)
Inner (buccal) slope of lingual cusp (triangular ridge of lingual cusp)
Create a plateau, halfway up a cuspalincline, that is perpendicular to the long axis of the tooth, to serve as a cusp seat.
These areas are not in the “normal” location of cusp seats,
they will still create long axis forces on the teeth.
Mark the occlusal contacts on the teeth using
articulating paper
Accu-Film II
Use — — to evaluate occlusal contacts
shim stock
Occlusal adjustments: (3)
small football-shaped carbide bur in a high-speed handpiece
lightly running the rotating bur over the tooth
remove only the center of the mark (bulls eye)
Anterior Teeth
Protrusion (2)
Mandible moves forward
Anterior teeth guide the movement
