Burstone’s T Loop

BURSTONE’S
T - loop
www.indiandentalacademy.com

10 mm
5 mm
2 mm
4 mm
ALPHA
(ANTERIOR) SEGMENT
BETA
(POSTERIOR) SEGMENT

• HOW TO USE T LOOPS FOR EXTRACTION
SPACE CLOSURE
• T-LOOPS vs VERTICAL LOOPS

HOW TO USE T LOOPS FOR
EXTRACTION SPACE CLOSURE
• POSITIONING OF THE LOOP DURING
SPACE CLOSURE

• IN GROUP A ANCHORAGE PLACE
THE TLOOP
a)offcentered towards anteriors
b)offcentered towards posteriors
c)centered
d)any of the above position

• What are preactivation bends? why are
they given?

BIOMECHANICS
• STATIC EQULIBRIUM PRINCIPLE

• What is moment to force ratio? What is its
significance?

Consider the moment created when force is applied Mf and the
counter balancing moment generated by the couple within the
bracket Mc
Mc/Mf = 0 –Pure tipping Crot and cres same,thus the
tooth rotates around the Cres
0 < Mc/Mf >1- Controlled tipping – Crot displaced away
from Cres – crown and root move in the same direction
Mc/Mf = 1– Bodily movement – equal movement of crown
and root
Mc/Mf > 1 Torque – root apex moves further than thewww.indiandentalacademy.com

M/F 5 : 1 Uncontrolled tipping
M/F 8 : 1 Controlled tipping
M/F 10 : 1 Translation
M/F >10 : 1 Root movement
MOMENT TO FORCE RATIO FOR VARIOUS
TOOTH MOVEMENTS

Off center bend
Points in the direction
of the force produced
on the tooth
Center bend
Short segmentLong segment
Points in the direction
opposite of the force
produced on tooth
No short or long
segment
No force produced
V - BEND
PRINCIPLE

T loop vs vertical loop
• FABRICATED IN TMA WIRE
• LOW LOAD DEFLECTION
RATE
• HIGH YEILD STRENGTH
• LESS CONSTANT FORCE
• HIGHER MOMENT/FORCE
RATIO
• STAINLESS STEEL WIRE

GROUP B ANCHORAGE
Distal force on anteriors Mesial forces on posteriors
Equal potential for tooth mvt.
Alpha moment Beta moment
Horizontal force acting on both segments are same
Moment to force ratio
EQUAL
EQUAL
RETRACTION OF ANTERIOR
PROTRACTION OF POSTERIOR

Group B ANCHORAGE CASE

• POSITION OF T-LOOP:
D = L-A
2
D = Distance from the center of the loop to
either the anterior bracket or posterior
auxillary tube.
L = Distance between the canine bracket
and Molar tube.
A = The millimeters of activation of the
spring (usually 6 mm)

αβ

GROUP A ANCHORAGE
Distal force on anteriors Mesial forces on posteriors
Maximum potential for tooth mvt. Miminised or counteracted
Decrease moment Increase moment
Horizontal force acting on both segments are same
Moment to force ratio
Reactive unit Anchor unitwww.indiandentalacademy.com

Alpha moment Beta moment
Anteriors posteriors
Vertical forces created
Extrusion
When unequal or unbalanced
Intrusion
alpha
beta
alpha
beta
Intrusion Extrusion

• GIVE EQUAL ALPHA AND BETA BENDS AND PLACE
THE LOOPS OFFCENTERED TOWARDS
POSTERIORS
• GIVE MORE BETA BEND AND PLACE THE LOOP
OFFCENTERED TOWARDS ANTERIORS
• GIVE EQUAL ALPHA AND BETA BENDS AND PLACE
THE LOOPS AT CENTER AND USE HEADGEAR TO
CONTROL THE POSTERIOR SEGMENT

T LOOP The preactivated spring with the anti tip
and anti rotation BENDS ARE placed
Activation on insertion is 6mm
The m/f is 8:1 – controlled tipping
Now as the tooth moves the activation
reduced to 4mm – the force is reduced
M/f ratio is increased - bodily movement further
The activation is reduced to 2mm – force is
further reduced
M/f ratio increased – 12:1
Root uprighting

ANTI RATIONAL BENDS-
OPTIONAL

THANK YOU

Burstone’s T Loop

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