MPKCPH – KTD – TQT: Detailed Supplement and Notes

1. What are the reference points of the occlusal plane on natural teeth?

• Reference points:
• The biting edge of the maxillary central incisors
• A point 0.5mm towards the mastication from the cusp tip of the N-G of the first maxillary molar

2. What are the characteristics of the occlusal plane of the natural tooth arch following the median sagittal plane?

• Characteristics:
• Located 1-2mm below the upper lip
• Parallel to the Camper plane
• Parallel to the HIP plane
• Creates an angle of approximately 10 degrees with the FH plane

Note: FH plane is the Frankfort plane, passing through points Po and Or (highest point of the upper margin of the external auditory canal, lowest point of the lower margin of the eye socket).

3. What are the characteristics of an ideal MPKCPH?

• Characteristics:
• Parallel and equidistant to the two alveolar ridges

4. What if the MPKCPH is not equidistant to the two alveolar ridges?

• If the MPKCPH is not equidistant to the two alveolar ridges:
• Further away: The lever force with a longer lever arm, the jaw is easy to pop out, not stable when subjected to force.
• Closer: The force transfers down to the supporting tissue more, causing bone resorption, but it is more stable.

5. When is the MPKCPH not parallel to the two alveolar ridges, how to handle it?

• When the alveolar ridge resorbs unevenly from front to back, it has a V-shape:
• Open forward: Touching the back causes the jaw to slide, making the tooth arch shorter, only reaching to the 6th tooth.
• Open backward: It is necessary to adjust the MPKCPH to match the new shape of the jaw, ensuring accurate and stable occlusion.

6. How to handle the MPKCPH that is not equidistant?

• Place it closer to the alveolar ridge with more bone resorption to increase stability.

7. How many stages are there to determine the MPKCPH?

• 3 stages:
• In the lab on the final model, not yet mounted on the articulator.
• Clinically: Aesthetics, speech.
• In the lab: Readjust the MPKCPH.

8. What is the distance from the KC arch to the base of the model, why?

• Distance: 15-20mm.
• Reason: To ensure that the model does not break.

9. What does the anterior bite ridge height of the lab depend on, what is the average HT?

• Depends on lip height.
• Average 22mm measured from the cusp of the canine.

10. Camper on a lateral skull X-ray and on the skin, reference points?

• Lateral skull: ANS and the center of the external auditory canal.
• On the skin: Across the ala and tragus.

Note: ANS is the anterior nasal spine. Ala is the wing of the nose. Tragus is the cartilage located in front of the external auditory canal.

11. Stages of MPKCPH adjustment clinically?

• Stages:
• Draw Camper.
• Determine aesthetics.
• Determine anterior bite ridge height.
• Posterior bite ridge height according to Camper.
• Adjust the lower jaw bite ridge according to the upper jaw.

12. What is aesthetic adjustment?

• To blur the nasolabial fold and the philtral ridge.
• The upper lip is well supported.
• The nasolabial angle is 90 degrees (in normal people).

13. What standard is the adjustment of the anterior HT bite ridge height based on?

• Standard:
• Resting posture: 0-2mm away from the upper lip depending on the patient, depending on the length of the lip.
• When smiling:
• Parallel to the lower lip margin, not necessarily touching the lower lip.
• Symmetrical on both sides.
• See 3-5mm of pink (from the cusp of the gingival).
• Parallel to the line connecting the two pupils.
• Speech.

14. What to do if the two pupils are uneven?

• Must be perpendicular to the midline of the face.

15. How to adjust speech?

• Saying the letter “phở”: Upper teeth touch the lower lip.
• Not touching: Short.
• Overlapping the lip: Long.

16. Why adjust support first, then adjust the length?

• The degree of protrusion will change the length of the lip compared to the bite ridge.

17. The nasolabial angle is appropriate depending on the bone relationship?

• Bone relationship:
• Normal: 90 degrees.
• Class II: Sharp.
• Class III: Obtuse.

18. The goal of adjusting the lower jaw bite ridge?

• Goal:
• Close contact with the upper jaw bite ridge at the centric relationship and achieve a correct bite.
• Recheck the position of the masticating surface relative to the physiological position of the tongue and buccal lips.

19. How to check if the vertical dimension of the occlusion is correct?

• How to check:
• Have the patient pronounce “Mississippi”.
• Pronounceable: Physiological clearance is stable.
• Slurred speech, blowing air: Still a lot of clearance, need to add more wax.
• Biting wax: Clearance is small, needs to be trimmed.

20. Why is it necessary to check speech again instead of just relying on the standard physiological clearance?

• Reason:
• The 2-4mm standard is statistical, not everyone is the same.
• 1-2-3 principle: A 2mm clearance outside does not fully represent the teeth.

21. The purpose of recording the facial arch?

• Purpose: To record the relationship of the lower jaw hinge axis to the upper jaw.

22. Groups of methods for locating the hinge axis?

• Group of methods:
• Palpation.
• Convention.
• Graphic.

23. Disadvantages of palpation method for locating the condyle?

• Disadvantage: Subjective, based on the dentist’s experience.

24. Locating the condyle by convention?

• Location:
• On the skin:
• NC thầy Hùng: 11mm in front of the coronoid process, 1mm down on the line connecting the coronoid process to the outer corner of the eye.
• Location by ruler.
• Location in the coronoid process:
• The ear cap is placed inside the coronoid process.

25. Stages of placing the facial arch?

• Stages:
• Locate the hinge axis and locate the condyle indicator.
• Fix the bite fork to the upper jaw bite ridge.
• Place the bite fork in the correct position and fix it to the facial arch.
• Fix the indicator pin under the eye socket.

26. Locate the hinge axis and locate the condyle indicator?

• Procedure:
• Locate the skin area corresponding to the conventional hinge axis location.
• Place the ruler touching the skin to indicate the hinge axis.
• Divide the distance of the ruler equally on both sides.
• Fix the distance of the ruler.

27. Fix the bite fork to the upper jaw bite ridge?

• Procedure:
• Have determined the transfer MP.
• Attach the bite fork to the HT bite ridge so that the bite fork is perpendicular to the midline recorded on the bite ridge & parallel to the transfer MP.

28. What to do when fixing the facial arch to the bite fork?

• Procedure:
• Place the lower jaw bite ridge in the mouth.
• Place the bite ridge, the upper jaw bite fork in.
• Guide the patient to close their mouth, the GC base always stays close to the supporting tissue.
• Slide the bite fork into the facial arch so that:
• The condyle indicator is in the correct position and the measurement is determined, fixed.
• The horizontal part is parallel to the line connecting the 2 pupils.

29. What happens if the indicator pin under the eye socket is missing, how to overcome it?

• Consequence: Not enough 3 points in space to determine the upper jaw block.
• Overcome:
• Replace with rubber band to create the masticating MP when going up to the centric occlusion.

30. What is the condylar guidance angle?

• Definition: The angle formed by the condylar path and the horizontal plane when the lower jaw slides forward and down.
• Average: 30-40 degrees.

31. What is the Bennett angle?

• Definition: The angle formed by the direction of the LC and the vertical plane when the working condyle moves inwards.
• Average: 10-15 degrees.

32. Standardizing the Hanau articulator?

• Procedure:
• Fix the condylar path: + 30o
• Fix the central locking screw (lowest and most anterior condyle).
• Fix the Bennett angle: 15o
• The incisal pin contacts the incisal MP, the upper end is horizontal to the articulator branch.
• Fix the incisal MP: 0o
• Fix the 2 side wings of the incisal MP: 0o
• Fix the ring to the upper and lower branches of the articulator.

33. Factors affecting the determination of KTD?

• Influencing factors:
• Patient posture.
• Psychology.
• Soft tissue condition.
• Factors causing disorders.
• Tongue balance in HD.

34. Determining KTD when missing data before extraction?

• Method:
• Pronunciation: HD returns to resting posture after “s” “yes”.
• Swallowing: Hold water for 5 minutes, swallow.
• Breathing: End of GD exhale.
• Current prosthesis: Must be good and not worn.

35. Methods for determining the occlusal KTD?

• Method:
• Direct:
• Use Bimeter de boos.
• Open mouth maximally.
• Indirect:
• Based on the physiological resting KTD.
• Based on body measurements.

36. Note when determining the occlusal KTD for patients with skeletal malocclusion?

• Note:
• Free clearance:
• Normal: 2mm.
• Class II: >2mm.
• Class III: 1mm.

37. Note when determining the occlusal KTD for patients of different ages?

• Note:
• The older, the lower muscle tension, the greater the clearance, the more you need to subtract.
• Children: The opposite.

38. Recheck the occlusal KTD?

• Procedure:
• Have the patient pronounce “mis sis si bi”. Normally the natural teeth do not touch.
• Swallow.
• Breathe.

39. Where should the locking screws be carved?

• Area of the upper jaw 6th tooth.

40. What is the requirement to record the centric relationship correctly?

• Requirement:
• Correct centric relationship and correct vertical dimension.

41. What direction does the centric relationship show the relationship in?

• Horizontal direction, movement forward and to the side.

42. What is the HIP plane?

• Definition: Incisal pin – 2 fossae of the maxillary molars.

43. What does the Frankfort plane pass through?

• Passes through points Po-Or: Highest point of the upper margin of the external auditory canal, lowest point of the lower margin of the eye socket.

44. Definition of MP KC?

• Definition: MPKC (masticating MP) HT passes through the biting edge of the HT central incisor – a point 0.5mm towards the mastication from the cusp tip of the NG of the first maxillary molar.

45. Limits and significance of the Pound triangle?

• Pound triangle: Formed by 2 lines: Canine cusp to the inner margin, outer margin of GHN.
• Significance: Place the posterior teeth in this area to avoid popping out the jaw.

46. Checking the position of the masticating surface with the physiological position of the buccal lips and tongue after adjusting the bite ridge is checking what?

• Checking:
• Must not exceed the largest circumference of the tongue (across the largest circumference of the tongue or across the muscle fold if the patient has just lost teeth).
• Must not exceed 2/3 of the height of the GHN.

47. How many mm is the base of the model from the deepest part of the KC?

• Distance: 15-20mm.

48. What data is the adjustment of aesthetics for protrusion prioritized on?

• Data: Old prosthesis, old picture.

49. Camper on the skin and on the bone?

• On the bone: Anterior nasal spine – center of the external auditory canal.
• On the skin: Top of the coronoid process – lower margin of the ala.
• Large – small coronoid process, choose the larger one.
• Coronoid process is the same, take the middle one.

50. What is the 1-2-3 rule?

• Rule:
• Posterior tooth clearance 1 → Anterior tooth clearance 2 → External surface clearance 3.

51. What parameter is paid attention to when adjusting aesthetics when looking from the side?

• Parameter: Nasolabial angle is 90 degrees in people with normal bone relationship.

52. What are angle L and angle H, how much is each standardized?

• Angle H: Condylar guidance angle when LC moves down and forward (forming with the horizontal MP) -> 30 degrees.
• Angle L: Bennette angle when HD moves to the side at LCBKLV (forming with the vertical plane) -> 15 degrees.

53. What to note when pinning the bite fork?

• Note:
• Perpendicular to the midline.
• Parallel to the MPKCPH.
• 5mm away from the MPKCPH (2-3mm cô Hạnh).
• Small screw facing upwards and right on the midline.
• Pin when placed on the model.

54. What is the KTD on the skin calculated from?

• The most prominent point of the nose and the most prominent point of the chin.

55. How to return to the resting KTD by breathing?

• Procedure:
• Exhale at the end.
• After blowing lightly.

56. Ideal condition for recording TQTT?

• Ideal condition:
• Hinge axis has been located and recorded.
• Physiological balance, psychology, musculoskeletal system.
• Patient sits comfortably, head has a point of support.
• Correct KTDCK.
• Temporary base – bite ridge stable: Tight contact with supporting tissue and tight contact with each other at the correct KTDCK (correct up to this stage, later you can adjust it when trying the teeth).

57. What is used to record the relationship?

• Material: Aluminum wax, pink wax, rubber impression.

58. Technique for determining direct KTD with maximum opening?

• Procedure:
• Place 2 temporary bases and bite ridges.
• Open maximally at least as wide as 3 fingers (about 43mm).

59. What to note when guiding the patient about TQTT?

• Note:
• Use your hand to hold the NTGS of the 2 jaws close to the 2 SHs, then guide the HD to move back.
• Because this temporary base is made of self-hardening plastic, it cannot be sucked like the final prosthesis.

60. Why does the KTDCK of a person with Class II occlusion need to be subtracted more?

• Reason: Class II patients often have a deep bite.

General note:

• This information is for reference only, depending on the specific case of each patient, the doctor will adjust accordingly.
• Consult a professional dentist for the best advice and treatment.