Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT05882526 |
| Other study ID # |
canine retraction in tooth |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
May 15, 2023 |
| Est. completion date |
December 2024 |
Study information
| Verified date |
May 2023 |
| Source |
Mansoura University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
evaluate and compare the efficiency between elastomeric chains and burston T-loop retractors
in terms of rate of maxillary canine retraction and canine movements
Description:
The purpose of orthodontic treatment is to move teeth as efficiently as possible with minimal
adverse effects on teeth and supporting tissue. Numerous methods of canine retraction are
currently in common use. Force can be applied through the elastics, closed coil springs, wire
loops of numerous designs, and a number of headgear types currently available.
The principles for retraction currently used in preadjusted edgewise mechanics can be
described as either:(a) a frictional system in which the canine is expected to slide distally
along a continuous archwire, (b) frictionless mechanics in which loops (springs) are
incorporated in a continuous or a segmental archwire to retract teeth. The sliding mechanism
in any application other than simple tipping movement has two disadvantages: (i) friction
(ii)force magnitudes cannot be easily determined since the amount of friction is relatively
unknown and unpredictable.1 Space closure in orthodontics is the second stage incomprehensive
fixed appliance treatment and can be accomplished by either sliding mechanics or loop
mechanics. Nickel-titanium closed-coil springs and elastomeric power chains (PC) are the most
common force delivery systems used in space closure
In vitro studies of the properties of PC showed that they lose force much more rapidly than
springs over time.2-3In addition, environmental factors and temperature have greater effects
on the properties of PC than on CS.4 Arch-length-to-tooth-mass discrepancy patients require
extraction of teeth and closure of those spaces to correct their malocclusion. There are
different mechanical methods used in orthodontic practice to move teeth, such as using
various types of elastic materials and coil springs5During the past few years, elastomeric
power chains (EPCs) have been used in preference to other retraction orthodontic materials
because of their elastic properties, ease of application and requiring no patient
co-operation, low cost, being relatively hygienic, and their irritation-free nature due to
their smooth surface6 The proper position of canines shares a very important role in oral
function and esthetics. Their unique position makes their orthodontic movement of great
clinical importance, especially in premolar extraction cases. Segmented arch technique is a
modified edgewise orthodontic procedure developed by Burstone7 in 1962 which consists of
multiple wires found in different portions of arch. The force systems are relatively constant
and with long ranges of activation and optimum force levels their resulting movement is
predictable, as stated by Burstone, Baldwin, Lawless.8 Later in 1966, Burstone CJ9 stated
that moment-to-force ratio, magnitude of force and the constancy of force determine the
success of an appliance. The segmented arch technique has many advantages like better control
over the forces, more efficient tooth movement over long distances with light constant
forces, as stated by Burstone, Koenig (1976).10 In 1980, Burstone and Goldberg11 introduced
beta titanium molybdenum alloy (TMA) wire (11%molybdenum, 6% zirconium and 6% beta titanium
alloy) which showed twice the amount of deflection and delivered half the amount of force as
compared to stainless steel wires. Burstone, van Steenbergen, Hanley12 in 1995 mentioned that
T-loops had three important characteristics, i.e."α" , i.e. anterior moment or β, i.e.
posterior moment and a horizontal moment.
Viecilli (2006)13 stated that the effects of steps, angles and vertical forces could be
combined to produce an ideal T-loop design. According to Proffit (2007),14 segmented
retraction of canines with frictionless springs reduces the strain on posterior teeth. The
T-loop design generally provides a constant moment:force (M:F) ratio, a light and constant
force throughout the entire activation range of a closing loop, and a constant low
load-deflection rate15
Canine retraction and space closure is considered the most time-consuming phase in
orthodontic treatment.16 Acceleration of this step would reduce overall treatment time,
improve patient cooperation, and decrease possible negative side effects.17,18 Manipulation
of tooth biomechanics16-19and tissue reaction20 have been widely attempted to reduce
treatment duration. Additionally, the rate and safety of different canine retraction
methods20 and different force Various techniques for canine retraction have been introduced
including Nickel Titanium closing coil, Elastomeric chains, and lace backs. On the other
hand, frictionless mechanics imply the use of the sectional method as the use of Burstone's T
- loop, Rickett's spring, or Gjessing's spring Researchers were interested in investigating
the effect of different force levels on the rate of canine retraction using sectional
springs. And many authors have described various designs of canine retraction springs, their
suitability and efficiency 21,22
