As in both cases slot would be in same angulation in relation to adjacent slots .
This is an old discussion. The A Company (now Ormco) did have a patent to make brackets with torque in the base. They mentioned, that only then, a straight wire could be used. If the slot angulation is the same for every bracket, the differencesin torque value should be in the bracket base. So, in my opinion, torque in the base should reduce the need for wire bendig. Since this patent is no longer excisting, every company (prodiucing high quality brackets) now uses torque in the base.
Dear Breuning thanks for reply but i havent got my answer. Most companies are using torque in the base as its technically more easy to cut the base at an angle and also A company patent is over .
My question remain there is there any difference if i use a bracket with torque in the face and not in the base . ?
If the torque is in the face than technically the slot point wont coincide with the base point and FA or LA point and eventually with the Andrew plane as purposed by Andrew
But do you think that putting the torque in the base will express all the toque in the bracket and torque in the face wont . ?
Do you think that torque in the face with create vertical positioning errors that will eventually effect effective torque . ?
Only fully customized bracket systems, with custom wires and indirect bonding, will be able to improve treatment result in a shorter treatment time. The Incognito system is an example. Full size wires are needed to get the result as planned in the digital set-up
Dear Sachin thanks for the Answer . But Can you elaborate how and why we need more bends ?For a wire either its a torque in base or face the wire have to engage in same angle in the bracket if same amount of torque is placed in both brackets. Bracket in past produced with torque in the face used same vertical and horizontal curves of contouring as the other bracket type. i mean a compound contoured base.
Dear Sachin i believe that when the torque is in the face there wont be any difference in torque expression on engagement of full dimension rectangular wire .because for rectangular wire two position are final outcome that is true horizontal and true vertical depending upon slot of bracket no mater the torque is in the base or face . There might be difference in vertical height of the bracket.
Dear Haris
In his book "systemized orthodontic treatment mechanics", Dr Mclaughlin touches on the subject. This is what is said " Torque-in-base was an important issue with the first- and second-generation preadjusted brackets, because level slot
line-up was not possible with brackets designed with torque in-
face. Technology was not available to set bracket slots in
the correct position relative to the facial surfaces of the crowns
without torque-in-base. Modern bracket systems, including
the MBT™ system, have been developed using computer aided
design and computer-aided machining - the CAD-CAM
system. This allows more flexibility of design, not only to
place the slots in the correct position in the brackets, but also
to enhance bracket strength and features such as depth of tie
wing and labio-lingual profile. The computer is first able to
locate the precise location for the bracket slot, relative to
in-out distance and torque position for each tooth. Once this
position is established, it can then build up the 'in-fill' areas
to optimize all requirements of the brackets (Figs 2.6-2.8).
The brackets may be finished with all torque-in-base (full
size and clear) or with a combination of torque-in-base and
torque-in-face (mid-size) with absolutely no difference in slot
position. Since the advent of CAD-CAM bracket design, it is
not necessary to discuss this historical issue any longer!
Thanks Hassan for the answer . i am in the process of writing a book on orthodontic brackets . So i wanted to know the difference . There is a BJO 1990.( Ferguson JW. Torque-in-base: another straight-wire myth? Br J Orthod. 1990 Feb;17(1):57-61.) article that its nothing but a myth that torque in the base and face has difference . vertical position errors can range 0.7 mm in lower and 0.5 mm in upper arch if torque in the face is used .
I dont agree with Mclaughlin that torque in the base was not possible before MBT . Correct torque in the base was possible in 1960 s .Mclaughlin talk about torque in base and negate Andrew plane . He advocate guages for bracket placement . how come one get the same torque by placing bracket at 4 different places on a tooth 0.5mm apart .
The very basis of MBT have proven wrong / They negated wagon wheel effects in upper arch and advocated bannect mechanics and canine tip back at initial wires . Both these have failed to gain evidence .
Use MBT and you are left with spaces distal to laterals . Finishing cases in MBT has always resulted in less than optimum results for me .
Thanks Dr Khan for your comment. I just wanted to know what you mean by "bannect mechanics".
Sorry spelling mistake its Bannett mechanics .The use of initial tight lacebacks on initial wires and later space closure on rectangular wire with combination of laceback wire and elastic ligature or laceback wire or elastic separator .Some people say only space closure on rectangular wires is Bannett mechanics but after having 3 workshop on MBT by 3M i have a understanding they say both component as bannett mechanics .
MBT negate wagon wheel effect and claim
The use of lacebacks during leveling and aligning and elastic module tie-backs during space closure substantially reduces adverse tipping in these stages of treatment, so there is no need for increased tip values.
As wagon wheel effect as virtue of arch shape and not mechanics so you find yourself with spaces distal to upper lateral at end of cases .
see following evidence on initial laceback for canine distalizzation
The effectiveness of laceback ligatures during initial orthodontic
alignment: a systematic review and meta-analysis.Eur J Orthod. 2013 Aug;35(4):539-46.
though no systematic review but almost all articles say that using elastic module tie-backs during space closure causes more anchorage loss than niti springs
See Larry Andrews publications on the difference in his articles around 1972 to present He describes the difference very well
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