2. Quadhelix appliances
fixed, slow-expansion appliance consisting of four helix springs that
expand the upper jaw which, Unlike the RME, does not require turning to
be activated.
It can be used to widen the upper jaw anteriorly and/or posteriorly as
as rotate the upper first molars.
introduced by dr. robert ricketts in 1975
Evolved from coffin spring expansion appliance
3. •Types
a) Custom made: 1-0.9mm stainless steel with four helices to
increase flexibility.
b) Preformed ready type.
Removable/Fixed; retained by bands cemented on upper
permenant first molars.
4. •material
• - Blue Elgiloy(0.95mm/0.037"): a cobalt-chromium-nickel alloy used for
increased flexibility/adjustibility, least resilient of elgiloy tempers. can be
heat treated to increase resilience
• contents : 40% cobalt, 20% chromium, 15% nickel, 7% molybdenum,
manganese, 0.15% carbon, 0.4% berylium, 15% iron
• shaping of wire is done in softer form--> heat treatment (500 c)--->
wire gets hardened (equivalent to ss)
• -stainless steel (0.038"/38 mil/0.9mm)
• -nickel titanium: removable version of appliance
• * study showed that the factor that effects the efficiency of the system
is the size of the appliance and diameter of wire not the material
5. •Design
-consists of a W-shaped 1mm spring, usually 38 mil SS, incorporating 4 helices to add
flexibility & increase range of action.
the quadhelix consists of a pair of anterior helices and a pair of posterior helices.
-all loops should be as horizontal as possible with the anterior loops circling toward the
palate and the posterior loops away from the palate.
the anterior loops are at the level of the primary canines or at the level of distal surfaces of
canines, the distance between the loops is called "anterior bridge" .
-the posterior loops should be extend 2-3mm distal to the molar bands for enhanced
rotation & expansion,but not extending to pterygomandibular raphe.
-the posterior loops are sloped parallel to the palatal surface.
-The palatal bridge should not be irritating the palate (1-2mm away).
the length of the anterior arms can be altered depending upon which teeth are in crossbite.
each loop adds about 2mm of additional wire to the appliance.
8. •1)Extra-oral activation
bilateral expansion with fingers till it is expanded half a molar tooth width on each
side
step 1: activate posterior helical loops by moving the free wires bucally
step 2: activate anterior helical loops by moving the bands bucally
Step 1 Step 2
9. •2)Intra-oral activation
-intra oral activation is done by using triple prong plier.
-1st bend: Anterior bridge is bent by keeping single beak anteriorly-
expansion
-2nd & 3rd bends are on the palatal bridges to expand lateral arms and
counteract mesial molar rotation,by keeping single beak posteriorly
-Our goal is to over-correct the crossbite
-a quadhelix can be activated to derotate a maxillary molar on one side of
arch provides distalizing force at the molar on the opposite side on the same
arch
by extending the anterior arms of the appliance on one side, it can involve
more teeth on that side to act as anchorage in the distal movement of a
molar on the opposite side of the arch
13. •Molar derotation :
Derotation of molars is done when the buccal arm is not touching the teeth, or is
absent, where any manipulation of the wire made will derotate molar according to the
wanted direction
14. •indications:
1-intermediate upper arch expansion.
2-expand the upper arch anteroposteriorly when its arm length increased.
3-provide space and access with cleft palate before bone grafting.
4-used with facemask (like RME).
5-molar derotation.
6-habit breaking effects.
7-method of attachement to align impacted teeth or to perform certain teeth movement.
8-provide some AP and trasverse anchorage.
9-Bi-helix used in mandibular arch in grossly narrowed or distorted arches &correction of
severe scissors bite.
10-quad-helix and tri-helix are useful in cleft cases.
11-correction of mild class 2 malocclusion where the upper palate needs to be expanded
and the upper molar rotated distally.
15.
16. •advantages:
1-reduced need for patient compliance (fixed).
2-efficient.
-produced a combination of buccal tipping and skeletal expansion
in the ratio 6:1.
-high success rate.
3-habit breaker.
4-cost effective.
5-molar rotation.
6-good retention.
7-large range.
18. •clinical management:
the desirable force of 400g can be delivered by activating the appliace by
8mm, which equates one molar width.
patients should be reviewed on a six-weeks basis.
appliance leaves imprint on tongue which eventually disappears.
expansion should be continued until the palatal cusps of the upper molars meet edge-
to-edge with the buccal cusps of the mandibular molars.
