牙合(英文).ppt

Occlusion Concepts of Occlusion Occlusion 牙合 is defined as the static relationship of teeth Articulation 咬合 is defined as the dynamic relationship of teeth Tooth alignment and occlusion is important in masticatory function Tooth positioning is not a random process A number of controlling factors are involved Concepts of Occlusion Balanced Occlusion Bilateral and balancing contacts through all excursive movements Protrusive 前伸 Laterotrusive 侧方 Developed for complete dentures Rationale was thought to provide stability to dentures through all excursive movements Concepts of Occlusion  Optimal Occlusion Dynamic Individual Occlusion Concept is based on function and health rather than any ideal occlusal arrangement In the absence of pathology, no treatment to change a patient’s occlusion would be necessary Developed in the late 1970’s Tooth Alignment and Occlusion Factors determining tooth position Normal intra-arch relationships Normal interarch relationships Tooth Alignment and Occlusion Factors determining tooth position Forces from many directions act to position the tooth in a position of equilibrium Lips Cheeks Tongue Forces are light and constant Have the ability to move teeth over time Tooth stability is achieved in the neutral position Tooth Alignment and Occlusion Factors determining tooth position When a tooth erupts out of alignment, forces from the tongue and lip can move the tooth to the neutral position Must be adequate space for the tooth If there is crowding, the muscular forces are insufficient to produce the necessary movement Orthodontic treatment would then be required Tooth Alignment and Occlusion Factors determining tooth position Erupted teeth will be moved until an equilibrium is established Large tongue Tongue thrust Oral habits Thumb sucking Finger sucking Pencil sucking Chewing on a pipe Musical instruments Tooth Alignment and Occlusion Factors determining tooth position Erupted teeth will be moved until an equilibrium is est