Under the guidence of :DEPT. OF ORTHODONTIA AND DENTOFACIAL

ORTHOPEDICSNORTH BENGAL DENTAL COLLEGE AND HOSPITAL

METHODS OF GAINING SPACE

WHY SPACE NEEDED????????????

IN SOME MALOCCLUSIONS AND IN THOSE CASES WHERE TOOTH MATERIAL AND ARCH LENGHT

DISCREPANCY PRESENT, SPACE IS NEEDED TO CORRECT THOSE MALOCCLUSIONS.

SUCH SITUATION WHICH REQUIRE SPACE FOR CORRECTION ARE:

1) CROWDING, 2) ANTERIOR PROCLINATION,

3) IMPACTED CANINE, 4) CURVE OF SPEE LEVELING,

5) CONSTRICTED ARCH,

VARIOUS METHODS FOR GAINING SPACE

PROXIMAL STIPPING ARCH EXPANSION EXTRACTION DISTALIZATION OF MOLAR UPRIGHTING OF TILTED MOLAR DEROTATION OF POSTERIOR TEETH PROCLINATION/FLARING OF ANTERIORS.

PROXIMAL STRIPPINGPROXIMAL STRIPPING IS A METHOD BY WHICH THE PROXIMAL

SURFACES OF THE TEETH ARE SLICED IN ORDER TO REDUCE THE MESIO-DISTAL WIDTH OF THE TEETH.

SYNNONYMS – REPROXIMATION, SLENDERIZATION,DISKING.

PROXIMAL STRIPPINGINDICATION OF PROXIMAL STRIPPING:1) IF BOLTON ANALSIS SHOWS MILD TOOTH MATERIAL EXCESS IN EITHER ARCH.2) IF CAREY’S ANALYSIS SHOWS TOTAL TOOTH MATERIAL EXCESS 0-2.5 mm.3) IN LOWER ANTERIOR REGION AS AN AID TO RETENTION.4) IN CASES WHERE INDIVIDUAL TOOTH SIZES PREVENTS A CLASS I MOLAR AND

CANINE RELATIONSHIP.5) TO OBTAIN MORE FAVOURABLE OVERJET AND OVERBITE.

CONTRAINDICATION OF PROXIMAL STRIPING:6) YOUNG PATIENT AS THEY POSSESS LARGE PULP CHAMBER,WHICH INCREASE

RISK OF PULP EXPOSURE.7) CARIES RISK PATIENT.8) TEETH WITH ENAMEL HYPOPLASIA.9) PATIENT WITH POOR ORAL HYGINE.

PROXIMAL STRIPPINGADVANTAGES OF PROXIMAL STRIPPING:1) POSSIBLE TO AVOID EXTRACTION IN BORDERLINE CASES WHERE SPACE

REQUIRMENT IDS MINIMUM.2) MORE FAVOURABLE OVERJET AND OVERBITE CAN BE ESTABLISHED.3) MINIMIZE THE POTENTIAL CONSEQUENCES OF EXTRACTION:• DIFFICULTY IN COMPLICATING SPACE CLOSURE.• DIFFICULTY IN PARALLELING THE ROOT AFTER EXTRACTION.• NEED FOR GREATER ANCHORAGE REINFORCEMENT.• POSSIBILITY OF SPACE RE-OPENING.DISADVANTAGES OF PROXIMAL STRIPPING:1) CARIES SUSCEPTIBILITY IS INCREASED.2) PATIENT MAY EXPERIENCES SENSITIVITY.3) LOSS OF CANTACT BETWEEN TEETH MAY LEAD TO FOOD IMPACTION.4) IMPROPER PROCEDURE MAY LEAD TO CHANGE IN MORPHOLOGY OF TOOTH.5) ROUGH PROXIMAL SURFACE ATTRACT PLAQUE.

INSTRUMENTS USED FOR PROXIMAL STRIPPING• DIAMOND PROXIMAL STRIPS: THIN STRIPS OF STAINLESS STEEL WITH ELECTROLYTICALLY BONDED DIAMONDS,USED WITH STRIP HOLDER AND AVAILABLE IN EITHER SINGLE OR DOUBLE SIDED COATINGS AND COME IN THREE GRADES OF COARSENESS (FINE, MEDIUM AND COARSE).• CARBIDE AND DIAMOND BAR: CROSS CUT CARBIDE FISSURE BURS AND MEDIUM OR FINE GRIT DIAMOND FINISHING BUR CAN BE USED.• DIAMOND DISCS: AS LIKE STRIPS THEY COME IN VARYING GRIT AND RECOMMENDED WITH DISC GUARD TO PREVENT LIP INJURY.• LEAF GAUGE: LEAVES ALLOW THE ACCURATE MEASUREMENT OF THE AMOUNT OF TOOTH STRUCTURE REDUCED.

EXPANSIONEXPANSION IS A NON-INVASIVE METHODS OF GAINING SPACE

WHICH IS DONE IN PATIENT WITH NARROW ARCH.ARCH EXPANSION HAS BEEN ONE OF THE OLDEST MEANS OF

CREATING SPACE IN DENTAL ARCHES.INDICATION: CROSSBITE.MILD CROWDING.SKELETAL CLASS III MALOCCLUSION.

EXPANSION WHEN WE CAN DO ARCH EXPANSION???? ACCORDING TO ASHLEY HOWE’S ANALYSIS: IF PREMOLAR DIAMETER(PMD) IS LESS THAN PREMOLAR BASAL

ARCH WIDTH(PMBAW) THEN ONLY ARCH EXPANSION IS INDICATED.

ACCORDING TO PONT’S ANALYSIS: IF MEASURED VALUE IS LESS THAN CALCULATED VALUE THEN

EXPANSION IS POSSIBLE.

EXPANSIONEXPANSION DEVICES CAN BE CLASSIFIED AS-RAPID MAXILLARY EXPANSION DEVICESSLOW EXPANSION DEVICES

FEATURE SLOW EXPANSION RAPID EXPANSION

TYPE OF EXPANSION MOSTLY DENTAL SKELETAL

RATE OF EXPANSION SLOW RAPID

TYPE OF TISSUE REACTION MORE PHYSIOLOGICAL MORE TRAUMATIC

FORCE USED MILDER FORCE GREATER FORCE

FREQUENCY OF ACTIVATION LESS FREQUENT MORE FREQUENT

DURATION OF TREATMENT LONG SHORT

TYPE OF APPLIANCE EITHER FIXED OR REMOVAL MOSTLY FIXED

AGE ANY AGE BEFORE FUSION OF MID PALATINE SUTURE

RETENTION LESSER CHANCE OF RELAPSE MORE CHANCE OF RELAPSE

EXPANSIONRAPID EXPANSION DEVICES: FIXED APPLIANCES-FIXED APPLIANCE CAN BE EITHER TOOTH-BORNE OR TOOTH AND TISSUE BORNE.TOOTH BORNE FIXED APPLIANCES:ISAACSON RME APPLIANCE.HYRAX RME APPLIANCE

BANDED HYRAX. BONDED HYRAX.

ISAACSON RME APPLIANCE BANDED HYRAX BONDED HYRAX

EXPANSIONTOOTH AND TISSUE FIXED APPLIANCE :DERICHSWEILER TYPE EXPANDER.HASS TYPE.

DERICHSWEILER TYPE EXPANDER HASS TYPE EXPANDER

EXPANSION SLOW EXPANSION DEVICES: REMOVABLE APPLIANCES-• Removable appliance mainly consist of split acrylic plate , a screw in

midline and retentive clasps in posterior teeth.• This appliance is more effective when used in the early mixed

dentition phase.

EXPANSION

OTHER SLOW EXPANSION DEVICES:COFFIN SPRINGQUAD HELIXNi-Ti EXPANDER

COFFIN SPRING QUAD HELIX Ni-Ti EXPANDER

EXTRACTIONTHERE ARE NUMBER OF CIMCUMSTANCES THAT NECESSITATE EXTRACTION OF TEETH AS A PART OF ROUTINE ORTHODONTIC

TREATMENT.THEY ARE LISTED AS FOLLOWS:Arch lenght – Tooth material discripency The following signs can be seen in this case -- absence of physiological space. ectopic eruption of teeth. malposition or impacted teeth. Mesial migration of posterior segment. Crowing in upper and lower anteriors.

EXTRACTION WHEN WE CAN DO EXTRACTION?????? According to carey’s analysis(applicable for lower

arch):If Arch lenght and tooth material discrepancy— 2.5mm-5mm ---- Extraction of second premolar . > 5 mm ------ Extraction of first premolar. According to howe’s analysis: If premolar basal arch width % (PMBAW%) is 37% or less it is

indicated for extraction. PMBAW % =PMBAW 100/TTM

EXTRACTIONWhy 1st premolar is the choice of tooth for

extraction in most cases (for upper arch):1) 1st premolar is very near to anterior segment.2) Their location in the arch is such that the space gained by their

extraction can be utilize for correction both anterior and posterior segment.

3) when 1st premolar is extracted anchorage given by 2nd premolar and 2 molars, which is satisfactory for retraction of anterior segment.

4) Contact that result between canine and second premolar is well.5) 1st premolar is less esthetically important.6) 1st premolar not so much useful in chewing.

DISTALIZATION OF MOLARSDistalization procedures are aimed at moving the molars in a distal direction so as to gain space. This approach became popular due to the fact that extraction can be avoided.The ideal timing for distalization is during the mixed dentition period

prior to eruption of second permanent molar.Objectives:1) To distalize(normalized) mesially migrated maxillary molars due to their

premature mesial shift.such as a situation may exist unilaterally or bilaterally.2) To correct mild maxillary dentoalveolar protrusion.3) The profile of such patient is normal or slightly protrusive at the upper lip due

to dental protrusion.4) In class I occlusion patient,distalization may indicated to gain space to resolve

minor anterior crowding.

DISTALIZATION OF MOLARS Distalization can be done by following methods:1) Extra oral approach.2) Intra oral approach. EXTRA ORAL APPROACH:• Head gear deriving anchorage from the cervical• and cranial region can be used to distalize molars. Disadvantage of extra oral method: Patient co operation is necessary for timely wearing the appliance. The appliance are no usually worn for a long time. Thus they are intermitent in their action resulting in prolonged treatment time.

DISTALIZATION OF MOLARSINTRA ORAL APPROACH:This appliance were introduce to overcome the various drawbacks of extra oral methods.this appliances are fixed with tooth and therefore produce a continuous effect.The devices are following:1) Sagittal appliance-This appliance consist of a split acrylic plate joined with jckscrew,the acrylic plate is sectioned in such a way that the tooth that to be distalized is isolated,and the rest ofthe arch is used for the purpose of anchorage.2) Pendulum appliance-Introduced by HIGERS.It incorporate a modified nance button for the purpose of anchorage.in addition it consist of a stainless steel wire with helix,the distal end of which is inserted on the palatal aspect of the molar to be distalized.Distalization is produced by opening the helix and forcefully engaging the the distal end.

DISTALIZATION OF MOLARS3) Jones jig appliance-Jones jig is a maxillary molar distalizing appliance that utilizes a modified nance palatalbutton and a superelastic nickle titanium coil spring to bring about the distal force onthe molar. It produce low and continuous force.Jones jig is placed on the buccal aspect of the maxillary molars.4) Trans palatal arch for distalization of molars –They can be used to bring about unilateral distalization of molars.

Other appliances used for distalization of molars are:

distal jet appliance fast back appliance

UPRIGHTING OF TILTED MOLARPremature loss of deciduous second molar or extraction of second premolar can cause mesial tipping of first permanent molar.Mesially tipped molar occupy more space than an uprightmolar.Thus by uprighting these tipped molars certain amount of space can be recovered.UPRIGHTING OF TILTED MOLAR CAN BE DONE BY :1) Uprighting spring.2) Space regainer.

DEROTATION OF POSTERIOR TEETHRotated posterior teeth occupy more space

thannormally placed posterior teeth.Derotation of of these teeth hence provide

someamount of space.Derotation is best achieved with fixed

applianceincorporating spring or elastic using a force

couple.

PROCLINATION/FLARING OF ANTERIORS

PROCLINATION OF RETRUDED ANTERIOR TOOTH RESULTS IN

GAIN OF ARCH LENGHT. THIS IS USUALLY INDICATED IN : Cases where the teeth are retroclined or In those cases where protracting the anteriors will not affect the

profile of patient. PROCLINATION DONE BY: Z-SPRING,T-SPRING.

REFERENCE: CONTEMPORARY ORTHODONTICS-

WILLIAM R.PROFFIT (4TH EDITION) TEXTBOOK OF ORTHODONTICS-

GURKEERAT SINGH ORTHODONTICS ,THE ART AND

SCIENCE-S.I.BHALAJHI (6TH EDITION)

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