iDentistry The Journal September-December 2017 | Page 14

The Journal
*Dr. Kavita
**Dr. Abhishek Sharma
“Basic Edgewise Mechanics in Contemporary
Orthodontics”
Edward Hartley Angle believed that an orthodontic appliance must have five properties i.e. Simplicity,
Stability, Efficiency, Delicacy, Inconspicuousness. Dr. Angle designed a standard appliance with
basic components being traction screws, attachment tubes, jackscrews, lever wires, band materials
and arch wire. Many changes were subsequently made on the Angle’s original design. Straight wire
appliance was developed by Dr. Lawrence Andrews in mid 70’s. Most of the orthodontists today
prefer preadjusted appliance system, in order to avoid tedious wire bending; but they do present with
limitations in treatment delivery for individual patient needs. Although preadjusted appliance system
has reduced the need for extensive and time consuming wire bending but still basic edgewise
mechanics are required to be incorporated to achieve stable results as the severity of malocclusions
is different in every patient. The edgewise mechanics has stood the test of time and will be used by
many more generations of orthodontists.
Introduction
Edward Hartley Angle’s compulsion for order
led him to introduce the edgewise multibanded
appliance, which has been the progenator of all
modern appliances. Dr. Angle was determined
to use it to correct malocclusions while
preserving the full complement of teeth. Dr.
Angle collaborated with Dr. Charles H. Tweed,
who, after countless failures, introduced the
extraction of four first premolars and anchorage
preparation to produce facial balance. He
believed that an orthodontic appliance must
have five properties: 1.Simplicity 2.Stability
3.Efficiency 4.Delicacy 5.Inconspicuousness. 1-3
Dr. Angle designed a standard appliance with
basic components being traction screws,
attachment tubes, jackscrews, lever wires,
band materials and arch wire. However, many
improvements were subsequently made on the
Angle’s original design, the edgewise
mechanics has stood the test of time and will be
used by many more generations of
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orthodontists. Straight
wire appliance was
developed by Dr. Lawrence Andrews in mid
70’s. Andrew’s idea was to create an appliance
that would transfer the work that was normally
done through wire bending to the brackets
themselves. He referred to Angle’s “latest and
best” appliance as oldest and among the least
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efficient of all edgewise appliances.
EDGEWISE Vs PREADJUSTED EDGEWISE
APPLIANCE
In Various comparative studies both appliance
syste ms produced similarly good results and no
significant differences were found. Most of the
orthodontists today prefer preadjusted
appliance system, in order to avoid tedious wire
bending; but they do present with limitations in
treatment delivery for individual patient needs.
Ÿ The bracket prescriptions are not suitable for
variations in face type and severity of
malocclusion and results in finishing all the
cases in the same manner that is not desirable.
The prescriptions build in the brackets may
poorly or incorrectly express due to improper
bracket position. There may be loss of torque
and rotation control during retraction that may
require additional wire bending despite of these
features already incorporated in brackets.
Preadjusted appliance system increases
inventory and resultant cost. 4
* Senior Lecturer, Department of Orthodontics and Dentofacial Orthopedics, Bhojia Dental College and Hospital, Baddi (Himachal Pradesh), India.
** Senior Lecturer, Department of Orthodontics and Dentofacial Orthopedics, Bhojia Dental College and Hospital, Baddi (Himachal Pradesh), India.
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Vol. 13 No. 3
Sep-Dec 2017