Complete Denture 4- Maxillo-mandibular Relation Records d- Centric Relation Registration
- 3. Dr. Amal Fathy Kaddah Professor of Prosthodontic, Faculty of Dentistry Cairo University
- 4. When you realize you've made a mistake, take immediate steps to correct it.
- 5. RECORDING JAW RELATIONSHIPS 1. Check denture foundation. 2. Establish facial contour. 3. Establish occlusal plane. 4. Maxillary face-bow record. 5. Determination of vertical dimension of centric occluding relation. 6. Determine centric relation at the accepted vertical dimension. 7. Locking device ( Recording the C.O.R.)
- 6. 1. Orientation relations 2. Vertical relation, and 3. Antero - posterior relation Three - dimensional record Boucher classified jaw relations into three groups
- 7. 1- ORIENTATION RELATIONS • Orientation of maxilla in relation to base of skull and the hinge axis The axis can be located by the facebow. 2- Vertical relation • Orientation of occlusal plane
- 8. Orientation of occlusal plane and the Vertical relation • Help in achieving esthetic, phonetics and mastication. • Affect stability of complete denture & ultimately result in alveolar bone resorption if not properly achieved.
- 9. Methods of determination of centric relation
- 11. • Occlusal blocks and facial contour • Occlusal Plane • Vertical Dimension • Centric Relation • Eccentric Relations Wax registration method (Wax wafer method)
- 12. Wax Registration Method I- Check denture foundation For Extension, Retention and Stability
- 13. Check Bite Method II- Establish facial contour and orientation of occlusal plane
- 14. III- Determination of occlusal plane 3- Physics and mechanics (leverage action and parallelism) Regarding: 1- Aesthetic appearance of the teeth 2- Function (chewing and speech)
- 15. III- Determination of occlusal plane
- 16. The interpupillary plane The Ala-tragus line III- Determination of occlusal plane
- 17. III- Determination of occlusal plane
- 18. Check Bite Method Guide lines 1- Central line (midline) 2- The corner line (canine line) 3- The high lip line and low lip line
- 19. Check Bite Method Notch Preparation
- 20. Occlusion rim notched to aid stabilizing the record bases
- 21. IV- Mounting to the upper cast V. Determination of the Vertical dimension of occlusion
- 22. 2 to 4 mm Vertical Dimension V D O = V D R - F W S
- 23. VI. Centric Jaw Relation Registration
- 24. Centric Relation Registering 1- Patient in a Slightly Supine position
- 25. 2. CRITICAL! Check that record base heels/rims do not touch Eliminate contact with record bases
- 26. 3- Equalize pressure of occluding forces Maintain even contact between the upper and lower occlusion blocks without displacement of denture supporting tissues, at the predetermined vertical dimension of centric occluding relation.
- 27. 4. Remove 2 mm. of wax from the lower occlusion block. Replace them by 4 mm. softened wax.
- 28. 5. Evenly soften the wax by tapping it with the edge of a heated wax spatula.
- 29. 6- Both rims should be inserted into the mouth and Stabilized using index fingers on the flange and the thumb under the symphysis to held it firmly in place
- 30. 7- Guiding the mandible into centric position a. Index fingers on the rim, thumbs under symphysis
- 31. Centric Relation Registering b. Jiggle the mandible to freely arc c. Allow the patient to close into contact d. Ask the patient to bite or close on your fingers posteriorly to close the rims together
- 32. – Do NOT push the mandible or dislodge the record base – Medium must be dead soft – Minimal closing pressure (Yurkstas and Kapur) Centric Relation Registering
- 33. e- Let the patient occlude lightly in centric and displace 2 mm from the soft wax 8- The vertical dimension is re-checked.
- 34. Check Bite Method 9. Mark the Central line and canine lines extending from upper rim to lower rim in centric relation position
- 35. Check Bite Method 10- Remove occlusion blocks together, Rinse. A sharp imprint of the V-shaped notches should be recognize. 11. Remove all displaced wax outside the occlusal surface of the lower block. It may act as inclined planes, Rinse. Registration Should be Sharp, Not Rounded Keep Wax Neat
- 36. 12- Return occlusion blocks to the mouth to check correctness of centric occluding relation record. The midline of the mouth should be rechecked and scored with a knife on the occlusion rim Recheck the registration repeatedly
- 37. 13. Assemble the two occlusion blocks together outside patient’s mouth according to the locking projections. The trial denture bases should not be touched posteriorly, Rinse.
- 38. Locking device The imprints of V-shaped notches are used to lock upper and lower occlusion blocks.
- 39. Methods to guide the mandible in centric relation 1- Patient in a Slightly Supine position. 2- Tongue retrusion. 3- Swallowing. 4- Biting operator’s fingers. 5- Relaxation. 6. Fatigue X 7- The temporalis muscle check X
- 40. Guiding the patient to close in centric relation is done by saying to the patient, "Close on your back teeth". If the thumb is not placed against the chin, most patients will close anteriorly to the centric occlusal position. However, strong pressure should not be used on the chin, otherwise the jaw will protrude 1- Chin push guidance (CPG) (Kabnacell 1964) Thumb at the menton
- 41. Guiding the patient to close in centric relation is done by asking the patient to touch a wax knob placed on the posterior border of the maxillary base in the midline by the tip of his tongue (tongue retrusion). Knob for tongue retrusion 2- Tongue retrusion Thumb at the menton Helkimo et al 1973
- 42. 3- Using index and thumb fingers of the left hand to stabilize the upper flange and the index fingers of the right hand to stabilize the lower flange and the thumb under the symphysis to held it firmly in place
- 43. 4- Bimanual guidance or manipulation Using index fingers on the flange and the thumbs under the symphysis to held it firmly in place
- 44. 5- Ramus assisted chin point guidance Simon and Nicholls (1980) Thumb at the chin (posterior pressure) while index and second finger on the lower border (upward pressure)
- 45. Take Care during Making the Record 1. Ensure wax is dead soft 2. Ensure smooth arc of closure, no horizontal deviations ( e.g. due to pain) Have patient close into record correctly 3. Use index fingers and thumb to stabilize the record bases. 4. Do NOT push the mandible or dislodge the record base
- 46. 5. Patient opens, relaxes, and slowly closes (Jiggle the mandible) • Gently arc the mandible in a hinge-like motion • Operator uses tactile senses to ensure the mandible does not translate Take Care during Making the Record
- 47. 6. Never instruct the patient to bite firmly nor quickly >> Causes translation or inaccuracy in the record. Take Care during Making the Record
- 48. 7. Ask patient to stop as soon as you asked him to stop (the correct position has been reached) Some may not be able to tell when wax records contact. 8. The trial denture bases should not be touched posteriorly Take Care during Making the Record
- 50. 1. The articulator still locked in centric, the incisal pin should be flush with the upper member of articulator and the upper mounting being properly secured in place. 2. Seal upper and lower occlusion rims in the proper relation before attaching the lower cast to the mounting ring with plaster. 3. Invert the articulator and place the lower occlusion rim to be properly related to the upper according to indices taken from the patient’s mouth. 4. Both occlusion blocks are properly seated on their casts without interference or hitting of the rears, Apply plaster on the lower cast and close the upper member upon it. 5. Trim the mounting neatly and wash all plaster off the articulator, never present a dirty articulator or rough untidy mounting.