orthodontics In summary

Does whitening have a role in orthodontics? A popular cosmetic procedure which 1 in 4 adults partake in, and was proposed recently at a conference as part of finishing in orthodontics. So this podcast reviews whitening as a topic and the latest evidence in combining whitening with aligners.

Reminder the podcast is an opinion piece and is the independent work of myself and the orthodontics in summary team.

24% of adults have whitening their teeth (dentalhealth.org)

How does it work:

Bleaching is the chemical changing of darker staining on teeth termed chromogens, with the active ingredient hydrogen peroxide. 

Hydrogen peroxide reacts to oxidize the chromogen, which becomes a lighter colored compound. 

Hydrogen Peroxide is not a stable chemical, so Carbamide peroxide  is used, which roughly breaks down to 1/3 H2O2 when mixed with water. 

Hydrogen Peroxide UK limit 6%, or Carbamide peroxide 16% is used, USA, greater concentrations are used with 10% hydrogen peroxide for at home whitening, and 35% hydrogen peroxide for in office bleaching. 

Children

UK guidelines GDC 2014 – no bleaching until 18, unless purpose of treating or preventing disease.’

USA: The AAPD 2023 s Safe and effective for whitening discolored teeth of children and adolescents. Avoid full-arch bleaching mixed dentition and primary dentitions

Risks

Sensitivity -

about 80% of patient’s experience sensitivity 

• Tooth sensitivity usually occurs at the time of treatment and can last several days

• Upper lateral incisors – greatest sensitivity

• Directly correlated with concentration

• Greater intensity if tooth was restored Bonafe 2013

Gingival irritation

• gingival irritation begins within a day of the treatment and can also last several days

Susceptibility to demineralisation

• Suggested surface demineralization occurs as the pH of the whitening agent are acidic and hydrogen ions affect the enamel crystals, 

• No difference when using manufacturers protocols including 35% H202 Tompkins 2014

• However aggressive whitening: excessive use of in office whitening Shi 2012

How long does the whitening last

Duration of correction, depends on lifestyle, with smoking and coffee reducing the correction. Expected 6-12 months of stable colour change. Wiegand 2008

Aligners

• Bleaching tray is different – reservoir for bleach, 1 or 1.5mm soft ethylene-vinyl acetate (EVA), Straight cut 2mm beyond gingiva or scalloped, with 2 mm extension onto the gingiva giving a better seal and greater patient comfort. Dosage dots to limit application beyond 2mm

• Aligners 

• Usually gingival bevelled, but as effective as bleaching trays, Levrini 2020 improvement of 3.5 shades on average  Seleem 2021

• tooth sensitivity and gingival irritation does not disrupt of treatment 16% Carbamide peroxide Oliverio 2019, Levrini 2020

• 2 mm thick layer of gel is advised at incisal or facial central surface of the aligner 

• Bleaching with attachments present, when bleaching complete attachments removed:

• hydrogen peroxide diffuses through spaces between enamel prisms

• The composite attachment was thought to affect pigment infiltration, however with enamel polishing after composite removal, color equalization occurs  without discrepancies Staley 2004

• Minimal change to aligner structure Oliverio 2019

Retainers as bleaching trays?

Use of 0.8mm Zendura, no resivoir, effective bleaching with marked or extremely marked improvement in 78% of cases with 10% Carbamide peroxide, however but this changed the VFRs’ biomechanical properties, decrease in tensile strength and an increase in hardness and internal roughness, unclear what the medium and long term effects are .Jin 2024 

Bond strength

• By Bleaching a tooth there is enamel bond strength reduction by 25 % Miguel 2006

• Wait 2 weeks after bleaching for aligner attachment placement.

• Bonded retainer has not been researched

Join me for a summary of direct to print aligners. This lecture explores the application of a relatively new resin material which can be used for aligner fabrication, without the need of a 3D printed model. The lecture was given by Simon Graf who expertly compared the differences between conventional and direct to print aligners, as well as the clinical application of specific features of direct to print aligners.

Limitations of current aligner material:

1.         Only small undercuts

2.         Limited aligner thickness to sheet thickness / no selective thickness

3.         During the manufacturing process material can get thinner or thicker depending on heat distribution and stretch, 54% change in thickness of the aligner Lee 2022

4.         Plastic and resin waste, (122 million aligners and models in 2022 Slaymaker 2024)

Advantages of direct to print aligners

·       Select thickness, 0.5-0.7mm, conventional aligners 0.75mm+

·       Gingival margin

·       Dentist in charge of design, not company

Manufacturing steps of Direct to Print aligners (Tera Harz ‘Graphy’)

1.         3D printing of resin aligner

2.         Centrifuge: Spin remove excess resin

3.         UV Light cure in Nitrogen chamber

4.         Washed twice, hot distilled water

Characteristics of Direct to print aligners

·       Greater accuracy: (Zendura, Essix Ace and DTP were compared and DTP were 20-30% more accurate Koenig 2022)

·       Less with DTP (Hertan 2022)

o   DTP 50% less still (2.59 Vs 5.26 N)

o   DTP Less force as strain increases

Shape memory effect

·       DTP Polymer chains crosslinked, not case in conventional aligners

o   The shape recovers in DTP when strain is removed, which does not occur to the same degree in conventional aligners Lee 2022

o   Accelerated by placing in water

Unknowns

·       How effective shape memory is remains unclear

·       Cytotoxicity – not enough data, although manufacturer protocols, lack of studies

·       Changing thickness, unclear how much of a difference in force it makes

Clinical points

Teeth extrusion

Lateral incisors

·       Difficult to do with conventional aligners,

·       Create ‘wedging’ gingival pressure columns to squeeze the teeth to cause an extrusive force.

Elastic Hooks without loss of force delivery on single tooth

·       Hook printed into aligner with DTP, instead of cut out which alters the force of the aligner instantly, maintain tooth control

·       Tip aligners and elastics: Still add attachment to tooth to prevent aligner displacing

Mandibular advancement

·       Problem of mandibular advancement with aligners

o   Wings soft and not maintaining the AP position

o   Hard block many breakages

·       DTP choice of thickness of block

Bite ramps

Conventional bite ramps: limited length and often too short

DTP no limit to size and thickness, and can be designed to not contact upper palatal surfaces, maintaining full tooth control

In the Transverse

o   Palatal coverage can be added as feature, similar to a TPA

o   Still being researched how much force can be delivered with palatal coverage

Concluding statement

Enjoy the variability of direct printed aligners.

Contributions

Contents: Abdallah Sharafeldin

Edited and produced: Farooq Ahmed

Join me for a summary looking at gingival recession in orthodontics, and whether it is detrimental or beneficial. This lecture was given by James Andrews, he explored the effect of orthodontics on the periodontium, an area under increasing interest within aesthetics to achieve the ideal ‘pink aesthetics’ with the increasing adult population receiving orthodontic treatment. His lecture was based on, is orthodontics good or bad for the gingiva?

What is the starting point ?

• Increase in adult orthodontics from 1970 by 800%

• 50% of adults have some element of periodontal disease

• Untreated adult population 51% dehiscence 37% areas of fenestration Evangelista 2010

Facial type and bone morphology Tunis 2021

• Dolichocephalic = narrow alveolus and elongated to compensate for vertical growth

• Brachycephalic = larger alveolus

• Dolichocephalic - Red flag patients

Tooth movement: 

What happens when teeth move buccally?

• facial tooth movement Wennström 1996

• Reduced bucco lingual width

• Therefore, reduced free gingiva

• Increased risk only if tooth is moved out of the alveolar housing

What type of movement

• Tipping (uncontrolled) increase likelihood of recession Condo 2017

• Proclination causes recession, but inconclusive 

• Thickness more relevant than final inclination Yared 2006

How to decide what to do?

WALA line – Will Andrews Larry Andrews ridge Andrews 2000

• Limit of labial bone – shape is coincident with the mucogingival junction, coincident with centre of resistance

• Upper incisors – located anterior 1/3 of alveolus

• Mandibular incisors – cantered within the alveolus 

• Gingival recession did not increase in treatment orthodontic population with segmental mechanics Melsen 2005

Aligners any different?

• Association between non-extraction clear aligner therapy and alveolar bone deficiency and fenestration

• Presence of both fenestration and dehiscence

What do we do to correct extra-alveolar teeth?

If teeth pushed outside of cortical plate then retracted, what happens

• Monkey – moved teeth outside of bone for 8 months, then reposition within bone with appliances =  repair bony dehiscence and fenestration

• Morten  Laursen and Melsen 12 consecutive patients 2020

• Teeth moved towards the centre of the cortical plate = improvement in gingival height of depth decrease of 23%, the width with 38%

Intrusion

• Use of intrusion arch increases the thickness of the periodontal fibres 0.7 to 2.3 mm  Melsen 1988

Gingival graft when to move teeth

• Free gingival graft – 6 weeks

• Connective tissue graft – 12 weeks

“Diagnose and treat each tooth no miracles shortcuts for good orthodontics” Peck 2017 

Join me for a summary of Tommaso’s lecture on aligner treatment, exploring questions on the use of aligners. Tommaso described how compliant patients are with the use of aligners, who is more likely to wear aligners well and methods to increase compliance. He critically reviewed the use of attachments, and revealed aligner deformation and staging as key areas of treatment. This podcast is a summary of the WFO online webinar from November patient compliance, biomechanics , rotation, distalisation and intrusion

Patient Compliance

Sample of over 200 patients treated with aligners under remote monitoring, Thirumoorthy 2021:

• 36% of the sample was fully compliant

• 25% has poor compliance

• 1st time Ortho patients are more compliant

• Conclusion: early detect non compliant patients with remote monitoring 

Patient factors which vary compliance of removable appliances Fleming 2019

The study came with some recommendations:

1. Effective communication with our patients, with visual aid, pictures or movies.

2. Using of tracking sensor included in the device

3. Using some reminding tools – remote monitoring Biomechanics and material properties. Distalisation class 2 Incisors intrusion Conclusion

• We need to consider the lines of forces and aligner deformation not only on the attachments

• Any malocclusion that can be corrected by tipping has better predictability 

• Add less activation Per aligner (to help flattening the steep decline in force over time and create consistent and continuous force system)

• Attachment driven mechanics are not always effective, aligner Activation is more effective

• Graphy is the trending technology in aligner activation

Join me for a podcast summary looking at the grey topic of lower third molar management. The podcast explores the different guidelines of removal, factors for consideration for removal as well as the effect orthodontics can have on third molar pathology. The lecture was given by Flavia Artese at this year’s British Orthodontic Conference in my city London.

Flavia Artese began with asking the clincal question we face, what would you do with an impacted 3rd molar?

Difference in international practice

·      UK NICE guidelines 2000: Surgical removal of impacted third molars should be limited to patients with evidence of pathology

·      AAOMS White paper USA 2016: currently or likely to be non-functional associated with disease or at a high risk of developing disease

What factors in decision making

1.     Eruption path

·      Mandible = mesial, whereas Maxilla = distal

o   Rate of impaction Mandible 25%, maxilla 14% Worthington 2016

2.     Mechanism of tooth eruption – explained by Frazier-Bowers

·      A pathway created by the dental follicle

o   Triggers eruption of intraosseous eruption

o   Genetic control of cell differentiation in dental follicle

§  Requires root elongation, vascular pressure and DL ise 2008

Orthodontic influence  = SPACE

·      Decrease with distal movement of posterior teeth

o   Distalisation, elastics

§  Kim 2014 = limit of lower molar distalisation

§  35% of cases already have contact with lingual cortical plate

·      Increase through mesial movement

o   80% of 3rd molars erupted in premolar extraction cases Kim 2003

o   Increase in retromolar area

o   2nd molars – removal of guidance = unpredictable alignment of 3rd molars, tipped, therefore will likely require orthodontic alignment Gooris 1990

§  Flavia suggested if 7s impacted, removal of 8s and 2nd molar uprighting, as no delay until full root development

Prediction method

·      Mandibular morphology

o   Longer the mandible = greater chance of 3rd molar eruption: Begtrub 2012

·      Retromolar space

o   OPG -  size of crown and space available: If space greater then size of the tooth = 75% eruption, if less space available than the tooth size = 75% of impaction Olive

Prediction of orthodontists and surgeons Bastos 2016

·      Orthodontists 38% extract

·      Surgeons 50% extract

·      Surgeons extract more

o   Surgical morbidly 10% Yamada 2022

o   Greater pathology: 82% when erupted, 74% in soft tissue, bone 33%

Surveillance protocol

·      No complaints from patients

Fully erupted

·      No consensus of protocol pathology

Review of guidelines Gadiwalla 2021

            Only 2 guidelines were recommended , RCS and SIGN

·      Recommended guidelines

Conclusion

·      Limited evidence

·      Orthodontists can influence the space

·      If second molars require extraction, will require time to erupt as well as

·      CBCT should be used for diagnosis

·      Refer to oral surgeon for assessment of difficulty in removal

Please join Flavia Artese at the 2025 International Orthodontic Conference in Rio De Janeiro

Contributions

Contents: AbdAllah Sharafeldin

Contents edited and produced: Farooq Ahmed

Join me for a summary of two lectures from this year’s international orthodontic symposium (IOF), looking at mouth breathing and paediatric obstructive sleep apnoea, by Hong He and Carlos Flores Mir. The lectures explore this controversial area in both medicine and orthodontics and review the current understanding of the topic, the relationship with facial features and current recommendations for orthodontists.

OSA is defined disruption to breathing American Academy of Sleep Medicine

• Adult  > 5 apnoea/hour & 10 seconds

• Child apnoea for duration of 2 breaths 1

Defining mouth breathing at airflow over 25% through the mouth

Evidence of craniofacial effects

1. Mouth breathing

• Retrusive maxilla -1.33o (SNA -2.03 -0.63) 

• Retrusive mandible -1.4 (SNB -2.20—0.6) Zhang 2020 SR

• Increased mandibular angle 3.38o (2.77-3.98)

• But is mouth breathing pathological?

1. pOSA

• no craniofacial difference in pOSA vs controls SR Fagundes 2022

• Recent study by Carlos Flores Mir, combine factors

•  Demographics, lifestyle, craniofacial features and sleep features. Investigating effects of treatment on these categories

Treatment

• Twinblock improves pOSA AHI 14.08 to 4.25 in the short term, severe to mild  Zhang 2012

• MARPE increases cross sectional area, by 40% oropharynx, 7% nasopharynx Zhao 2020

• RME increases nasal airway volume initially of 1604 mm3, but reduce to 579mm3 after 3-5 months and non-significant SR Zhao 2021

• Tonsillectomy

• Does not stop mouth breathing, even if OSA resolved Bae 2020

Conclusions

• Breathing involves complexity of 3D structures and fluid dynamics is not well understood

• Mouth breathing does seem to have craniofacial influence, however OSA does not

• Orthodontists role in OSA

• screening for OSA

• Refer to physician if risk factors present

• Refer adenoid hypertrophy to ENT

Contributions 

Contents and video editing – Shanya Kapoor

Editing and Production – Farooq Ahmed

Orthodontics and the airway

“Lots of patients are struggling with the symptoms (of obstructive sleep apnoea) when a little kid doesn't sleep it's not just the child's problem, their parents and other family member who also become sleep deprived”

Audrey describes her motivation in the young field of dental sleep medicine, the role of orthodontics in the management of paediatric obstructive sleep apnoea, the patient’s orthodontic treatment is appropriate in managing OSA, as well as those patients it is inappropriate for. Audrey explains her thoughts on why the field of airways and orthodontics is controversial, and answers critical questions regarding orthodontics and sleep medicine.

We get to hear of Audrey’s take on the AAO White paper on obstructive sleep apnoea.

Click on the link below to view previous episodes, to refresh topics, pick up tricks and stay up to date.

Please like and subscribe if you find it useful!

Instagram:  www.instagram.com/draudreyyoonhappycamper

Facebook: https://www.facebook.com/audrey.yoon

@audrey.yoon

@draudreyyoonhappycamper

Farooq Ahmed

Join me for a summary looking at impacted teeth and key components of timing which affect not only the success of alignment, but also root formation. This podcast also explores the occurrence of asymmetries of both dental and facial due to impacted teeth, and what can be done about it. This podcast is a summary of the AAO lecture by Stella Chaushu and Adrian Becker.

Timing

Role of timing to the impacted tooth, the adjacent teeth and alveolar and skeletal growth.

Implications of timing on impacted teeth:

1. Eruptive potential

2. Root development

1/ Eruptive potential and timing

• Interceptive treatment Ideal time for spontaneous eruption is ½ to 2/3 of final root length.

• Orthodontic traction: Ideal time for active (orthodontic traction) eruption is 2/3 to ¾  final root length.

• Principle:

• Peak of eruptive potential is at 2/3  to ¾ of final root length

• Root completed within 2.5 to 3 yrs post eruption

Timing of impacted maxillary canine interceptive treatment

• Dental age of 9-10 years

• Interceptive treatment includes: extraction C, D, distalisation molars, RME

• Prognosis of treatment of impacted canines is uncertain and reduces with age.

• Ideal early adolescence

Timing of impacted maxillary incisor interceptive treatment

• Before age of eruption 7-8 years

• Likely spontaneous eruption, but risk of damage to permanent incisor in surgery

• After age of eruption  > 8 years

• Spontaneous eruption not predictable, likely require active (orthodontic traction)

• Interceptive treatment 

• Removal of obstruction, spontaneous eruption 36-75% 

• Removal of obstruction + space creation spontaneous eruption 82-89% 

(Sun et al AJODO 2006)

Root development

• Impacted incisor due to obstruction – ideal time =7-8 yrs 

• Dilacerated upper incisors – ideal time – at ½ root or less = 6-7 yrs, as removal of root proximity to the anatomical barrier can reduce the dilaceration of the forming root

Timing of impacted premolar interceptive treatment

• What to do when premolar root formation has not occurred in adolescent patient

• If apex is open = root formation occurring

Timing of obstruction management

• Removal: As early as possible

• Orthodontic traction: Delay until bony infil, otherwise loss of gingivla and alveolar supoort

2/ Root development 

Canine root development

• Hooked apex 3-4 times more likely with impacted canines

• Shorter root

• impacted incisor 2.3mm shorter root Sun 2016, Impacted canine 2.3mm shorter roo Cao 2021

• Total volume unaffected (length + hook)

• Prevalence and severity of dilaceration increase with age until apex closed

• Dilacerated root respond to traction/

• Yes but increased treatment difficulty and duration , example of 2 years

Arrested root development

• Can arrested root development be reversed? 

• If root abuts with an anatomical barrier. Such as nasal floor, it is the cause of the arrested development 

• Orthodontic traction and movement away from the barrier = continued root development

• Early exposure and orthodontic traction

Implication of impacted tooth and asymmetry

• Impacted tooth can affect alveolar and skeletal growth

• Cases with asymmetry significantly higher in impacted group.

• Asymmetry index 27% Vs 3.4%

• Chin asymmetry 52% Vs 14%

• Occlusal cant 38% Vs 10%

• Timing of treatment,  if delayed = occlusal cant increased with age.

• After treatment, asymmetry can persist = treat as early as possible to limit asymmetry (managing impaction will not correct asymmetry)

Join me for a summary looking at the use of botox for deep bite management and bruxism. This was an interesting lecture by Dr Nan Hatch from Seattle, which was presented at this year’s AAO 2023. She explored the use of Botox for masseter hypertrophy and the evidence around it.

Masseter hypertrophy when combined with bruxism can result in:

o  Long term changes in function

o  Fixation breakages

o  Orofacial pain, tmd, mobility

How does it work?

·        Injection of neurotoxin into muscle

·        Temporary partial paralysis through chemical denervation

·        Most common Botulinum toxin or Botox

·        Mechanism of action

o  Block acetylcholine (neuromuscular transmission) release.

o  Also inhibit pain sensory neuron

How to inject

·        Extra oral – use of facial landmarks

·        Intra-oral Use MRI / EMG guided injection

What are the effects

·        Anticipate change facial aesthetics

·        Greater facial contouring achieved with higher dosage Review Wu 2023

·        Last up to 180 days

·        Greater complications with greater dosage

Anticipated change from botox

·        Treatment for masseteric hypertrophy

o  35 units to masseter , two injections

o  91% reported improvement headaches

o  Duration 25 months

Decrease bite force Ahn 2007

·        25 units to each massenteric muscle

·        Mean bite force 51kg /cm using bite block attached to a transducer

o  Reduced to 30-36kg/cm for 8 weeks (29%-41% reduction)

o  After 41kg after 12 weeks , no longer statistically significant

·        Significantly reduced bite force up to  8 weeks

Potential adverse effects

·        Chewing weakness

·        Sunken cheeks – high volume

·        Headaches

·        Sagging skin

·        Asymmetry

·        Paradoxical Bulging – miss masseter and affect other muscles

·        Distant spread of toxin

·        Speech disturbance

·        Muscle fiber atrophy 4-6 weeks, remover 4-6 weeks

Chemical denervation protocol

·        25 units per muscle, both masetter and temporalis

·        Interval 4-5 months and patient response

·        3-5 serial injections

o  Some patients changes can be permanent

Join me for a summary of a lecture by Ramesh Sabhlok, looking at one of the most popular sites for TAD placement, the maxillary buccal interradicular site.

The most common site in maxilla for implant placement is between 2nd premolar and 1st molar  in the keratinized gingiva.

Two factors

1.    Buccal bone thickness

2.    Inter radicular distance

Bone thickness:

·      Greatest bone width of bone is between 2nd premolar and 1st molar, and considered ‘safe zone’ thickness of bucco-palatal bone 10.2-11.4mm ( Pogio 2006 Angle orthodontics )

Inter-radicular distance

·      2nd premolar and 1st molar: 3.2mm (SD 0.6mm)-  3.5mm (SD 0.8mm) when 4-6mm from the CEJ, largest clearance of interradicular space in the buccal aspect of maxilla Lee 2009

·      Gradually decreases apically, therefore it is advised to place the mini implant at height of 4-6 mm from CEJ, at 2 mm height only 2.7mm interradicular

·      In the maxilla, the more anterior and the more apical, the safer the location becomes.

·      Increased after levelling and alignment, delay placing if possible

‘SAFE DEPTH’ proposed by Ramesh

·      depth of from the bone surface to the narrowest interradicular space at a given height which is safe = 3.2mm interradicular distance for 1.2mm width TAD AND 3.5mm for a 1.5mm TAD.

·      Safety depth (height) is 4mm.

o   2mm depth the greatest inter radicular distance 2.4mm, not safe

Angulation

·      A 20-30o angle, places the interradicular aspect of the miniscrw apically, where the interradicular is the greatest. This reduces root contact, increases retention with more cortical plate engagement, allows use of longer miniscrews as well as greater distalisation prior to relocation Deguchi 2006.

Extraction of 3rd molars

·      Classic papers looking at the Pendulum appliance by Kinzinger 2004 showed extraction of 3rd molars resulted in greater bodily distalisation on the maxillary arch.

·      However recent CBCT paper by Lee 2019 show that with miniscrew distalisation there was no difference bodily movement with extraction of 3rd molars and non-extraction.   

Concept of biologic width

1-1.5mm of periodontium surrounding the implant,

Lecture title

Summary from AAO 2022 lecture: Non- compliance & Predictable class II correction with Micro implant Anchorage

Dedication

Episode is dedicated to the late Dr Anam Humdani, a London based dentist who tragically died aged 29

https://www.justgiving.com/fundraising/zayaan-humdani

·       Contents: Shanya Kapoor

·       Editing and Production: Farooq Ahmed

Join me for a summary looking at accelerating orthodontic tooth movement, this podcast is a summary of two lectures from the AAO, by Ali Darendelier and Peter Buschang. Mechanical acceleration through vibration, photobiomodulation, minisurgery (Peizocision and Micro-Osteoperforation MOP) and Distraction.

1. Vibrational mechanical

1. Low magnitude / high frequency, used for 20 minutes per day 25g at 30Hz/ 50 Hz,

2. Canine retraction: 30Hz NS, 50Hz 15% quicker, Significant but not clinically

3. No increase in root resorption - split mouth study, except for 50Hz, reduced RRRR Tan 2011, Yilmaz 2021

1. Photobiomodulation (PBM)

1. Low level laser therapy: LED device used for 20-30 minutes her day

2. Tooth movement increase rate of 1.73mm over 2-3 months Yavagal 2021 SR

3. Root resorption no difference Sambevski 2022

1. Minisurgery: Piezocision/ Micro-osteperforation(MOP)

1. Piesocision – series of vertical bone cuts of 2-3mm depth vary lengths,  Vs MOP – round punctures of 2-3mm depth. With or without flaps.

2. The movements were twice as fast (Lino et al 2017, Cho et al 2007, Mostafa et al 2009)

3. But limited duration of effect  Buschang 2010 

1. Peak at around 3-4 weeks 

2. No differences after 6 weeks - Similar to human trials: Aboul-Ela 2011

4. Root resorption Patterson 2017

1. Peizocision and MOP produced significantly (44% / 42%) MORE root resorption. 

2. Peizocision 36% additional iatrogenic damage (performed by periodontist)

1. Distraction

Mechanical removal of the bony obstruction

• Remove all or most of the bone in a way so that you can move teeth faster reliably

• Osteotomy, callus formation followed by Rapid separation of distal and proximal bone and healing with new bone formation.

• 1mm per day Moore 2011

• Teeth vial with Dappler meter

• Vitality through histology as electronic pulp test not reliable during orthodontic treatment, Alomari 2011, increase in treatment but return to normal in retention.

What do we know reliably extents treatment duration are 3:

1. Wrong diagnosis

2. Wrong mechanics

3. Bracket position

Conclusion:  

Distraction is the most reliable method at increasing tooth movement but the most invasive

Peizocision / Micro-osteoperforation: Increases tooth movement but greatest risk of root resorption

Photobiomodulation: Modest increase in tooth movement, no root resorption

Vibration: No increase in tooth movement or root resorption

Contributions

Content creation: Shanya Kapoor

Editing and production: Farooq Ahmed

Join me for the next interview in orthodontics with Luis Carrière

“The Carrière Motion Appliance is a story of simplicity, but not simplism”

Luis describes how he conceived the Carrière Motion Appliance, and addresses in his own words addresses claims regarding changes to the occlusion, TMJ and airway. He describes the limited research regarding the appliance, as well as why he does not conduct the research himself.

We get to hear of Luis thoughts on what he sees as the future of orthodontics.

Click on the link below to view previous episodes, to refresh topics, pick up tricks and stay up to date.

Please like and subscribe if you find it useful!

www.carrieresystem.com/

Instagram @instagram.com/luiscarriere

Facebook @luis.carriere.1

Farooq Ahmed

Lower arch missing lower 2nd premolars

• Hemisection lower E – distal half – Old school
• Allow mesial drift of 6s, L4s do not distally tip, important in class 2 cases
• Use mesial aspect for anchorage if ankylosed
• Remove remaining

Other options

• TADs 30% failure in the mandible in Caucasian
• Herbst
• Mini-plates – very evasive
  • But hemisection is simple

Gingivectomy

After extrusion of impacted tooth,  need for gingivectomy

• Orthodontists should learn as common need
• Process
  • Scan
  • Plan a gingivectomy guide
  • Laser or electrosurgery for gingivectomy

Cant and TADs

• adult cases are the future of orthodontics, more challenging
• RHS>> Gincevectomy
• LHS>> extrusion using TADs TAD – opencoil to bracket on the tooth, and aligner to guide the tooth, cover incisal edges only
• And few aligners
• Patient did not want perfect result

Space closure and TADs Georgios Kanavakis 2014

• Space closure and mesial slider
• 2 x palatal tads
• SS spring close
• Mesialization of molars
• High tech
  • But Space closure can be achieved with timely extractions, such a smissing UEs and extractions with mesial drift..
  • Less likely lower arch, miniplates used to mesialise

Expansion

Digital planning

• Digitally decompensate the lower arch.

MARPE

• Changes to the midface through MARPE
  • Hard tissue changes to the midface and nasal complex
• Caution in use, for selective cases only, and critical in use

SARPE

• Indicated due to resistance for Maxillary expansion in adults from 3 potential structures
• Zygomatic buttress, Pterygoid plates, Sutures from the mid face Published 1984 by Andrew Glassman
• Using a finite element analysis programme,  fusion 360,  identify the resistance individual to patient
• Case: Surgical guide to do a small lateral osteotomy under local = future as it is individualized to each patient

Hybrid treatment brackets Vs aligners

• Class 2 correction
• Change from fixed to aligners with Onyx Ceph planned wings for class 2 correction – like functional appliance

Problems

• Distalisation with Miniscrews
  • Later on posterior crowding of 2nd molars and risk anterior recession
• Fracture of palatal appliance
• Failure at welding point between expander and abutment
• Can stop people using designs
• Solution
  • print 1 piece appliance CADCAM
• Overuse

TAKE HOME MESSAGE BY ME FROM THE LECTURE

• Sometimes effort is not equal the benefit so always evaluate your benefit
• Always assess your outcome and see if technology you invested in worth it
• Orthodontists are Dentists and should do some gingival contouring and temporaries ..etc
• Always match arch before and after treatment and maintain your arch form
• Future is Hybrid Therapy … using strength of both aligners and fixed braces

Join me for a summary of Dr Nikhilesh Vaid’s lecture entitled More Than Meets The EYE!    Aligner Evidence Through Clinicians Eye It was part of the first International Orthodontic Foundation online symposium, with Ravi Nanda and co.

Evidence available

There are about 7000 papers available on clear aligner therapy

• 39 are prospective clinical trials
• 20 are systematic reviews

What do the systematic review and meta-analysis conclude?

• Overall we don’t have sufficient good quality trials and there is a need of more such trials
• In addition to that ratio of prospective trials to systematic review is merely 2: 1.

Systemic review topics

Treatment outcomes

• Aligners work well for mild to moderate cases.
• Alignment with aligners is reasonably competent.
• In Vertical sagittal and transverse dimension possess a bit of challenge.
• If compared with fixed appliances – doesn’t fit well.
• *** Outcomes mainly depend on the measurement criteria.

Deleterious effects

• Slight improvement in terms of periodontal effects
• Advantageous in external apical root resorption
• Some of periodontal indices improved, also no adverse effect was found
• Overall need for more studies.

Other effects

• Force levels, only in vitro studies available with conflicting results.
• Pain level, it was initially lower, thereafter similar, short term
• QoL (Quality of life) there were less incidences of eating disturbances.

Nikhilesh conclusion: Although stated in one of systematic review (Papageorgiou) the current evidence doesn’t supports the use of clear aligner therapy.

• That this doesn’t meant that it never worked.
• So according to Dr Vaid its on us to be able to gather some evidence.

Nikhilesh’s research: Effectiveness, wear, refinement

1st study - Are aligner effective

Does wear protocol makes a difference? Nadawi 2021

3rd study- Can we predict the number of refinements needed?

Nikhilesh’s conclusion:

• Refinements are non-negotiable.
• Patients will be requiring nearly double the number of initially decided aligners.
  • Planned Vs total aligners 108.11%
• Greater refinements class 3, deep bite, crowding, posterior crossbites

Contributions

Contents: Shanya Kapoor

Editing and production: Farooq Ahmed

Join me for the next interview in orthodontics with Carlos Flores-Mir

Carlos is a Professor in orthodontics with an exceptional contribution to the field. He has published over 350 peer review papers and is an award winning educator within dentistry. He is an associate editor for the Angle Orthodontist journal and JWFO.

We get to hear of Carlos’ story of how he came to be a leading authority in orthodontics, his opinion on class 2 correction, why he chose to present clinical failures at this year’s AAO meeting, and his favourite hobbies.

Join me for a summary of early treatment lectures from this years AAO meeting from May 2022. Topics will cover trauma, airway diagnosis and orthodontic treatment, and optimal timing of class 2 correction

Lectures:

• Dental Trauma Eustaquio A. Araujo
• Airway-centered Orthodontic Diagnosis & Treatment for Pediatric Patients Hong He
• Predictors of Success for Early Mixed Dentition Treatment Heesoo Oh

Dental Trauma Eustaquio A. Araujo

Trauma protocol

• Reposition with firm grip
• 16x22NT
• Bite props to eliminate occlusal interference
• Soft diet
• Recall 2 weeks

Re-implantation of avulsion success

• Less than 1hour 75%
• Up to 24 hours 25%

• Conclusion – look at the neighbours

Airway-centered Orthodontic Diagnosis & Treatment for Pediatric Patients Hong He

Nasal breathing Vs mouth breathing

• NB = Tongue rests on the palate.  MB = Tongue floor of the mouth
• NB = Pressure of the cheeks is balanced with the tongue. MB Pressure of the cheeks is unopposed by tongue
• NB = U shape upper arch (normal). MB = V shaped arch

Tonsillar hypertrophy

• Oropharynx obstruction
• Ventilation impaired
• Occlusal effects
  • Tongue and mandible forwards Iwasaki 2017
  • Mandibular protrusion
    • Class 3 malocclusion
• He’s study n=1776
• Greater tonsillar hypertrophy in children with class 3

Caution as limited studies pre-pubertal and controls also improved in scores

Predictors of Success for Early Mixed Dentition Treatment Heesoo Oh

When is it best to treat class 2 cases

Study: optimal timing of the effectiveness and efficiency

• Early class 2 equally effective not as efficient
• BUT
  • Mean changes = mask individual response
  • Philosophy – correct some / all features of malocclusion
    • Reduce / eliminate need for phase 2
• Angle orthodontist Oh 2017

Treatment protocol

• 7-9 years
• Headgear night wear 11 hours
• RME
• 2 x 4 fixed appliances
• Lingual arch
• Greater 33 months = unsuccessful (time only marker of success, as occlusal and skeletal the same at the end)

Results

• 15/54 (28%) phase 1 only
• Comparison
  • No differences in occlusal and skeletal outcomes
• Time
  • Total treatment times (phase 1 + phase 2):
    • 67% less than 18 months in treatment active treatment
    • 20% 4-5 years of total treatment time

Join me for a summary looking at Dental Sleep Medicine and NICE guidelines. This summary describes obstructive sleep apnoea and the new guidelines of its management. There is a focus on the Mandibular Advancement Splint and the occlusal outcomes for patients using this appliance. This lecture was given by Professor Ama Johal. Ama is a member of the advisory committee to NICE sleep apnoea/hypopnoea syndrome

Introduction

Obstructive sleep apnoea –

· Sleep related breathing disorder

· Poorly understood

· 70% collapse retroglossal area

· Stops breathing

· Body movement occurs – body tries to wake patient up as suffocating

o = disturbed sleep

Health consequences

· Day time sleepiness

· Hypertension, heart disease, stroke – all stroke patients screened for OSA

Treatment

· Severe / mod- gold standard Continuous positive airway pressure CPAP

o Filters air and pushes at high force

o To be effective 4-6 hours, 7 days a week – NOT curative

o Compliance / adherence 30%

NICE guidelines 2021

· Symptomatic receive CPAP

· if not comply then if a person Mandibular Advancement Splint

· Require good dental and periodontal health

· Age 18 +

MAS appliance

1. Anatomical – increase size of pharyngeal airway

a. Mandible move forwards, tongue advances with it

i. Post lingual - Best impact of patients who have tongue contribution to collapse 70% of patients

2. Reduces airway collapsibility

3. Physiological role – stimulate dilation of upper airway muscle – improving muscle strength and control

MAS appliance

semi customised Vs customised

Johal 2018 S/R

o Overall effects better with customised Vs semi customised

§ AHI 3

§ Daytime sleepiness 1

§ Self reported wear: 7 Vs 3 nights per week

§ Pt preference 95% prefer customised to semi-customised

Ideal design features  customised Johal 2018

· Good retention - customised

· Semi adjustable – incremental advancement

o Allowing for further advancement and slow increase in airway

· Full occlusal coverage

· Minimal vertical opening

In high angle cases clockwise rotation of mandible – compresses post-palatal area and worsens airway IF increase vertical opening. Minimal occlusal opening prevents clockwise rotation

Follow up long term

· Unwanted occlusal change

o Mesial molar movement

o Reduction of OJ and OB approx. 1mm

o Proclination of 1mm lower incisors

Thank you to the sponsors who have allowed the podcast to continue, Triple O, Orthocare and the Aligner Intensive Fellowship.

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Join me for the next interview in orthodontics with Steffen Decker

Steffen is a leading lingual an aligner provider and a Kois recognised specialist. He has been a global advisor for 3M and is a key opinion leader for Align technology.

We get to hear of Steffen’s story of how he came to use lingual appliances and aligners, his opinion on interceptive / phase 1 treatment and where he sees the future of orthodontics.

Facebook: @steffen.decker.503

Instagram @theorthodonticspecialist Instagram

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.

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

Join me for a summary of Dalia El Bokle’s lecture exploring finishing in orthodontics. Part 3 focuses on digital indirect bonding, from scan to tray production

Introduction

Straight wire appliance – based on bracket placement will correct tooth in 3 planes of space

· Not true – evidenced by finishing bends

Ideal bracket placement through indirect bonding IDB

· Level marginal ridges posteriorly

· Constant smile arc anteriorly

Digital indirect bonding time saving

· Brackets placed Layman 2019

o Time saving

§ 21 minutes – digital indirect bonding Vs manual direct bonding

§ 8 minutes – clinical time indirect Vs direct bonding

Different methods of making an indirect digital bonding tray

Method 1:

· Printed model

· VFR transfer tray

· Transfer tray made from the model

Method 2

· Printer tray (not model)

· Cost $105

· Tray biocompatible tray

· Cover occlusal half of the teeth and lingual aspect

· Insert bracket into model

· Advantage

o No model printing

o Clean base technique

Method 3 –

· Key pads – digitally planned material between bracket base and tooth

o Customises the bracket base

o Advantage

§ Less flash

§ Accuracy of bracket position in on the keypad

§ Torque + in and out can be customised per tooth

· Models printed

· Lab place the brackets manually with composite onto the model with jigs

· Transfer tray made from the model

Case submission for DIDB

· Send STL file to lab

· Prescription for set up, e.g.

o Bracket selection customisation: Standard Damon Brackets, low torque lower incisors, high torque LL4.

o Teeth bonded: 7-7 Upper and lower

o Bracket positioning customisation: Smile arc – 0.5mm incisal U1s Vs U2s

· Clinician approval of set up

o Library of brackets – specify which type of bracket

Digital indirect bonding workflow overview

1. Scan patients

2. Orthodontist prescription

3. CAD –Software system to place bracket and customise base / bracket

4. Print model

5. Brackets placed on model: allowing for bracket base customisation through either keypads or jigs, customising bracket base with composite

6. CAM - Lab design indirect bonding tray (IBT)

a. VFR

b. Silicone transfer tray / Memosil material

7. Process IBT

8. Post processing chemical and UV light

9. Insert bracket into tray with key holes as guides

Advantages of DIDB

· Full digital pathway with scanning

· Less working time

· Fewer appointments

· Can alter prescription

Disadvantage

· Cost

· Learning curve

· Production waste

Join me for a summary of Dalia El Bokle’s lecture exploring finishing in orthodontics. Part 2 focuses on indirect bonding, a step by step process from model analysis to clinical delivery

Mark position on models

Intersection of horizontal and vertical lines

· Posterior teeth

o Vertical line: Long axis using OPG buccal, occlusal and lingual

o Horizontal line x 2

§ 1/ Marginal ridge line (outcome of treatment)

§ 2/ Slot line (position of bracket, depending on bracket system 2mm from marginal ridge line

§ Start with 1st molar

§ Measure cusp to slot line using gauge distance marginal ridge to slot line

§ Mark slot line for rest of the teeth, using the difference in height from marginal ridge to slot line from the 1stmolar measurement

§ Ensure gauge is used perpendicular to the teeth

· Anterior teeth

o Vertical line: Draw long axis using OPG, labially and lingually

o 1/ Horizontal line start with canine

§ Slot line marginal ridge level distal canine and mesial 1st premolar

§ Position canine mesial to the long axis

o 2/ Lateral = bracket gauge of the canine to tooth tip, 0.25mm more cervical or same as canine if lateral small

o 3 / Central – add 0.25-0.5mm than canine

§ = subtle smile arc

Transfer tray

· Intersection of long axis to slot line – mark with wax knife

o Mark where brackets should go

· Tacky Glue to stick bracket to the model  – water soluble glue, remove excess with probe

o Tip – use loupes / magnifying lens

· Allow set for 10 minutes

· Check occlusally, vertically and tip

o Digitally check glue is set

o Marginal ridge to slot line should be consistent

o Visualise tooth movement

· Relieve over the bracket hooks – wax or Tachy glue

· Vacuum forming machine

o 1mm soft sheet

· Check brackets have not moved – check vertical and horizontal lines

· Trim excess retainer material

· Soak 10 minutes, wash with water and interdental brush (ensure mesh of brackets clean)

· Slits from the gingival aspect of the retainer to the gingival aspect of the bracket

o Purpose is to expose the hooks of the brackets – difficult to remove when bond, aiming to uncover the hook from the retainer

· Wax placed under the hooks – prevent composite

· Section the tray if significant crowding

Clinical bonding IDB

· Etch bracket surface only – looking at model of the tooth

· Composite (light cure)

o Small quantity on mesh base of each bracket

o Microbrush to cover all surface and imbed into bracket mesh base

· Bond

· Seat IDB tray

o Apply perpendicular pressure on each bracket with scaler

§ Avoids excessive composite on the bracket base

· Light cure 20 seconds each tooth

· Remove tray – from palatal aspect from distal molar

· Flash removal

Trouble shooting

· Bracket off

o Don’t panic!

o Maintain isolation

o Remove excess composite, sharp scaler

o Trim tray

o Replace bracket in tray and re-insert transfer tray

· Bracket positioning incorrect

o Defective impression

o Bracket not glued well on model

o Defective vacuum forming

o Ensure no drags

Disadvantage of IDB

· Extra lab time

o 1 hour lab time

§ However reduced time in treatment and repositions / bends

o Extra cost

§ $12 if in house

o Excess flash

o Technique sensitivity

§ Multiple check points

o Accuracy

§ In Dalia’s opinion more accurate than direct bonding