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55 Cards in this Set
- Front
- Back
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ROTATIONAL MOVEMENT
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rotation is movement between the superior surface of the condyle and the inferior surface of the articular disc. In each plane it occurs around a point, called the axis
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Rotational movement of the mandible can occur in all three reference planes:what are they
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1) horizontal, (2) frontal (i.e., vertical), and (3) sagittal.
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horizontal rotation
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basic opening and closing of the mouth
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vertical rotation
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one condyle moves anteriorly out of the terminal hinge position with the vertical axis of the opposite condyle remaining in the terminal hinge position. (A twist)the anterior pterygoid muscle contracts
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sagittal rotation
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this is the rotation that occurs when you have food on one side of the mouth and not on the other. One side of mandible is lower than other
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Occlusal table
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Represents 50-60% of the BL dimension
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outer inclines
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outer = 1/3 buccal (supporting cusps)
outer = 1/6 lingual (guiding cusps) inner inclines consist of occlusal table |
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Plane of occlusion
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A plane determined by imaginary line connecting buccal and lingual cusp tips and incisal edges of mandibular teeth
determined by the inclincations of the teeth |
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two types of planes of occlusion
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sagittal- curve of spee
frontal(coronal)- curve of wilson |
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Tooth angulation (inclination)is based on what
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based on crown position as opposed to root.
if crown tilts lingual it is a lingual angulation |
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inclination of manidibular posteriors
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lingual
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Maxilla tooth angulations from sagittal
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-anterior: facial
-posterior: mesial |
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mandibular tooth angulations from sagittal
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-anterior: facial
-posterior: mesial |
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Tooth Inclinations
Largest : Mesio-distally |
Max. Canine 17 degrees
Max. 1st Molar 14 degrees Mand. 2nd Molar 14 degrees |
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Tooth Inclinations
Largest : Facio-lingually |
Max. Incisors 27 degrees
Max. 1st/2nd Molars 20 degrees Mand. 1st/2nd Molars 20 degrees |
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Tooth Inclinations
Smallest : Facio-lingually |
Max. Premolars 5-6 degrees
Mand. Premolars 9 degrees |
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Tooth Inclinations
Smallest : Mesio-distally |
Mand. Laterals 0 degrees
Max and Mand Centrals 2 degrees |
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all teeth have facial inclination
except |
Mand. 2nd Premolar
Mand. 1st Molars Mand. 2nd Molars |
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Arch length
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Distance from the distal of a 3rd molar, going mesially through the proximal contacts, to the distal surface of the opposite 3rd molar.
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Arch width
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the distance across the arch from lingual side to lingual side of opposite tooth
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Supporting cusps
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-Maxillary lingual and
mandibular buccal -maintain distance between maxilla & mandible = Vertical dimension of occlusion -located 1/3 the BL distance -Supporting cusps can contact on outside and inside |
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Guiding cusps
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-Maxillary buccal and
mandibular lingual -Relatively sharp -Located ~ 1/6th the BL distance -Only inner incline has potential for contact |
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Incisal Guidance
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a measurement of movement
the angle at which lower incisors and mandible must move from overlapping position (maximum intercuspation) to edge to edge relationship with max. incisors |
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Canine Guidance Angle of Students
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mean: 56.5 degrees
range: 0 - 84 |
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Cross bite
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the maxillary buccal cusps rest on opposing teeth
the mandibular lingual cusps rest on opposing teeth |
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Ginglymoarthrodial joint*
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the TMJ
made of two parts Ginglymoid = hinging Arthroidial = gliding -Considered compound joint* Even though it is not -Requires presence of at least 3 bones -TMJ made of only 2 bones |
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the TMJ landmarks
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the condyle sits in the mandibullar fossa of the temporal bone of the skull
posterior to articular eminance |
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Articular disc
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-serves as non-ossified bone
-FIBROUS CONNECTIVE TISSUE devoid of blood vessels or nerves (extreme periphery slightly innervated) |
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Diphyodont
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2 dentitions:
Deciduous Permanent |
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Heterodont
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Different types of teeth (morphologically)
Anterior Premolar Molar |
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Gomphosis
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a type of attachment
Socketed – root in alveolar bone Specialized tissues for attachment – pdl , cementum |
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lip-tongue-cheek system
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one of the forces that determines tooth position
-Lips and cheeks force: Constant light lingually directed forces -Tongue force: Labially and buccally directed forces -When forces equal - > NEUTRAL SPACE / position or normal occlusion |
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Proximal surfaces
– contact areas what do these do |
a factor that determines tooth position
-Help maintain normal alignment -Stabilize tooth within bony socket -Prevent food impaction -Protects interdental papilla Interdental col if Lack of contacts – mesial migration or mesial drift |
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MICP Rule
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-Max Teeth
occlude with ManD Namesake + D Neighbor -Mandibular teeth occlude with Max Namesake + M Neighbor |
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exceptions to MICP rule
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man central (only max CI)
last tooth on max arch (only last molar on mand) |
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distal cusp of mandibular first molar lies where in MICP (an exception)
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obliques ridge of maxillary first molar
only buccal cusp of mandible that is not in MR or central fossa |
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lateral excursions are when what muscle contracts
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Rt Lateral Pterygoid = left lateral excursion
Left Lateral Pterygoid = right lateral excursion |
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when moving mandible to left which is orbiting condyle and which is rotating
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orbiting = right
rotating = left |
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when moving mandible left which is working side
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left
-Contraction of rt inferior lateral pterygoid (side of contraction is always non working side) |
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Border movements: Horizontal plane (baseball diamond)
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is in shape of baseball diamond with
CR= centric relation (home plate) ICP= intercuspal position (pitchers mound) 1 = left lateral (3rd to home) 2 = cont left lateral w/ protrusion (3rd to 2nd) 3 = right lateral (home to 1st) 4 = cont right lateral w/ protrusion (1st to 2nd) |
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jaw movement measurements
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right = 8-9
left = 8-9 protrusive = 8 |
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coronal plane border movements (shield)
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-top line is lateral movement
-there is a dip in top line showing canine rise (guidance) - length of shield shows opening of mouth (to max opening) |
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border movements of sagittal plane (sabertooth)steps
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-backside shows hing and rotation/translation (broken line)
-front shows closing from maximum opening(in protrusion) -cr to micp(is a line from top of broken line going up and forward, this is movement of mandible) -then line goes down from MICP to cusp to cusp -straight forward line showing protrusion across incisal edge -line up again showing sliding up maxillary facial side with lingual side of mandibular incisors -straight line to link up front with top showing maximum protrusion - |
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label sagittal plane border movements
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1. posterior opening border (this is the break in the back line and shows the most retrusive position on mandible)
2. anterior opening border (this is the front line and shows most protrusive position of mandible from open (bottom) to close (top)) 3. Superior contact border (this is decided by occlusion of teeth and is straight line showing tip to tip position) |
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direction of mandibular supporting cusps over maxillary teeth during lateral excursion (working and non working)
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-buccal on working side
-mesiolingual on non working side |
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direction of maxilalry supporting cusps over mandibular teeth during lateral excursion
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-lingual on the working side
-distalbuccal on non working side |
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Steps to name an incline plane
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1. determine what side of cusp the plane is on
2. link number 1 to the side of tooth the plane is FACING 3. list the name of the cusp example: mesiolingual incline plane of distal buccal cusp. |
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bennett angle
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path of the NON WORKING condyle in lateral translation
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immediate side shift
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from MICP to medial wall on NON WORKING side (A to B) in triangle
-a is center of condyle -b is medial wall -bigger ISS the bigger the bennet angle and movement -translation and rotation |
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progressive side shift
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along the median wall angle
on NON WORKING side -B to C in triangle -rotation only |
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Bennett Movement
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lateral translation on WORKING side
-rotational and translational |
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if given bennett movements, which side has larger bennett angle
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the side that has the smaller bennett movement
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Occlusal equilibration is based on what
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-Canine guidance, if not group guidance
-Stability -Forces along the long axis of tooth |
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where are the contacts for the mandible on the maxilla in MICP
where is an exception |
the dots on marginal ridges and central fossa.
the exception is Man 1 D goes in obliques ridge DB of Man molars is in CF of namesake MB lie in MR |
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contacts of Maxilla in MICP on mandible
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look at dots down middle
-MR-CF-MR-CF-MR ML of Max molar lies in CF |
