4 requirements for diagnostic casts….
- Must be accurate reproduction of both arches
- Should contain no bubbles
- Should contain no positive nodules on occlusal surfaces.
- Questionable impressions and casts should be discarded.
What are the 2 schools of thought regarding articulator design?
Geometric (Non-anatomic) = teeth guide movement
Condylar (Anatomic)
- Average value instruments
- Adjustable condylar guides
Describe the equilateral triangle theory….
- Condyle to condyle = 10cm
- Condyle to incisor = 10 cm
- Makes bonwill triangle
Describe the Balkwill angle…
Angle formed btwn the occlusal plane and the Bonwill triangle. *about 26 degrees
Center of curve of spee is where?
@ the level of the mid orbital plane.
What is Christensen’s Phenomenon?
Space formed between maxilla and mandible during protrusion of mandible.
*Christensons articulator proved protrusion can occur along a curved path.
What is monsons spherical theory?
Center of rotation is in the sella tursica.
What is curve of speed and wilson?
Spee is posterior to anterior
Wilson side to side
Describe Halls conical theory of mandibular movement…
The external occipital protuberance was considered as the anatomic rotation.
