AAO / AAPD Scottsdale 2018

Transcription

1 AAO / AAPD Scottsdale 2018 Missing Premolars : What are the Options? David Kennedy Clinical Professor UBC Vancouver Canada drdavidkennedy@yahoo.ca At what age can you know second premolars are absent? chronological age 8 to 9 compare to first premolar compare to opposing arch family history late eruption 1

2 Missing Second Premolars- Associated Anomalies Infraocclusion 25% vs 9% Distoangular premolar 8% vs 0.2% Garib et al Angle Orthod 2009 : 79 : Should we save or extract the E? Systematic Review Outcomes of preserving vs extract E when 5 missing in normal occlusion No evidence to support either extraction or preservation Naoumova J et al J World Fed Ortho (2017) 6:

3 Missing Premolars Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 4 Principles Kennedy DB Eur Arch Ped Dent : Establish correct space 3

4 4 Principles Kennedy DB Eur Arch Ped Dent : Establish correct space Preserve occlusal table 4 Principles Kennedy DB Eur Arch Ped Dent : Establish correct space Preserve occlusal table Preserve alveolar ridge 4

5 4 Principles Kennedy DB Eur Arch Ped Dent : Establish correct space Preserve occlusal table Preserve alveolar ridge Correct incisor position 3 Questions What would you do if the absent tooth were present? Can this malocclusion be satisfactorily treated with extractions? What is the likelihood of survival of deciduous molar? 5

6 What is the survival rate of deciduous second molar with absent premolar? What is the survival rate of deciduous second molar with absent premolar? reduced numbers of retained maxillary deciduous molars mandibular molars maybe more durable mandibular molars show increased infraocclusion resorption occurs in about 50% sample bias? Sletten et al AJODO 2004 : 124 : Rune & Sarnas Eur J. Ortho 1984 : 6 : Bjerklin K and Bennett J Eur J. Ortho 2000 : 22 :

7 What is the survival rate of deciduous second molar with absent premolar? age 36 to 48 years negligible root resorption no infraocclusion Sletten et al AJODO 2004 : 124 : What is the survival rate of deciduous second molar with absent premolar? If deciduous molar lasts to adulthood without resorption or infraocclusion : excellent prognosis for longevity. Bjerklin K and Bennett J Eur J. Ortho 2000 : 22 :

8 Retained Second Deciduous Molar Problems : size of molar deciduous molar wider than absent premolar results in end on / ½ cusp Class ΙΙ molar Retained Second Deciduous Molar Problems : root resorption Before After resorption progressive reduced crown root ratio for restoration 8

9 When ankylosed E is left non restorable space too wide end on molar surgical removal compromised bone for implant Retained Second Deciduous Molar Problems : infraocclusion impact magnified with growth early ankylosis worse than late infraocclusion worse when absent premolar than if premolar present Kurol 1981 Comm Dent Oral Epid 9-94 Kurol 1984 Eur J Ortho 6: Kurol 1984 Angle Orthod 54 :

10 Retained Second Deciduous Molar Problems : infraocclusion infraocclusion magnified with growth space loss > leeway space adjacent teeth tipping reduced vertical growth of adjacent teeth midline deflection in unilateral cases Becker A et al AJO Becker A et al AJO Becker A et al AJO Before After 10

11 When baby teeth behave badly thanks Dr. Lesley Williams Impact of Extraction of Infraoccluded Deciduous Molars - vertical don t let infraocclusion extend beyond proximal contact - non restorable Before ext After ext 11

12 Can we enhance extraction socket for future implant? Random Clinical Trial of coral granules placed in primary molar extraction sites Posterior Mx and Mn 93.5 % successful in preserving alveolar width No pre- implant grafting needed Socket preservation Sandor et al : Dent Traumat : 19 : : 2003 Missing Teeth Treatment Costs to replace missing teeth orthodontic treatment prosthetic replacement adjunctive procedures ( CBCT / grafting ) maintenance of prosthesis $ 5000 per tooth competes with college funds / availablity space closure eliminates these 12

13 Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars Missing Lower Second Premolars Class 1 non crowded 13

14 Before After Before After interproximal reduction of mandibular second deciduous molars limited by root proximity / pulp size occlusal build up 14

15 Before After Leave upper space to obtain Class I canine and molar Final Post restorative 15

16 Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADs to protract molars Missing Lower Second Premolars Class 1 minimal crowding 16

17 What would you do if the absent tooth were present? Can the malocclusion be satisfactorily treated with extractions or not? What is the longevity of the deciduous second molar? extract lower primary molars / lingual arch non extraction treatment to open space for lower second premolar replacements 17

18 Impact of Extraction of Infraoccluded Deciduous Molars ridge width Ridge changes with missing lower second premolars 25% of buccal lingual reduction occurs in first 3 years 4% more loss over next 4 years limited vertical change adequate bone for implant Ostler & Kokich J. Prosth. Dent Final 18

19 Before After early extraction preserved bone height eruption of teeth brings bone with them Ostler & Kokich J. Prosth. Dent Other anomalies late 1. 7 absent 3 rd molars absent

20 Implant supported crowns-after growth finished 6 years after implant 20

21 Before 3 unit bridge After Maryland bridge until growth complete less invasive less cost future implant still an option 21

22 Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars Class I mild crowding : missing lower left second premolar 22

23 What would you do if the absent tooth were present? Can the malocclusion be satisfactorily treated with extractions or not? What is the longevity of the deciduous second molar? extract all second premolars slightly protrusive incisors steep mandibular plane encourages mesial drift of molars 23

24 Final Note mesial drift of molars, increased space for third molar eruption, no impact on profile 24

25 Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars Initial - Missing Lower Second Premolars TSALD 7 mm lower 5 mm upper 25

26 Extract Upper 4 and Lower E 26

27 Post Ext 4 / E / Drift Progress Post Ext / Drift 27

28 Progress Post Ext / Drift Final 28

29 Static Working Non working Final 29

30 More room for 8 s molars come forward Final Initial Post Drift Final 30

31 Missing maxillary right second premolar Class 1 crowded What would you do if the absent tooth were present? Can the malocclusion be satisfactorily treated with extractions or not? What is the longevity of the deciduous second molar? 31

32 Modified serial extraction Place Nance control molar / midline Phase 2 with maxillary expansion and fixed appliances Post Driftodontics 32

33 Initial Post Drift Initial Post Drift Post Drift 33

34 Before ext After drift Final Thanks Dr Flanagan 34

35 Initial Initial Final Final Missing Lower Second Premolars Class 2 crowded 35

36 What would you do if the absent tooth were present? Can the malocclusion be satisfactorily treated with extractions or not? What is the longevity of the deciduous second molar? Treatment Plan full treatment skeletal camouflage (Class II) extraction of upper first permanent first premolars and lower second premolars 36

37 Extract lower E / Drift Post Lower E Extraction and Drift 37

38 midline correction due to extraction timing Mesial drift of lower 6 with Minimal incisor retraction 38

39 Before After Initial Mesial drift improves Class 2 molar Post Drift 39

40 Before ext After ext / drift Tipping at lower extraction sites Phase 2-extract upper 4-critical anchorage 40

41 Final Mesial drift improves Class 2 molar Upper molar held in position 41

42 10 years 42

43 Dental Changes Following Serial Extraction of Mandibular Second Premolars Rob Mintenko 3 rd Year Resident-UBC MSc Craniofacial Sciences/Diploma in Orthodontics Methodology Two principal measurement methods: 1) Change in tooth angulation using lateral cephalometric radiographs Yoshihara

44 Results Dental Tipping T0 = white T1 = blue T2 = red + change indicates distal tipping of teeth - change indicates mesial tipping of teeth Group 1: Early extraction of lower 5 s Palatal Plane T0 T1-6.0⁰ +13.5⁰ +7.3⁰ +1.2⁰ T1 T ⁰ -13.8⁰ -8.3⁰ -3.0⁰ Teeth: Mandibular First Molar Mandibular First Premolar Mandibular Canine Mandibular Central Incisor Methodology Two principal measurement methods: 2) Changes in occlusal curves Digitize plaster models Placement of points on digitized models Analysis via spheres Curve of Spee Curve of Wilson Monson s Sphere 44

45 Results Occlusal Curves 34.0 Curve of Spee from T0-T1-T Sphere Radii (mm) Curve of Spee Curve of Spee Curve of Spee T0 T1 T2 Group 1: Early ext 5's Group 2: Early ext E's Group 3: Late ext 5's Group 4: Control Results Occlusal Curves 66.0 Curve of Wilson from T0-T1-T SPhere Radii (mm) Curve of Wilson Curve of Wilson Curve of Wilson T0 T1 T2 Group 1: Early ext 5's Group 2: Early ext E's Group 3: Late ext 5's Group 4: Control 45

46 Results Occlusal Curves 60.0 Monson's sphere from T0-T1-T2 SPhere Radii (mm) Monson's Sphere Monson's Sphere Monson's Sphere T0 T1 T2 Group 1: Early ext 5's Group 2: Early ext E's Group 3: Late ext 5's Group 4: Control Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 46

47 Missing all second premolars Class 1 minimal crowding Extract all second primary molars / driftodontics What would you do if the absent tooth were present? Can the malocclusion be satisfactorily treated with extractions or not? What is the longevity of the deciduous second molar? 47

48 Post E Extraction 5 years of Drift Before After 48

49 Mesial drift of 6 with Minimal incisor retraction Final 49

50 Early extraction results in mesial drift of posterior teeth. 50

51 Spontaneous Space Closure after Extraction 11 patients mean age 11.8 years Class Ι non crowded with missing second premolars models before, 1, 2 and 4 years ceph before, 2 and 4 years Mamopouloua A et al E.J.O : 18 :

52 Spontaneous Space Closure after Extraction 55% Mx space closed in 1 st year 46% Mn space closed in 1 st year at year 4-89% of Mx space closed : 0.9 mm left at year 4-80% of Mn space closed : 2.0 mm left Mamopouloua A et al E.J.O : 18 : Lindqvist B E.J.O : 2 : Spontaneous Space Closure after Extraction Mx premolar tipped 7º by year 4 Mx molar tipped 4.5º by year 4 Mn premolar tipped 9º by year 4 Mn molar tipped 5.7º by year 4 most tipping occurred in 1 st year Mamopouloua A et al E.J.O : 18 : Lindqvist B E.J.O : 2 :

53 Spontaneous Space Closure after Extraction minimal incisor movement Mx incisor retroclined 3.5º Mn incisor retroclined 3.0º Mn incisors 0.9 mm posterior to A-Pg line unilateral case showed midline shift Mamopouloua A et al E.J.O : 18 : Lindqvist B E.J.O : 2 : Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 53

54 Premolar to Premolar Transplant Class II Camouflage Tx / Missing Premolar Initial 54

55 55

56 Donor Pre Transplant Post Transplant Post Transplant 56

57 Final static occlusion working occlusion non working occlusion 57

58 Donor tooth Final Donor tooth Donor tooth Immediate post transplant During orthodontics Final 58

59 Initial Final Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 59

60 Decoronation Preserve vertical bone Preserve buccal lingual bone Must be done before growth spurt No research available yet on primary molars a Proffit WR, Fields HW, Larson BE, Sarver DM. Contemporary Orthodontics, Chapter 12, 6th Edition, Elsevier, Philadelphia PA, USA. Treatment Options Leave primary molars + build up + disk Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 60

61 Initial Initial 61

62 Initial - Extract Upper 4 Lower E Progress Buccal and Lingual sliding mechanics for lower space closure 62

63 Indirect anchorage Lace 3 and 4 to TAD Buccal and Lingual sliding mechanics for lower arch space closure Final 63

64 Final Final 64

65 Missing Premolars : What are the Options? Longevity of primary molar Leave primary molars + build up + disk Thank You Extract hold space restore Extract close space Extract early drift close Transplant Decoronation TADS to protract molars 65