Join me as I describe Jassin Arnold’s lecture describing lower incisor extraction, its indications and management

Why should we use it?

o Reduces anchorage demand, entact posterior segments

o Improve dental occlusion in a shorter time frame

o Profile improves in mandibular protrusion cases Levin 1964

When should we use it? Systematic review Zhylich 2011

o Mild-moderate class 3

o Edge to edge anterior occlusion

o Crossbite with mild anterior mandibulae excess

o 4.5mm tooth size discrepancy of lower to upper Matsumoto 2010

When should we not use it?

o Severe OB

o Bimaxillary crowding

o Triangular lower incisor and minimal crowding 3mm less

o High insertion of labial frenum = gingival recession I removed

Risks of lower incisor extraction

o Black triangle

o Increased overjet and overbite

o Tendency for spaces to reopen an aesthetic zone

o Create tooth size discrepancy

Bolton’s anterior analysis

o Anterior ratio 77% 3-3 lower Vs 3-3 upper

Cases:

o Class 1

o 4mm of crowding of the lower incisors

o Bolton’s anterior analysis 87% - excess lower incisor tissue

§ = Extraction 1 lower incisor = 74.8% – TOO LOW (ideal 77%)

· = Solution strip upper 2-2 by 2mm = 78% Bolton’ ratio

o Case 2

o Molars ½ II, increased overjet 6mm, lower incisors 4mm of crowding

o Bolton’s anterior analysis 87% - excess lower incisor tissue

§ = Extraction 1 lower incisor and stripping of upper incisors = 77%

§ = Extraction of 2 upper premolars as well

· Stripping upper 2-2 to achieve ideal occlusion in the anterior 3-3 segment

· Extraction of Upper 4s to correct the increased overjet

References

Zhylich, D. and Suri, S., 2011. Mandibular incisor extraction: a systematic review of an uncommon extraction choice in orthodontic treatment. Journal of Orthodontics, 38(3), pp.185-195.

Join me for part 2 where we explore Mohammed’s rules on which teeth to extract, anchorage assessment and management, Bonding 2nd permanent molars, elastics and treatment planning adults Vs children

Which to extract 4 or 5

o CAT-V principle

§ C: Clinical condition of the teeth

§ A: Anterior crowding: 8mm + extract the 4s, 8mm – 5s or 4s

§ T: Transverse: Lower 5 will help narrow the arch

§ V: Vertical: Extraction of 5s for high angle cases will improve the overbite

Molar outcomes in treatment planning

o Non-extraction or extraction of 4 premolars = class 1

o Extraction of 2 upper premolars: Class 2

o Extraction of 2 lower premolars: Class 3

o Extraction of 1stmolars: Ignore them! Will not change the final molar relationship

o Type A (absolute) No movement of the posterior segment

o TADs – HG – extraction pattern

o Type B posterior movement moves mesially by 25%

o Nance, sectional archwires, intermaxillary elastics, HG

o Type C posterior movement moves mesially by 50%

o Reciprocal movement of anterior retraction

o Type D posterior movement moves mesially by 75%

o Anterior anchorage (reverse HG, TADS)

o Biomechanics: intermaxillary elastics – 2nd order bends – inverted lower brackets

Anchorage loss in the lower arch is less than upper arch

· Differential alveolar bone density

· differential root surface area

· differential Buccolingual width of molar

· differential anterior palatal root torques

o Don’t bond to for anchorage

o Bonding results in loss of anchorage due to 7s distally tipped, uprighting results in loss of anchorage

o Elastics =  rotation of mandible

o Overjet 0.5mm correction per month with class 2 elastics

o 1:3 ratio of vertical: horizontal effects

o Unilateral intermaxillary elastics in one side only =  cant

o = Use vertical part time elastics on the other side

o Elastic should be stretched 3 times its diameter to give the force

o Don’t expect you can distalize more than 2.5 mm unless you extract 7 OR 8

o Distalization lowers without TADS is very limited

Adults Vs growing patients

· Growing patient:

o Elastics +++

o Distalisation +++

o Functional appliances +++

o Extractions +++

· Adult

o Extractions +++

o Elastics ++

o Distalisation +

Join me for Mohammed Al Muzian’s rules in orthodontic practice

Part 1 we will cover half of the 32 tips the following topics: Knowledge Vs confidence, space requirements and creation, IPR, expansion, inclination changes and treatment planning

Knowledge Vs confidence

· We tend to be overconfident at the beginning of our careers, and under-confident in the middle. Kruger’s curve

Space assessment

Calculate space requirements in the lower arch Use T-SCOTAR

o Torque

o Spee curve

o Crowding

o Overjet

o Teeth size discrepancy

o Angulation of teeth

o Rotation

Space creation

Use SPEEDAR for space provision

o Stripping

o Proclination of incisors

o Extraction

o Expansion

o Distalisation

o Angulation

o Rotation

IPR

· A maximum of 0.75mmof IPR per tooth can be tolerated depending on the shape and size

· Up to 4-6mm can be achieved sometime, but you need to balance that with the opposing to avoid TSD

Inclination change and effects

o 2 mm of crowding= 50 of proclination =1 mm change in the overjet and overbite (draw bridge effect)

o 2 mmof spacing= 50 of retroclination=1 mm change in the overjet and overbite Eberhart et al (1990), Sangcharearn and Hob (2007), Kapoor 2014, Aziz et. al 2011

o All cases can be retroclined or proclined by 5 degrees without affecting the PDL..

o Some may accept 10 degrees if I have good gingival biotype, thick symphasis, no recession, no PDL problem and Avoid Jiggling forces.

o Do not procline the uppers more than 1200

o Do not retrocline the lowers to less than 800

· Lower arch: Cannot expand (unless Class II/2 and canines trapped )

· Upper arch: Can expand

o Maximum 0.5mm of space per 1mm expansion

o Why do you lose half of the expanded space? Due to the backward movement of the anterior teeth.

· Expansion retainer:– wire reinforcement of essix retainer

· Bonded RME

o Design with big hole in housing: to easily remove the RME

o Expansion amount guided by lower arch ideal alignment (Andrews plane)

o Use Monoject or Water jet (flosser) with CORSYDOL to clean under the RME

o Plan around the lower arch

o Rationale:

§ Limited labio-lingual alveolar bone

§ Upper arch labio-palatal bone can be remodelled

o MOOH – planning around the lower arch

o Midline

o Overjet

o Overbite

o Health of PDL

§ If ALL above cannot be achieved non-extraction = extractions required

Join me as I summaries Kleber’s lecture on the use of intermaxillary elastics in orthodontics, topics of force magnitude, side effects and how to counter them, use of a sliding jig and stability are described.

Force magnitude more important than the size of the elastics

· Large variation forces used by orthodontists in Kurol 1996

· Use a gauge on every patient

· Excessive = damage to PDL and RR

· Force required

o Retraction of upper incisors = 250g each side Oesterle 2012 / 350 g Proffit

o Individual

Class 2 elastics effects

· Distalise anterior teeth

· Mesial of lower posterior teeth

· Extrusion of upper anterior teeth

· Extrusion of lower posterior teeth

· Rotate occlusal plane clockwise

· Retrusive upper lip

· Protrusive lower lip

How to avoid side effects

· Case selection: avoid high angle cases

· Avoid upper arch retraction on round wire

· Reduce vertical vector

o Increase horizontal distance mesial of U2s and L7s

o Change the vertical vector by using a sliding jig

§ Sliding jig moves vector from above the brackets upper, to below the bracket, lower arch force from below the bracket to above the bracket

§ Sliding jig – directs upper arch forces to the molars – more efficient than to archwire only or canine

Class 2 subdivision

· Class 2 one side, class 1 other side.

· Of dental origin, no skeletal

· Usually cant on class 2 side, with arch up on the RHS

· Class 2 elastic on effected side

· Distalisation on URQ with sliding jig

· Retraction of the arch – on rectangular SS – 350g

Torque

· Can be lost upper incisors

· Place torque into the archwire during the retraction – not after retraction

Finishing

· Triangular elastics

Class 2 elastic stability

· Patient may posture: assess displaced mandible / CR

· Tooth movement:

o Bony formation may not be complete

o PDL may not be reorganised

§ REQUIRE 3 months of wear for stability, bone growth and PDL

Join me as I interview Daniela Storino. Dainiela is dual trained in both pedodontics and orthodontics and has been in private practice for 21 years. She is a guest Professor at Vienna School (VieSID) and studied under Professor Sadao Sato and Dr. Rudolf Slavicek. She is an expert in craniofacial medicine and occlusal medicine.

We get to hear Daniela’s one piece of advice to all orthodontists and where she hopes orthodontics is going in the future, as well as more about Daniela's thoughts on extractions and IPR.

Want to know more, please see the link  Vienna School of Interdisciplinary Dentistry

Daniela’s lecture on the aetiology of malocclusion was also the very 1st podcast  with orthodontics in summary in April 2020, see the link below

True Aetiology of Malocclusion

Join me as I summarise day 3 of the Saudi Orthodontic Clear Aligner meeting, where class 2, class 3, Invisalign first and SLX aligners  are discussed.

NOTES FOR EACH LECTURE ARE AVAILABLE FROM THE DESCRIPTION ON THE WEBSITE WWW.ORTHOINSUMMARY.COM

The following lectures are covered:

1. Biomechanical protocols and strategies for the correction of sagittal malocclusions part 1 and part 2 Juan Carlos Rivero Lesmes

2. Invisalign First - after 50 cases. Pedro Costa-Moneiro

3. The Keys of Sagittal Treatment with Aligners Flores Allen

4. How to plan the perfect clincheck. Pedro Costa-Monterio Isabel Flores Allen

5. A new paradigm for clear aligner therapy. Mario Chorak

Please like and subscribe if you find it useful!

*Important to note the information is from our interpretation as individual professionals, and may incorporate our opinions*

#orthodontics #farooqahmed #almuzian #orthodonticsinsummary #aligners, #invisalign, #occlusion #class2, #class3, #SLX # PedroCostaMoneiro, #JuanCarlosRiveroLesmes, #MarioChorak, #FloresAllen

#orthodontics #farooqahmed

@farooqahmed_orthodontist

@orthoinsummary

Join me as I summarise day 2 of the Saudi Orthodontic Clear Aligner meeting, where basic biomechanics, in house aligners and aligner research is discussed.

NOTES FOR EACH LECTURE ARE AVAILABLE FROM THE DESCRIPTION ON THE WEBSITE WWW.ORTHOINSUMMARY.COM

The following lectures are covered:

1. Aligner orthodontics. from basic research to clinical application. Tommaso Castroflorio

2. Aligner orthodontics. in growing patients. a research based approach. Tommaso Castroflorio

3. Overcoming aligner limitations by using palatal mini-implants. Benedict Wilmes

4. Important pearls for in house aligners. Renato Martins

5. Clear aligner therapy. Empty promises or wishful thinking. Ki Beom Kim

Please like and subscribe if you find it useful!

Join me as I summarise the 1st day of the Saudi Orthodontic Clear Aligner meeting, where Mazyar Moshiri delivered a masterclass on biomechanics with aligners.

Conclusions:

· Attachment design: perpendicular to resultant force

· Rotations: Place oblique attachment to counter intrusive force of aligner

· Overcorrect torque, add mesial crown tip due to wagon wheel effect

· Deep bite: synergistic movements: proclinatiion and extrusion

· AOB: synergistic movements: retroclination and extrusion

Concepts

Intrusion attachment

1. Intrusion on aligners

a. No intrusion attachment

o Require attachments on adjacent teeth

o If loss of tracking = occurs on adjacent teeth, with the aligner extruded off the teeth

Rotation and intrusion

· Force labial face and palatal face to create rotation moment.

· ‘Squeeze force’ occurs =  vertical force = intrusion force.

· Solution

o Optimised attachment = Extrusive vector, usually gingival bevel and oblique

o Resolve resultant force, horizontal and vertical = oblique attachment

Torque

· Wagon wheel effect, for every 4 degrees of lingual crown torque there is distal crown tipping / mesial root tipping.

o Solution: OFFSET with 1 degree of mesial crown tip

· Torque lags behind, takes longer , like rectangular NiTi archwire

· Buccal root torque: Upper molar buccal attachment to provide extrusive buccal force to create moment.

Design of attachment

· KEY CONCENT: Attachment perpendicular to the force

· Perpendicular force to rotation = Long vertical attachment

· But rotational force has intrusive force the ‘squeeze force’

o Therefore horizontal and vertical force = attachment perpendicular to the force = oblique attachment

Root tip

· Open space 0.2mm interproximal =  so more plastic wrap around tooth

· Then start root movement in staged way.

Deep bite

Concept:

Synergistic movements, procline = relative intrusion

Staging AP movements

o Proclination 1st to open the bite

o Then IPR

§ Not at the same time as IPR = retroclination, therefore should not procline and iPR at the same time as bite will  not open

§ Does round trip – procline and intrude, then IPR and align

Staging deep bite

· Staging of OB, canines intrude 1st, then 2-2

· Likely loose tracking on lower incisors or 4s – anchorage horizontal G5/G7 attachments

Curve of Spee

· If COS not corrected, then AP also difficult to correct

· If not correct COS:

o Posterior openbite – caused by anterior interferences

§ Caused by inadequate attachment

§ Lack of over correction

OGN case deep bite

· Order 10 passive aligners near end stage pre surgery = minimum 2 months to make up for ‘lag’ or vivera retainer / essix – thicker, greater expression of torque

· TAD – intermaxillary elastics x 2

o TAD maxilla:

§ Buttons lower premolars

§ Intermaxillary elastics to guide lower premolar teeth into the tray

Openbites

Concept

Synergistic movement: Retrocline and extrude

· Aligners do not extrude along the long access

· Aligner pushes tooth lingually and extrudes in the process, retroclines

Posterior intrusion is unpredictable, anterior extrusion is more likely

Thank you to the Saudi Orthodontic Society for facilitating this podcast

Join me as I summarise Kevin O’Brien’s lecture looking at class 2 treatment, and answering the question of early Vs late treatment and fixed Vs removable appliances.

Kevin answered 3 main questions looking at systematic reviews:

1. Early Vs late treatment

2. Fixed Vs removable treatment

3. Patient relevant outcomes of Class 2 treatment

1. Early treatment (8-10 years) Vs late treatment (2-phase Vs 1-phase)

Cochrane Review: Orthodontic treatment for Class 2 Batista 2018

o No difference OJ ANB, PAR, Self concept Small order overjet 0.21mm

o No benefit to early treatment for most, and KOB suggests treatment at conventional timing in adolescence is appropriate

o Statistical difference in Trauma:

§ Experience of trauma:

· Adolescence 31.7%, Early 19.7% = 12% difference

o Relative risk reduction: 33%. Define terms, 12% is absolute risk, looks at total sample, those who have trauma and not. Relative risk is looking at the trauma sample, and what is the reduction through the intervention in the chance of it.

§ Through the intervention, 1/3 of those who would have has trauma as an adolescent, wont with early intervention

o Numbers needed to treat 1:10,

Information of benefit of early treatment

o Reduction in trauma is clinically significant

o Overall treatment time, nearly 2 x longer

o Greater cost

o Poorer occlusal outcomes

§ Patients ‘burn out’

· Moderate uncertainty in early Vs adolescent treatment

o Repeat study as lots has changed

2. Fixed Vs removable in late treatment (1-phase)

Cochrane review 2018 Batista

· Skeletal changes ANB:

o Removable: 2.37o = Statistically significant

o Fixed: 0.53 o = Statistically significant

§ Removable greater difference = 1.84, clinician to decide if clinically

· Overjet:

o Removable: 4.6 = Statistically significant

o Fixed: 5.4  = Statistically significant

§ No real difference

· Uncertainty was high in this review repeat studies

3. Patient outcomes

· Trials focus on treatment outcomes, but RCTs in orthodontics describe QOL in only 10% of trials, smaller number of functional improvement

· Might be missing effects of treatment

o Example of missed effects: KOB Twinblock Vs Herbst 2003

o Compliance:

· Herbst 2 x greater chance complete treatment

· Patient perception: TB worse

o Non-compliance of twinblock

§ Problems eating (speech, sleep)

§ Influenced school work

§ Bullying (embarrassed)

References

Batista, K.B., Thiruvenkatachari, B., Harrison, J.E. and D O'Brien, K., 2018. Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children and adolescents. Cochrane Database of Systematic Reviews, (3).

Thiruvenkatachari, Badri, Jayne Harrison, Helen Worthington, and Kevin O'Brien. "Early orthodontic treatment for Class II malocclusion reduces the chance of incisal trauma: Results of a Cochrane systematic review." American Journal of Orthodontics and Dentofacial Orthopedics 148, no. 1 (2015): 47-59.

Tsichlaki, A. and O'Brien, K., 2014. Do orthodontic research outcomes reflect patient values? A systematic review of randomized controlled trials involving children. American Journal of Orthodontics and Dentofacial Orthopedics, 146(3), pp.279-285.

Join me as I summarise Roberto’s lecture looking at transpositions.

Roberto describes 2 cases of true transpositions, treatment options, mechanics and methods of camouflage.

Transposition: defined an anomaly in which 2 adjacent teeth have interchanged their position in the arch Peck 1993

Classification: 1995 by Peck and Peck

1. True transposition: root and crown

2. False transposition: crown only

Up to 2003 the majority of orthodontists accept transposition and this figure changed as currently most orthodontist tend to correct transpositions.

Case 1 Maxillary canine-premolar transposition - camouflage

Treatment:

1. Interceptive early RME spontaneous correction of maxillary canine-premolar transposition Maspero 2016 86% corrected.

2. Premolar camouflage: Although Sandler 2017 no difference in canine and premolar aesthetics for professionals and lay people transposition are different:

· Gingival height of the canine high compared to the premolar, if we don’t grind the canine tip,

a. Check smile line, low smile line = result will be acceptable by the patient.

b. End with slight intrusion in the premolar – so gingival height matches the canine Build up the premolar to make It look longer

Case 2 Maxillary canine-premolar transposition, canine high - correction

Treatment:

· Cannot apply conventional mechanics through the center of resistance of the canine due to vertical position

· Sectional wire:

· Wire from 1st molar to 1st premolar (bypass canine)

· Bent back on itself to then engage the canine (in the premolar position)

· = Class 6 Geometry (burstone) allowing intrusion of the canine during meisalization and by passing the premolar

· Torque:  Need to keep the root palatal

· Apply couple one wire and with another wire he prevents the crown movement

· Auxiliary springs like warren spring or Goodman springs

· Single root torque to a tooth

Mandibular arch transpositions

· Less demanding to correct the lower arch transpositions due to decreased aesthetic requirements

· Word of caution to correct transition:  Limited bucco-lingual width

Danielsen JC, Karimian K, Ciarlantini R, Melsen B, Kjær I. Unilateral and bilateral dental transpositions in the maxilla—dental and skeletal findings in 63 individuals. Eur Arch Paediatr Dent [Internet]. 2015 Dec 1 [cited 2020 Nov 18];16(6):467–76. Available from: https://link.springer.com/article/10.1007/s40368-015-0196-6

Leonardi R, … MF-TEJ of, 2011 undefined. An association between sella turcica bridging and dental transposition. academic.oup.com [Internet]. [cited 2020 Nov 18]; Available from: https://academic.oup.com/ejo/article-abstract/33/4/461/398881

Maspero C, Giannini L, Galbiati G, … MF-M, 2016 undefined. Effect of rapid palatal expansion in early tratment and spontaneous correction of maxillary canine-first premolar transposition. europepmc.org [Internet]. [cited 2020 Nov 18]; Available from: https://europepmc.org/article/med/27075370

Shapira Y, Finkelstein T, Kadry R, Schonberger S, Shpack N. Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations. Case Rep Dent [Internet]. 2016 [cited 2020 Nov 18];2016:1–6. Available from: https://www.hindawi.com/journals/crid/2016/5043801/abs/

Sandler P. Extraction of maxillary canines: Esthetic perceptions of patient smiles among dental professionals and laypeople. 2017 [cited 2020 Nov 19]; Available from: http://derbyhospitals-nhs.archive.knowledgearc.net/handle/123456789/1160