Orthodontics Chapter 60 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Chapter 60 Lesson 60.1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Introduction Orthodontics is the specialty of dentistry concerned with the supervision, guidance, and correction of the growing and mature dentofacial structure. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Understanding Malocclusion Malocclusion is an abnormal or malpositioned relationship of the maxillary teeth to the mandibular teeth when they are in occlusion. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Factors Related to Malocclusion Developmental causes Congenitally missing teeth Malformed teeth Supernumerary teeth Interference with eruption Ectopic eruption (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Factors Related to Malocclusion (Cont’d) Genetic causes Discrepancies in the size of the jaw, teeth, or both Environmental causes Birth injuries Fetal molding Trauma (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Factors Related to Malocclusion (Cont’d) Habits Tongue thrusting Tongue-thrust swallowing Thumb and finger sucking Bruxism Mouth breathing Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Malocclusion Any deviation from class I occlusion is considered malocclusion. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-2 A, Diagram showing class II malocclusion. B, Photo showing class II malocclusion. (A, From Proffit WR, Fields HW: Contemporary orthodontics, ed 4, St Louis, 2007, Mosby.) B Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-3 A, Diagram showing class III malocclusion. B, Photo showing class III malocclusion. (A, From Proffit WR, Fields HW: Contemporary orthodontics, ed 4, St Louis, 2007, Mosby.) B Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Malaligned Teeth (Cont’d) Overbite Open bite This is an increased vertical overlap of the maxillary incisors. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Benefits of Orthodontic Treatment Psychosocial Oral function Dental disease Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Management of Orthodontic Problems Preventive orthodontics Interceptive orthodontics To prevent or eliminate irregularities and malpositioning in the developing dentofacial region To intercede or correct problems as they are developing Corrective orthodontics To move teeth and correct malocclusion and malformations. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Orthodontic Records and Treatment Planning Medical and dental history Evaluation of physical growth Social and behavioral evaluation Clinical examination Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Clinical Examination Used to document, measure, and evaluate the: Facial aspects Oral health Jaw and occlusal relationship Functional characteristics of the jaws Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Diagnostic Records Photographs are useful as an aid in: Patient identification Treatment planning Case presentation Case documentation Patient education Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-9 A and B, Standard extraoral photographs. (From Proffit WR, Fields H, Sarver DM: Contemporary orthodontics, ed 4, St Louis, 2007, Mosby.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-11 A and B Cephalometric radiograph and analysis. A B Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Diagnostic Models Diagnostic models Diagnosis Case presentation Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Chapter 60 Lesson 60.2 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Specialized Instruments and Accessories (Cont’d) Band plugger Bite stick Used to help seat a molar band for a fixed appliance 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-13 A to E, Intraoral instruments. (From Boyd L: Dental instruments, a pocket guide, ed 3, St Louis, 2009, Saunders.) A C B D E Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Specialized Instruments and 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Specialized Instruments and Accessories (Cont’d) Posterior band–remover pliers Pin and ligature cutter Used to remove bands 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Specialized Instruments and 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 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-14 A to I, Orthodontic pliers. (Courtesy of Miltex, Inc, York, Pa.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fixed Appliances 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-15 Full braces. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Separators Teeth are separated before fitting and the placement of the molar bands. Brass-wire separators Steel separating springs Elastomeric separators Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-16 Varying sizes of bands. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-18 Bracket ready for placement. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Arch Wire 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. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Fig. 60-23 Four types of traction. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Table 60-2 Dietary Habits and Orthodontics Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.