Overcorrection With Aligners, Why, When How? 7 MINUTE SUMMARY

15, January 2025

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Hosted by

Farooq Ahmed

Overcorrection with aligners, why, when, how?

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Click here for Mazyar Moshiri’s overcorrection protocol table

“We cannot have a reasonable discussion of efficacy and accuracy until we study the appliance as orthodontic clinicians, and not as scientists Mazyar Moshiri

“If you are not willing you use elastics – you are not able to get finishing like braces” Mazyar Moshiri

“We do not accept the weaknesses of out appliances as absolutes, but rather we adjust out treatment mechanics to account for them Mazyar Moshiri,

Join me for the first summary of 2025, exploring finishing with clear aligners. Mazyar Moshiri explores overcorrection with aligners, when they should be used and his protocol. It was a lecture from last year’s AAO winter meeting.

This episode consists of overcorrection protocol of 4 malocclusions: deep bite, anterior openbite, class 3, and expansion. Maz also have tips and pearls on what to watch out for when using clear aligners with overcorrection.

EXTRAS: Mazyar Moshiri has kindly given permission for the summary slide of his overcorrection protocol at the bottom of this page

Overcorrection (also see table by Mazyar Moshiri below)

Deep bite – achieve AOB

Over-intrusion lower incisors to achieve a 50-100% of total movement predicted

Favourable if proclaining teeth, unfavourable if retroclining
Use of attachments on premolars, note the hierarchy of attachment design places anchorage for anterior intrusion 5th, “Drs have to doctor the Clincheck”.

Anterior openbite

Posterior intrusion – overcorrect with occlusal bite blocks
class 3 triangular elastics canine and premolars
Force down on posterior bite blocks
May require controlled relapse following overcorrection, done in refinement
NOTE – aligners continuous force system, reciprocal extrusion of anterior teeth is expected

Class 3 case

Retract lower incisors with retromolar tads and 6 Oz 3’16th
Side effect – increase in curve of spee – similar to retraction on a NiTi wire, aligner is not stiff enough to resist
Correction in refinement with anterior intrusion to eliminate premature contacts, DO NOT EXTRUDE POSTERIOR TEETH, as aetilogy is anterior iatrogenic extrusion

Expansion

Overcorrecion of 1-2 mm, greater the further posterior
Attachments, plan buccal attachments +/- palatal attachments, to account for likely buccal tipping, ensuring buccal root torque and preventing palatal cusp dropping
Tip: for palatal cusp dropping place occlusal attachment on the palatal cusp to prevent extrusion during expansion
Caution – if already in buccal version, consider limited correction

Overcorrection table Mazyar Moshiri

Movement	Overcorrection Recommended	Other consideration	Attachment consideration
Tipping	None	May lead to unintentional consequences, i.e. extrusion during lingual tipping with resultant bite deepening	Only if combined with other movements of anchorage needs
Intrusion	50-100% of total movement predicted	More predictable during labial movement for incisors, more challenging during lingual movement of incisors	Required on the adjacent teeth for anchorage
Extrusion	None anteriorly, posterior only when adding reverse curve mechanics	More predictable during lingual movement, less during labial movement or down long axis (may need elastics to finish)	Either optimized or conventional bevelled attachments needed
Rotation	5o	Decrease predictability if greater than 15 o , may need auxiliaries	Either optimized or conventional needed
Root movement	5-10o	May benefit from wrap of plastic and segmented staging	Either optimized or conventional needed
Torque	Double up to 15o	May need more time than one-week, no more than 1 degree per aligner	Horizontal bevelled attachment when power ridge feature not used
Expansion	1-2mm, increase more towards molars	Skeletal aetiologies and limitations need to be considered carefully	Recommended, especially when buccal root torque desired