The labial bow is a component of removable orthodontic appliances that helps retract and retain anterior teeth. It has several functions including moving teeth lingually/palatally, restraining the lip, aligning anterior teeth, and acting as a fulcrum. The main components are the horizontal bow portion, vertical loops, occlusal crossover section, and retentive ends. There are different types of labial bows including short, long, split, reverse, fitted, Mill's retractor, and Robert's retractor, each used to address different orthodontic issues like overjet reduction, space closure, and anterior retraction.

1. LABIAL BOW

2. Labial bow
An component of the removable
orthodontics appliance which helps in
retracting and retaining the anterior teeth
in both mandible and maxilla
•Contributes for the retention of the
appliance
•Can be passive or active

3. Functions:
-Move teeth in a lingual or palatal direction
(to reduce overjet and provide an anterior
fixation)
-Restrains the lip away from the anterior
teeth allowing ant. teeth in a more labial
direction
-Align the anterior teeth to create a
harmonious dental arch.
-Acts as clasps enhancing the fit of palate
-Serves as fulcrum when rotating teeth with
springs or screws

4. Components
1.Horizontal bow portion
2.Vertical loops
3.Occlusal crossover section
4.Retentive ends

5. Horizontal bow portion
Either contacts or stands slightly away
from middle thirds of crowns of incisors(in most
appliances) and ends with right angle bends at
the distal third of lateral incisor, mesial third of
canines, or distal third of canine.

6. Vertical loops
Consists of parallel vertical legs joined by
a smooth curve.
Allows for the adjustments of wire.
Constriction of loops shortens wire and opening
of loops lengthen it.
Repeated bending cause breakage of wire

7. Occlusal crossover section
Distal leg of the vertical loop enters the embrasure
between canine and premolar or between premolars,
crossing the occlusal surface and entering into acrylic

8. Retentive ends
Are placed in the palatal or lingual surface 0.5mm-1.0mm
gap is placed retentive arm and palatal/lingual surface so
acrylic can flow. This prevents dislocation from acrylic base
plate

9. Types of labial bow
A. With U loops
oShort Labial Bow
oLong Labial Bow
oSplit Labial Bow
oReverse Labial Bow
oFitted Labial Bow
B. Without U loops
oMill’s Retractor
oHigh Labial Bow with Apron Springs
oRobert’s Retractor

10. Short Labial Bow
Made from 0.7 mm round SS
wire.
contacts the most prominent
labial surfaces of the anterior teeth
and ends in two U-shaped loops that
extend as retentive arm between
the canine and premolar before
getting embedded in the acrylic
base plate.
Indication:
-closure of spaces mesial to canines
-minor overjet reduction
-retention

11. Long Labial Bow
It is a modification of the short
labial bow design
The distal arm of the U-loop
extends between the two premolars
and ends as the retentive arm.
Indication:
-minor overjet reduction
-small amounts of anterior space
closure
-closure of space distal to canine
-guide of canine during canine
retraction.

12. Split Labial Bow
Modification of the conventional short labial bow in that it is split
in the middle.
Increase the flexibility of the otherwise stiff short labial bow.
The bow is made up of 0.7 mm round SS wire and has 2 separate
short buccal arms, each with a U-loop ending distal to canine.
Indication:
-anterior retraction.
- closure of midline diastema (for which it has been modified such that the
2 buccal arms extend across the opposite central incisor and engage onto
its distal surface)

13. Reverse Labial Bow
The loop is placed distal to
the canine and the distal arm is bent
at right angles to extend anteriorly
as the labial part of the bow.
Activation is done by opening
the loop which results in lowering of
the labial bow in the incisor region.
To maintain the proper level
of the bow, a compensatory bend is
then given at the base of the U-loop.
Indication:
-Minor retraction of incisors
-Minor crowding

14. Fitted Labial Bow
It is adapted to the
contours of the labial surface
of anterior.
It is mainly for
retention after completion of
fixed orthodontic treatment.
The U-loop is smaller
compared to the conventional
labial bows.
Indication:
-retention appliance after
orthodontic treatment

15. Mill’s Retractor
made of 0.7mm SS wire
has extensive looping in its
design to increase the flexibility and
range of action of the retractor.
activated by compressing the
extended loop and bending the bow
palatally
Indication:
-patients with increased overjet.
- Alignment of irregular incissors
!! due to difficulty in construction
and poor patient compliance, it is not
widely used.

16. High Labial Bow with Apron Springs
It is made up of a thicker
gauge SS wire (0.9-1 mm).
extends high into the
labial vestibule.
support onto which apron
springs (made from 0.4 mm wire)
help in retraction of one
or more upper anterior.

17. two components
1. Heavy base arch wire
2. Apron strings

18. Robert’s Retractor
made of 0.5 mm round SS
wire
extends over the labial
surfaces from canine to canine and
instead of a reguhelix at the base of
the loop
adjusted by bending the
vertical limb below the coil.
as the incisor moves palatally,
the bow will drop anteriorly and the
level of horizontal part should be
adjusted
Indications:
- Retraction of proclined
incisors(more than 4mm)