Childrens

Front 1

Inherent problems of orthodontic banding 3

Back 1

- Teeth require separation which needs extra appointment and minor discomfort
- Bands require intermediate cementing medium regardless of how well they are contoured to tooth surface
- Non-resin (Zinc Phosphate) cements are soluble in saliva and property can lead to cement wash out, demin, and caries

Front 2

Definition of Direct Bonding

Back 2

Using acid etch and adhesive resins to apply orthodontic brackets and attachments directly to the teeth without need for circumferential metal bands

Front 3

Three types of bonding resins

Back 3

1) Unfilled: Bracket bond
2) Lightly filled: Up to 30% Inorganic fillers
3) Heavily filled: 60-70% fillers

Front 4

Bonding products that require use of intermediate resin (Sealant)

Back 4

Need intermediate Resin (CUNB)
- Concise
- Unique
- Nuva Tach
- Bondmor I and II

Others do not need an intermediate resin

Front 5

Metal bases for bonding

Back 5

Brackets
- Plastic: Polycarbonate
- Metal: Stainless steel

Base of metal brackets that contact bonding resins
- Perforated
- Multi-perforated
- Foil mesh-backed
- Undercut with holes or slots

- Foil mesh-backed or undercut with holes are the base of choice

Front 6

Difference in mechanism of adhesion between plastic and metal brackets

Back 6

Plastic
- Chemical reaction between polycarbonate bracket base and acrylic monomer
- Base of bracket is treated with primer coating immediately prior to bonding
- Primer composed to methyl methacrylate or acetone softens base of plastic bracket enabling a chemical reaction with resin to occur

Metal brackets
- Retained by mechanical interlocking of resin through perforations, mesh, or undercut areas of bracket base
- No chemical bonding
- No primer needed

Front 7

Problems with plastic brackets 5

Back 7

- Stress cracking and fracture along lines of stress
- Flexible so will bend and soften
- Easily wear due to friction from wires
- Stain and discolor from tobacco, smoke, tea, coffee, and cosmetic products
- Not all bonding materials are compatible with plastic brackets

Front 8

Three principle steps in de-bonding protocol

Back 8

- Removal of bracket
- Removal of resin bulk
- Restoration of pre-treatment characteristics of the tooth surface

Front 9

Removal Modalities suggested for debonding

Back 9

Hand instruments
- Pliers
- Knives
- Scalers
- Hand instruments cause ditching and chipping

Rotary
- Diamond burs
- Stones
- Finishing burs
- Rubber wheels
- Cups and Slurries
- Rotary instruments cause grooving, ditching, and cratering
- High speed rotary causes grooving and scalloping

Ultrasonic instruments
- Ultrasonic is slow and causes ditching and cratering

Front 10

Know considerations involved in debonding

Back 10

- Type of resin used: Highly filled resins are more difficult to remove
- Removal modality, Chair time, Patient comfort
- Restoration of enamel surface
1) Restore natural esthetics polishing
2) Remove gross and minute resin remnants
3) Restore enamel surface smoothness

Front 11

Objectives in de-bonding protocol

Back 11

- Remove bracket with ligature cutter or bracket removing plier using a peel force
- Reduce resin down to natural tooth contour with air-cooled green medium Dedico rubber wheel
- Polish enamel with fine pumpce slurry and rubber cup

Front 12

Primary sites of plaque accumulation

Back 12

- Plaque will accumulate on bonding resins even with patients who have good oral hygiene

Front 13

Plaque accumulation on Resin Surfaces

Back 13

- Preferential wear of resin matrix exposes filler particles to produce a roughened surface
- Both lightly and heavily filled resins are predisposed to plaque formation without significant qualitative differences between them

Front 14

Most common location for demineralization using direct bonding

Back 14

- Junction between bonding resin and enamel. Just peripheral and commonly gingival to bracket base

Front 15

Two factors related to plaque accumulation during direct bonding brackets

Back 15

Strict bonding protocol
- Use only enough material to cover base of bracket
- Remove any excess resin around the periphery
- Keep resin as far away from gingiva as possible

Rigorous Home Care program
- Brushing, Oral irrigation devices, Topical flouride by rinsing

Front 16

Bracket of choice for Hygiene

Back 16

Mesh back has tendency to have less plaque accumulation than perforated base

Front 17

Advantage and Disadvantage of direct bonding techniques

Back 17

Advantage
- No separation
- No subgingival placement of metal
- No band material located interproximally to usurp arch space
- No disfiguring decalcification beneath bands
- More esthetic
- Radiographs can be taken periodically

Disadvantage
- Higher failure rate on posterior teeth
- Plastic brackets soften and discolor
- Replacement of lost or broken brackets are pain
- Demineralization and Caries are still problem
- Use on lower incisors in deep bites are difficult
- Resin material has short shelf life

Front 18

Two main reasons to extract

Back 18

- Provide space to align remaining teeth in presence of severe crowding
- To allow teeth to be moved to reduce protrusion or to hide class 2 or 3 problems

Front 19

Extraction guidelines

Back 19

Less than 4mm discrepancy
- Exo rarely indicated
- Only if there is severe incisor protrusion or vertical discrepancy

5-9mm discrepancy
- Non exo or exo depending on both hard and soft tissue characteristics and how final position of incisors are controlled
- Any of several teeth could be chosen
- Non-exo treatment usually requires transverse expansion across molars and premolars

10mm or more
- Exo almost always required
- Four 1st premolars or upper premolars and mandibular laterals

Front 20

Transverse Maxillary Deficiency corrections

Back 20

Best way to correct is to grow out of it - unlikely without treatment

Transverse Maxillary Deficiency
- Rapid or slow expander
- Induce new bone growth
- Clinically evident because diastema forms

Front 21

Class II corrections

Back 21

Class II general
- Modifications tend to be diminished or eliminated by subsequent growth
- Alignment and Occlusion are similar in children who did not have early treatment and those who did
- Chances of trauma to protruding upper incisors reduced by early tx
- Signs of TMD reduced by early tx

Short face class II
- Mandible catch up with maxilla
- Block eruption of incisors
- Control eruption of Upper posterior teeth
- Facilitate eruption of lower posterior teeth
- Most effective with *Activator-Bionator type

Class II with normal height
- Equal success with two stage headgear or functional appliance in stage 1 or with one-stage tx during adolescence
- Either headgear or any type of functional appliance is acceptable
- Straight pull or high pull is preferred over cervical to reduce elongation of maxillary molars and control inclination of mandibular plane
- Appliances that minimize tooth movement are preferred to maximize skeletal effects and minimize compensatory tooth movement

Class II with long face: Skeletal open bite
- Goal is to restrain vertical development and encourage anteroposterior mandibular growth while controlling tooth eruption in both jaws
Hierarchy of effectiveness
- High pull headgear to functional with bite blocks
- Biteblocks on functional appliance
- High-pull headgear to maxillary splint
- High-pull headgear to molars

Front 22

Class III problems corrections

Back 22

Horizontal-Vertical Maxillary Deficiency
- Headgear to compress or reverse(Forward-pull) headgear to stimulate growth
- Mandibular excess adjusted via chin cup

Front 23

Treatment planning of patients with multiple problems

Back 23

1) Disease control
- Caries control
- Endodontics
- Initial periodontics (No osseous)
- Initial restorative (No case restoration)

2) Establishment of occlusion
- Orthodontics
- Orthognathics
- Periodontal maintenance

3) Definitive Periodontics (Including osseous)

4) Definitive restorations
- Cast restorations
- Splints, Partial dentures

Front 24

Treatment relating to Periodontics and Orthodontics

Back 24

- Perio must be under control to prevent irreversible damage to periodontium
- OHI is a must due to bracket plaque retention
- Ortho changes soft tissue and bone contour

Severe perio
- Ortho forces kept to minimum due to reduced PDL area
- Greater attachment loss so less supported root and center of resistance becomes closer to apex
- Further force application from center of resistance results in greater tipping

Front 25

When ortho treatment is initiated prior to elimination of inflammation

Back 25

More harm than good
- Uncontrolled recession
- Excessive tipping
- More advanced perio problems because plaque control is difficult

6 Months must be allowed for healing and resolution of inflammation before tooth movement

Front 26

Factors that retard action of bone remodeling in adult patient

Back 26

- After several years, resorption results leaving less vertical bone height and buccal-lingual narrowing of alveolar process
- Cortical bone will respond to ortho but is slower due to reshaping of cortical bone comprises buccal and lingual plates

Front 27

Stress vs Strain

Back 27

Stress - Internal distribution of load. Force per unit area

Strain - Internal distortion produced by the load. Deflection per unit length

Front 28

Force and Deflection

Back 28

- Response to a force can be measured as the deflection produced by force aka bending or twisting
- Internal stress and strain can be calculated from force and deflection by considering area and length of beam

Front 29

Three major properties of beam materials

Back 29

Strength: Three points
- Proportional limit: Point at which any permanent deformation is observed. aka Elastic limit
- Yield strength: Point at which a deformation of 0.1% is observed
- Ultimate tensile strength: Maximum load the wire can sustain.

Stiffness or Springiness
- Reciprocal properties
- Proportional to slope of elastic portion of force-deflection curve
- More horizontal the slope, the springier. More vertical is more stiff

Range
- Distance wire will bend before permanent deformation
- If deflected beyond yield str, will not return to original str
- Springback can be used and is measured along horizontal axis of force-deflection curve
- Often times, orthodontic wires are deformed beyond their elastic limit

**Strength = Stiffness x Range**

Front 30

Resilience vs Formability

Back 30

Resilience - Area under stress-strain curve representing energy storage capacity. Combination of Strength and Springiness

Formability - Amount of permanent deformation that a wire can withstand before failing/breaking

Front 31

Properties of an idea Ortho wire

Back 31

High strength
Low stiffness
High range
High formability
Should be weldable or soderable and of reasonable cost

Front 32

Precious Metal alloys

Back 32

- Gold is too soft but alloys with Pt, Pd, Co are useful
- Introduction of stainless steel made them obsolete
- Only Crozat appliance is occasionally made of gold

Front 33

Stainless steel and Cobalt-Chromium Alloys

Back 33

- Better strength and springiness with equivalent corrosion resistance compared to precious metals
- Rust resistance is due to high Chromium content
- Elgiloy is supplied in a softer and more formable state and then hardened by heat treatment to increase strength
- After heat treatment, softest Elgiloy is equivalent to regular stainless steel

Front 34

Nickle Titanium Alloys

Back 34

- Shape memory and superelasticity due to phase transitions within NiTi alloy
- Martensite form at lower temps and Austenite at high temps
- Remembers original shape after being deformed in Martensitic form. Restores to original shape when heated again

A-NiTi - produces a hardly varying force, unloading curve differs from loading curve. Preferred material when long range of activation with relatively constant force is needed
M-NiTi - Useful in later stages for flexible but larger stiffer wires

Front 35

Beta Titanium

Back 35

- Highly desirable combination of Strength and Springiness with good formability
- Good for auxillary springs, intermediate wires, and finishing arch wires especially rectangular wires

Front 36

Composite plastic arch wires

Back 36

- Possible to produce fibers with better strength and springiness than non-superelastic wires
- Pultrusion allows fabrication of round and rectangular wires
- Possible ligature adapted around a wire and bracket to reduce friction
- Tooth colored for esthetics
- Shape difficult to change once manufacturing is complete

Front 37

Hooke's Law and Ratios

Back 37

- Hooke's law defines elastic behavior of materials except SuperElastic A-NiTi

- Ratios are functions of both physica properties and geometric factors
- Bending describes round wires completely but rectangular wires have torsional stresses
- Ratios do not apply to linear portion of load-deflection curve and don't reflect wires stressed beyond their elastic limit

Front 38

Effects of Diameter or Cross-Section

Back 38

Beam size increase
- Strength increases cubic
- Springiness decreased fourth power
- Range decreases proportionately

Rectangular wires torsional, shear stress rather than bending stress is encountered

Upper and lower limits of beam diameter related to strength establish wire sizes useful in orthodontics

Front 39

Effects of Length

Back 39

When Cantilever beam length increases
- Strength decreases proportionally
- Springiness increases cubic
- Range increases squared

- Springiness and Range are affected by length but torsional strength is not

Front 40

Controlling ortho force by varying materials and size-shape

Back 40

Adequate strength
- Wire size must not deform permanently in use
- Relatively large wire can be given desired spring qualities by increasing length
- Length by doubling wire on itself or wind a helix

Combination of two or more strands of small and springy wire
- Multi-stranded wire depends on both the characteristics of individual wires and how tightly they been woven together

Can carry out ortho treatment with series of wires of appx the same size.
- NiTi, to TMA, to Steel.

Front 41

Center of resistance

Back 41

- Object in free space: Same as center of mass

- Tooth root: Halfway between root apex and crest of alveolus

Front 42

Moment

Back 42

Force acting at a distance when ling of action does not pass through center of resistance
- Causes translation and rotation of object

Front 43

Couple

Back 43

Two forces equal and opposite in direction
- Results in pure moment since translatory effects cancels out
- Couples will produce rotation and spin the object around its center of resistance

Front 44

Center of Rotation

Back 44

Point around which rotation occurs when object is moved
- If a force and couple are applied, center of rotation can be controlled to any location
- Application of force and a couple to crown is mechanism to get bodily movement of tooth or even greater movement of root than crown

Front 45

How to decrease magnitude of force

Back 45

Apply it closer to center of resistance

Front 46

Anchorage and methods to control

Back 46

- Resistance to unwanted tooth movement

Methods to control
1) Reinforcement:
- Extent to which anchorage should be reinforced depends on tooth movement desired
- Typically involves as many teeth as possible in anchorage unit
2) Subdivision of desired movement
- Pit resistance of a group of teeth against the movement of a single tooth
3) Tipping/Uprighting
- Tip teeth and then upright them rather than bodily movement
4) Friction and Anchorage control strategies
- Typical extraction situation in which to close extraction space 60% by retracting anterior teeth and 40% by forward movement of posterior teeth
- Greater the strain on anchorage when brackets slide along an arch wire must be compensated by more conservative approaches to anchorage control

Front 47

Factors related to successful therapy of midline diastema

Back 47

- Removal of causitive factor
- Whether the inherent tendency of periodontal or muscular tissues to regain their original shape can be overcome. Depends on balance of new tooth position and retention time
- Fulfillment of all orthodontic treatment objectives including tooth position with optimal interdigitation and axial inclination

Front 48

Types of appliances used to correct midline diastema

Back 48

Maxillary Hawley with Labial bow and Finger springs
- Crowns should only require a tipping movement to achieve space closure. Roots should be in proper axial position so teeth will be almost parallel or slightly distal to prevent space reopening
- Need to control movement of each incisor independently
- With a deep overbite, bite plane may be added to help open the bite before space closure
- With excessive overjet, labial bow may be used for retraction and to prevent rotations or overlap of incisors

Orthodontic bands or directly bonded attachments with Archwires and Elastics
- Necessary to obtain bodily movement of crown and root to achieve proper axial inclination and post treatment stability
- More than two teeth are involved to correct space problem
- Rotational control is desired

Free elastics around crowns of central incisors
- Do NOT use this technique
- Elastics can lodge in the gingival crevice without patient's knowledge and lead to eventual loss of tooth. Classic sign is extrusion of incisor without observable cause

Front 49

Diastema retainer

Back 49

Removable
- Used where etiology has pathology
- Removable Hawley with finger springs used in cases that does not require lengthy or permanent retention

Fixed
- Cemented orthodontic appliance, intra-coronal splinting or fixed bridgework
- Used where etiology was abnormal labial frenum, heredity, severe rotations

Front 50

Etiology of crossbite

Back 50

- Trauma with displacement
- Occlusal interferences
- Periodontal conditions
- Jaw shifts due to alterations in occlusion
Habits
- Poor eruption pattern(Ectopic)

Front 51

Appliances to correct anterior and posterior crossbites in adult dentition

Back 51

Anterior sectional arch: Banding molars and bonding anterior four incisors. Mix of facial tipping and lingual root torque to bring maxillary incisors out of crossbite

Posterior: Cross elastic to tip teeth in opposite directions to correct occlusion. Causes some extrusion
- If 1 arch has correct axial incline use cross Palatal Bar appliance. Acts as a point of attachment/anchorage to reposition mandibular molars. Contraindications is poor OH and molars can't be banded

Front 52

Questions to ask about crossbite

Back 52

How long
Any attempt in the past to fix and was it successful
Did this occur after an accident, dental treatment, anything?

Front 53

Banding advantage vs disadvantage

Back 53

Advantage
- When heavy forces used
- Where B-L attachments are used. Decreases risk of swallowing
- Teeth with short crowns
- Teeth incompatible with bonding

Disadvantage
- Extra appt
- Discomfort
- Require intermediate cementing medium
- Subgingival placement
- Non-resin cements soluble
- Band width 2-4mm if full banded arch
- Unesthetic

Front 54

Debonding instruments

Back 54

Scaler - Some resin left, scratches in enamel. Simplest and quickest way for unfilled and light filled. Can use green rubber wheen for heavily filled

Stone - Deep grooves in enamel with some scratches

Sandpaper discs - Pretty effective with some facets

Rubber wheel - Light pressure most effective with minimal tooth damage

Carbide finishing bur - Faster results but more enamel loss. Can use stainless steel bur for less enamel loss

Front 55

Mouth rinse

Back 55

0.2% NaF 0.09%F weekly

0.05% NaF daily

- Using lower concentration daily showed 50% caries reduction vs 20% weekly use

Front 56

Etiology of diastemas

Back 56

Developmental
- Missing teeth
- Supernumerary teeth
- Impacted teeth

Habits
- Thumb suck
- Tongue thrust
- Can stop with bluegrass appliance

Anatomy
- Frenum
- Bone loss
- Root blunting causing poor crown to root ratio

Front 57

Treatment of developmental diastemas

Back 57

Class 1 - Flared maxillary anteriors
- Use Hawley to tip teeth distally

Class 2 - Flared max anterior due to skeletal etiology.
- Cannot tip maxillary teeth distally if its mandibular retrognathia
- Better corrected with twin block appliance
- Close diastema with braces

Class 3 - Occlusion with diastema
- Can't retract maxillary anterior teeth
- Use class 3 interceptive device
- Protraction headgear and rapid palatal expander

Front 58

Using ortho to upright adult teeth and examples

Back 58

Removable
- Used if one tooth requiring less than 20deg of uprighting
- Appliance must have maximum tissue and tooth contact on all teeth that are not to be moved
- Acrylic appliance with recurved helical finger spring: Gives maximum control but requires most skill. Can get up to 4mm movement
- Split saddle space retainer: Effective but less control
- Slingshot: Least control

Fixed
- Tooth tipped up to 60deg from vertical: Band desired tooth and 3 teeth mesial to it
- If two teeth: band most distal tooth and use buccal tube
- Tips molars upright with distal root as fulcrum: Get distal extrusion of teeth
- Takes a few months

Front 59

Most common cause of relapse for a diastema

Back 59

Inter-incisive soft tissues and their fibers
- Can do a circumferential suprac-crestal fiberotomy