Dynamic Occlusion (complete) Flashcards
What are the three planes in which mandibular movement is possible
- Sagittal (anterior/posterior)
- Horizontal (side to side)
- Frontal (up and down) (open close)
What are the two types of contacts caused by movements of the mandible
desirable and undesirable
what are interferences
undesirable contacts
What is an eccentric movement
any movement from maximum intercuspation resulting in tooth contact
what are the three types of eccentric movements of the mandible
- protrusion (anterior movement of mandible)
- retrusion (posterior movement of mandible)
- lateral excursive (side to side movement)
what is centric relation
not a tooth relationship, but a condyle-disk relationshipin which the muscles of mastication are most relaxed
What is centric relation contact
the initial tooth contact after centric relation
after a patient is in centric relation contact, what happens when they squeeze their teeth together?
the mandible will slide foreward or eccentrically depending on the position of the interference
what is occlusal adjustment
AKA selective grinding
the removal of any interference in Centric relation to obtain freedom in centric
what is selective grinding
AKA occlusal adjustment
the removal of any interference in Centric Relation to obtain freedom in centric
Does the Maxilla move
nope, only the mandible
What is protrusion
the mandible moving forward from MIP
What is MIP
maximum intercusptation
What is the desirable contact that occurs in protrusion of the mandible
contact only among the anterior teeth
What is anterior guidance
the way that a protrusive movement of the mandible is guided by the anterior teeth
What are the guiding inclines of the anterior teeth
the parts of the teeth that touch in anterior guidance
- Mx lingual fossa and incisal edges
- Md labial surface and incisal edges
What are the undesirable contacts in a protrusive movement
- the distal inclines of the maxillary lingual cusps against the mesial inclines of mandibular fossae and marginal ridges
- the mesial inclines of the mandibular buccal cusps against the distal inclines of maxillary fossae and marginal ridges
What are protrusive interferences
undesirable contacts that occur in protrusive movements
what happens with the working side condyle and the non-working side condyle in protrusion
both condyles move simultaneously forward and downward along the articular eminence
What are the desirable contacts in protrusion
- the facial surface and incisal edge of the mandibular incisors contacting the lingual fossa and incisal edge of the maxillary incisors
What is a retrusive mandibular movement
the mandible moving posteriorly from ICP (intercuspal position)
how far can a patient usually do retrusive madibular movement
only 1-2 mm
What are the undesirable contacts in protrusive movements
- the mesial incline of the mandibular distobuccal cusps contacting the mesial marginal ridge of the opposing maxillary tooth
- the distal incline of the Maxillary mesiolingual cusp contacting the distal marginal ridge of the opposing tooth
What are the desirable contacts in retrusive movements
there are none. No desirable contacts in retrusive movements
What are the undesirable contacts in retrusive movements
- the mesial incline of the maxillary mesiolingual cusps pass through the central groove then against the mesial marginal ridge on the man molar
- the distal incline of the mandibular distobuccal cusps pass through the central groove then against the distal marginal ridge on the max molar
in retrusion, what are the movements of both the working and non-working side condyles
they both move simultaneously back and upward into the mandibular fossa
Does the maxilla move
nope, only the mandible
What kind of contact normally occurs between the incisors during a lateral movement
they normally don’t contact, but if they do it is similar to the contacts in anterior guidance
what kind of contact normally occurs between the canines during a lateral movement
the distal cusp ridge of the mandibular canine contacts the mesial cusp ridges of the maxillary canine (sometimes)
What are the laterotrusive contacts
the guiding contacts of the canines in a lateral mandibular movement
the labial surface and incisal edges of mandibular canines against the lingual fossae and incisal edges of maxillary canines
When you move your mandible to the left, what guides the movement of the mandible
contacts between the upper and lower posterior teeth on the left side
when you move your mandible to the right, what guides the movement of the mandible
contacts between the upper and lower posterior teeth on the right side
when you move your mandible to the left, the left upper and posterior teeth guide the mandible. what parts of those teeth do you want to contact each other
you only want contact between the buccal cusps of both the maxillary and mandibular posterior teeth on the left side
what would be the problem if both the buccal and lingual cusps of the posterior teeth of both arches contacted when you move your jaw to the side
it would cause a lot of wear on the teeth
when moving your mandible to the left, what do you want to contact on the right side of the mouth
nothing! you only want contact between the buccal cusps of the posterior teeth on the side of the mouth toward which your mandible is moving
in lateral excursive movements, how do you distinguish between the working and non-working side
the working side is the side toward which the mandible is moving, and is the side on which you want the buccal to buccal contact
the non-working side is the side away from which the mandible is moving, and is the side on which you don’t want any contact
what are the desirable contacts on the working side in a lateral excursive movement?
the inner incline of the maxillary buccal cusps contacting the outer incline of the mandibular buccal cusps
What are the desirable passages on the working side in a lateral excursive movement
The Mx mesiolingual cusp passes through the lingual groove on the Md molar
The Md distobuccal cusp passes through the buccal groove on the Mx molar
is there supposed to be any contact between the lingual cusps on the working side in a lateral excursive movement
nope, on the working side the lingual cusps pass through the mandibular lingual and maxillary buccal grooves
What are the undesirable contacts on the working side in a lateral excursive movement
the outer incline of the lingual cusps of the maxillary molars with the inner incline of the lingual cusps of the mandibular molars
what do you call the non-working side contacts that occur in a lateral excursive movement
mediotrusive interferences
what is the contact that happens in mediotrusive interference
the inner inclines of the maxillary lingual cusps contacting the inner inclines of the mandibular buccal cusps
in which direction is the mandible moving on the working side in a lateral excursive movement
laterally
in which direction is the mandible moving on the non-working side in a lateral excursive movement
mesially
on the non-working side in a lateral excursive movement, where does the DB cusp of the Md 1st molar pass
through the supplemental groove mesial to the triangular ridge of the mesiolingual cusp of the maxillary first molar (parallel to the oblique ridge)
where does the ML cusp of the Mx 1st molar pass on the non-working side in a lateral excursive movement
through the DB groove of the Md 1st molar
what does the MB ridge of the Md 1st premolar contact
the distal cusp ridge of the Mx canine
what does the DB cusp ridge of the Md 1st premolar contact
the MB slope of the buccal cusp of the Mx 1st premolar
what does the MB cusp ridge of the Md 2nd premolar contact
the DB slope of the buccal cusp of the Mx 1st premolar
What does the DB cusp ridge of the Md 2nd premolar contact
the Mesioocclusal slope of the buccal cusp of the Max 2nd premolar
all ligual cusps of premolars are out of contact until when
until centric relation is attained
once centric relation is attained, the lingual cusps of which premolars will come into contact
the lingual cusps of the maxillary premolars (maybe even the distolingual cusp of the mand 2nd premolar when it is the 3 cusp type)
