Occlusion 1 Flashcards
What muscles are involved in mandibular movement?
- Muscles of Mastication
- Involved in depression, elevation + lateral movements of the mandible - Suprahyoid Muscles
- Elevate the hyoid bone or depress the mandible
List the muscles of mastication (4)
- Temporalis
- Lateral Pteryogid
- Medial pterygoid
- Masseter
Function of temporalis
Elevates + retracts mandible
Assists in rotation
Function of lateral pterygoid
- Lateral movement + protrusion + depression
Function of medial pterygoid
- Elevates mandible
- Lateral movement + protrusion
Function of the masseter
- Elevates + protracts the mandible
- Assists in lateral movement
What are the 2 main mandibular movements?
- Rotation
- Translation:
- Lateral translation
Occlusal vertical dimension
Teeth clenched together
Resting vertical dimension
Resting position of TMJ
- Mouth slightly open, lips together and teeth not in contact
What type of movements occur in rotation?
Hinge movements
- Rotation of the condylar heads
Function of a facebow (2)
Recording relationship of maxilla to:
- Terminal hinge axis
- Distance between the condyles
Translation of the condyle steps (4)
- Lateral pterygoid contracts
- Articular disc + condyle begin to move
- Travels downwards + forwards along the incline of the articular eminence
- May also travel laterally (laterotrusive movement)
What does posselts envelope show? (3)
Border movements of the mandible in the:
- Frontal plane
- Sagittal plane
- Horizontal plane
What do the:
- Letters
- Lines
In Posselts Envelope relate to?
- Letters
- Tooth positions - lines
- Jaw position
What does:
ICP E PR T R RCP
Stand for
ICP - Intercuspal position
E - Edge to edge
PR - Protrusion
T - Maximum opening
R - Retruded axis position
RCP - Retruded contact position
What is ICP? (3)
- Comfortable bite
- Max interdigitation of teeth
- Can be called centric occlusion
What is edge to edge? (2)
- Teeth slide forward from ICP guiding on palatal surfaces of anterior teeth
- Incisal edges of upper and lower incisors touch
If edge to edge and theres space between posteriors what does this mean?
Anterior guidance
If edge to edge and theres no space between posteriors
Grouped function
What is protrusion?
- Condyle moves forwards and downwards on articular eminence
Tooth contacts in protrusion (3)
- Only incisors +/- canines
- No posterior tooth contacts
- Eventually no tooth contacts
What is maximum opening? (3)
- No tooth contacts
- Mouth wide open
- Full translation of condyle over the articular eminence
What is retruded axis position? (3)
- No tooth contacts
- In the most superior anterior position of the condylar head in the fossa
- Terminal hinge axis
What is retruded contact position?
First tooth contact from retruded arch of closure
What position do we aim to make most restorations in?
ICP
What 2 sides make up lateral translation?
- Working side
- The side the mandible moves to - Non-working side
