Orthodontics Chapter Guide

Orthodontics
Chapter 60
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Chapter 60
Lesson 60.1

Learning Objectives
 Pronounce, define, and spell the Key Terms.
 Describe the environment of an orthodontic
practice.
 Describe the types of malocclusion.
 Discuss corrective orthodontics and describe
what type of treatment is involved.
 List the types of diagnostic records used to
assess orthodontic problems.

Orthodontics is the specialty of dentistry
concerned with the supervision,
guidance, and correction of the growing
and mature dentofacial structure.
Introduction

Malocclusion is an abnormal or
malpositioned relationship of the
maxillary teeth to the mandibular
teeth when they are in occlusion.
Understanding Malocclusion

Factors Related to Malocclusion
 Developmental causes
 Congenitally missing teeth
 Malformed teeth
 Supernumerary teeth
 Interference with eruption
 Ectopic eruption
(Cont’d)

(Cont’d)
 Genetic causes
 Discrepancies in the size of the jaw, teeth, or both
 Environmental causes
 Birth injuries
 Fetal molding
 Trauma
(Cont’d)

(Cont’d)
 Habits
 Tongue thrusting
 Tongue-thrust swallowing
 Thumb and finger sucking
 Bruxism
 Mouth breathing

Any deviation from class I occlusion
is considered malocclusion.
Malocclusion

Fig. 60-1 A, Diagram showing class I occlusion.
B, Photo showing class I occlusion.
(A, From Proffit WR, Fields HW: Contemporary orthodontics, ed 4, St Louis, 2007, Mosby.)
B

Class II Malocclusion
 This condition is also referred to as istoclusion.
 The body of the mandible is in an abnormal distal
relationship to the maxilla.
 Class II malocclusion causes the maxillary anterior
teeth to protrude over the mandibular anterior
teeth.

Fig. 60-2 A, Diagram showing class II malocclusion.
B, Photo showing class II malocclusion.
B

Class III Malocclusion
 This condition is also referred to as mesioclusion.
 The body of the mandible is in an abnormal mesial
relationship to the maxilla.
 Class III malocclusion causes the mandibular
anterior teeth to protrude in front of the maxillary
anterior teeth.

Fig. 60-3 A, Diagram showing class III malocclusion.
B, Photo showing class III malocclusion.
B

Malaligned Teeth
 Crowding
 In this, the most common contributor to
malocclusion, one or many teeth are involved in
misplacement.
 Overjet
 An excessive protrusion of the maxillary incisors
results in space or distance between the facial
surfaces of the mandibular incisors and the lingual
surface of the maxillary incisors.
(Cont’d)

Malaligned Teeth
(Cont’d)
 Overbite
 This is an increased vertical overlap of the
maxillary incisors.
 Open bite
 A lack of vertical overlap of the maxillary incisors
results in an opening of the anterior teeth when
occluded.
 Crossbite
 A tooth is not properly aligned with its opposing
tooth.

Benefits of Orthodontic Treatment
Psychosocial
Oral function
Dental disease

Management of Orthodontic
Problems
 Preventive orthodontics
 To prevent or eliminate irregularities and
malpositioning in the developing dentofacial region
 Interceptive orthodontics
 To intercede or correct problems as they are
developing
 Corrective orthodontics
 To move teeth and correct malocclusion and
malformations.

Medical and dental history
Evaluation of physical growth
Social and behavioral evaluation
Clinical examination
Orthodontic Records
and Treatment Planning

Clinical Examination
 Used to document, measure, and evaluate
the:
 Facial aspects
 Oral health
 Jaw and occlusal relationship
 Functional characteristics of the jaws

Diagnostic Records
 Photographs are useful as an aid in:
 Patient identification
 Treatment planning
 Case presentation
 Case documentation
 Patient education

Fig. 60-9 A and B, Standard extraoral photographs.
(From Proffit WR, Fields H, Sarver DM: Contemporary
orthodontics, ed 4, St Louis, 2007, Mosby.)

Fig. 60-10 A-C Intraoral photographs showing (A) the patient’s
front view in occlusion, (B) the maxillary occlusal view, and (C) the right
buccal view.

Radiographs
 Cephalometric radiographs
 Extraoral radiographs make it possible to evaluate
the anatomic bases for malocclusion, as well as
the skull, bones, and soft tissue.
 Cephalometric analysis
 Tracing or computerized drawing involving a
series of points makes it possible to compute a
means of mathematical descriptions and
measurement of the status of the skull.

Fig. 60-11 A and B Cephalometric radiograph and analysis.
A B

Diagnostic Models
 Diagnostic models
 Diagnosis
 Case presentation

Chapter 60
Lesson 60.2

Learning Objectives
 Describe the components of the fixed
appliance.
 Place and remove brass wire separators.
 Place and remove steel separating springs.
 Place and remove elastomeric ring
separators.
 Assist in the fitting and cementation of
orthodontic bands.
 Assist in the direct bonding of orthodontic
brackets.
(Cont’d)

Learning Objectives
(Cont’d)
 Place an arch wire.
 Place and remove ligature ties.
 Place and remove elastomeric ties.
 Describe the use and function of headgear.
 Describe ways to convey to the patient the
importance of good dietary and oral hygiene
habits in orthodontic treatment.

Specialized Instruments and
Accessories
 Intraoral instruments
 Orthodontic scaler
• Used in bracket placement, removal of elastomeric rings,
and removal of excess cement or bonding material
 Ligature director
• Used to guide the elastic or wire ligature tie around the
bracket and to tuck the twisted
and cut ligature tie under the arch wire
(Cont’d)

Accessories
(Cont’d)
 Band plugger
 Used to help seat a molar band for a fixed
appliance
 Bite stick
 Used to help seat a molar band for a fixed
appliance
 Bracket-placement tweezers
 Used to carry and place the bonded bracket on
the tooth
(Cont’d)

Fig. 60-13 A to E, Intraoral instruments.
(From Boyd L: Dental instruments, a pocket guide, ed 3, St Louis, 2009, Saunders.)
A
B
C
D
E

Accessories
(Cont’d)
 Pliers
 Bird-beak pliers
• Used to form and bend wires
 Contouring pliers
• Used in fitting bands
 Weingart utility pliers
• Used in placing arch wires
 Three-prong pliers
• Used to close and adjust clasps
(Cont’d)

Accessories
(Cont’d)
 Posterior band–remover pliers
 Used to remove bands
 Pin and ligature cutter
 Cuts the ligature wire for removal
 Howe (110) pliers
 Allows placement and removal of, and the making
of adjustment bends in, the arch wire
(Cont’d)

Accessories
(Cont’d)
 Wire-bending pliers
 Used to hold, bend, and adjust arch wires to
create movement
 Ligature-tying pliers
 Used for ease in ligature tying

Fig. 60-14 A to I, Orthodontic pliers.
(Courtesy of Miltex, Inc, York, Pa.)

Fixed appliances, also referred to as
braces, are a combination of bands,
brackets, and auxiliaries that can be
used to move a tooth in six directions:
mesially, distally, lingually, facially,
apically, and occlusally.
Fixed Appliances

Fig. 60-15 Full braces.

Sequence of Appointments
for Fixed Appliances
 Placement of separators
 Cementation of molar bands
 Bonding of brackets
 Insertion of arch wire and tying in with ligature
ties or elastomeric ties
 Adjustment checks
 Removal of appliance
 Retention of teeth

Separators
 Teeth are separated before fitting and the
placement of the molar bands.
 Brass-wire separators
 Steel separating springs
 Elastomeric separators

Orthodontic Bands
 Preformed stainless steel bands are fitted
and cemented to molar teeth.
 Buttons, tubes, and cleats are attached for the
arch wire and power products.

Fig. 60-16 Varying sizes of bands.

Bonded Brackets
 On the bonded bracket, the arch wire is
placed horizontally through the wings of the
bracket and then ligated in place.
 This stabilization initiates tooth movement by
allowing the forces from the arch wire to be
transmitted to the tooth.

Fig. 60-18 Bracket ready for placement.

Auxiliary Attachments
 Headgear tubes
 These round tubes, routinely placed on maxillary
first molar bands, are used for the insertion of the
inner bow of a facebow appliance.
 Edgewise tubes
 Rectangular tubes are placed on the buccal
surfaces of the upper and lower first molar bands
to receive the arch wire.
(Cont’d)

Auxiliary Attachments
(Cont’d)
 Labial hooks
 Located on the facial surfaces of the first and
second molar bands for both arches, these hooks
hold the interarch elastics.
 Lingual arch attachment
 This button or bracket, located on the lingual
portion of the bands, stabilizes the arch and
reinforces anchorage and tooth movement.

Preformed thin wire is placed within the
bracket to provide a pattern for the
dental arch to take its shape from and
to guide the teeth in movement.
Arch Wire
(Cont’d)

Arch Wire
(Cont’d)
 Types of arch wires
 Nickel-titanium
• For movement because of its flexibility
 Stainless-steel wire
• Stiffer and stronger
 Beta titanium (TMA)
• Provides a combination of strength, flexibility, and
memory
 Optiflex
• Used for light force and its aesthetics
(Cont’d)

Arch Wire
(Cont’d)
 Shapes of arch wires
 Round wires are used in the initial and
intermediate stages of treatment to correct
crowding, level the arch, open a bite, and close
spaces.
 Square or rectangular wires are used during the
final stages of treatment to position the crown and
root in the correct maxillary and mandibular
relationship.

Ligature Ties
 Stainless steel
 A 0.010-gauge stainless-steel wire ligature is used
to “tie” in arch wires.
 Kobayashi hooks
 Ligature ties that have been spot welded at the tip
form hooks for the attachment of elastics.

Elastomeric Ties
 A small elastic ring stretched around a
bracket is used to hold the arch wire in place.
 Elastomeric ties are available in a variety of
colors.

Power Products
 Elastic chain ties
 These ties, continuous O’s that form a chain, are
used to close space between teeth or correct
rotated teeth.
 Elastics
 Commonly referred to as rubber bands, elastics
are placed from one tooth to another in the same
arch or from one tooth to another tooth in the
opposing arch. Elastics help close spaces
between teeth and correct occlusal relationships.
(Cont’d)

Power Products
(Cont’d)
 Elastic thread is a type of tubing used to close
space or aid in the eruption of impacted teeth.
 Comfort tubing aids in patient comfort by
covering an arch wire that may be causing
discomfort.

Headgear
 Headgear is an orthopedic device used to
control growth and tooth movement.
 Facebow
 Used to stabilize or move the maxillary first molar
distally and create more room in the arch.
 Traction device
 Used to apply the extraoral force necessary to
achieve the desired treatment results

Fig. 60-23 Four types of traction.

Oral-Hygiene Instructions
 Toothbrushing instructions
 Floss your teeth, using a floss threader for easy
application.
 Brush your teeth at least once every day.
 After brushing, rinse and swish water around to
remove any debris.
 Inspect your teeth and braces carefully to make
sure that they are spotless.

Table 60-2 Dietary Habits and Orthodontics

Retention
 Orthodontic positioner
 Retains the teeth in their desired positions
 Permits the alveolus to rebuild support around the
teeth before the patient wears a retainer
 Massages the gingiva
(Cont’d)

Retention
 Hawley retainer
 This removable retainer is worn to passively retain
the teeth in their new position.
 Lingual retainer
 A fixed lingual wire bonded canine to canine on
the lingual surfaces provides lower-incisor position
during late growth.

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