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Orthodontics

2

Introduction

• Orthodontics – Area of specialty dealing with the

recognition, prevention, and treatment of malalignment and irregularities of the teeth, jaws, and face

3

The Orthodontic Practice

• Orthodontic office

• Orthodontic team– Orthodontist– Reception and business office staff– Office coordinator– Laboratory technician– Orthodontic assistant

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Occlusion and Malocclusion

• Normal (ideal) occlusion describes the contact relationship of the mandibular arch with the maxillary arch.– Mandibular teeth are in maximum contact

with maxillary teeth and spaced normally

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Occlusion and Malocclusion

• Normal (ideal) occlusion – Maxillary anterior teeth overlap incisal

edge of mandibular anterior teeth by 2 mm– Maxillary posterior teeth are one cusp

distal to mandibular posterior teeth

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Normal Occlusion

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Occlusion and Malocclusion

• Malocclusion: – Any deviation from normal occlusion– Includes misalignment of a single tooth, a

group of teeth, or an entire arch

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Angle’s Classification

• Neutroclusion– Cusp of the maxillary cuspid (canine)

occludes between the distal of the mandibular cuspid and the mesial of the mandibular first bicuspid

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Angle’s Classification

• Distoclusion– Cusp of the maxillary cuspid (canine) is

moved forward and occludes between the distal of the mandibular lateral incisor and the mesial of the mandibular cuspid

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Angle’s Classification

• Mesioclusion– Cusp of the maxillary cuspid (canine) is

moved back and occludes behind the mandibular cuspid and in the middle of the mandibular first molar

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Malposition of Individual Teeth

• Torsiversion– Tooth is rotated or turned

• Mesioversion– Tooth is mesial to normal position

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Malposition of Individual Teeth

• Distoversion– Tooth is distal to normal position

• Linguoversion– Tooth is lingual to normal position

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Malpositions of Individual Teeth

• Labioversion or buccoversion – Tooth is tipped toward the lip or cheek

• Supraversion – Tooth extends above the normal line of

occlusion

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Malpositions of Individual Teeth

• Infraversion– Tooth is positioned below normal line of

occlusion

• Transversion or transposition– Tooth is in the wrong order in the arch

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Malpositions of Groups of Teeth

• Anterior cross-bite

• Posterior cross-bite

• Edge-to-edge bite

• End-to-end bite

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Malpositions of Groups of Teeth

• Open bite

• Overjet – Horizontal overlap

• Overbite – Vertical overlap

• Underjet

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Etiology of Malocclusion

• Genetic or heredity

• Systemic

• Local

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Types of Orthodontic Treatment

• Preventive or interceptive– Placing restorations– Space maintainers– Observations

• Corrective– Fixed appliances– Removable appliances

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Process of Tooth Movement

• Resorption– Process that eliminates tissues no longer

needed in the body, therefore allowing teeth to be moved

• Deposition– Retains teeth by creating new deposits or

cells

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Process of Tooth Movement

• Osteoclast– Cause bone to resorb or break down

• Osteoblasts– Deposit new bone to hold tooth in new

position

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Preorthodontic Treatment

• Diagnostic records

• Medical-dental history

• Clinical examination

• Radiographs

• Photographs

• Study models

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Panoramic Radiograph

(Courtesy of Dr. Steven Gregg)

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The Consultation Appointment• Orthodontist presents patient with

treatment plan

• Responsibilities of patient is reviewed

• If patient accepts the treatment plan– Consent papers are signed and financial

arrangements made

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Orthodontic Appliances

• Fixed– Orthodontic

bands– Brackets– Arch wires– Ligature wire and

plastic bags

– Buccal tubes– Springs– Elastics

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Orthodontic Appliances

(Courtesy of Rita Johnson, RDH, Professor, MCC, Lowell, MA; and Dr. Vincent de Angelis, Associate Professor, Harvard School of Dental Medicine.)

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Special Fixed Appliances

• Lingual braces

• Lingual arch wire

• Space maintainer

• Palatal separating appliance

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Removable Appliances

• Headgear

• Functional appliances

• Retainers

• Tooth positioner

• Aesthetic orthodontic aligners

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Orthodontic Instruments

• Coons’ ligature-tying pliers

• Mathieu needle holder

• Ligature director

• Pin and ligature cutter or light wire cutter

• Howe pliers

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Orthodontic Instruments

• Band seater

• Bite stick band seater

• Band driver

• Posterior band removing pliers

• Band contouring pliers

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Orthodontic Instruments

• Bracket forceps

• “Bird-beak” pliers

• Three-prong pliers

• Weingart utility pliers

• Tweed-loop pliers

• Distal-end cutting pliers

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Orthodontic Treatment

• Application of separators

• Placement of posterior bands

• Placement of anterior brackets

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Orthodontic Treatment

• Placement of arch wire

• Oral hygiene instructions

• Interval checkups

• Completion appointment

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Completion Appointment

• Ligature ties removed

• Elastic ties removed

• Elastic released

• Wire cut

• Wire removed from wing

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Completion Appointment

• Arch wire removed from bracket

• Anterior brackets removed

• Posterior bands are removed

• Above process repeated on lingual surface

• Cement and direct bonding materials removed

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Completion Appointment

• Rubber cup polish completed

• Alginate impression taken of arches

• Patient reappointed for later that day or for next day

• Retainer or positioner placed

• Patient given instructions on how to wear appliance