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

 Orthodontics is the specialty of dentistry concerned with the supervision, guidance, and correction of the growing and mature dentofacial structure.  Deals with the diagnosis, treatment and maintenance of correction of all levels of malocclusion Orthodontics defined: Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

 Malocclusion is an abnormal or malpositioned relationship of the maxillary teeth to the mandibular teeth when they are in occlusion.  Any deviation from class I occlusion is considered malocclusion. Understanding Malocclusion 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  Genetic causes  Discrepancies in the size of the jaw, teeth or both  Environmental causes  Birth injuries  Fetal molding  Trauma Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Habits Related to Malocclusion  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.

Angle’s Classification of Occlusion  Dr. Edward Angle- introduced the most widely accepted classification of malocclusion and developed many appliances  The relationship between maxillary and mandibular 1 st molar is key to determining a patient’s occlusion class

Class I Neutroclusion B Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. In centric occlusion mesiobuccal cusp of the maxillary 1 st molar rests in the buccal groove of mandibular 1 st molar

Class II Malocclusion  This condition is also referred to as distoclusion.  In centric occlusion mesiobuccal cusp of the maxillary 1 st molar rests in the interdental space between mandibular 2 nd premolar and mandibular 1 st molar  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.

Class III Malocclusion  This condition is also referred to as mesioclusion.  In centric occlusion the mesiobuccal cusp of the maxillary 1 st molar occludes in the interdental space between the distal cusp of the mandibular 1 st molar and mesial cusp of the mandibular 2 nd molar  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.

Orthodontic Problems: 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.  Can be measured horizontally in mm Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Orthodontic Problems: Malaligned Teeth  Overbite  This is an increased vertical overlap of the maxillary incisors  Measured vertically in percentage  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  When mandibular teeth are positioned labial to maxillary teeth.

Visualize the orthodontic problem  Overjet  Overbite  Crossbite  Openbite

Visualize the orthodontic problem:  Overjet  Overbite  Crossbite  Openbite

Visualize the orthodontic problem:  Overjet  Overbite  Crossbite  Openbite

Visualize the orthodontic problem:  Overjet  Overbite  Crossbite  Openbite

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  To prevent or eliminate irregularities and malpositioning in the developing dentofacial region  Caries control; space maintainers, correction of oral habits  Interceptive orthodontics  To intercede or correct problems as they are developing  Palate expansion  Monitoring of exfoliation of primary teeth  Corrective orthodontics  To move teeth and correct malocclusion and malformations  Fixed and removal appliances are used to correct malocclusion

Components of Fixed Appliances  Band: usually used on posterior teeth, fitted on individual and cemented  Buccal surface Archwire tube- place for archwire to attach Archwire tube- place for archwire to attach Headgear tube- place for inner bow to attach Headgear tube- place for inner bow to attach Labial hook – attachment for rubber bands Labial hook – attachment for rubber bands  Lingual surface Lingual cleat- attachment used if any palatal stability or appliance is needed Lingual cleat- attachment used if any palatal stability or appliance is needed

Components of Fixed Appliances  Brackets: most commonly used type of attachment  Bonded to enamel  Composed of metal, plastic or ceramic  Archwire: preformed wire, horseshoe shaped, placed within bracket and band to apply force to enable movement of teeth  Types: Nickel titanium Nickel titanium Stainless steel Stainless steel Square, rectangular, round Square, rectangular, round

Components of Fixed Appliances  Ligatures: used to stabilize archwire within bracket and band  Types: Wire ligatures single Wire ligatures single Wire continuous Wire continuous Rubber single (elastic) Rubber single (elastic) Rubber chains (elastic Rubber chains (elastic  Elastics: rubber bands, placed between maxillary and mandibular arches to bring about tooth movement  Separators: Rubber bands or brass, used to open contacts prior to placement of bands

Sequence of Appointments for Fixed Appliances  Consultation  Records visit  Placement of separators (if needed)  Banding, bonding and archwire placement  Adjustment visits  Debanding and debonding  Retention of teeth Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

 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.  Generally fixed orthodontics takes an average of 18 months to 2 years of active treatment Fixed Appliances Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Full braces. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Oral-Hygiene Instructions  Instructions  Floss your teeth, using a floss threader for easy application.  Brush your teeth as often as possible especially at night and in the morning.  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.

Post Orthodontic Complications Emergency  Broken brackets  Loose bands  Broken archwire Non-emergency  Soreness of teeth  Soreness of gums  Wire sticking out the back of buccal tube

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  See page 1052 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Four types of traction. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Retention  In order to maintain alignment the patient must understand that retention is very important.  The most frequently encountered post-orthodontic problem is the retention of re-established tooth position. Relapse may occur anywhere, but it is often associated with teeth that have undergone rotation (twisting) as part of the orthodontic therapy.  A fiberotomy(PDL) involves the detachment of the fibers that attach the tooth to the bone via the gum.

Retention  Used to make final refinement if unable to complete with fixed appliances  Much bulkier than other long term retainers  Orthodontic positioner  Generally worn 24 hours day during 1 st week then can be cut back  Moves teeth into final position  Patient must continually bite while wearing  Permits the alveolus to rebuild support around the teeth before the patient wears a retainer around the teeth before the patient wears a retainer  Massages the gingiva

Retention  Retainers should be worn as much as possible and for as long as possible as possible and for as long as possible  Types of Retainers:  Essix retainer vacuum formed  Hawley retainer This removable retainer is worn to passively retain the teeth in their new position. This removable retainer is worn to passively retain the teeth in their new position. Labial wire bow and acrylic possible Labial wire bow and acrylic possible  Lingual retainer A fixed lingual wire bonded canine to canine on the lingual surfaces provides lower-incisor position during late growth. A fixed lingual wire bonded canine to canine on the lingual surfaces provides lower-incisor position during late growth.