Fixed Orthodontic Appliance (Dentistry) #Braces

#ORTHODONTICFixed AppliancesDR. SARANG SURESH HOTCHANDANI| CHAPTER 10

05/02/2023DR. SARANG - S - HOTCHANDANI

2Contents

Introduction to Fixed Appliances Indications & Contraindications of Fixed Appliances Difference b/w Fixed & Removable Appliances Types of Fixed Appliances Orthodontic Bends in Fixed Appliances Components along with Placement Removal of Fixed Appliances Prevention & Treatment of White Spots after Orthodontic Tx. Problems with Fixed Appliances Temporary Anchorage Devices


3Orthodontic Appliances

Fixed Orthodontic Appliances Functional Orthodontic ApplianceRemovable Orthodontic Appliances


4Introduction to Fixed Appliances

These are orthodontic devices, which have attachments that are fixed onto the tooth surface, and force are exerted on tooth via these attachments using arch wires and other auxiliaries.

These appliances cannot be removed or activated by patient.


5Indications of Fixed Appliances

Correction of mild to moderate skeletal discrepancy.

Intrusion/Extrusion of teeth.

Corrections of rotation.

Overbite reduction by intrusion of incisors.

Multiple tooth movements required in one arch.

Active closure of extraction space, or space due to Hypodontia.


6Contraindications of Fixed Appliances

Poorly motivated patient

Poor dental health

Extremely sever malocclusion requiring orthognathic surgery


7Fixed V/S Removable Appliances

FIXED APPLIANCE REMOVABLE APPLIANCEPrecise 3 dimensional tooth movement Less precise control of tooth movementBodily tooth movement Tipping tooth movement onlyComplex malocclusions can be treated Simple malocclusions onlyHigh anchorage requirements Small anchorage requirementsControlled space closure possible Space closure is difficultMultiple tooth movements Few tooth movementsCan be used in upper or lower arch Retention in lower arch is poorSimple to correct rotations More difficult to correct rotationsOral hygiene can be problematic Can be removed for oral hygieneNot dependent on patient’s compliance

Depend on patient’s compliance

Long chairside time Short chair side timeRequire extensive training Require less training to manage.


8Fixed Appliances

Contemporary fixed appliances are variations of Edge wise appliance system.

Another system of fixed appliance is Begg appliance system. It contains rectangular slot but does not use rectangular arch wire.

Currently Begg appliance system has been modified into Tip – Edge appliance system.


9

Fixed Appliances

Edgewise

Standard Edgewise

Contemporary /Straight Edgewise

Begg Appliance

Tip Edge Appliance


10Ribbon Arch

It was made by Edward Angle.

It contains vertically positioned rectangular slots in which arch wire of 10x20 gold wire was placed into the vertical slots and held with pins.

It had poor control of root position and does not generated torque.


11Edgewise

angle modified that ribbon arch appliance, in which he Reoriented the slot from vertical to horizontal and inserted a rectangular wire rotated 90 degrees to the orientation it had with ribbon arch, thus the name edge wise.

The dimension in that slot were 22 x 28 mils & wire of 22 x 28 mil precious metal was used.


12Begg Appliance

It is a modification of ribbon arch appliance, in which Raymond Begg modified following things in the appliance. He replaced the precious metal ribbon arch with 16 mils round stainless steel wire

He retained original ribbon arch bracket, but turned it upside down so that the bracket pointed gingival rather occlusally.

He added auxiliary springs to the appliance for control of root position & cause rotation in tooth.


13Advantages & Limitations of Begg Appliance

Advantage of Begg Appliance Tipping movement Bite opening Friction was minimized Binding was minimized (mentioned in chapter 9)

Limitations of Begg Appliance Finishing Cumbersome Technique


14Tip Edgewise Appliance

It is a hybrid appliance having combination of Begg & Edge wise mechanics (straight wire mechanics of edge wise)

It allows tipping of tooth in the initial stages of treatment with round wires – Begg technique. In latter stages, rectangular wires are used for final tooth

positioning.


15

Contemporary Edgewise Appliances


16Modern edgewise appliances are of two types;

Standard/Original Edge wise appliance system

Straight wire/ Contemporary edgewise appliance system


17STANDARD EDGEWISE APPLIANCE SYSTEM

Rotation of tooth was controlled by separate ligatures tied to the eyelets soldered to the corners of bands

Bracket slot size was 22 x 18

Same bracket on all teeth That’s why bends were given to

compensate for difference in tooth anatomy.


18Bends in Standard Edgewise

1st Order Bends/ In – Out Bend/ Facio – Lingual Bends

2nd Order Bends/ Tip Bends/ Artistic Bends

3rd Order Bends/ Torque Bends


191st order Bend OR in – out bend ORfacio – lingual bends

This bend was given to compensate for variation in the contour of labial surface of individual teeth (differing tooth width & buccolingual direction of teeth).

These bends are given in horizontal or in the plane of arch wire.

Can be given in rectangular or round wire


202nd order bend/ tip bends/ artistic positioning bends

These bends were given to achieve proper mesiodistal root position or tilting of teeth.

They are given in vertical plane

Can be given in rectangular or round wire.


213rd order bends/ torque bends

These bends are given only in rectangular wire.

These bends are made by twisting the wire and is inserted into bracket slot so that is can exert Bucco lingual force on the root apex.

These bends were given for moving the roots facially or lingually and also to avoid movement of properly positioned teeth.


22

Orthodontic Bends

a) 1st order bend

b) 2nd order bend

c) 3rd order bend

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23

Straight wire Edge Appliance


24Straight wire edgewise appliance

They are modern edgewise appliances

In these appliance rotation is not controlled by separate ligature but it is built in the bracket itself.

Bracket slot size is available in two forms; 18 x 28 mills & 22 x 28 mill slot size.



Different brackets for different teeth. This thing eliminated the bends which were given in standard edgewise.

In these appliances no any 1st order bend is given, instead, compensation for the contour of labial surface of teeth is built into the base of bracket.

In straight arch wire appliances, positioning of root is accomplished by proper angulation of bracket or bracket slot. This thing decreased the need for 2nd order bends.



The bracket slots in the straight wire edgewise appliances are inclined to compensate for proper inclination of facial surface, so that’s why 3rd order bends are not given.


27

Straight wire edgewise appliance

Diagram (a) shows an edgewise bracket with a 2nd order bend placed in the arch wire to achieve the desired movement of tip.

Diagram (b) shows a pre – adjusted bracket with tip built into the bracket slot.


28Components of Fixed Appliances

Bands Bonds/ BracketsOrthodontic Adhesive

Auxiliaries

Arch wires


29

Orthodontic Bands


30Orthodontic Bands

These are the rings which encircle the tooth & to which buccal and/or lingual attachments are soldered or welded.

Before acid etching technique, brackets were attached on bands which are then cemented on tooth.

They are not used now days except only on molar teeth.


31Indications Where Brackets Are Still Applied On Bands

Teeth that will receive heavy intermittent force; maxillary 1st molar in which force is

applied via headgear

Teeth that will need both labial and lingual attachments Molar with both headgear and lingual

arch tube. Isolated lingual bracket.

Teeth with short clinical crowns

Teeth with extensive restoration Bond strength is low on restorations.

De bonding from porcelain damages its appearance.


32

Rules of Banding & Bonding in Contemporary Orthodontics


33Steps in Placement of Orthodontic Bands

Separation

Fitting

Cementation


34Separation

Teeth must be separated before banding, because tight inter proximal contacts make it impossible to properly seat a band.

Principle of Separation; a device to force or wedge the teeth apart is left in place long enough for initial tooth movement to occur, so that the teeth are slightly separated by the appointment at which bands are to be fitted.


35Methods of Separation

Separating Springs

Elastomeric Separators / doughnuts


36Separating Springs

They exert scissor action above and below the contact.

Open the contact points within 1 week. Should not be placed more than 1 week.

Easier to tolerate.

Disadvantages; these separators tend to become loose & fall out as they accomplish their purpose.


37Method of Separation with Steel Separating Spring

A. The spring is grasped at the base.

B. The bent – over end of the longer leg is placed in lingual embrasure, and the spring is pulled open so the shorter leg can slip beneath the contact.

C. The spring in place, with the helix to the buccal.

D. The spring can be removed most easily by squeezing the helix, forcing the legs apart.


38Method of Separation with Steel Separating Spring


39ELASTOMERIC SEPARATORS (DOUGHNUTS)

They surround the contact point & squeeze the teeth apart.

More difficult to insert but they are retained for long time without fall.

Always use bright colored elastomeric separators because they are radiolucent.

They should be placed not more than 2 weeks.


40Method of Separation with Elastomeric Ring

The elastomeric ring is placed over the beaks of a special pliers and stretched, then

one side is snapped through the contact and the pliers slipped out so that the doughnut now surrounds the contact; C,

an alternative to the special pliers is two loops of dental floss, placed so they can be used to stretch the ring.

The dental floss is snapped through the contact and the doughnut is pulled underneath the contact;

the doughnut is pulled upward, and the doughnut is snapped into position. At that point, the dental floss is removed.


41Method of Separation with Elastomeric Ring


42Fitting the Bands

Maxillary molar band placement placed initially by hand pressure on the

mesial & distal surfaces. After placement

pressure is applied on mesiobuccal and distolingual surfaces.

Final seating is with heavy biting force by patient on the distolingual corner.

Mandibular molar band placement Seated initially with hand

pressure on proximal surfaces and then with

Heavy biting force along the buccal but not lingual margins.


43Cementation of Molar Bands

All interior surfaces of orthodontic band must be coated with cement before it is placed.

Place a gloved finger over the top of the band when it is carried to place, to help in keeping cement on the gingival aspect of band.

Cement Materials; Zinc phosphate GIC Resin modified GIC


44

Orthodontic Brackets


45Brackets

They are appliances that are fixed to crown & mediate forces applied by the arch wire & auxiliaries on tooth.


46Types of Brackets

MATERIALS Cast or metal injected molded

stainless steel brackets

Titanium brackets

Cobalt chromium brackets

Ceramic brackets

DESIGN Edgewise bracket/ straight wire

Light wire appliance brackets/ tip edge bracket

Self-ligating brackets

Lingual brackets


47Components of Brackets

• 18 x 18 or 22 X 18

Wings Slots

BaseMesh


48Bonding of Bracket

Bonding is based on the mechanical locking of an adhesive to irregularities in the enamel surface of the tooth and to mechanical locks formed in the base of bracket.

Brackets are mechanically bonded to tooth surface. Chemical bonded is avoided because it will create problems in debonding of bracket

Bonding Materials in Orthodontics Light cured bis – GMA resin Self-cured or light cured

composites GIC

Less decalcification because of fluoride release

Less strength & greater chance of loos brackets


49Types of Bonding Bracket

DIRECT BONDING places the brackets on the teeth

individually at the chairside; and

Advantages; easier, faster, less expensive

Disadvantage; no proper position of bracket

INDIRECT BONDING places the brackets on study models in the

laboratory and these are transferred to the teeth using a positioning tray. it is used when placing lingual fixed appliances.

Advantages greater accuracy of bracket positioning

Disadvantage extra cost and time


50Cleaning the tooth surface, to remove any pellicle using a slow hand piece and prophy brush

or cup;

Acid-etching the enamel surface

using 37% unbuffered

phosphoric acid for 20 – 30 seconds;

Washing and drying the tooth

surface

Placing unfilled primer on the

etched area of the tooth;

Placing composite resin on the bracket base

Positioning the bracket on the

tooth crown

Cleaning up excess composite from around the

bracket base

Curing the composite, either chemically or with a blue light source

Steps in Direct Bonding of Bracket


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52

INDIRECT BONDING


53

The teeth are isolated, etched, and a chemically cured two-paste resin is painted on the etched enamel and the brackets. Then, the transfer trays are inserted. D, After the resin has completely set, the trays are carefully removed, leaving the brackets bonded to the

teeth.

After the brackets are cured in the ideal position, a transfer tray is formed from a vinyl polysiloxane puttyThe trays are removed from the working cast after soaking in warm water

and trimmed

Brackets are placed precisely as desired on a cast of the teeth and held in place with a filled resin.


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55

De Banding & De Bonding


56Removal of Molar Band

Distort the band with force which will break the cement away from band & tooth and remove it.


57Removal of Bracket

When bracket is one of the following things happen; Breakage b/w cement & bracket (preferred) Breakage within the cement material itself Breakage b/w enamel surface & cement (least desired)

The safest way to remove metal bracket is to distort the bracket base, which cause breakage b/w bracket & cement. This damages the bracket and it cannot be reused.

Ceramic brackets on removal damages the enamel because they break before bend.

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58

Prevention & Treatment of Enamel Decalcification/White Spots after Orthodontic Tx.


59Prevention

Fluoridated water & fluoride containing toothpaste

0.05% neutral sodium fluoride rinse

Caries Prone patient; fluoride varnish application at 6-month interval

Chlorhexidine mouthwash for 14 days.


60Remineralizati

on Therapy

External Bleaching

Micro Abrasion

Veneers

Treatment of White Spots after Ortho Tx.


61Characteristics of Contemporary Brackets – CERAMIC BRACKETS

Durable, resist staining, dimensionally stable

Types of ceramic bracket based on the material; Polycrystalline alumina Polycrystalline alumina with metal slot Monocrystalline alumina


62Problems with Ceramic Brackets

Fracture of bracket

Friction within bracket slot

Attrition on teeth contacting the bracket That’s why mostly placed on upper

teeth only.

Enamel damage on bracket removal

Chemical bonding which is strong, mechanical bonding difficult in ceramic bracket.

Brittle, that’s why they are made bulky and act as wide bracket. (effects of wide bracket learnt in 9th chapter)


63

Straight Wire Concept in Bracket


64Straight Wire Concept in Bracket

Compensation for 1st order bends; For anterior teeth and

premolars, changing the bracket thickness eliminate in – out bends in anterior portion of arch wire. But molar tube on molar bend should be offset position to prevent molar rotation.



Because for good occlusion, the buccal surface of molar must sit at an angle to line of occlusion. Mesio buccal cusp more prominent

That’s why the tube on the molar band should be at least 10 degree offset for maxillary molar. On mandibular molar it should be 5 – 7 degrees.



A distal inclination or tip of the maxillary first molar is important for proper posterior occlusal interdigitating. If the mesiobuccal cusp occludes in the mesial groove of the mandibular first molar, creating an apparently ideal Class I relationship, proper interdigitating of the premolars still cannot be obtained if the molar is positioned too upright

Tipping the molar distally allows the premolars to interdigitate properly


67Self Ligating Brackets

In this ligatures are not needed for holding wire, but the mechanism for retention of wire is built within the brackets.

Types of self – ligating brackets; Springy latching cap

Smart clip system Springy retaining clips

Innovation system Speed system

Rigid latching caps Damon system


68

Archwires


69Orthodontic Archwires

During initial alignment phase; NiTi wire Stainless steel wire Coaxial wire

To complete the process of levelling, beginning of overbite reduction, sliding of teeth along arch wire; Round Stainless steel wire

Arch wires during the later stages of overbite reduction and for space closure; Rectangular stainless steel wire



NiTi wire is ideal for aligning teeth during initial stages of Tx. However, for later stages, space closure & overbite reduction, NiTi

cannot be used.

In the initial stages of treatment, a wire which is flexible with good resistance to permanent deformation is desirable, so that displaced teeth can be aligned without the application of excessive forces.



Initial Alignment (minimum stiffness, maximum range) Ni-Ti wire Multi-stranded wires

Mid Treatment (Series of working wires with increasing stiffness and reduced range)

Finishing & Detailing (Maximum Stiffness, snuggly fit rectangular wire)


72

Auxiliaries


73Auxiliaries

They are used to apply active forces for space opening or closure.

Elastic materials can be used for intra-arch (intra-maxillary) space closure, and springs constructed from stainless steel or nickel titanium can be used for space opening.

Types of Auxiliaries;Elastic bandsWire ligaturesIntra oral elasticsPalatal or lingual archesCoiled springsPower chains


74Problems with Fixed Appliances

Pain

Tooth mobility

Mucosal trauma Orthodontic wax can be used to cushion the wire

Bracket failure


75

Temporary Anchorage Devices

• BONE SCREWS• MINIPLATES


76Indications of bone screws

Positioning of individual teeth: Missing teeth – lack of anchorage Impacted teeth

Position of groups of teeth; Space closure

Major incisor retraction Incisor retraction & intrusion

Mesial movement Maxillary & mandibular posterior teeth Entire mandibular arch

Intrusion of anterior or posterior but not both simultaneously


77Indications of miniplates

Positioning groups of teeth. Distalization of entire maxillary & mandibular arch. Intrusion of anterior & posterior teeth

Growth modification. Class III elastics, maxillary deficient child. Restriction of vertical maxillary growth.


78References

Cobourne, M. T. (2010). Handbook of Orthodontics. Mosby Elsevier.

Gill, D. (n.d.). Orthodontics at a Glance 1st Edition. Blackwell.

Mitchell, L. (n.d.). Introduction to Orthodontics 4th Edition. Oxford.

Proffit, W. R. (n.d.). Contemporary Orthodontics 5th Edition. Elsevier.

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79

THE ENDDR. SARANG SURESH

HOTCHANDANIBDSBibi Aseefa Dental College, SMBBMU.Larkana, Sindh, Pakistan

Email: [email protected]: http://www.slideshare.net/sarangsureshhotchandaniTwitter: https://twitter.com/fetusdentista

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Fixed Orthodontic Appliance (Dentistry) #Braces