Adams Clasp

Question 1

What is the role of an Adams clasp?

Answer 1

Retention:

helps keep in appliance
engages undercut on mesial and distal surfaces

Question 2

What is an adams crib made of?

Answer 2

0.7mm diameter stainless steel wire
= engages 1mm of under cut (in children where teeth not yet fully erupted it engages below the gingivae)

N.B. uses 0.6mm wire on premolars

Question 3

What are the elements of a removable appliance?

Answer 3

Active components
Retentive components
Anchorage
Baseplate

Question 4

What is retention?

Answer 4

The capacity of an appliance to remain fixed in the mouth = needs an undercut

Question 5

What are the possible different forms of retention for a removable appliance?

Answer 5

Posterior teeth = adams clasp
Anterior teeth = southend clasp & labial bow (these both also keep the teeth in the right place and prevent tipping)

Question 6

What is the role of the baseplate?

Answer 6

Keeps the components in the right place

Collets

Question 7

What are southend clasps made of?

Answer 7

0.7mm stainless steel wire

Question 8

What are (reversed loop) labial bow?

Answer 8

0.8mm stainless steel wire

Question 9

What is a baseplate made from?

Answer 9

Acrylic resin (autopolymerising/self cure)

Question 10

Why are adams clasps rarely used on anteriors and canines?

Answer 10

Theres not very much undercut to engage = not very retentive

Question 11

What are the component parts of an adams crib?

Answer 11

• A bridge
• 2 X Arrowheads
• 2 X flyovers
• 2 X tags

Question 12

What is the purpose of the tags?

Answer 12

So there is a small amount of space below the wire on the palate for the resin to flow under to hold the whole thing in place

Question 13

What do the arrow heads do?

Answer 13

Engage the undercuts

Question 14

In an adams crib which palatal clasp needs to curve towards the other? and why?

Answer 14

The distal arm to keep it within the baseplate

Question 15

What are the common faults of adams cribs?

Answer 15

• Bridge too low
• Bridge too short
• Arrowheads too small (bridge too close)
• Arrowheads too low
• Flyover too high
• Flyover not close enough to distal of tooth
• Retention tags too close together

Question 16

What is the problem with a bridge that is too low?

Answer 16

There’s no room for adjustment

Question 17

How far up a tooth is the bridge meant to be?

Answer 17

2/3rds of the way up the crown

Question 18

What is the problem with a bridge that is too short?

Answer 18

The arrow heads flare at the wrong angle, they need to dip in to engage the undercut

Question 19

What is the problem with having bridges that are too small?

Answer 19

The arrowheads are too upright so dont engage the undercut

Question 20

What is the problem with having undercuts that are too low?

Answer 20

Tissue trauma

Question 21

What is the problem with having a flyover that is too high?

Answer 21

It interferes with occlusion (n.b. this can be adjusted)

Question 22

Faults in which parts of an adams cribs cannot be adjusted and need to be redone completely?

Answer 22

The arrowheads and bridge (sharp bends fracture when rebent)

Question 23

What is the problem with the distal flyover being too far from the tooth?

Answer 23

Interrupt with eruption of second molar

Question 24

What is the problem with the retention tags being too close together??

Answer 24

Resin cannot flow between them and hold them in place properly