Removable appliances in orthodontics /certified fixed orthodontic courses by Indian dental academy

CLASPS
INDIAN DENTAL ACADEMY

www.indiandentalacademy.com


DEFINITION
• The name clasp is derived from a
French word “UYPTAN” which means
“to embrace”.
• Clasps are the retentive
components of the orthodontic
appliances.

This unit of removable orthodontic appliance holds the appliance
in position and is called clasp.

There are many types of clasps.

1.’ C ’ clasp
2.Full clasp or Jackson’s clasp
3.Triangular clasp
4.Adam’s clasp and their modifications
5.Schwarz clasp
6.South end clasp
7.Duyzing clasp
8.Ball end clasp
9.Crozat clasp
10.Delta clasp
11.Eyelet clasp

Retention -
-”Holding of teeth in
ideal aesthetic and
functional positions”
BY RIEDEL


IDEAL REQUIREMENTS
• Unobtrusive.
• Not impinge.
• Close contact to the
tooth.
• Usable in both deciduous
and permanent
dentition.
• Adequate retention.


• No active force on the anchor
tooth.
• Rigid
• Easy to fabricate and also replace
if needed.
• Not interfere in the growth of
jaws and eruption of teeth.


USES
To secure the appliance in
position
To prevent rolling of appliances
To resist forces of displacement
To provide retention & anchorage
For engaging elastics


CLASSIFICATION
A. Hand Made
Machine Made.

B. Single tag arm
Double tag arm


MODE OF ACTION OF
CLASPS
Clasp engage onto the undercuts
(constricted areas on the teeth.)

Two types of undercuts.
Buccal / Lingual Cervical undercuts.
Mesial / Distal Proximal undercuts.


ANGLE’S
Line of occlusion
It is a smooth (catenary)curve passing
through the central fossa of each upper
molar and across the cingulum of the upper
canine and incisor teeth.

The same line runs along the buccal cusps
and incisal edges in the mandibular arch.

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www.indiandentalacademy.com N

CIRCUMFERENTIAL
CLASP


• Circumferential clasp / C-Clasp /
3/4th Clasp.
• It uses the bucco-cervical
undercut.
• 2nd molars and canines.
• Single retention arm.
• 1mm wire used in molars.


Advantages

• Good retention.
• Easy to fabricate.
• Single occlusal crossover wire.
• Easy to replace.


Disadvantages

• Not on semi-erupted tooth.
• Decalcification of cervical
margin.
• Gingival irritation.
• Plaque accumulation enhanced.
• Easily distort.


JACKSONS
CLASP


• V.H. Jackson 1906
• Jacksons Clasp / Full Clasp / U
Clasp.
• Both bucco-cervical and proximal
undercuts.
• 0.7mm to 1mm.


Advantages

• Simple design
• Adequate retention.


Disadvantages

• Not useful in partially erupted
teeth.
• Difficult to adjust.
• Not on unfavorably inclined
tooth.


SOUTHEND
CLASP


• Most common for anterior
anchorage.
• Single arrowhead between
Central Incisors with wire
following the gingival margin.
.Stephen’s
-1979 www.indiandentalacademy.com

TRIANGULAR
CLASP


• Also called as MODIFIED
ZIMMER CLASP.
• Excellent retention by the single
arrowhead in the interproximal
area.
• Free end towards distal to
facilitate the engagement of
elastics.
• 0.7mm wire


Advantages
• Excellent retention.
• Pre fabricated available.
• Elastics can be engaged.


Disadvantages
• Not useful if adjacent tooth is
absent.
• Used as secondary / additional
retention.


BALL END
CLASP


• Action and location similar to
triangular clasp.
• Pre fabricated available. Can be
made by adding solder to end of a
wire.


Advantages
• Single occlusal interference.
• Less gingival irritation.
• Easy to replace.


Disadvantages
• Short arm makes adjustment
difficult.
• Cannot be used for primary
retention.
• Cannot be used in absence of
adjacent tooth.


SCHWARZ
CLASP


• Also called as ARROWHEAD
CLASP.
• A.M. Schwarz 1935.
• Mesial and distal undercuts of the
teeth.


Advantages
• Reliable retention.
• Does not interfere in posterior
occlusion.
• More length of wire hence more
flexible.
• More easy to adjust.
• Enhances eruption.


Disadvantages
• Difficult to fabricate.
• Needs special plier.
• Irritates soft tissue.
• Tends to separate teeth.
• Is bulky hence less patient
compliance.


CROZAT
CLASP


• Crozat in 1920
• Along with the u clasp another
curved wire is soldered on the base
(Crescent).
• Strong retention is possible


DUYZING CLASP
DUYZING,S J.A.C. –1969

0.7m.m WIRE USED.

This clasp is used to engage the buccal undercuts
of molars.

This clasp is constructed in two halves .


ADAMS
CLASP

• Adams clasp / modified
arrowhead clasp / liverpool clasp
/ universal clasp.

• C. PHILIPS ADAMS in May 1950.

• Most widely used clasp.

• Distobuccal and mesiobuccal undercuts.

• Does not separate teeth like a arrowhead
clasp.

• 0.7mm posteriors
0.6mm anteriors.

Parts
BRIDGE
2 ARROWHEADS
2 TAG ARMS


BRIDGE
• Is 2/3rd the mesio-distal width of
the tooth, or slightly less then the
distance between mesiobuccal
and distobuccal undercuts, or
length should be equal to the
intercuspal distance.

• Is 1-2mm away from the buccal
surface of the tooth.
• Is at 45o to the buccal surface of
the tooth.
• Should be straight.


Arrowheads
• They should lie in the disto and
mesio buccal undercuts.
• Shaped according to the curve of
the gum margins into the
interdental papilla.
• Long enough to keep the bridge
at a proper distance.
• Should not touch the adjacent
teeth


Tag arms
• Closely fitted to the contact
points, down to the interdental
embrassure.
• Space between the tag arms and
palate for flow of acrylic.
• No sharp bends.


FABRICATION


Advantages
• Small,neat and unobtrusive.
• Any tooth.
• Both deciduous and permanent dentition.
• Even on semi erupted tooth.
• No specialized pliers required.
• Can be modified as needed.
• No. of modifications are available.


Disadvantages
• Unwanted palatal tipping if gets activated.
• May lead to elongation of tooth if is fitting
tightly.
• Can be repaired only if fractured through
the arrowheads.
• Cannot be given on proclined anteriors.


MODIFICATIONS
OF ADAMS CLASP


Anterior Adams
• 0.6mm
• Also called double clasp.


With distal extension/ traction
hook

• To engage elastics
• Not given if sulcus is shallow.


With eyelet


With a soldered hook


With a soldered tube


With a single arrowhead


With accessory arrowhead


Smart clasp


• It is used in magnetic activator
devices
• Wire used 0.7mm
• Bend 2mm loop on each side along
with arrow head
• It can be modified to double clasp on
premolars and molars for extraoral
traction

ADVANTAGES
• Coils of the smart clasp increases
spring back property.
• Reduces frequent tightening.
• Can be used with any type of
removable appliances like bite
blocks, palatal expanders.


Delta clasp


TWIN BLOCK

• William J. Clark
• Used in twin block appliances
• Retentive loops were triangular
in shape hence the name “Delta”
• Retains the basic elements of Adams
clasp like retentive loops and a
buccal bridge


ADVANTAGES
• Design of the closed loop does not
open up with repeated removal.
• Less subject to breakage.
• Provides excellent retention on lower
premolars.
• Suitable for use on most posterior
teeth.


Removable appliances in orthodontics /certified fixed orthodontic courses by Indian dental academy

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Removable appliances in orthodontics /certified fixed orthodontic courses by Indian dental academy