Articulators Flashcards
Pantograph
What is it
What is it used with
used in conjuntion w/ fully adjustable articulators to adjust condylar elements to follow tracings obtain intraorally
Arcon vs non-arcon
Arcon: condyles connected to lower member
non-arcon: condyles connected to upper member
With the face bow transfer, which cast is mounted first?
Maxillary
Significance of earbow transfer
Relates max cast to hinge axis
Orients max cast in space
Aligned parallel to interpupillary line (horizontal)
Permits max cast mount on semi adjustable
Allows mand. cast to be mounted
Orienting max cast in space is particularly important when?
Whenever extensive anterior restarations are done
How should the relationship of the mandible to the maxilla in terminal hing position be obtained?
Without tooth contact
How to manipulate mandible into CR
Chin point guidance
anterior deprogrammer
Bimanual manipulation
Which is worse, doing a poor job of equilibration or leaving malocclusion
Doing a poor job of equilibration
What types of movements do anterior teeth guide and what is the purpose
Excursive movements so that posterior teeth are not contacting each other in lateral or protrusive movement
Equilibration procedures (4)
- Reduce structure interfering w/ closure
- Reduce structure interfering w/ lateral excursions
- Reduce structure interfering w/ protrusive excursions
- Harmonization of anterior guidance
Most failures in equilibration come from
improper mandible manipulation
Grinding rule to correct anterior slide (arc of closure)
Mesial inclines of
Upper
Distal inclines of
Lower
Grinding rule to correct deviation toward buccal (line of closure)
Buccal incline of
Upper
Lingual incline of
Lower
Grinding rule to correct deviation toward lingual (line of closure)
Lingual incline of
Upper
Buccal incline of
Lower
Grinding rule to correct Non working interferences
Buccal inclines of
Upper
Lingual inclines of
Lower
Grinding rule to correct working interferences
Lingual inclines of
Upper
Buccal inclines of
Lower
Patients with large horizontal overlap will benefit more from ______ than _______
Group function than anterior guidance (usually preferred)
Eliminating protrusive interferences
Distal incline of
Upper
Mesial incline of
Lower
Needs for contouring teeth
Mechanical
Biological
Esthetic
Purpose of custom incisal guide tables
record existing guidance
protect wax patterns
Non working condyle travels
Horizontal plane: forward and medial
Frontal plane: downward and medial
Working condyle travels
Horizontal plane: Bennett movement (slight lateral translation)
Frontal plane: Upward and lateral
Which side is the working condyle
The mandible moves toward the side of the working condyle
Reproducing habitual arc of closure
Not able to
Posterior determinants of mandibular movement (3)
Incincation of articular eminence
Medial wall of glenoid fossa
Intercondylar distance
Anterior determinants of mandibular movement (2)
Horizontal overlap of anterior teeth
Vertical overlap of anterior teeth
Other determinants of mandibular movement (3)
Occlusal plane
Curve of spee
Neuromuscular response
Increased horizontal overlap requires
Decreased horizontal overlap requires
shorter cusps
Longer
incisal guidance vs articular eminence influence with angle
steeper angle=more articular eminence influence
Rule of thirds
Selective grinding: central groove third
Fixed prost: middle third
Orthodontic treatment: cusp tip third
Triangle
Bonwill’s equilateral triangle
Angle
Balkwill angle
26 degrees
Between occlusal plane and Bonwill triangle
Sphere
Monsons’ spherical theory
Cone
Hall’s conical theory
External occipital protuberance is center of rotation for mandible
