Orthodontic Appliance 2024 PDF

G O O D M O RN I N G Shaimaa El-Marhoumy 12/15/2024  Principles of Orthodont...

G O O D M O RN I N G Shaimaa El-Marhoumy 12/15/2024  Principles of Orthodontic Appliances By Shaimaa Mohamed El-Marhoumy  Classification Intraoral Extraoral  Intraoral Appliances Simplest classification is probably based on the patient’s ability to remove the orthodontic …appliance Removable Fixed Semi-fixed  Intraoral Appliances Active According to force application: Passive  Active device: that applies force to the teeth and their supporting structures to produce changes in their relationship to each other.   Are passive orthodontic appliances that help in maintaining the position of a Retainers single tooth or a group of teeth to permit reorganization of the supporting structures.  General Requirements: Comfortable to wear and acceptable by the patient. Fabricated from a biocompatible material. Not interfere with proper cleansing of teeth & soft tissue Firmly positioned in the mouth. Produce the desired force that cause a well controlled tooth movements.  Removable Classification Passive appliances: No force Example as: Space maintainer ,Retention appliances Mechanical appliances: Carry some active components which are activated to exert active forces. Functional appliances: Transmitting muscle forces to the dental arches and even jaw bones for growth modification, tooth movement or both. Example as: Activator, lip bumper  Removable Mechanical appliance: Which type of F and movement?? Produce intermittent force and tipping movement only.  Removable Myofunctional appliance  Removable Myofunctional appliance  Removable Myofunctional appliance  Removable Components of removable appliance 1 2 3 4 Active Retentive Anchorag Base part part e plate  The active components the components of the Removable Appliance, which apply forces to the teeth to bring about the desired tooth movement. The active components include: Springs Bow Screws Elastics  springs Springs for labial movement ( palatal springs) Finger spring Z spring 1 1 Springs for Mesio-distal movement: Helical coil spring Springs for arch expansion : Coffin spring 1 1 Buccal spring Buccal Canine Retractor springs The flexibility of a spring depends on the wire length & its diameter: F α r4 / L3 (F) is the force exerted by an orthodontic spring (r) is the radius of the wire, ( L) is the length of the spring. The space available within the mouth is limited, So incorporating helix into the design → ↑ the length of wire → ↓force with a long range of action. PROBLEM 1: Cross bite of 1 Retentive component: Adams cribs 6/6 and 4/4 Active component: Z-spring to 1/ BITE OPENING: Posterior bite capping to 654 / 456 BASEPLATE: to connect everything together, also some anchorage ACTIVATE THE Z-SPRING.... Helical coil spring Bows Labial bow consists of three parts, namely: 1. Horizontal bow portion 2. Vertical loops 3. Retentive arms Indication:  Retracting & closing spaces between the anterior teeth.  Retaining the anterior teeth.  Retention of the appliances.  Increased Overjet OR Deep bite? WHY IS IT NECESSARY TO REDUCE THE OVERBITE BEFORE REDUCING THE OVERJET? As incisors tip, the lower incisors prevent further overjet reduction due to increasing overbite By incorporating an anterior bite plane, the overjet can be successfully reduced without increasing the overbite as the incisors tip palatally Bite opening - posterior teeth erupt into the space Trimming to allow the incisors to retrocline: trim on palatal aspect, with bur parallel to palatal surface. Don’t trim from the occlusal surface - reduces width of bite plane excessively. Passive short labial arch - Ve Labial bow Adam’s clasp Acrylic base  Prevent the anterior teeth from rotating, proclined or developing Labial bow spaces. Capable of closing minor spaces in the anterior segment. The clasps prevents movement of Adam’s clasp the molars. The acrylic base with (festooning) Acrylic base prevents the lingual movement of the teeth. Screws 1 2 PROBLEM 2: All four incisors inside bite, with deep reverse overbite RETENTION: Adams cribs 6/6 and 4/4 ANTERIOR RETENTION: Southend clasp 1/1 ACTIVE COMPONENT: Expansion screw to section 21/12 BITE OPENING: occlusal capping posteriorly Screw is opened by one quarter turn twice a week and pushes upper incisors forward over the bite Problem 7: an unerupted 5/ where extraction of the 4/ would give too much space  Screws Screw can be activated by the patient at regular intervals using a key. Indications: 1. Anterior and posterior cross bite (slow expansion). 1 2. Distal movement of molars. Disadvantages: 3. They are bulky and expensive. 4. The patient is responsible for activation 2  Retentive component clasps 1. Seating it in the correct position. 2. Contribute to anchorage.  Base plate  It acts as a foundation into which the remaining components of the removable appliance are embedded.  It serves as anchorage by engaging the teeth which will not move.  It can be used as an active element of the appliance itself e.g. anterior bite plane and posterior bite plane.  Protect the palatal spring if they Base plate Anterior bite-plane is used to correct deep bite by Increasing the thickness of acrylic behind the upper incisors forms a bite-plane onto which the lower incisors occlude. Posterior bite plane Free the posterior occlusion in case of anterior C.B.  Removable Indications Growth modifications during mixed dentition. Limited tipping tooth movement. Arch expansion. Retention after fixed treatment. Interfere with abnormal orofacial habits  Removable Contraindications 1. Sever rotation of the tooth (couple force needed). 2. Bodily movements are required. 3. Where severe crowding or spaces exist.  Removable Advantages 1- Routine oral hygiene can be performed easily. 2- More acceptable to the patients as it can be removed in some social situations. 3- Can be delivered and monitored by the general dentist.  Removable Disadvantages 1- Patient cooperation is the most important. 2- Capable of only certain types of movements (tipping movement). 3- Patient need certain amount of skill to be able to remove and replace it. 4- Lower removable appliances are not well tolerated (tongue) 5- May affect the speech. 6- Good technician required. Instructions for removable appliance  Your appliance should be worn all the time, including meals and in bed at night.  Your appliance should be removed for tooth cleaning and during vigorous sports.  It is usual to experience some discomfort and a little difficulty with speech initially, but this should pass in a few days as you become accustomed to wearing the appliance.  It is important to avoid hard or sticky foods and chewing gum.  If you cannot wear your appliance as instructed, or if it becomes damaged or causes pain, please contact …….. immediately. Instructions for removable appliance  Instruction on the insertion and removal.  Ask the child to repeat the instructions. Also demonstrate them to the parent and make sure that they can do so unaided. Follow up  Activation.  inspection of the general oral condition (ulcer or trauma)  Observe whether speech is affected by the appliance. Semifixed Extraoral Appliances Orthopedic Appliances  ORTHOPAEDIC FORCE Heavy intermittent 400-600 gm/side for 16 hours. Acts on basal bone of the jaws → redirect, restrain or enhance growth So used in growing patient ↑↑ Skeletal effect- ↓↓dental effect Ex. Face mask , chin cup, headgear 70 Skeletal Class II malocclusion Prognathic/Large maxilla Retrognathic/Small mandible Both 72 Skeletal Class III malocclusion Retrognathic/small maxilla Prognathic/ Large mandible Both 75 ADD A FOOTER 76 ADD A FOOTER 77 78  Indications Multiple tooth movement required in one arch Especially rotation , torque (root movement ), bodily movement ,intrusion and extrusion Active closure of extraction space  Contraindication No absolute cotraindication but may be in case of Poor dental health Systemic disease : Advantages of fixed orthodontics A precise tooth movement is achieved as no need for patient cooperation Good control of movement by an area of contact not only a point like in removable. Nearly all types of malocclusion can be treated, especially bodily movement , rotation, torque. Multiple teeth can be moved simultaneously. In the same tooth to be moved multiple movements can be done.  Disadvantages Biological gingival inflammation Oral hygiene is required to prevent entrapment of food debris and plaque around brackets and retainers Enamel decalcification (WSL) Due to bonding …… disadvantage Time & cost Increased chair side time Long time is needed for treatment somehow expensive Esthetics Probably due to metallic compartments which was overcomed by tooth colored brackets and lingual technique Operators Special training of operators. If the Forces applied are misdirected they will lead to deleterious effects. Brass wire Elastic separator  Arch wire Available in variable dimension, cross section, materials and various shapes depending upon arch type  Elastics Special intra-oral elastics are manufactured for orthodontic use. These elastics are usually classified by their size, ranging from 1/8 inch to 3/4 inch, and they are designed to be used mainly with fixed appliance  Class 1 elastics (intra Elastics arch elastic) placed between molars and ant. in same arch. used to close the extraction space Class 2 elastics( inter max elastics) placed between max ant. and mand molars used to decrease overjet Class 3 elastics (inter max elastics ) placed between mand ant. and max molars used to treat class III. by retracting mand ant. and protracting max molars  Diagonal elastics placed across ant teeth diagonally. used to correct midline deviation. Cross elastics used to ttt cross bite. Box elastics used to ttt ant open bite. Springs Springs Passive Component s  Buccal Tubes horizontal hollow tubes used on molars and help provide better three dimension control of these anchor teeth. They can be classified as: a. Mode of attachment Weldable Bondable b. Lumen shape Round Oval Rectangular c. Number of tubes Single Double used for auxiliary wires or facebow Brackets The force required for orthodontic tooth movement is transmitted from the active components through the brackets Lingual Orthodontic Bonding instruction s  Fixed Removable 1- Precise control over force distribution to Single-point application of forces mean that only individual teeth means that rotation and tipping movements are readily produced. controlled root movement are possible. 2- Multiple teeth movements can be performed Usually only a few teeth should be moved on any simultaneously. one time. 3- Complex to make and use, so special Comparatively simple and should be with the Training is needed. scope of the dental practitioner for carefully selected cases. 4- Chair side time is comparatively long. Chair side time is short but laboratory time greater than for fixed appliances. 5- Components are costly. Components are cheep. 6- Does not depend on cooperation of Depend on cooperation of patient  Fixed Expander  Fixed Distalize r Clear aligner Invisal ign  They are sets of clear, thin, plastic like, custom made trays that sequentially apply pressure required to move the teeth. Digital tooth scan is made. The program suggests stages between the current and the desired teeth positions. Aligners are created for each stage. Each aligner is worn for 22 hours/day for 2 weeks These slowly move the teeth (fraction of mm) into the required position Aligners must be removed during eating, drinking, brushing and flossing Mild malocclusion T hank Y ou!