Dr Nicolas Salesse talks us through 2D lingual appliances in the lower arch for alignment, how the appliances work, the application as well as his protocol.
Advantages:
2d Vs 3d
Direct bonding
· Unlikely to debond, due to low profile
· No complex bonding required (same as conventional labial brackets)
· 0 prescription bracket – no torque treatment conducted round wires round wires only
Cost
· Headway 2 dollars
· forestadent 2d 10-20 dollars per bracket
Disadvantages:
· Metal bracket can deform on opening / closing
· Complete alignment if required with aligners
Lower incisor alignment ideal:
· Bracket positioning lower arch
o Same height of centrals and laterals
o Relatively upright teeth, no significant tip
· Upper arch difficult for 2D brackets:
o large variation in bracket positioning between 1s and 2s
· Patient expectations: Lower expectation of lower arch
Challenges lingual appliances:
1. Reduced inter-bracket distance
2. In out discrepancy on the labial face due to lingual bonding
3. Bracket position height
4. Prescription
1/ Inter-bracket distance
· Smaller distance = wire is stiffer = greater force
· 2d brackets can have the archwire placed above the 2D bracket, increasing the interbracket distance, similar to Incognito
2/ In out discrepancy on the labial face due to lingual bonding
· Lingual appliances align lingual surfaces = discrepancy labial aspect due to variation in AP anatomy.
· Further from labial face – harder to control labial alignment
· Anterior teeth increase in thickness more Gingival
Height of bracket position
· Ideal 2D lingual bracket position = incisal as possible, less AP in out thickness, less variability.
· Lower arch incisal heights 2-2 same, no bend required
Prescription
· Only bend required is 2-3 in out direction
o Only bend lower 2-3 region = 2 bends
Protocol lower 2D brackets
· Digital set up plan IPR
· Bonddirectly, close to incisal edge. (no overcorrection)
· IPR
· Bond canine and premolar together: bonding composite prevent adverse affects on 3s
· Wires:
o Initially straight wire: such as 012NT
o 016NT + wire bends
