W7 - Practice Flashcards
What is centric relation?
a maxillomandibular relation independent of tooth contact, in which the condyles contact the posterior slope of the articular eminence in an upper-anterior position.
In this position “ Centric relation”, which movements can the mandible initiate?
- only perform rotational movements
-> but from this tension-free, physiological maxillomandibular position, vertical, latero- and protrusion movements can be initiated.
What is Centric occlusion?
The contact of antagonistic teeth in centric relational condyle position is called centric occlusion, which does not necessarily identical with the intercuspidation position
-> The centric occlusion is therefore nothing, but the first tooth contact created in the central position of the articular heads.
What is Postural rest position of the mandible?
The resting (postural) position of the mandible is the relationship between the upper and lower jaws when the head is upright, which is created as a balance between the antigravity tone of the muscles that raise and lowers the mandible and the force of gravity.
-> In this position, the joint heads are in a neutral, tension-free position.
What is Rest vertical dimension (RVD)?
- There’s no contact between the opposing teeth
- The interocclusal space between the dental arches can be measured (approx. 2-3 mm)
- It is recorded in relation to some measurement points of the face:
1/ Nasion - gnathion
2/ Subnasale - gnathion
What is Occlusal vertical dimension (OVD)?
- Rest vertical dimension (RVD) – interocclusal space
Identify 1 - 3
1: OVD
2: RVD
3: interocclusal/ freeway space
8 steps for Determination of the vertical dimension of CR
- Marking subnasale (nasion in the clinic!) and gnathion measuring points
- Setting rest vertical dimension (RVD) of the mandibule
- Registration of rest vertical dimension (RVD)
- Adjusting upper rim
- Adjusting lower rim
- Spatula try-in
- Fixing together the rims
- Determining aesthetic guidelines
