Presentation is loading. Please wait.

Presentation is loading. Please wait.

Truly Invisible Braces: The Story of Serial Disking Dr Jabbarifar Associate Professor IsfahanUniversity School of Dentistry 2009.

Similar presentations


Presentation on theme: "Truly Invisible Braces: The Story of Serial Disking Dr Jabbarifar Associate Professor IsfahanUniversity School of Dentistry 2009."— Presentation transcript:

1 Truly Invisible Braces: The Story of Serial Disking Dr Jabbarifar Associate Professor IsfahanUniversity School of Dentistry 2009

2 objective part 1 Discuss the transition of the primery dentition to the permanent dentition. part 2 Review a simplified Mixed Dention Analysis procedure. part 3 Discuss indications and procedures for Serial disking.

3 Part 1 - Transition From Primary to Permanent Teeth Transition of molar relationships Transition of molar relationships Transition of Incisors Transition of Incisors Transition of Buccal Segment Transition of Buccal Segment Leeway Space Leeway Space Late Mesial Shift Late Mesial Shift

4 Distal Mesial Flush Terminal Plane

5 Distal Mesial Mesial Step

6 Distal Mesial Disto Step

7 Distal Mesial Mesio Step

8 Incisor Liability Permanent incisors are larger than primary incisors Permanent incisors are larger than primary incisors This difference in size is termed "incisor liability This difference in size is termed "incisor liability How does the body create enough room for the larger, permanent incisors? How does the body create enough room for the larger, permanent incisors?

9 Overcoming Incisor Liability Interdental spacing of primary incisors Interdental spacing of primary incisors Intercanine arch width growth Intercanine arch width growth Labial positioning of the permanent incisors Labial positioning of the permanent incisors Favorable size ratio between the primary and permanent incisors Favorable size ratio between the primary and permanent incisors

10 Arch Length Prediction from Alignment of Primary Teeth

11 Good Spacing

12 No Primary Spacing

13 Fair Spacing

14 Leeway Space Sum of (c-d-e) > (3-4-5) Sum of (c-d-e) > (3-4-5) This allows more space for 3-4-5 This allows more space for 3-4-5 This "leeway space" averages 1.7 mm. in the mandibular buccal segment; 0.9 in the maxillary buccal segment This "leeway space" averages 1.7 mm. in the mandibular buccal segment; 0.9 in the maxillary buccal segment

15 E Space

16 Late Mesial Shift Refers to mandibular permanent molar moving mesially Refers to mandibular permanent molar moving mesially Good news - if permanent molars are ETE, late mesial shift allows mandibular molar to move into a Class I occlusion Good news - if permanent molars are ETE, late mesial shift allows mandibular molar to move into a Class I occlusion Bad news - the above reduces arch length Bad news - the above reduces arch length

17 FTP Class I Molar moves into this space... Late Mesial Shift (cont.)

18

19 Part 2 Mixed Dentition Analysis Purpose: predict amount of crowding after permanent teeth come in Purpose: predict amount of crowding after permanent teeth come in Timing: mixed dentition Timing: mixed dentition Materials: Boley gauge Materials: Boley gauge Where: At the chair Where: At the chair

20 4 Step Simplified MDA Basic Steps Basic Steps –Mentally align incisors »In other words…. how far over onto the primary cuspid will it take to make the incisors straight? –Measure space left over for C, B1, B2 –Predict size of C, B1, B2 –Compare size vs. space for C, B1, B2 to determine amount of crowding

21 Step 1 MDA Methodology n Measure mesial-distal diameter of the mandibular incisors, sum and divide by two

22

23 Step 1 Example

24 Step 2 MDA Methodology Select a midline point Select a midline point Expand the Boley gauge to the amount determined in Step 1 Expand the Boley gauge to the amount determined in Step 1 Mark the point on each primary cuspid from the midline point Mark the point on each primary cuspid from the midline point This represents the space required for well aligned incisors This represents the space required for well aligned incisors

25 11.7 mm

26 Step 3 MDA Methodology Measure from the point on each cuspid (derived in Step 2) to the mesial of the first permanent molar Measure from the point on each cuspid (derived in Step 2) to the mesial of the first permanent molar This represents the space available for the permanent cuspid and bicuspids (C, B1, B2) This represents the space available for the permanent cuspid and bicuspids (C, B1, B2)

27 22.4 mm 22.7 mm

28 Step 3 Example

29 Step 4 MDA Methodology To the number derived in Step 1, add 10.5 mm for the mandibular teeth To the number derived in Step 1, add 10.5 mm for the mandibular teeth This represents the size of the permanent cuspid and bicuspids in each quadrant This represents the size of the permanent cuspid and bicuspids in each quadrant Subtract the number determined in Step 4 (the predicted size of C, B1, B2) from the number determined in Step 3 (the amount of space for C, B1, B2) for both sides of the arch Subtract the number determined in Step 4 (the predicted size of C, B1, B2) from the number determined in Step 3 (the amount of space for C, B1, B2) for both sides of the arch

30 MDA Methodology If the space available is less than the amount of tooth mass, a negative number will result If the space available is less than the amount of tooth mass, a negative number will result This number is the predicted amount of crowding This number is the predicted amount of crowding

31 Step 4 Example

32 Allowance for Late Mesial Shift If permanent molars are end to end, mandibular molar should move mesially to obtain Class I interdigitation. If permanent molars are end to end, mandibular molar should move mesially to obtain Class I interdigitation. This will decrease the arch length available for 3-4-5. This will decrease the arch length available for 3-4-5. Figure 1.7 mm. per side with ETE relationship. Figure 1.7 mm. per side with ETE relationship.

33 MDA Procedure Maxillary Arch Mentally align the maxillary incisors as was done in the mandibular arch Mentally align the maxillary incisors as was done in the mandibular arch Measure the space left over for the maxillary C, B1, B2 Measure the space left over for the maxillary C, B1, B2 Add 11.0 mm. to 1/2 the sum of the MANDIBULAR INCISORS to predict the size of the maxillary C, B1, B2 Add 11.0 mm. to 1/2 the sum of the MANDIBULAR INCISORS to predict the size of the maxillary C, B1, B2 Subtract the predicted size from the space available Subtract the predicted size from the space available

34 Part 3 Serial Disking Result without treatment Result without treatment Description of Ideal Patient Description of Ideal Patient Description of Technique Description of Technique Steps in Serial Disking Steps in Serial Disking

35 What Happens With No Intervention?

36 Cuspid Labial Eruption No anterior alignment

37 1st Premolar Eruption Distal cuspid movement?

38 2nd Premolar Eruption Late mesial shift of 1st molar

39 Spaces close from posterior!!! 2nd Premolar Eruption Late mesial shift of 1st molar

40 Result Without Disking Same anterior crowding Same anterior crowding Blocked out cuspids Blocked out cuspids Less arch length to work with Less arch length to work with

41 Ideal Patient for Serial Disking n Class I molars and cuspids (Not FTP) n Normal overbite and overjet n 3 mm or less of anterior crowding

42

43 Serial Disking Technique 699, 169 carbide bur or tapered diamond 699, 169 carbide bur or tapered diamond Anesthetic considerations Anesthetic considerations local local electronic electronic none none Prepare mesial surface as stainless steel crown prep Prepare mesial surface as stainless steel crown prep No ledges!…. Feather edge margin No ledges!…. Feather edge margin

44 Serial Disking Steps: Mandibular Arch Lateral incisor eruption - disk mesial of primary cuspids Lateral incisor eruption - disk mesial of primary cuspids Permanent cuspid eruption - disk mesial of either 1st or 2nd primary molar Permanent cuspid eruption - disk mesial of either 1st or 2nd primary molar

45 Mild Anterior Crowding Disk Primary Cuspids

46

47

48

49

50

51

52 Cuspid Eruption Extract 1st Primary Molar?

53

54 1st Premolar Eruption Disk 2nd Primary Molar

55

56

57

58

59

60

61 Disk 2nd Primary Molar

62

63

64

65

66

67 Class I Molars Class I Molars Preferred No late mesial shift required

68 2nd Premolar Eruption

69 End to End Molars No late mesial shift

70 If You Cant Disk Enough… and <5 mm. Crowding... Extract mandibular primary cuspids Extract mandibular primary cuspids Support with bilateral holding arch Support with bilateral holding arch Mandibular incisors will generally align Mandibular incisors will generally align Just because 5 mm. of crowding is predicted does not mean it is an extraction case! Why? Just because 5 mm. of crowding is predicted does not mean it is an extraction case! Why?

71 Other Factors to Consider Tooth size prediction is at approximately 75 percentile Tooth size prediction is at approximately 75 percentile therefore….. Tendency is to overestimate crowding therefore….. Tendency is to overestimate crowding MDA does not take into account: MDA does not take into account: angulation of incisors angulation of incisors arch form arch form Curve of Spee Curve of Spee

72

73

74 Visit Us on the Web! Creighton University http://www.creighton.edu Creighton School of Dentistry http://cudental.creighton.edu ASDC Web site http://cudental.creighton.edu/asdc Creighton University http://www.creighton.edu Creighton School of Dentistry http://cudental.creighton.edu ASDC Web site http://cudental.creighton.edu/asdc Creighton UniversityCreighton School of Dentistry ASDC Web site Creighton UniversityCreighton School of Dentistry ASDC Web site


Download ppt "Truly Invisible Braces: The Story of Serial Disking Dr Jabbarifar Associate Professor IsfahanUniversity School of Dentistry 2009."

Similar presentations


Ads by Google