ANCHORAGE IN ORTHODONTICS INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
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NEWTON’S third law of motion : “ Every action has an equal and opposite reaction.”
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DEFINITIONS : Moyers : “ Resistance to displacement.” Active elements and reactive elements. T.M. Graber : “The nature and degree of resistance to displacement offered by an anatomic unit when used for the purpose of effecting tooth movement.” www.indiandentalacademy.com
DEFINITIONS : Proffit : “Resistance to unwanted tooth movement.” “Resistance to reaction forces that is provided (usually) by other teeth, or (sometimes) by the palate, head or neck (via extraoral force), or implants in bone.”
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DEFINITIONS : Nanda : “The amount of movement of posterior teeth (molars, premolars) to close the extraction space in order to achieve selected treatment goals.�
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CLASSIFICATIONS: Moyers : According to the manner of force application: 1. Simple anchorage : Resistance to tipping. 2. Stationary anchorage : Resistance to bodily movement. www.indiandentalacademy.com
CLASSIFICATIONS:
3.
Reciprocal anchorage : Two or more teeth moving in opposite directions and pitted against each other by the appliance.
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CLASSIFICATIONS: Moyers : According to the jaws involved: 1. Intra maxillary : Anchorage established in the same jaw.
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CLASSIFICATIONS:
2. Inter maxillary : Anchorage distributed to both jaws. Baker’s anchorage (1904)
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CLASSIFICATIONS: Moyers : According to the site of anchorage: 1. Intra oral : Anchorage established within the mouth.
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CLASSIFICATIONS: 2. Extra oral : Anchorage obtained outside the oral cavity. a.) Cervical : eg. neck straps b.) Occipital : eg. Head gears c.) Cranial : eg. High pull headgears d.) Facial : eg. Face masks www.indiandentalacademy.com
CLASSIFICATIONS:
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CLASSIFICATIONS:
3. Muscular : Anchorage derived from action of muscles. eg. Vestibular shields.
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CLASSIFICATIONS: Moyers : According to the number of anchorage units : 1. Single or primary anchorage: Anchorage involving only one tooth. 2. Compound anchorage: Anchorage involving two or more teeth. www.indiandentalacademy.com
CLASSIFICATIONS: 3.
Reinforced anchorage: Addition of non dental anchorage sites. eg. Mucosa, muscle, head, etc.
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CLASSIFICATIONS: Nanda : A anchorage : critical / severe 75 % or more of the extraction space is needed for anterior retraction. B anchorage : moderate Relatively symmetric space closure (50%) C anchorage : mild / non critical 75% or more of space closure by mesial movement of posterior teeth www.indiandentalacademy.com
CLASSIFICATIONS:
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CLASSIFICATIONS: Burstone : Group A arches Group B arches Group C arches
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CLASSIFICATIONS:
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BIOLOGICAL ASPECTS OF ANCHORAGE : Factors affecting anchorage: Number of roots Shape, size and length of each root multirooted > single rooted longer rooted > shorter rooted triangular shaped root > conical or ovoid root larger surface area > smaller surface area www.indiandentalacademy.com
BIOLOGICAL ASPECTS OF ANCHORAGE : Factors affecting anchorage: Cortical anchorage: Cortical bone vs. medullary bone Muscular forces: Horizontal growers vs. vertical growers
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BIOLOGICAL ASPECTS OF ANCHORAGE : Factors affecting anchorage: Relation of contiguous teeth Forces of occlusion Age of the patient Individual tissue response
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BIOLOGICAL ASPECTS OF ANCHORAGE : Pressure in the PDL= Force applied to a tooth Area of distribution in PDL Tooth movement increases as pressure increases upto a point, remains at same level over a broad range and then may gradually decline with extremely heavy pressure. Anchorage control : Concentration of desired force and dissipation of reactionary force www.indiandentalacademy.com
BIOLOGICAL ASPECTS OF ANCHORAGE : PRESSURE RESPONSE CURVE :
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BIOLOGICAL ASPECTS OF ANCHORAGE : Anchorage situations : Reciprocal tooth movement : Equal force distribution over the PDL eg. Midline diastema, First premolar extraction site Anchorage value depends on the root surface area www.indiandentalacademy.com
BIOLOGICAL ASPECTS OF ANCHORAGE : Anchorage situations : Reinforced anchorage: Distribution of force over a larger surface area Light forces vs. heavy forces eg. Addition of extra teeth, Extra oral anchorage www.indiandentalacademy.com
BIOLOGICAL ASPECTS OF ANCHORAGE : Anchorage situations : Stationary anchorage: Bodily movement of anchor teeth vs. tipping of teeth to be moved
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BIOLOGICAL ASPECTS OF ANCHORAGE : Anchorage situations : Differential effect of very large forces: More movement of arch segment with the larger PDL area. Questionable response.
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MECHANICAL ASPECTS OF ANCHORAGE : Tooth movement is brought about after overcoming the frictional resistance during sliding of wire in the bracket. Frictional force is proportional to the force with which the contacting surfaces are pressed together Affected by the nature of the surface Independent of the area of contact www.indiandentalacademy.com
MECHANICAL ASPECTS OF ANCHORAGE : Asperities : Peaks of surface irregularities.
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MECHANICAL ASPECTS OF ANCHORAGE : Local pressure at asperities causes plastic deformation At low sliding speeds, ‘stick slip’ phenomenon occurs Anchor teeth feel reaction to both friction and tooth moving forces
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ANCHORAGE LOSS: Anchor loss in all 3 planes of space : Sagittal plane: - Mesial movement of molars, - Proclination of anteriors
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ANCHORAGE LOSS: Vertical plane: - Extrusion of molars, - Bite deepening due to anterior extrusion
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ANCHORAGE LOSS: Transverse plane: - Buccal flaring due to over expanded arch form and unintentional lingual root torque, - Lingual dumping of molars,
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ANCHORAGE IN REMOVABLE APPLIANCES: Early removable appliances: Completely tooth borne Partly cast, partly wrought wire Bimler appliance
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ANCHORAGE IN REMOVABLE APPLIANCES: Early removable appliances: Crozat appliance - Lingual extensions - Heavy palatal bar - High labial base wire - Rest on molar clasp
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ANCHORAGE IN REMOVABLE APPLIANCES: CLASPED REMOVABLE APPLIANCES: - Active part, - Clasps, - Baseplate. Baseplate : - Point of attachment for the active components, - Distribution of the reactionary forces to the teeth and tissues. www.indiandentalacademy.com
ANCHORAGE IN REMOVABLE APPLIANCES: To ensure adequate anchorage from baseplates: - Extension as far as possible, also for stability, - Close fit to the tissues, - Contouring along the lingual gum margins, - Adequate bulk of acrylic. - Eg. Schwartz expansion plate www.indiandentalacademy.com
ANCHORAGE IN REMOVABLE APPLIANCES: Wire components: - Labial bow: Prevents proclination of incisors Stationary anchorage. Intermaxillary anchorage: - Elastics Headgears www.indiandentalacademy.com
ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Reactionary forces: - Sagittal - Vertical - Transverse
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ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Tooth borne appliances: - Sved bite plane: stationary anchorage
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ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Tooth borne appliances: Activator, bionator, twin block
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ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Anchorage obtained by: - capping of incisal margins of lower incisors - proper fit of cusps of teeth into the acrylic - deciduous molars used as anchor teeth
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ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: - edentulous areas after loss of deciduous molars - noses in upper and lower interdental spaces - labial bow prevents anterior flaring and posterior displacement of appliance
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ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Tissue borne appliances: - Vestibular screen, Frankel’s function regulator Anchorage by acrylic extending into vestibule Headgears www.indiandentalacademy.com
ANCHORAGE IN REMOVABLE APPLIANCES: REMOVABLE FUNCTIONAL APPLIANCES: Tissue borne appliances: - Vestibular screen
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ANCHORAGE IN FIXED APPIANCES: Historical perspective Edgewise: Angle, Tweed, Andrews, Ricketts, Alexander, Roth, Burstone, Bennett and Mclaughlin Methods to reinforce anchorage Begg: conventional and refined Tipedge Studies in anchorage Newer methods inanchorage conservation www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: HISTORICAL PERSPECTIVE: ANGLE; E arch : - tipping tooth movements - first to utilise stationary anchorage of 1st permanent molars with clamp bands www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Long clamp band: crown tipping resistance of posterior teeth pitted against crown tipping resistance of cuspid. - simple anchorage vs. simple anchorage
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ANCHORAGE IN FIXED APPIANCES: Pin and tube appliance: root control by pins soldered to labial archwire Ribbon arch appliance: size of archwire itself did not provide anchorage of posterior teeth
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ANCHORAGE IN FIXED APPIANCES: Edgewise appliance: 0.022� slot Utilised by Tweed
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ANCHORAGE IN FIXED APPIANCES: TWEED TECHNIQUE: “ When teeth are tipped distally as they are in anchorage preparation, osteoid tissue appears to be laid down adjacent to the mesial surface of the tooth being moved distally.” - Kaare Reitan www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Anchorage preparation: First degree: ANB = 0 – 4 - mandibular molars must be uprighted and maintained - direction of pull of intermaxillary elastics should be perpendicular to long axis of the tooth
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ANCHORAGE IN FIXED APPIANCES: Second degree: ANB > 4.5 - mandibular molars must be distally tipped till distal marginal ridges are at gum level - direction of pull of Cl II elastics should be greater than 90 to the long axis of the tooth
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ANCHORAGE IN FIXED APPIANCES: Third degree: ANB =5, - total discrepancy = 14- 20 mm. - mandibular molars must be distally tipped till distal marginal ridges are below gum level - jigs are required for anchorage www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Mandibular anchorage prepared first by distal tipping of the canines, premolars and first and second molars. Resist displacement by Cl II elastic force Stabilizing arch wire: .0215 by .0275 www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Hooks soldered for intermaxillary elastics and/ or headgear on the wires High pull headgear: b/w centrals and laterals Intermediate pull headgear and elastics: b/w laterals and canines
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ANCHORAGE IN FIXED APPIANCES: TWEED MERRIFIELD TECHNIQUE: Sequential directional force edgewise technique – 1965 .022 slot 20 degree tip back achieved J hook headgear used to upright cuspids and apply distal force to terminal molars www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Denture preparation: Mandible: 20 degree tip back achieved Straight pull J hook headgear used to upright cuspids and apply distal force to terminal molars
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ANCHORAGE IN FIXED APPIANCES: Maxilla: 10 degree distal tip achieved High pull J hook headgear used
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ANCHORAGE IN FIXED APPIANCES: Class III elastics not used Tip backs used instead of second order bends: better incisor control Maxillary third order bends applied sequentially ( anterior lingual root torque, posterior buccal root torque)
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ANCHORAGE IN FIXED APPIANCES: Sequential anchorage: the 10-2 system MANDIBLE: .0215 by .028 continuous archwire used Ten teeth anterior to the second molars are stabilised while the two terminal molars receive the active force High pull headgear used Second molars: +10 to +15 First molars: 0 to –3 tip Second premolars: 0 to –5 www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Distal tip of 10 degree in first molars with compensation bends in 2nd molars High pull headgear End of 1 month: second molars: +10 to +15 first molars: +5 to +8 second premolars: 0 to -3
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ANCHORAGE IN FIXED APPIANCES: 10 degree tip in second premolar region with compensating bend just mesial to first molar bracket High pull headgear only at night Second premolars: 0 to 5 degree tip
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ANCHORAGE IN FIXED APPIANCES: MAXILLA: Sequential force from first molar onwards 10 degree tip placed
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ANCHORAGE IN FIXED APPIANCES: High pull headgear used for enhancing molar effect and incisor intrusion Next appointment: additional 5 degree tip placed on 1st molar Second molar : 20 first molar : 15 second premolar: 10 www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: RICKETTS’ BIOPROGRESSIVE TECHNIQUE: 1978 Quad helix: holding appliance
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ANCHORAGE IN FIXED APPIANCES: RICKETTS’ BIOPROGRESSIVE TECHNIQUE: Adverse effects of light continuous round wires with reverse curve of Spee and tieback: lower incisors thrown against the lingual cortical plate causing forward movement of lower molars Class III elastics with high pull headgear: extrusive effect on lower incisors and upper molars
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ANCHORAGE IN FIXED APPIANCES: Lower utility arch: late 1950s Position of lower molar to allow for cortical anchorage: - tooth movement through dense cortical bone is retarded because of reduced blood supply, which diminishes resorption - buccal root torque of lower molars Tip back: gain in arch length – 4mm Headgears: cervical, combination and high pull www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES:
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ANCHORAGE IN FIXED APPIANCES: THE STRAIGHT WIRE APPLIANCE: Dr. Lawrence Andrews , mid 70s Preadjusted bracket system Extra torque added to incisor brackets to prevent bite deepening Anti-tip and anti-rotation features in canine, premolar and molar brackets: extraction and nonextraction series Same force levels and treatment mechanics as previous systems www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: LEVEL ANCHORAGE SYSTEM: Terrell Root Preadjusted appliance used with .018 slot Anchorage: - inherent resistance of teeth to move - distance they can be allowed to move Orderly manipulation of need and availability of anchorage High pull headgear to maxillary 1st molars or J hook headgear towww.indiandentalacademy.com anteriors: reduction in ANB by
ANCHORAGE IN FIXED APPIANCES: Anchorage savers: Palatal bar: decreases vertical descent due to tongue pressure; reduction in space by 1mm Delaying upper first molar extraction by one year: reduces mandibular anchorage space by 1mm Class III elastics worn 24 hrs: flatten the curve of Spee and upright buccal segments at the rate of 1mm / month
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ANCHORAGE IN FIXED APPIANCES:
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ANCHORAGE IN FIXED APPIANCES: Anchorage conservation during treatment in level anchorage system: Stabilization of upper arch: .018* .025 s.s. Anchorage preparation in lower arch: Class III elastics: level curve of Spee High pull headgear Vertical loops in mandibular archwire to prevent space loss with class II elastics www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Anchorage conservation during treatment in level anchorage system: Delaying the extraction of maxillary premolars Upper anterior retraction: tying of first and second molars ; palatal bar inserted
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ANCHORAGE IN FIXED APPIANCES: ALEXANDER DISCIPLINE: Vari-Simplex discipline -6 degrees angulation of lower first molar tubes for gain in arch length ‘Retractors’ ( Dr. Fred Schudy) Cervical, combination or high pull depending on growth pattern and control needed www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Other intra oral appliances to control anchorage: 1. Transpalatal arch in high angle cases with high pull headgear 1. Nance holding arch in class I cases with crowding; preserves sagittal anchorage and retards vertical eruption www.indiandentalacademy.com
ANCHORAGE IN FIXED APPIANCES: Other intra oral appliances to control anchorage: 4. Mandibular lingual arch: sagittal and transverse control 5. Lip bumper: - uprighting of mandibular first molars - distal force on lower molars - muscular anchorage www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: BURSTONE’S SEGMENTAL ARCH TECHNIQUE: Arch divided into 1 anterior and 2 posterior segments, treated as separate units Frictionless mechanics using TMA springs; low load deflection rate Differential space closure: anterior retraction or posterior protraction or both should be possible Proper moment to force ratios www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Anterior retraction: group A arches: (AJO 1982) Buccal stabilizing segment with a transpalatal arch in maxilla and lingual arch in mandible: posterior anchorage unit Anterior segment Two tooth concept: large distance b/w canine and molar; low load- deflection rates www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: En masse controlled tipping followed by en masse root movement TMA 0.018 loop welded to 00.017 by 0.025 base arch - magnitude of moment on molar increases due to additional wire in the loop - low load deflection rate www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Heavy base arch withstands the higher moments without permanent deformation Spring is positioned mesially Posterior tipping of buccal segments along with TPA and consolidation of posterior teeth : anchorage reinforcement
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ANCHORAGE IN FIXED APPLIANCES: Group B arches: M/F ratio needed = 10:1 for translation Spring placed centrally b/w the two tubes for same rate of change in M/F in both alpha and beta moments
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ANCHORAGE IN FIXED APPLIANCES: Group C arches: Loop is positioned at 1/3 rd interbracket distance from the molar tube or Symmetrically placed spring with Cl II or Cl III elastics Side effects: flaring of anteriors, vertical extrusion of anteriors Can be eliminated by using headgear to upper arch www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Staggers and Germane (1991) Placement of gable bend near the beta moment to increase the M/F ratio Kuhlberg and Burstone (1997) Use of a loop with symmetric angulation but asymmetric placement
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ANCHORAGE IN FIXED APPLIANCES: ROTH’S TECHNIQUE: .022 slot Double key hole loops used b/w lateral and canine, and canine and premolar - control canine rotation during extraction space closure
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ANCHORAGE IN FIXED APPLIANCES: Things that tend to slip posterior anchorage forward: Use of resilient wires and continuous wires to level a deep curve of Spee Rapid bracket alignment with very resilient wires Attempts to upright distally inclined canines Attempts at moving maxillary incisor roots lingually Attempts at expansion with a labial arch wire Using a reciprocal force system to retract extremely proclined anteriors www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Ways to avoid anchor loss: Leveling with small flexible wire Retraction of lower anteriors using a facebow Band second molars in the beginning of treatment Use of utility arch to level curve of Spee Use of multiple short Cl II or Cl III elastics for intra-arch adjustment: do not extrude molars and do not change cant of occlusal plane www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Use of mandibular lingual arch with finger springs to widen premolar areas
Transpalatal bar: intrusion of molars and rotational control www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Critical anchorage cases: Asher facebow used to retract anteriors
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ANCHORAGE IN FIXED APPLIANCES: BENNETT AND MCLAUGHLIN: Anchorage control: ‘The manoeuvres used to restrict undesirable changes during the opening phase of treatment, so that leveling and aligning is achieved without key features of the malocclusion becoming worse.’
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ANCHORAGE IN FIXED APPLIANCES: Anchorage control in the horizontal plane: Inbuilt tip: proclination of anteriors (especially uppers) Elastic forces : anchorage loss, distal rotation of anteriors, bite deepening and increase in curve of Spee
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ANCHORAGE IN FIXED APPLIANCES: Control of anterior segment: Lacebacks from most distally banded molars to canines
Bending the archwire back immediately distal to the molar tube www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Robinson in 1989: - lower molars moved forward 1.76 mm on an average with lacebacks and 1.53mm without lacebacks - lower incisors moved distally 1.0 mm with lacebacks and 1.47 mm without lacebacks
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ANCHORAGE IN FIXED APPLIANCES: Control of the posterior segments: Greater need in upper arch: - larger teeth - greater tip - more torque control and bodily movement - upper molars move mesially more readily - greater number of class II cases Headgears : cervical, combination and high pull with long outer bow Palatal bar www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Control of posterior segments: lower arch Soldered lingual arch Severe anterior crowding cases: push coil springs with class III elastics; reinforced with upper palatal bar and high pull headgear
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ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES: Anchorage assessment in the vertical plane: Incisor vertical control: temporary increases in overbite
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ANCHORAGE IN FIXED APPLIANCES: Avoid bracketing incisors or avoid tying the wire in the incisor brackets Avoid early engagement of highly placed canines
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ANCHORAGE IN FIXED APPLIANCES: Molar vertical control: prevent extrusion of posterior teeth and opening up of mandibular plane angle ( high angle cases) Upper second molars not banded or archwire step placed distal to first molars Avoid extrusion of palatal cusps during expansion : fixed expander with headgear
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ANCHORAGE IN FIXED APPLIANCES: Palatal bars lie away from palate by 2mm: vertical intrusive effect of the tongue Avoid cervical pull headgear (combination pull or high pull) Upper or lower posterior biteplates
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ANCHORAGE IN FIXED APPLIANCES: Anchorage assessment in the lateral plane: Intercanine width maintained: avoid uncontrolled expansion Molar crossbites: bodily correction to avoid overhanging palatal cusps
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ANCHORAGE IN FIXED APPLIANCES: INVERSE ANCHORAGE TECHNIQUE: Jose Carriere- 1991 Mandible is a preferred point of reference for diagnosis and treatment planning, while maxilla is better suited to adapting orthodontic correction - maxilla is anatomically a more stable reference than mandible - functionally mandible is the center of convergence of force vectors, while maxilla is less influenced by forces www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: - histological difference between maxilla and mandible ; maxilla has more plasticity of response Treatment starts from the distal segments and moves towards the mesial part sectionally ( distomesial sequence)
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ANCHORAGE IN FIXED APPLIANCES: Inverse anchorage equation: C - Dc/2 – R1 = 0 where, C= horizontal distance b/w the vertical line passing through the cusp tip of the upper canine and the vertical line passing through the posterior end of the distal ridge of the lower canine Dc= arch length discrepancy of the mandibular arch, measured from distal of both lower canines R1= amount in mm which the anterior limit of the lower incisors should be moved in the ceph for the correction of a case www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Stages: Maxillary stage: treatment started in the maxilla with posterior leveling, canine retraction, anterior leveling and anterior retraction Mandibular stage: same sequence www.indiandentalacademy.com
Class II Div 1
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Other anchorage reinforcements used: - lingual arch, labial arch and transpalatal arch - extraoral anchorage with Cl III elastics
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ANCHORAGE IN FIXED APPLIANCES: BEGG TECHNIQUE: 1950s by Dr. Begg in Australia Use of vertical slot Use of light forces for tipping teeth Use of optimal forces, so that extra oral forces are not required No anchorage preparation necessary www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Storey and Smith’s experiment on differential forces: 1954 Series of animal experiments Bodily applied force will slow the rate of tooth movement through a bone compared with a tipping force Optimal force concept by Storey: “ There is an optimum range of force which produces maximum amount of tooth movement through bone, and with forces above or below this range there is reduced tooth movement.” www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Experiment using cuspid retraction spring: Free crown tipping retraction of cuspid and bodily movement anchorage resistance by molar and bicuspid
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ANCHORAGE IN FIXED APPLIANCES: Optimal force range for moving canines distally: 150-200 gm. Further increase of force reduced the canine movement till it approached zero Movement of molar unit occurred with force values of 300-500 gm. Therefore, use of light differential forces in Begg technique www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Anchorage considerations in stage I: 1. Sagittal: Upper molar anchorage: - upper Cl I elastics not used - TPA , when using power arms and palatal elastics ( also consolidating the first and second molars)
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ANCHORAGE IN FIXED APPLIANCES: Anchorage considerations in stage I: 1. Sagittal: lower molar anchorage: - stiff lower wire ( 0.018� P or P+) - light (yellow or road runner) elastics - molar stop in case of Cl II and lower Cl I elastics - lip bumper in critical anchorage cases www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Causes of anchorage loss in sagittal direction in stage I: Insufficient resistance from anchor bends due to inadequate anchor bends or use of flexible wires like NiTi and undersize or multilooped SS wire Excessively heavy elastic pull www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES: Causes of anchorage loss in sagittal direction in stage I: Increased resistance from anterior teeth: - incisor and/ or canine roots touching labial cortical plate - abnormal tongue or lip function - overjet reduction before overbite reduction High mandibular plane angle with reduced masticatory forces www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Causes of anchorage loss in vertical direction in stage I: Extrusion of molars due to the anchor bends
Vertical component of Cl II elastics in lower arch www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Resistance to extrusion of upper molars by masticatory forces in normal or low angle cases In high angle cases, reinforcement with TPA kept slightly away from palate High pull headgear Lower molars: light elastics with mild anchor bends; posterior acrylic bite blocks or EVAA appliance Engagement of wire in first and second molars www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Causes of anchorage loss in the transverse direction: Anchor bends and Cl II elastics cause lingual rolling of lower molars Control of anchor loss: Sufficiently stiff wires kept expanded TPA or expanded headgear facebow or lip bumper
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ANCHORAGE IN FIXED APPLIANCES: Anchorage control in stage II: Use of heavy arch wires ( 0.018 or 0.020) to maintain rotational correction, deep bite correction and arch form Also resist distobuccal rotational tendency of molars due to Cl I elastics Mild anchor bends to maintain over bite correction www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Anchorage control in stage II: Anterior anchorage for posterior protraction: - braking springs, - angulated T pins - combination wires with anterior rectangular ribbon mode and posterior round wire - torquing auxiliaries like two spur and four spur or MAA www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Anchorage control in pre stage III: Upper wire: Gable bend for holding the deep bite correction and uprighting distally tipped molars Lower wire: gable and anchor bends Inversion of segments to avoid canine extrusion due to gable bends End of arch wires are bent back to prevent opening of extraction spaces www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Causes of anchorage loss in stage III: Torquing auxiliaries and uprighting springs cause reciprocal reactions in all three planes of space: - lingual root torquing and distal root uprighting: labial crown movements, extrusion of anteriors and intrusion of posteriors, buccal crown movement of posteriors - reverse effects for labial root torquing and mesial root movements www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Control of anchorage in stage III: Minimise need for root movements by: - careful diagnosis and planning of extractions - controlled tipping of incisors - use of brakes Use of heavy base wires ( 0.020 P) Lighter auxiliaries and uprighting springs Light Cl II elastics www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Control of anchorage in stage III: Reinforcement of anchorage: 1. Sagittal: - reverse torquing auxiliary on lower incisors - headgear or TPA on upper molars and lip bumper on lower molars 2. Vertical: - high pull headgear, TPA or posterior bite blocks - molar uprighting springs in case of second premolar and first molar extraction cases www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Control of anchorage in stage III: Reinforcement of anchorage: 3. Transverse: - contraction and toe-in in heavy base wires - TPA or overlay wires - molar torquing auxiliary for buccal root torque www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Differences between conventional Begg and refined Begg: Use of Special grade wire in conventional Begg as opposed to P and P+ and Supreme Use of lighter elastic forces in refined Begg Use of extraoral anchorage and other reinforcements Use of lighter auxiliaries and springs ( 0.009, 0.010, 0.012 as opposed to 0.014 and 0.016) www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: DIFFERENTIAL STRAIGHT ARCH TECHNIQUE: TIP-EDGE Peter Kesling 0.022 by 0.028 slot size with increase to 0.028 Vertical slot for placement of auxiliaries Finishing possible with rectangular wires
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ANCHORAGE IN FIXED APPLIANCES: ANCHORAGE IN FIXED FUNCTIONAL APPLIANCES: Herbst appliance: - partial anchorage: maxilla: first permanent molars and first premolars are banded and connected with a lingual or buccal sectional wire mandible: first premolars are banded and connected with a lingual sectional wire touching anterior teeth www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Partial anchorage
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ANCHORAGE IN FIXED APPLIANCES: - total anchorage: maxilla: labial arch wire attached to brackets on premolars, canines and incisors Mandible: lingual sectional arch wire extended to permanent first molars Bands are replaced by cast splints
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ANCHORAGE IN FIXED APPLIANCES: total anchorage
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ANCHORAGE IN FIXED APPLIANCES: Jasper jumper:
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ANCHORAGE IN FIXED APPLIANCES: Jasper jumper: Preparation of anchorage: - full size arch wires cinched back at the ends; inclusion of second molars - anterior lingual crown torque in lower wire - TPA and lingual arch www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Jasper jumper: Expansion of molar area
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IMPLANTS : Boucher: Implants are alloplastic devices which are surgically inserted into or onto jaw bone. Anchorage source: Orthopedic anchorage: - maxillary expansion - headgear like effects Dental anchorage: - space closure - intrusion ( anterior and posterior) - distalization www.indiandentalacademy.com
IMPLANTS : Implant designs for orthodontic usage: - onplant - mini-implant - impacted titanium post - skeletal anchorage system
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IMPLANTS : Why implants? Limitations of fixed orthodontic therapy: Headgear compliance and safety Reactive forces from dental anchors
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IMPLANTS: Implants for orthopedic anchorage: Maxillary protraction: - Smalley (1988) - insertion of titanium implants into maxilla, zygoma, orbital and occipital bones of monkeys -12-16mm widening of sutures with 5-7mm increase in overjet www.indiandentalacademy.com
IMPLANTS: Implants for skeletal expansion: -Guyman (1980) intentionally ankylosed maxillary permanent lateral incisors of monkeys No movement of laterals during expansion
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IMPLANTS: Parr, Roberts, et al (1997): Midnasal expansion using endosseous titanium screws; Rabbit study Stability of implants seen for 1N and 3N loading
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IMPLANTS : Implants for intrusion of teeth: Creekmore ( 1983) Vitallium implant for anchorage while intruding upper anterior teeth 6mm intrusion with 25degrees torque www.indiandentalacademy.com
IMPLANTS : Southard (1995) Comparison of intrusion potential of titanium implants and that of teeth Titanium implants placed in extracted 4th premolar area of dogs Intrusive force = 60gms www.indiandentalacademy.com
IMPLANTS : Implants for space closure: Linkow ( 1970): implanto-orthodontics
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IMPLANTS :
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IMPLANTS : Implants for space closure: Eugene Roberts: use of retromolar implants for anchorage Size of implant: 3.8mm width and 6.9mm length 0.019 x 0.025 TMA wire from premolar to retromolar implant to prevent distal movement of premolar www.indiandentalacademy.com
IMPLANTS :
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IMPLANTS : Other implant designs: Onplant: Block and Hoffman (1995) “an absolute anchorage device� Titanium disc- coated with hydroxyapatite on one side and threaded hole on the other Inserted subperiosteally
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IMPLANTS : Impacted titanium posts: Bousquet and Mauran (1996) Post impacted between upper right first molar and second premolar extraction space on labial surface of alveolar process Perpendicular to bone surface www.indiandentalacademy.com
Molar connected to implant with 0.040 ss wire www.indiandentalacademy.com
IMPLANTS : Mini-implant: Ryuzo Kanomi ( 1997) Small titanium screws 1.2mm diameter and 6mm length Initially used for incisor intrusion 6mm intrusion of mandibular incisors www.indiandentalacademy.com
Incisor intrusion:
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Incisor intrusion
Cuspid retraction
Molar intrusion www.indiandentalacademy.com
IMPLANTS : Skeletal anchorage system (SAS): Sugawara and Umemori (1999) Titanium miniplates Placement in key ridge for upper molar and ramus for lower molar intrusion Uses: - molar intrusion - Molar intrusion and distalisation - Incisor intrusion - Molar protraction - Molar extrusion www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Zygoma ligatures: Melsen et al JCO ’98 Anchorage for intrusion and retraction of maxillary incisors in partially edentulous patients Horizontal bony canal drilled 1cm lateral to alveolar process with entrance and exit holes in superior portion of infrazygomatic crest Double twisted 0.012 ligature wire inserted through the canal www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES:
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ANCHORAGE IN FIXED APPLIANCES: Methods of anchorage conservation: Transpalatal arch: Introduced by Goshgarian 0.036 SS wire Anchorage reinforcement Other uses: distalization, rotation, torque, expansion or contraction, vertical control www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Burstone : ( JCO ’88-’89) use of 0.032 by 0.032 SS or TMA in transpalatal arches depending on the passive or active
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ANCHORAGE IN FIXED APPLIANCES: Lip bumper: Alters equilibrium b/w cheeks, lips and tongue Transmits forces from perioral muscles to the lower molars Can be used for distalization of molars Attachment of Cl III elastics www.indiandentalacademy.com
ANCHORAGE IN FIXED APPLIANCES: Lingual arch: Introduced by Hotz 0.036 SS wire Loops mesial to the lower molars Prevents mesial migration of molars Can be used for gaining arch length Springs soldered to lingual arches for premolar movements www.indiandentalacademy.com
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