AAO / AAPD Scottsdale 2018 Missing Premolars : What Are the Options?
AAO / AAPD Scottsdale 2018
Missing Premolars : What are the Options?
• David Kennedy • Clinical Professor UBC • Vancouver Canada • [email protected]
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 Missing Second Premolars- Associated Anomalies
Infraocclusion – 25% vs 9% Distoangular premolar – 8% vs 0.2%
Garib et al Angle Orthod 2009 : 79 : 436-41
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) 6:142-6
2 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 2009 10 : 201-10
• Establish correct space
3 4 Principles Kennedy DB Eur Arch Ped Dent 2009 10 : 201-10
• Establish correct space • Preserve occlusal table
4 Principles Kennedy DB Eur Arch Ped Dent 2009 10 : 201-10
• Establish correct space • Preserve occlusal table • Preserve alveolar ridge
4 4 Principles Kennedy DB Eur Arch Ped Dent 2009 10 : 201-10
• 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 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 : 625-630 Rune & Sarnas Eur J. Ortho 1984 : 6 : 123-131 Bjerklin K and Bennett J Eur J. Ortho 2000 : 22 : 245-255
6 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 : 625-630
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 : 245-255
7 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 • 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: 277-93 Kurol 1984 Angle Orthod 54 :283-94
9 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 1992 102 256-264 Becker A et al AJO 1992 102 302-309 Becker A et al AJO 1992 102 427-433
Before After
10 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 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 : 221-7 : 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 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 Before
After
Before After
• interproximal reduction of mandibular second deciduous molars • limited by root proximity / pulp size • occlusal build up
14 Before After
Leave upper space to obtain Class I canine and molar
Final Post restorative
15 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 • 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 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. 1996
Final
18 Before After
• early extraction preserved bone height • eruption of teeth brings bone with them
Ostler & Kokich J. Prosth. Dent. 1996
• Other anomalies • late 1 . 7 • absent 3rd molars • absent 3.5 4.5
19 Implant supported crowns-after growth finished
6 years after implant
20 Before3 unit bridge After
• Maryland bridge until growth complete • less invasive • less cost • future implant still an option
21 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 • 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 Final
Note mesial drift of molars, increased space for third molar eruption, no impact on profile
24 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 Extract Upper 4 and Lower E
26 Post Ext 4 / E / Drift
Progress – Post Ext / Drift
27 Progress – Post Ext / Drift
Final
28 Static Working Non working
Final
29 More room for 8’s – molars come forward Final
Initial Post Drift
Final
30 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 • Modified serial extraction • Place Nance – control molar / midline • Phase 2 with maxillary expansion and fixed appliances
Post Driftodontics
32 Initial
Post Drift
Initial
Post Drift
Post Drift
33 Before ext After drift
Final Thanks Dr Flanagan
34 Initial Initial
Final Final
Missing Lower Second Premolars Class 2 crowded
35 • 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 Extract lower E / Drift
Post Lower E Extraction and Drift
37 • midline correction due to extraction timing
• Mesial drift of lower 6 with Minimal incisor retraction
38 Before After
Initial
• Mesial drift improves Class 2 molar
Post Drift
39 Before ext After ext / drift
• Tipping at lower extraction sites
Phase 2-extract upper 4-critical anchorage
40 Final
• Mesial drift improves Class 2 molar • Upper molar held in position
41 10 years
42 Dental Changes Following Serial Extraction of Mandibular Second Premolars
Rob Mintenko 3rd Year Resident-UBC MSc Craniofacial Sciences/Diploma in Orthodontics
Methodology • Two principal measurement methods: – 1) Change in tooth angulation using lateral cephalometric radiographs
Yoshihara 2000
43 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 →T2 +10.1⁰ -13.8⁰ -8.3⁰ -3.0⁰
Teeth: Mandibular Mandibular Mandibular Mandibular First Molar First Premolar Canine 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 Results – Occlusal Curves
Curve of Spee from T0-T1-T2 34.0
32.0
30.0
28.0
26.0
24.0 Sphere Radii (mm)
22.0
20.0 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
Curve of Wilson from T0-T1-T2 66.0
64.0
62.0
60.0
58.0
56.0
54.0 SPhere (mm) Radii 52.0
50.0
48.0 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 Results – Occlusal Curves
Monson's sphere from T0-T1-T2 60.0
58.0
56.0
54.0
52.0
50.0
48.0
SPhere (mm) Radii 46.0
44.0
42.0 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 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 Post E Extraction
5 years of Drift
Before After
48 • Mesial drift of 6 with Minimal incisor retraction
Final
49 Early extraction results in mesial drift of posterior teeth.
50 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. 1996 : 18 : 589-600
51 Spontaneous Space Closure after Extraction
• 55% Mx space closed in 1st year • 46% Mn space closed in 1st 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. 1996 : 18 : 589-600 Lindqvist B E.J.O. 1980 : 2 : 173-181
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 1st year
Mamopouloua A et al E.J.O. 1996 : 18 : 589-600 Lindqvist B E.J.O. 1980 : 2 : 173-181
52 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. 1996 : 18 : 589-600 Lindqvist B E.J.O. 1980 : 2 : 173-181
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 Premolar to Premolar Transplant Class II Camouflage Tx / Missing Premolar
Initial
54 55 Donor Pre Transplant Post Transplant Post Transplant
56 Final
• static • working • non working occlusion occlusion occlusion
57 Donor tooth
Final
Donor tooth Immediate post transplant Donor tooth
During orthodontics Final
58 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 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 Initial
Initial
61 Initial - Extract Upper 4 Lower E
Progress
Buccal and Lingual sliding mechanics for lower space closure
62 Indirect anchorage Lace 3 and 4 to TAD
Buccal and Lingual sliding mechanics for lower arch space closure
Final
63 Final
Final
64 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