| 1. Stable Skull only |
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Opening/Closing motion without muscles. |
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Purposes |
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Introduces centric relation. |
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Position of the condyle. |
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Function of the hard collagen disc. |
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Condyle fully seated when all teeth
contact simultaneously. |
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Opening/closing motion of jaw: |
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- rotation for first inch of opening. |
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- rotation + translation for wider opening. |
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Presenting |
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Begin by pointing out the two convex boney surfaces: condyle and anterior eminence and the relationship to the bi-concave articular disc. |
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Show the client how the red lines line up and the condyle is in its most upward position possible. |
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Explain that both of these need to occur to have a centric relation position. |
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As you open the mouth explain how the jaw merely rotates for about an inch of opening and than moves down and forward as the jaw opens further. |
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Notice how the disc travels smoothly with the two bones and maintains it’s shape and relationship throughout all movement. |
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As you close the jaw point out how the jaw and disc fully seat and assume the original shape and position. |
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Point out how the jaw goes to its uppermost position prior to the teeth coming into full intense contact and the bite supports and reinforces this centric relation position. |
