Movements of Temporomandibular Joint | Axes of Movements | Muscles producing the Movements with AA скачать в хорошем качестве

Movements of Temporomandibular Joint | Axes of Movements | Muscles producing the Movements with AA

Movements: • Depression – open mouth • Elevation – closed mouth • Protrusion – protraction of chin • Retrusion – retraction of chin • Lateral/ side to side movement in chewing or grinding Protraction & Retraction: • Occurs in upper compartment • Articular disc + head of mandible glides forwards over upper articular surface • Reversal action occurs in retraction • Axis – horizontal axis connecting two condyles Depression Slight opening • The head of mandible moves on the undersurface of disc like a hinge in lower compartment • Axis–vertical axis passing through condyle & posterior border of ramus of mandible Wide opening • Hinge like movement in lower compartment • Followed by gliding movement in upper compartment as in protraction. • At the end of movement, the head lie under the articular tubercle • lateral pterygoid pulls the disc forwards, so movement occurs in both compartments Chewing movements: • Side to side movement • Head glides forwards along with disc as in protrusion on one side. • Head of opposite side rotates on vertical axis • Axis – imaginary axis along mid- sagital plane • Chewing of one side Muscles – medial & lateral pterygoids of opposite side + temporalis & masseter of same side Dislocation: • Occurs during excessive opening of mouth • Head of one side or both slip anteriorly into infratemporal fossa • Results in inability to close the mouth • Reduction done by depressing the jaw at last molar teeth & elevating the chin at the same time • Derangement of articular disc results in overclosure or malocclusion • In operations of TMJ, facial N and auriculotemporal N should be preserved with care. ------------------------------------------------------------------------------------------------------------- My website - https://human-anatomy-lessons.busines... My Blog - https://human-anatomylessons.blogspot... ----------------------------------------------------------------------------------------------------- Follow me in blogspot - https://human-anatomylessons.blogspot... _________________________________________________________________________________________________________________ Visit my blogs - https://humananatomyonline.in/ Contact me @ https://t.me/humananatomylessons