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Orthodontics
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Introduction
• Orthodontics – Area of specialty dealing with the
recognition, prevention, and treatment of malalignment and irregularities of the teeth, jaws, and face
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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
