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IN THE NAME
OFGOD
Ehsan MotamediDepartment of orthodonticShahid Beheshti medical sciences university
Tehran , Iran
Retention components in orthodontic removable appliance
DEFINITION&
TYPES
• Clasps are wire components that aid in retention of a removable appliance. These are the retentive components that aid in keeping the appliance in place and resist displacement of the appliance
• Type of clasps in orthodontic :1. 'C' clasp or ¾ 'C' clasp2. Adam’s clasp and it’s modifications3. Jackson’s clasp4. Triangular clasp5. Eylet clasp6. South end clasp7. Schwartz clasp8. Duyzing clasp9. prefabricated clasp
'C' CLASPAdvantages :
Disadvantage :
Simple to construct
Prevent mesial migration of tooth
It can’t be used in partially erupted teeth.
Inadequate retention in primary teeth.
Just for molar and premolar
Hard to adjust and Easily set out
Easy to fabricate
Throw Distance between teeth
ADAM'S CLASPParts of Adam’s clasp• Two arrowheads• Bridge• Two retentive arms
Advantages:• This clasp is strong, simple and easily
constructed.• It can be used on any tooth (deciduous or
permanent, partially or fully erupted, incisors or premolars or molars).
• It is comfortable to wear and resistant to breakage.
• It is small and occupies minimum space.• It can be modified in a number of ways.• Nospecialized instrument is needed for
construction of clasp. Routinely used Young’s Universal plier or Adam’s plier can be used.
MODIFICATIONS OF ADAM’S CLASP
SOLDERED HOOK
DISTAL TRACTION
HELIX
ADDITIONAL ARROWHEAD
BUCCAL TUBE
ON INCISORS
JACKSON’S CLASPAdvantages:
Disadvantage:
Simple to construct
Offers adequate retention
Inadequate retention in partially erupted teeth.
Just for molar and premolar
Hard to adjust and Easily set out
Throw Distance between teeth
TRIANGULAR CLASP• engages the proximal undercut of two
adjacent teeth
• It provides excellent retention.
• It doesn’t cause irritation of gingiva.
• It is used when additional retention is required.
EYLET CLASPAdvantages:
Disadvantage:
Probability of breaking is very low
Not interrupt The tooth eruption.
Requires special pliers
Occupies more space
Hard to adjust and Easily set out
Throw Distance between teeth
SOUTH END CLASP• It provides retention in the anterior region.
• The wire is adapted along the cervical margin of both the central incisors.
• The distal end of the wire crosses over the Occlusal embrasures and end as retentive arms on the palatal side.
SCHWARTZ CLASPAdvantage :
• This clasp has a number of arrowheads that engage the inter-proximal undercuts of posterior teeth.
• Not interrupt The unerupted tooth or primary teeth.• Can set it up for mesial or distal easily
Disadvantage :
• It needs special arrowhead forming pliers.• It occupies a large amount of space in the buccal
vestibule.• The arrowheads can injure the interdental soft tissues.• It is difficult and time consuming to fabricate.
DUYZING CLASPAdvantages:
Disadvantage:
Possible to use only one-half of the clasp
One-half may be made to extend fully to the anterior or posterior part of the tooth
Provides limited retention
Accumulation of food debris is more in this type of clasp
Does not irritate of the gingiva
PREFABRICATED CLASPARROWHEAD
CLASPINTERDENTAL
CLASPARROWHEAD
ANCHOR CLASPTRIANGULAR
CLASPBALL END
CLASP
THANK YOU FOR YOUR ATTENTION