tads - what we really know - aao in uk orthodontics routine hg use - 38% never use hg - 20% other...

Anchorage types

Science

ClinicalAP problemsCaninesMolars

Vertical problemsAOB

What’s being done?

TADs - What we really know

ANCHORAGE IN UK ORTHODONTICS

Routine HG use - 38%

Never use HG - 20%

Other methods:

Trans palatal arch 25%, Nance 20%

Implants 0.2%, TADs 65%,

Palatal implants 13%,

SALESMEN PROMISES ON TADSSmart, patient friendly . . . safe, secure . . . easy, intuitive, effective?

Annie C 126 Horizontal problem

JCC with restorative dentists from CCDH

Time for anchorage supplementation

Class 1 canines

Implantologists requirements?

11

Annie C 186

Charlotte 156, Vertical problems

Contact only on second molars

Time for extraction decision…

X X

2mm overbite finally!

Overcorrect molars - 30% relapse risk reported!

Treatment time28 months

Lisa 28

XXX

X

Modified arch toallow intrusion

Added hooks give options

Power chain applied on buccal & palatal

Horizontal issuesOlivia - 149

Referred by GDP for extraction of 47!

Major risk of over-retracting LLS

Overjet is still only 2.5mm, OB hasn’t ⬆d

All lower space closed, LLS looks good

8s have kept up with the mesialised 7s

Theresa 166 - uprighting 7s

Horizontal and vertical problem . . .

Horizontally impacted LR7, slight mesial impaction LL7

X X

Mesial marginal ridge of LR7 now visible

26 months of conventional orthodontics

Natalie - 166

1

11

12 2

8mm in total - for two lateral incisor pontics!

More horizontal problems

Treatment time - 18 months

Updated 2011 - Safa, Sandler et al

What about the science?

TADS - WHAT WE REALLY KNOW•Simple to place and remove

•Well tolerated

•Low failure rate < 20%

•Inexpensive

•Minimal co-operation required

•Some evidence demonstrating they work better than HG or palatal arches

What else is being done?

Science in Cyprus

TADs literature review

Design of the study

Anchorage loss measurement

ResultsMolar movementProcessPatient views

Conclusions

TADs literature review

Design of the study

Stability of the rugae

ResultsMolar movementProcessPatient views

Conclusions

3364 abstracts

3312 excluded

General Selection Criteria

success of mini-implants measured

human studies, > 10 screws

ignored technique articles, case reports, opinion pieces, reviews, lab studies, animal

studies, in-vitro . . .

implant diameter < 2.5mm

excluded mini-plates

52 scrutinisedFurther 21 excluded

General Selection Criteria

success of mini-implants measured

human studies, > 10 screws

ignored technique articles, case reports, opinion pieces, reviews, lab studies, animal

studies, in-vitro . . .

31 dissected

Further 12 excluded

19!

Specific Selection Criteria

only if they specifically defined success

only if they defined force duration

only if they measured success @ > 3/12

only if they pre-defined time to measure success or measured @ Tx completion

Assessment of validity clear in only 3

Fewer than 50% wereprospective studies

Conclusion: Poor methodology and lack of clarity generally Clinical studies considered in their infancy More RCTs - standardized methodology proposed

4115 abstracts

4063 excluded

Reasons for exclusion explained

52 included infailure estimate

Only 30 in risk factor estimate

CONCLUSIONSRisk Factors

• 4987 miniscrews in 2281 patients - failure rate 13.5% (95% CI 11.5-15.8)

• No association with sex, age, insertion site (BL vs PL), thread morphology

• Jaw of insertion was important: failure in mandible (19%) maxilla (12%)

Exploratory analyses (< 5 studies)

• Self drilling vs no drilling & immediate loading vs late loading - no difference

• No association with cortical notching or type of soft tissue

• Root contact results in 30% failures - absence of root contact - 8% failures

Examined all randomised and quasi-randomised studies

Only Benson et al (2007) of ‘Cochrane’ quality for scientific assessment of surgically assisted anchorage

Conclusion: Quality of almost all the studies pre-2007 was lowLimited evidence suggests palatal implants support anchorageMore RCTs are required

. . . the Cochrane Collaboration policy is reviews updated every

two years or include a commentary why not . . .

Update of the Cochrane review - surgical anchorage

Safa Jamba was the lead researcher

Contacted CCDH - offered to do r/v

Reviews need 2 reviewers

PJS - co-researcher

K.D.O’B the adjudicator

108 reports identified by initial search

!

!

!

!

!

!

25 abstracts remained

Study eligibility form

11 reports included3 unclear, authors contacted ultimately

excluded

11 excluded

7 reports finally included

Title and abstract scanned

Duplicates identified

!

ONLY 4 STUDIEDMOLAR MOVEMENT

MOLAR MOVEMENT STUDIES

Study InterventionInterventionInterventionIntervention

Chesterfield HeadgearHeadgear Palatal implantsPalatal implants

Upadhyay 1 HeadgearHeadgear TADsTADs

Upadhyay 2 ConventionalConventional TADsTADs

Feldmann HG Palatal arch Onplant Palatal

implants

RESULTS

StudySurgical

NMean Conventional

NMean Mean

differenceMean

differenceMean

difference

Chesterfield 23 1.5 24 3 -1.5

Feldmann 54 -0.1 59 1.5 -1.7

Upadhyay 1 18 0.7 18 3.2 -2.4

Upadhyay 2 15 0.8 15 2.0 -1.2

Total 110 116 -1.75

Favours surgical anchorage

Favours conventional

• Many papers have been written on TADs since 1983

• Very few would stand scientific scrutiny

• Seven scientifically sound RCTs have been published on anchorage

• Four demonstrate surgically assisted anchorage superior to conventional anchorage, for maintaining molar position (226 pts)

• Further high quality RCTs desirable

THE BOTTOM LINE

. . . time for another RCT

Any difference in anchorage supplementation capability

. . . in maximum anchorage cases . . . treated with

Headgear Nance TADs?

WHAT DID I ASK?

!!

v v

. . . and what was the ‘process’ of treatment?

• Based on clinically meaningful difference in anchorage loss of 1.5mm

• Common SD 3.03 (Luecke and Johnston, AJODO 1992)

• Power 80%, alpha 0.05

• Non-compliance 20% (Sandler et al. AJODO2008) . . . therefore 25 patients per group needed nQuery Advisor statistical software

Sample Size Calculation

Maximum anchorage cases - no forward movement of upper molars allowed

Give patients ownership of the decisions

WHAT DID I DO?

78 patients

!

!

10m, 15f 19m, 7f 10m, 17f

2f discontinued 2f & 3m discontinued

22 analysed26 analysed23 analysed

14.38(1.67) 14.14(1.48) 14.15(1.25)

90 patients12 declined

WHAT DID I DO?

78 patients

!!

10m, 15f 19m, 7f10m, 17f

22 analysed26 analysed23 analysed

14.38(1.67) 14.14(1.48) 14.15(1.25)

90 patients

12 declined

Didn’t want: orthodontics - 1, to be in a study - 4 Nance - 3, HG - 3, TADs - 1

WHAT DID I DO?

78 patients

!

!

10m, 15f 19m, 7f 10m, 17f

2f discontinued 2f & 3m discontinued

22 analysed26 analysed23 analysed

14.38(1.67) 14.14(1.48) 14.15(1.25)

90 patients12 declined

WHAT DID I DO?

78 patients

!

!

10m, 15f 19m, 7f 10m, 17f

2f discontinued

2f & 3m discontinued

22 analysed26 analysed23 analysed

14.38(1.67) 14.14(1.48) 14.15(1.25)

90 patients12 declined

Mesial molar movement measured on cephalogram

!

!

97

ANCHORAGE LOSS MEASURED BY:

!

!

!

!

!

!

ANCHORAGE LOSS MEASURED ON

DIGITAL MODELS

!!

Iterative Closest Point

= algorithm for superimposition of 3D objects

“Cross section” of upper model

TARGET

SOURCE

Identify correspondences

If overall ‘fit’ < 0.8mm deemed acceptable

then move to regional superimposition

101

6 degrees of freedom

TARGET

SOURCE

ITERATION 1- ROTATE

TARGET

SOURCE

ITERATION 2- TRANSLATE

ITERATION 3 - another rotation . . . etc.

ITERATION n - TRANSLATE

Iterative closest point - ‘least squares fit’

Initial molar shell used for both start of anchorage and end of anchorage ‘Centres of

Mass’

X Y Z

X: Bucco-Palatal Y: Vertical Movement

Z: Mesio-Distal movement of the post-treatment molar

Double determination demonstrated method as precise

Analysis of CovarianceRegression models for effects of treatment on outcomes

CRIME SCENE DO NOT CROSS

CRIME SCENE DO NOT CROSS

CRIME SCENE DO NOT CROSS

0.07

0.09

0.01

0.06

0.23

R2

Analysis of CovarianceRegression models for effects of treatment on outcomes

Right molar position, as measured on digital models

P = 0.05 therefore statistically significant

BUT Nance and TAD differences clinically small & CI cross zero

Therefore - no ‘overall effect of treatment’

R2

0.07

Analysis of CovarianceRegression models for effects of treatment on outcomes

Also no ‘overall effect of treatment’ on:Left Molar positionor . . . total treatment timeor . . . total number of visits

0.09

0.01

0.06

R2

Analysis of CovarianceRegression models for effects of treatment on outcomes

Statistically significant effect of treatment on the final PAR

TADs 4 PAR points better than headgear

. . . the only real difference so far!

Investigate process of treatment

R2

0.23

GroupDuration of anchorage

months

Total treatment time (months)

Number of visits Casuals DNA

13.01+5.7 28.01+5.4 19.2+6.4 1.88+1.8 1+1.8

15.9+2.9 27.43+6.3 21.8+4.4 1.81+2.0 1+1.3

9.0+4.2 26.8+9.3 18.3+5.9 1.78+1.7 1.2+2

What did I find about treatment process?

!

!

No real effect of Tx method on molar position

Another determinant of treatment method required

Process Placement discomfort

Discomfort level days 1-3

Number of discomfort days No Problems?

4.6+2.1 3.5+2.8 2.6+4.2

Removal discomfort

Discomfort level after 3 days

Number of discomfort days

Recommend to a friend

4.3+0.78 4.9+1.1 1.1+1.4

Levels of discomfort - 6-pt. Likert scale

!

!

4.3+1.1 3.7+1.6 3+2.1 17

4.3+1.4 4.8+1.5 1.1+1.4 20/22

20

24/26

V.s imi lar

levels

both highly

recommended

!

Free comments about Nance problems

food got stuck under arch

sometimes would catch roof of mouth

it felt like it was dislodged into the gums

little inflammation

concerned how to clean under it

catching skin on roof of mouth

!

Free comments about Nance after removal

it was comfortable when fitted

easy to get used to

not very painful and easy to get on with

good and comfortable treatment

very effective

no particular discomfort in removal, the area tickled and

was tender

Free comments about TADs

uncomfortable at first, but all worth while

didn’t know he had removed screw

after a couple of days of hurting, I couldn’t feel anything

microscrews pain free, tightening braces very painful

worked well, comfortable

tender for a bit after, but all ok 24hrs later

very impressive on how the screws work

Process Requested hrs Actual hrsReported months of

HGComfort

(1-5)

13.9+3.3 10.9+4 9.9+4.7 2.87+1.4

Convenience(1-5)

Social interference

(1-5)Did it bother

you? (1-5)Recommend to a friend

2.9+1.4 3.8+1.5 2.8+1.5 13/23

What did I find in the HG group

!

!

Free comments about HG problems

!

hard to sleep

pain sometimes

at beginning getting used to fitting in right slots

broke whilst on holiday, pain sometimes

uncomfortable at night when sleeping, also when putting in

left mark on hair

difficult to eat and drink, rubbed cheek

impracticle (sic)

hurt to lay down on pillow

Free comments about HG after removal

!

wouldn’t rec if alternative,

makes you very conscious

very happy with teeth afterwards

uncomfortable to sleep, but got used to it

got used to it but glad not to wear now

it works but embarrassing to wear

don’t understand how people can wear it,

even in sleep I would take it off

Few differences between techniques, in terms of molar position, as measured by superimposition of 3D models

Benson at al. (2007) and Feldmann and Bondemark (2008) both reported surgical anchorage better . . . they were using OSSEO INTEGRATED implants

Discussion

All previous studies based on cephalograms with all the inherent errors:

patient positioning errors

errors of projection

measurement errors

landmark identification errors

bilateral structures ‘averaged‘ on imprecise sketchings

Discussion

Being able to separate left and right molar movement adds a degree of precision

Discussion

TAD problemsone placement issueone became loose

one TAD fracturedtherefore 2.8% failure rate

No differences in terms of molar position

Best PAR scores in TADs cases

Discomfort levels similar with Nance and TADs

Nance and TADs both highly recommended

HG least recommended method

TADs - treatment of choice if absolute anchorage

Conclusions