Join me for the next interview in orthodontics with Ravi Nanda

Ravi is an authority in orthodontics, having authored 10 textbooks and published over 200 peer review publications, he is also the current editor-in-chief of Progress in Orthodontics

We get to hear of Ravi’s story of how he came in to orthodontics, his drive to ask research questions and how he has achieved so much. Ravi describes his mentors, and explains why he has never stopped learning, and why no orthodontist should either.

Facebook: @ravi.nanda.35

Instagram: @ravinanda

Textbooks

Esthetics and biomechanics in orthodontics

https://www.elsevier.com/books/esthetics-and-biomechanics-in-orthodontics/nanda/978-1-4557-5085-6

Principles and biomechanics or aligner treatment

https://www.elsevier.com/books/principles-and-biomechanics-of-aligner-treatment/nanda/978-0-323-68382-1

Join me for a summary of Madhur’s lecture on the biomechanics and aligners, where he describes the fundamentals biomechanics of aligners, explains the reason for the shortcomings of aligners and his tips to reduce them.

How do aligner work?

Two approaches

How to aligners treat malocclusions

Deep bite

Openbite

Advantages in aligners when compared to fixed

Space closure

How good are aligners at moving teeth

Root movement

Space closure

Root movement

Why can’t aligners move teeth as efficiently as braces?

First principles based understanding

Material factors

Biomechanics is the law – everything else is just a recommendation

Madur’s lecture in full available on youtube:

https://www.youtube.com/watch?v=ycNokW1ojIY&t=3s&ab_channel=orthobites.org

Join me for a summary of Dalia El-Bokle’s lecture looking at disarticulation, and how they can be utilised to correct malocclusions in 3 planes of space. In this summary a novel use of disarticulation is described for class 2 and class 3 correction. This lecture follows Dalia’s publication in the AJODO 2020.

Definition:

disocclusion by using bite turbos or so the teeth has freedom to move in the three planes of space

Indications:

Vertical

1. Deep bite: Anterior bite block to enable posterior eruption

2. AOB: Posterior bite blocks to enable posterior intrusion

a. 1mm intrusion posterior 4mm OB increase Hernandez et al 2017

Transverse

1. Correction of functional displacement / shift : Posterior bite block in conjunction with expansion appliance – bite blocks preventing inteference

2. Pseudo class III: With a Catlan’s appliance or resin blocks Kravitz 2019, mindful when using on lower arch to include multiple teeth as it may result in mobility of the lower incisors f placed an 2 only.

Using an anterior bite block will help in the clockwise rotation of the mandible that will help in Class III correction Liou et al 2018 APOS

Other

1. Anchorage reinforcement, large amounts of bite block create deep intercuspation between upper and lower teeth, preventing mesial movement of the posterior segment Georgio Fiorelli et al 2013

2. Unlocking the occlusion.

New methods

1. D-BIBRE AP correction AlBokle 2020

2. Transverse correction Georgio Fiorelli 2013

Bonded inclined bite raisers elastics D- BIBRE .

Use of disarticulation as a functional appliance for class 2 correction

What is it?

Flowable composite Triad Gel placed on the upper and lower 1stpremolar

How does it work?

· 45 degree Inclined planes are formed from the RMGIC which disarticulate the patient in a forward direction.

· Activation 2mm

· Indirectly made on models, transferred by transfer tray

· Reactivate chairside with Triad gel

· Removed after 7 months

· Night time class 2 elastics guide the patient into a forwards position

Occlusal cant and Asymmetries

Mild mod cases, Georgio Fiorelli 2013

· Mandibular repositioning with triad gel, full coverage bonded in the lower arch buccal cusps group guidance

· Results  22/32 stable TMJ 2 years after treatment follow up.

Recommend CBCT for condyle assessment

Bite turbos:

Anterior bite turbos:

· Bonded Resin or Metal turbos (High incidence of Debonding)

· Acrylic plane with modified Nance

· Digitally designed – even occlusion

Increased overjet

· Bite turbo extended = increase fracture and trauma

· Apply turbo to caninex

Placement tip

· Use Articulating paper to mark contact (so minimize the area covered by turbo)

· Don’t etch the fossa so easily removed

· Bite turbos need to be planned based on the estimated CR and the movement required,

Link to full lecture

The Art of Disarticulation in Orthodontic Therapy - YouTube

Content by AbdAllah Sharafeldin

Edited and produced by Farooq Ahmed

Join me for the next interview in orthodontic, with video!

Simon is an orthodontic innovator and contributor of research, based in private practice in Bern with a commitment to digital technology in orthodontics, having lectured 61 times on the topic.

We get to hear of Simons’ story of how he came across digital technology in orthodontics and what drives him to continue to innovate in orthodontics. Simon describes his mentors, what he took for them and how he applies these principles to his decision making. We discuss expansion in orthodontics and how Simon uses a skiing hardware to motivating patients!

Facebook: @Simon.Daniel.Graf

Instagram: @simon_graf_at_smile_ag

www.orthoinsummary.com

Join me for Neal Kravitz’s lecture on canine substitution and the clinical management of it. Focusing on bracket selection and canine recontouring

Case selection

· 2 key factors

o Profile

o Mandibular crowding

Bracket selection

· Goal:

o Canine substitution:

§ Reduce canine root prominence

o Premolar substitution:

§ Hide palatal cusp

o Molar interdigitation:

§ class 2 cases

4 bracket choices for canine

· UR1 (+17 tq, + 4 tip)

· Achieves ideal torque

· Requires flattening of canine labial face = plasty

· UR2 (+10 tq, + 8 tip)

o plasty and step out

· UR3 inverted (+7tq, +8 tip)

o Flipped U3

o Likely require addional torque

· LL5 inverted (+17 tq, +2 tip)

o Suggested by Marco Rosa

o Same torque but no reduction labial face – compound contour

Upper 1st premolar bracket selection

· U3 or U4 slightly distal – palatal cusp hidden

· See orthoinsummary blog on Premolar substitution

Upper molar tube selection for class 2 finish

· Achieve good interdigitation, the U6s tubes have 10 degree rotation labially, which does not interdigitate with the lower 5/6 embrasure space well, the 0 degree offset on lower 6s / 7s (-20 / -10 torque)

· No change in tip and torque

Tooth reshaping

· Canine morphology frequently triangular, more so mesial then distal

· Reduction – frequently underdone

o Mesial IPR – Kailasam 2021 1.2mm enamel mesial

o Incisal reduction

o Palatal reduction

Interproximal reduction for Bolton’s discrepancy

Class 1

· Canine substitution with lower extractions = maxillary excess

o = IPR uppers to correct Bolton’s discrepancy (U 1, 3, 4)

Class 2

· Canine substitution, lower non-ext = Mandibular excess

o = IPR lower anterior to correct Bolton excess (U 1, 3, 4)

Cosmetic bonding

· Step 1: Mesial step out

o Improve marginal ridge with central

o Reduce occlusal interference lower arch

· Step 2: Mesial build up

o Mesial incisal

o Line angle not that I practice it but they are essentially

§ Transition between proximal and labial face

§ Can make canine look narrower through altering this transition, ie the shallower gradient  narrower the tooth

Retention and review

· Group function and lateral clearance

· Long term fixed retention 4-4

o Length of bonded retainer

§ Lower canine mid to distal lateral incisor labial measurement = lingual 3-3 measurement

o Material – memotain Custom NiTi

References

Rosa, M.A.R.C.O. and Zachrisson, B.U., 2001. Integrating esthetic dentistry and space closure in patients with missing maxillary lateral incisors. Journal of Clinical Orthodontics, 35(4), pp.221-238

Kokich Jr, V.O. and Kinzer, G.A., 2005. Managing congenitally missing lateral incisors. Part I: Canine substitution. Journal of esthetic and restorative dentistry, 17(1), pp.5-10.

Kravitz, N.D. and Shirck, J.M., 2017. Measuring Bonded Lingual Retainers. Journal of clinical orthodontics: JCO, 51(5), pp.294-294.

Kravitz, N.D., Miller, S., Prakash, A. and Eapen, J.C., 2017. Canine bracket guide for substitution cases. J Clin Orthod, 51, pp.450-453.

Join me for the next interview in orthodontic, with video!

James is a private orthodontist from Perth Australia, a clinician with a passion to share, teach and learn. James has authored a chapter on 3D diagnosis and treatment planning and has 22,000 followers on Instagram with 625 posts relating to orthodontics on a variety of topics including biomechanics, TADs, orthodontics and restorative / periodontal management

We get to hear of James’ thoughts on social media Vs conventional orthodontic education, his thoughts on biomechanics, and advice for orthodontists.

Facebook: @jamesandrewsortho

Instagram: @dr.jamesandrews

Youttube video

Indications and application of minimum anchorage mechanics Vishnu Raj

VIDEO NOW AVAILABLE : https://youtu.be/UMFlDdPCopY

Join me for a summary of Vishnu Raj’s lecture looking at minimum anchorage mechanics, with a focus on utilising Burstone’s Geometries for a simple and effective way to manage anchorage, a well explained lecture with useful tips.

Indications

Classification

· Group C minimum anchorage

o 75% or greater posterior movement into the extraction space

o Incisor movement minimal

Indications

· Mild anterior crowding

· Posterior crowding, ectopic 2n molars

· Missing 5s

Aetiology of crowding

· Compared to pre-historic man = 30% increase = greater likelihood of impaction of 8s and 7s

2nd molar eruption – posterior crowding associated with Hwang 2017

· Wider teeth and crowding

· Maintenance of E space

Premolar extraction and posterior crowding Turkos 2013

· Increase space for 3rd molars

· Mesial movement of 1st and 2nd molars

· Mesial movement molars = 3.2-4.6mm

Biology and mechanical considerations

Anchorage considerations

· Upper molars move more mesial then mandibular molars due to :

o Growth of mandible

o Bone type and density

§ Cortical bone more resistance to tooth movement Devlin 1998

· Posterior maxilla = 0.31gcm2

· Anterior maxilla 0.55 gcm2

· Mandible 1.11gcm2

· Upper incisors tend t retract less then lower incisors Gu 2017

o Large root surface area upper 2-2

o Prescription torque upper high – anchorage loss

Preparing anterior anchorage

· Allow working archwires to be passive for 4-6 weeks

· Start space closure 1-2 weeks after extractions

· Curve in archwire to accentuate inclination to resist over retraction

·

· Increase 2nd order 2-2

· Increase 3rd order 2-2

· Elastics

2nd order bend what is it

· Gable bend or V bend 15-25 degrees

· Bend closer to anterior segment

· 6 geometries between slots Burstone 1988

· Effects:

o Increases anterior anchorage

o Root parallelism

Increase 3rd order

· Increase stiffness SS,

· Torsional stiffness SS:TMA:NitI 10:3:1

· increase cross section 21x25

Decrease wire slot engagement angle

3rd order bend

Conclusion

· Posterior crowding to be considered

· Mesial movement 1st molre more predicable to resolve posterior crowding

· Anterior anchorage

· Control of incisor and lip position

Join me for the next interview in orthodontic,

Maz is a private practice orthodontist from Saint Louis, a Diplomate of the American Board of Orthodontics and a Key Opinion Leader for Align Technology

We get to hear of Maz’s interest in aligners, his thoughts on aligners Vs fixed appliances, and on key opinion leaders in orthodontics.

@mazmoshiri

To watch the video click below

Dr Maz Moshiri interview video

Please do subscribe to catch the next episode and see the website for more episodes

www.orthoinsummary.com

Orthodontic treatment in stage IV periodontitis patients. Spyridon Papageorgiou. EFP Euro series

Join me for a summary of the EFP’s lectures on periodontitis and orthodontic treatment. The orthodontic lecture was by Spyridon Papageorgiou and two lectures from periodontists, The topic explored related to stage IV periodontitis and orthodontics

Stage IV – new classification from world workshop Papapanou 2017

· Clinical attachment loss 5mm+

· Bone loss extend to mid third of root

· Malocclusion / masticatory dysfunction

o Bite collapse:  Loss of posterior support resulting in tooth movement in the direction of force – (complex), over-eruption and incorrect relationship with antagonistic teeth

o Drifting Due to mastication forces

o hypermobility due to secondary occlusal trauma

o Even if periodontally stable Further tooth movement 33% at 2 years Zhang 2017.

§ Orthodontic pathological tooth movement: Loss of space in the arch, mesial migration, crowding, crossbites

Periodontal Treatment for stage IV Sanz 2020 Kloukos 2021

1. Stage 1 : Supragingival debridement, oral hygiene, professional plaque removal, risk factors

2. Stage 2 – Supra and subgingival debridement – change the subgingival biofilm Interventions: Repeat subgingival therapy, surgical: flap, reactive, regenerative (Barrier membrane, Enamel matrix derivative)

3. Supportive periodontal care

Effects of appliances on the periodontium R/V Papageorgiou 2018 / 2021

· Transient change in microbiology from orthodontic appliances

· Bone loss marginal 0.5mm

· Clinical attachment loss 0.11mm

· Recession

o Greater recession 1.9mm

o Gingival recession and loss of attachments Salti 2017

· Greater if hyperdivergent

· GTR no consistent clinical benefit

· Fixed better than aligners PPD 1.6mm – small study

· No difference in ligation, conventional self ligating

· 1-3 months periodontal intervals in orthodontic treatment better outcomes than 6 monthly Jiang 2021

Biomechanics

Adapting orthodontic treatment

· Centre of rotation moves apically

o Same force = larger moment

o Greater extrusion forces

· Simulate intrusion in normal periodontal support vs reduced Kettenbeil 2013 Bagdadi 2019

o Centre of resistance moves apically 2-3mm

o Increased tooth movement 1.6-2.5, increase strain in PDL 1.4-2  possible harm to periodontium

Retention

· Generally different fixed retainers compatible with periodontal health and not detrimental Arn 2020

· Metal bonded retainers still allow physiological movement

· Effect of mobility – UNKNOWN

· Greater failure of bonded retainers in more severe periodontal cases (up to stage 3) Han 2021

· 10 year follow up of ortho and perio = no significant recession or tooth loss BUT increase in root fracture – possibly due to increased forces?

Conclusions

· Orthodontics does not negatively impact periodontal condition

· Initial anti-infective periodontal treatment

o Unsure type of periodontal treatment, GTR unclear, unsure what time to start after perio

· Appliances

o Fixed maybe better

o Segmental better than continuous archwire

o Adapt biomechanics due to attachment loss

· In orthodontic treatment – patients attend periodontics at 1-3 months

· Retention after orthodontic treatment – greater failure rates

· Possible increase in root fractures

· Limited evidence