Space Regainer in Pediatric Dentistry

The transition from mixed dentition to a permanent one is seldom accurate, the hurdles being space loss, tooth size arch length discrepancy, early exfoliation of primary teeth, or premature eruption of permanent teeth. When the usual sequence of eruption of permanent teeth does not occur, it must warn the clinician of monitoring the arches and intervening with extractions, space maintainers or space regainers. This article highlights the various types of space regainersused in pediatric dentistry.


INTRODUCTION
The transition from mixed dentition to a permanent one is seldom accurate, the hurdles being space loss, tooth size arch length discrepancy, early exfoliation of primary teeth, or premature eruption of permanent teeth.When the usual sequence of eruption of permanent teeth does not occur, it must warn the clinician of monitoring the arches and intervening with extractions, space maintainers or space regainers.This article highlights the various types of space regainersused in pediatric dentistry.

Types of space regainers Fixed space regainers a)
Pendulum appliance b) Herbst space regainer c) Lip bumper d) Hotz lingual arch e) Sectional arch technique f) Anterior space regainer g) Gerber space regainer Removable space regainers a) Jack screw space regainer b) Split saddle /split block space regainer c) Sling shot space regainer d) Free end loop space regainer

Fixed space regainer a) Pendulum appliance
Pendulum appliance is used mainly to regain space in case of mesial drift of upper first molar due to early loss of primary molars.

Construction -steps 1.
Pendulum appliance uses palate as anchorage unit to distalise first molars.

2.
It consists of acrylic plate retained by clasps to first premolars.

3.
Distal arm or springs are constructed using 0.6mm stainless steel.

4.
It consists of closed helix and U loop.

5.
Closed helix is for activation of distalisation arms.

6.
It is activated extra orally.Generates a force of 250 g per side.This pressure can be used to distalise molars by: 5.

Indication of pendulum appliance
Incorporating loops in the arch wire just before it enters buccal tube.6.
Utilising coil spring.

b) Hotz lingual arch type regainer
A distal movement of permanent first molar is achieved by means of wire spring attached to lingual arch.Also an addition of a loop in the arch that is gradually opened to gain space.Anchorage is necessary for exerting force to move the first molar distally Construction -steps 1.
A molar band is fitted to the first permanent molar.

2.
Molar tubes are soldered or spot welded in horizontal position both buccally and lingually to the band.
stainless steel wire slightly smaller than the tube size is selected and bent into a 'U' shape.

5.
Base of the U should contain a reverse bend to contact the distal surface of first premolar.6.
The wire comes out of the tube towards the premolar at a point below the greatest convexity of the first premolar.7.
A spaced coil spring is selected and is cut about 2 to 3mm longer than the anterior stop to the molar tube.The band is cemented with the coil springs compressed.
It is used where bilateral movements are desired.

2.
It consists of heavy labial arch wire over which an acrylic flange is prepared in anterior region such that it does not contact lower anterior.

c) Sectional arch technique
Sectional arch technique can be used to regain lost arch length.By this technique , a space of upto 4 mm can be regained effectively.itcan be used in cases where second molar is erupted.The distal movement is limited to 1 to 2 mm.

C} Sling shot type space regainer
• From distal end of this appliance , hooks are attached on the buccal and lingual sides of first permanent molar which needs to be move distally.

•
An elastic band is stretched between the hooks and force from elastic band produces distal movement of first permanent molar.

•
The distal movement is limited to 1 to 2 mm.

Sling shot space regainer
• It is called sling shot appliance since distalising force is produced by elastic stretched on middle of lingual surface of the

Removable space regainers A. Screw type of space regainers
An expansion screw is embedded in resin base of removal appliance by expanding the screw , the distal movement of the first permanent molar is achieved.The expansion of screw is done by the patient once a week.The permanent first molar can be distalised by maximum opening width of screw

B. Spring type space regainer
In this appliance, springs are incorporated to produce the movement.This is used to produce distal movement of first permanent molar.The movement is achieved by the force produced by the spring using 0.7 mm wire Jackscrew space regainer • Jackscrew regainer is used to recover the loss of space caused by tooth drift into an edentulous area.

CONCLUSION
Thus regaining of space is important in case of premature loss of decidiousteeth .After regaining the space,it is even more important to maintain the regained space .The regained space can be maintained by the use of space maintainers.
It is a technique using anterior space regainer by direct bonding.A labial tube is attached to the lateral incisor.0.014 inch wire was inserted in open coil spring and activated g) Gerber space regainer • This type of appliance may be fabricated directly in the mouth .• It requires no laboratory work.• In this a U shaped assembly is used into which the U shaped wire can be fitted.• It is soldered onto the mesial aspect of the band .• The coiled spring is fitted onto U shaped wire which is fitted into u assembly.It is cemented to the teeth.the impressions made.• A 0.036 inch buccal tube is soldered or welded to the molar band.• The tube should be centered in the middle one-third of the band and aligned with the other banded abutment teeth.• A jackscrew unit consists of one adjustment nut and one lock nut on a threaded shaft.• The mesial end of the shaft is trimmed and contoured to band surface.• It is then soldered to the band.• End of the shaft should be trimmed so that it extends 2mm from the distal end of the tube.It is then cemented into the patient mouth.b) Split saddle type space regainer • It is also known as split block space regainer.• This appliance is commonly used in lower arch.• A distal movement of first permanent molar can be achieved by this appliance.• It is activated by flattening the bent portion of wire connecting the split saddles of acrylic base plate.•