TEMPROMANDIBULAR JOINT AND MOVEMENTS MANDIBULAR [ T M J ]

1. TEMPROMANDIBULAR JOINT AND MOVEMENTS MANDIBULAR [ T M J ] • Is the articulation between the mandible and the cranium . • It is a bilateral articulation .

2. Anatomy • Articular fossa and eminence . • Condylar head . • Articular disc (meniscus). • Articular capsule (capsular ligament) . • TMJ ligament . • Synovial membrane .

6. Muscles of mastication • Temporalis . • Masseter . • Medial pterygoid . • Lateral pterygoid .

7. Temporalis Masseter

10. THE BASIC MOVEMENTS OF THE MANDIELE • Rotation Movement • = hinge movement . • Translation Movement • (gliding movement.)

11. Hinge movement = rotation • Rotation movement = hinge movement. • It is the rotation of the mandible around an imaginary hinge axis at the centers of the condyles. • It occurs in the lower compartment of the joint

12. Gliding or translation • It is the body movement of the mandible. • It occurs in the upper compartment.

13. Condyle in retroded .no movement position Condyle performing rotation=hinge movement Condyle performing anterior translation=gliding.

14. Sagittal view=lateral view intercusbal position from which hinge movement will start No Translation

15. Translation

16. Protrosion movement • It is the forward movement of the mandible. • The mandible does not move in pure forward movement. • The mandible moves down ward and forward = Gliding = translation movement. • It occurs when the mandible moves from retroded position to -edge to edge position- to- reverse over jet, of anterior teeth.

17. Excursive Movements Protrusive – No Posterior Contact The lower anterior teeth ride up the lingual of the maxillary anterior teeth as the jaw goes forward.

18. Incisal path

19. Condylar path

20. Condylar path inclinationvaries according to the amount of protrusion. a-b Sagittal condylar path inclination. Centric relation position of the condyle. 4-P. 4 mm protrusion.8P. 8 mm protrusion

21. No Translation

22. Translation

25. Posselt’s Figure

26. Posselt’s Figure MP ICP RCP Habitual Arc of Closure HA MP = Maximal protrusion ICP = Intercuspal position RCP= Retruded Contact position HA = Hinge axis MO = Maximum opening EE=edge to edge MO

27. Edge to edge position.

28. Protrusive Record Christensen Phenomena When the mandible moves to edge to edge position , separation occurs distally between the natural dentition or occlusion rims . The protrusive relationship determines the angle of the horizontal condylar path

29. Anterior biting to reverse vertical overlap.

30. Lateral movement of the mandible Lateral Movement . (non working side = the side which the mandible moves away from. Lateral Movement . Working side = the side which the movement take place

31. The Condylar Path • Horizontal Condylar Path . • Lateral Condylar Path . • The Condylar Path Angle .

32. 2. Vertical relations.

33. Vertical Dimensionof rest The vertical dimension of the face when the mandible is in rest position.

34. Vertical Dimension of occlusion The vertical dimension of the face when the teeth are in contact in centric occlusion.

35. Freeway space= V.D.R. – V.D.O. = 2-4mm

36. The centric relation • It is the relation between the mandible and the maxilla when the mandible in the physiologic retroded position at the vertical dimension of occlusion. • Importance: it is the point from which all movemnt of the mandible will start and end must be recorded to arrange the teeth in this position

37. Thank you