“Ideal Occlusion; Mutually Protected Occlusion” Flashcards
(19 cards)
Ideal Occlusion:
When are MIP and CR coincident?
when the teeth meet in MIP, the condyles are in the CR position
What is the ideal occlusion also called mutually protected occlusion?
⚫ MIP and CR are coincident
⚫ The patient has multiple, bilateral, even and simultaneous contacts in MIP/CR.
⚫ The patient has “light occlusal contacts” on the anterior teeth in MIP/CR. (due to angulation of dif. planes…ex: sag.)
⚫ The patients has anterior guidance in protrusion and lateral excursive movements
What are the four types of occlusal interferences?
⚫ Centric Interferences
⚫ Working side Interferences
⚫ Non-Working side Interferences
⚫ Protrusive Interferences
an unwanted or premature interocclusal contact
Occlusal Interference
premature contact occuring when the condyles are manipulated into CR
-in general only one, maybe two teeth will contact
–once this occurs, the mandible moves forwards and upwards (and usually slightly laterally) into MIP
Centric Interference
What teeth does centric interference occur on?
the mesial inclines of the maxillary teeth and distal inclines of the mandibular teeth
Name the interference:
Centric Interference
The anterior guidance (canine guidance) during lateral excursion happens on which side: working or nonworking?
working side
no other teeth on working or nw side should contact
non-working condyle=balancing condyle
No other teeth on the working or non-working side should contact besides the ______ during a lateral excursion?
canine
Where does the working side interference occur?
Occur between maxillary and mandibular posterior teeth on the working side as the patient makes a lateral movement.
What can happen if the working side interferences are too heavy?
disclude the anterior teeth and interfere with the smooth harmonious movement of the NWS condyle
What is a non-working side interference?
Any contact between the maxillary and mandibular teeth on the non-working side (side opposite to which the mandible moves) as the patient makes a lateral movement.
What is the most destructive type of all interferences?
non-working side interferences
They change the lever system of the mandible and place considerable stress on the TMJ joints
On what inclines do non-working side interferences occur?
On the NW side between the inner inclines of the maxillary lingual cusps and the inner inclines of the mandibular buccal cusps
On what inclines do the working side interferences occur?
- Between the outer incline of the mandibular buccal cusp and the inner inclines of the maxillary buccal cusp
and /or - Between the outer inclines of the maxillary lingual cusps and the inner inclines of the mandibular lingual cusps
What are protrusive interferences?
Any contact between the posterior teeth as the mandible moves forward in protrusion
can be so severe it will prevent contact between anterior teeth
What can happen if protrusive interferences are very severe?
it could prevent contact of the anterior teeth
Why are protrusive interferences so destructive?
they are positioned close to the fulcrum (TMJs) and the resulting source of power (muscles) is large and destructive forces
On which inclines do protrusive interferences occur?
Between the mesial inclines of the mandibular cusps and the distal inclines of the maxillary teeth (posterior)
between posterior teeth
