Clinical Relevance and Management

IATROGENIC EFFECT OF ORTHODONTICS

Deleterious damage to individual patient as a result of orthodontic treatment

DEFINITION

TYPES OF EFFECTS

Intraoral

Extraoral

Systemic

INTRAORAL EFFECTS

Teeth

Periodontium

Soft tissue

Crown decalcification

due to attack by acidic by-products of plaque metabolism requires 4 elements:

• Plaque -Strep. mutans count in FA wearers • Substrate - depends on diet• Susceptible tooth surface - depends on patient variability • Time - in contact with tooth surface

TEETH

ALSO CALLED WHITE SPOT LESION (WSL)

• Highly variable 50% of patients are found to have at least one white spot after treatment:

23% on max incisors 6.6% had cavitation

INCIDENCE

• Fixed App: Labially• Removable: Palatally• Upper canine and lateral, lower premolar and canine

most commonly affected• May be influenced by dominant hand brushing i.e. in

right- handed patient decalcification occurs on right side through less effective cleaning

SITE

• Appropriate patient selection, i.e. exclude patients with poor oral hygienemonitor patientseducation programme:

• Dietary advice- OH advice-topical fluoride, only 13% patient comply; daily fluoride

• Mouthwash can decrease prevalence of white spot lesions -other fluoride sources. e.g. bonding agents, elastomerics, slow release mechanisms - resin sealants over labial surface

• Chlorhexidine rinses• Identify, prevent or remove stagnation areas

PREVENTION

• Use of glass ionomer cement to bond e.g. Fuji II LC • Fluoride release from composite resin• MDPB - antibacterial agent incorporated into resin

Compomer• Removal of archwires for a visit • Remove appliance (last resort)

The problem with RMGS that it has low initial SBS although some studies have found no significant difference in the bracket failure rate

Methacryloyloxy dodecyl pyridinuim bromiide is quaternary ammonium that has bactericidal effect

MDPB

INHIBITION OF PLAQUE FORMATION IN COMPOSITE CONTAINING MDPB

Control group MDPB containing composite

• Interproximal caries• Poor oral hygiene • Long treatment times • Poor compliance

CLINICAL PREDICTORS

41%of patients with initial IPC developed WSL 11% with no IPS developed WSL

Bitewings seems to be a good adjunctive method predicting the risk of WSL

WSL

Gorelick et al (1982) classification • Stage 0 (none) • Stage 1 (slight rim )• Stage 2 (broad rim )• Stage 3 (cavitation )

• can resolve to certain extent spontaneously • acid/pumice microabrasion • restorative intervention if cavitation ocurred

TREATMENT

A conservative procedure uses chemical and mechanical removal of 0.2mm of the outer layer of the enamel

Hydrochloric acid and pumice

MICROABRASION

ENAMEL TRAUMA

• Metal brackets - lower 3's brackets can damage cusps of upper canines during canine retraction

• Ceramic brackets- lower brackets can abrade 21/12 • Damage to enamel when debonding or with burs when

debonding and removing excess composite• Careless use o f band seater

AETIOLOGY

• careful bracket positioning- removal of certain brackets during canine retraction if necessary- do not place ceramic brackets on lower incisors in cases with increased/normal OB

• careful operating, particularly when working on 'risk' teeth e.g. heavily restored teeth, hypoplastic teeth

• use tungsten carbide burs in slow handpiece to remove compositecare when debonding ceramic brackets

• remove composite around bases before debonding• ceramic brackets with plastic inserts • the use of color changing composite for ceramic brackets• C02 lasers for debonding• electrothermal debonders can be used

PREVENTION

Cordless device that generates heat , the heat is transferred to the bracket breaking the bracket/adhesive interface

ELECTROTHERMAL DEBONDER

a dual color-change adhesive developed by Ormco Corporation which claims an optimized formulation for esthetic brackets. At cooler temperatures the adhesive

possesses a blue color, which then changes to a translucent color when the adhesive increases to warmer body

temperatures. This color-change property allows for removal of excess adhesive during bracket placement and

cleanup of the adhesive remnants after debonding once the adhesive is cooled with air or water

COLOR CHANGE ADHESIVE

• AVOIDANCE if possible

• composite restorations on worn cusps/fractured teeth

TREATMENT

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