Week 1 Anterior Crossbites

Question 1

True or False?

There has to be a space to move the tooth into; otherwise you cannot correct the crossbite if it is a dental cross bite

Answer 1

True

Question 2

What is an overjet?

Answer 2

Horizontal distance of upper incisor ahead of the lower incisor

Question 3

What is the indication of anterior crossbite?

Answer 3

Negative overjet

Question 4

What type of anterior cross bites should we treat?

Answer 4

1. Class 3 malocclusions with maxillary retrusion
2. Class 3 with mandibular protrusion
3. Those that have anterior cross bites with class 1 skeletal relationships

Question 5

Do you treat patients with class 3 skeletal problems?

Answer 5

No

Consider treating anterior cross bites where ONLY the teeth are the problem. Not the jaws!

Question 6

What is the class 3 malocclusion?

Answer 6

Lower molar mesial to upper molar, other teeth really don’t matter

Question 7

How to determine a class 3 skeletal?

Answer 7

Straight or Concave profile

Molar class 3 and 0 or negative overjet

Question 8

Anterior dental crossbites presents as…

Answer 8

Skeletal class 3 or class 1

If it is skeletal class 1, there is pseudo class 3 either max dental retrusion or mand dental protrusion

Question 9

Anterior dental crossbite etiology?

Answer 9

Tooth bud position (ectopic eruption)

Retained primary teeth

Supernumerary tooth

Trauma or crowding

Question 10

Treatment needed for anterior crossbite to tip the maxillary retroclined central incisors ?

Answer 10

Removable appliances

round wire, dimension 0.022, formable, springness

Question 11

Treatment options for anterior dental crossbite?

Answer 11

1. Removable appliance

2. Fixed bonded appliances

Question 12

Treatment needed tipping movement and rotation of the maxillary retroclined central incisors.

Answer 12

Bonded fixed appliance with round wire to get the rotation.

Rectangular wire if you need bodily movement.

Question 13

What kind of removable appliance is used for anterior crossbite?

Answer 13

Maxillary removable applaince (Hawley) with double helical cantilever

(round wire, formable, springness, dimension 0.22)

Question 14

Function of double helix?

Answer 14

to increase the length of wire to increase range and springness, but decreases stiffness

Question 15

Double vs single cantilever?

Answer 15

easier to adjust, further increase in wire length in constrained space

Question 16

Biomechanics of Hawley with double helical cantilever?

Answer 16

Force applied on lingual surface of the crown
Not thru Cres (force is coronal to Cres)
Tipping force

Question 17

What provides the retention in Hawley with double helical cantilever?

Answer 17

Adam’s clasps

Question 18

Anchorage of hawley double cantilever?

Answer 18

Teeth (because we are moving against the teeth that are clasped)

When teeth are pushed forward, there is NO anchorage from the palate.

Question 19

Why no labial bow in hawley with double cantilever?

Answer 19

The labial bow would be in the way since the teeth are moved forward. The labial bow would be where you want to move the teeth.

Question 20

How much adjustment can be made with the hawley?

Answer 20

Activate spring facially and apically. Activate it 2mm. This will give you 1 mm of movement in a month.

Question 21

Problems associated with Hawley?

Answer 21

Not activating properly

Not enough retention in the appliance

Patient compliance

Question 22

How long to use Hawley to fix the problem?

Answer 22

should be corrected in 1-3 months if everything works well

Question 23

Bonded fixed appliance material to fix anterior crossbite?

Answer 23

NiTi (flexible), not formable, lots of springness

Dimension: 0.014,0.016 (small) very light

Round wire

Question 24

Biomechanics of Bonded Fixed Appliance?

Answer 24

Force applied on facial surface of crown

Not thru Cres (applied where the brackets are, when the teeth move foward, the forces will be coronal to Cres)

Question 25

Type of movement by using bonded fixed appliance?

Answer 25

round wire - for rotation
Rectangular wire - Bodily movement

(both have some tipping movement)

Question 26

Problems with fixed bonded fixed appliance?

Answer 26

Hygiene and some inflammation along the borders of the soft tissue.

Question 27

What to use to make bodily movement for anterior crossbite correction?

Answer 27

Need a fixed appliance

Need a rectangular wire that engages the bracket

Question 28

True or false?

You can achieve mesiodistal bodily movement with a round wire?

Answer 28

True