BEGGS' TECHNIQUE (STAGE I, II & III)
Beggs' appliance elaboration with pcture...
BEGG’S APPLIANCE Introduced by Dr. PR Begg in 1950. It is based on light wire differential force technique. The Begg technique has been divided into three stages. From a categorical standpoint the treatment is divided into the crown tipping phase which includes the first two stages and the root tipping phase which covers the third phase. From a clinical standpoint, the three phases are characterized by the specific treatment objectives and tooth movements. Stage I:
(Usually 4 to 8 months)
Objectives: Closure of Anterior spaces. Correction of crowding. Overcorrection of rotation of anterior teeth. Overcorrection of Overjet to an edge to edge incisor relation. Overcorrection of Overbite to an edge to edge incisor relation. Correction of Cross bites. Correction of molar relation. Overcorrection of disto-occlusion of the buccal segments. Correction of midline discrepancies. Correction of axial inclination of mandibular incisors.
Characteristic anterior tooth movements in stage I Labiolingual movements as required for alignment on the anterior curve of the archwire. Over rotating - To positions that are reverse of the original rotation.
Creating space for overlapped teeth or closing spaces as required, so that the incisors and cuspid of each dental arch are placed and maintained in a single segment of six anterior teeth. Intruding the anterior teeth for correction of overbite, all 12 teeth should be intruded evenly. Retracting anterior teeth for correction of overjet and for placing them in a slightly lingual inclination. Proper retraction means that the central incisor crowns tip lingually, lateral incisor crowns tip lingually and distally, and cuspid crowns tip distally.
Characteristic posterior teeth movement The anchor molars are maintained in upright positions throughout treatment. Specifically, mesially inclined molars are overcorrected to mild distal inclinations and distally inclined molars are maintained in mild distal inclinations. These positions are most efficient for molar anchorage requirements. Molar rotations are corrected. Mesiolingual rotations are corrected to mild mesiobuccal rotation and mesiobuccal rotations are maintained as such. Cross bite relationships are overcorrected. Chracteristic archwires and elastics in the first stage Plain or looped archwires. Looped archwires are replaced as soon as possible. In class I and class II cases, class II elastics are used. In class III, class III elastics are used. Bracket Placement: It may be bandable (welded to the bands which are then cemented to individual tooth) or bondable. They have single vertical slot which faces gingivally. Brackets are centered mesio-distally on the labial or buccal surface with the base of the arch wire slot 4mm from the incisal edge of cusp tips.
Upper arch – Central incisor – 4 mm. Lateral incisor – 3.5 mm. Cuspid – 4.5 mm.
Bicuspid – 4 mm.
Lower arch – Central incisor – 3.5 mm. Lateral incisor – 3.5 mm. Cuspid – 4 mm. Bicuspid – 4 mm.
Lingual Button: It is placed directly opposite to the areas of engagement of the archwire on the opposite side of the teeth. This is to permit free mesio distal tipping or uprighting of the teeth. If the lingual button is placed incisal or occlusal to the level of base of arch wire the steel ligature would be loosen or tighten during mesio-distal uprighting.
Buccal Tube: Molar tubes should be parallel to the occlusal surface when viewed from buccal and parallel with a line bisecting the occlusal surface mesio-distally.
Arch wire: Different diameters of wire are available but the most commonly used one is 0.016” wire. 0.016” special plus
- Looped arch wire in any case.
0.016” special plus extracted.
- Plain arch wire in extraction cases or in which 1st and 2nd premolars are
- Plain arch wire in molar extraction cases.
Initial Arch wire: The basic shape of the initial archwire depends upon the shape of malocclusion and although it is similar it is seldom identical. The archwire shape is proportional to the width, the form and symmetry of dental arch. There may be localized modifications of archwire in the vertical and horizontal plane and these are called Offset bends.
Offset bends: In Anterior segment Vertical offset
- To Intrude or Extrude
- To Expand, contract and rotate
In posterior segment Gingival offset
- to avoid occlusal distortion and interference with bicuspids
Cuspid offset bend (canine curve) : The labiolingual width of the cuspid is greater than that of the lateral when measured at bracket level. To avoid lingual tipping of the cuspid and labial tipping of the lateral a horizontal offset bend is given distal to the intermaxillary hook. It is usually called the cuspid offset bend, however it provides for proper positioning of both lateral and canine.
Shape of Anterior segment: The anterior curve of the initial arch wire is usually a compromise between the shape of the malocclusion and that of normal occlusion. E.g.: If anterior segment is narrow and protrusive the arch wire is made slightly broader in the cuspid region and flatter opposite to central incisors.
Dental Arch Width And Archwire Width Since there is a tendency for the anchor molars to contract and tip lingually during the first stage of treatment, hence the archwire should be made greater than the dental arch width this is called expansion for prevention. In considering the initial archwire for a bicuspid extraction case 1. If the dental arch width is satisfactory, the wire should be made 2-3mm wider at each cuspid and 8-10 mm at the molar region. 2. If the dental arch requires expansion, the arch wire should be made 4-6mmwider at the cuspid and 15-25mm at the anchor molar. 3. If a bilateral cross bite is present the archwire is made 25-40 mm wider at the side where cross bite is present. The widths given above are for first bicuspid extraction cases and they should be decreased for second bicspid and molar extraction cases. Although archwire variations are essential for correcting cross bite, they cannot do so without cross bite elastics that exert six to eight times more force than archwire
Intermaxillary Hooks: Routinely bent into the arch wire for both the upper and lower arches and are positioned 1mm mesial to the cuspid brackets. The coil Pattern is usually a small helical loop 2 to 2.5mm of outside diameter. The helical Intermaxillary hook two primary and two secondary advantagesArchwire is stiffer and aids in overbite correction. Wire is stiffer in horizontal plane and aids in correction of arch form, width and symmetry.
Helical loops can be formed quickly
Helical hook is seldom distorted or broken
If Boot shaped loops are used they are angulated buccally away the vertical in order to avoid any possibility if wedging of distal arm of loop into slot.
Variation in the location of intermaxillary hooks The location of the intermaxillary hook varies with the type of archwire being used (looped or plain) and the malocclusion. When plain archwires are used alongwith anteriors in good alignment the hooks are 1-2mm mesial to the cuspid bracket. If slight space is required for the alignment of the anteriors, the hooks are placed against the mesial side of the cuspid bracket. After the anteriors have been aligned the hooks will be 2-3 mm mesial to the bracket on either side. If anterior spacing is present the hooks should be placed in such a way that after the spaces are closed the hooks are 1-2 mm mesial to the cuspid bracket. When looped archwires are placed the hooks are placed right at the mesial surface of the cuspid bracket.
Vertical Loops: Used to supply local increased arch flexibility or used for space opening or closing, stops, rotation or root torque. The most vertical loops to align six anterior teeth are five, one in each interproximal area. Generally loops are made 6 to 8mm long but greater the length of the loop, the more gentle the force on the tooth. The Loop between the maxillary central incisors should be avoided, when indicated the loop is made shorter because
-To avoid irritation to the labial frenum. -Loop in midline causes arch wire to assume “V” shape when contracted by placement in the molar tube
Horizontal bracket area for severly lingually placed tooth is bent 1mm further gingivally than plane of arch wire to prevent elongation of tooth as it tips labially
Contraction Loop in midline with incisor stops to tip crowns of upper centrals
Vertical loops bent in case of high frenum attachment
MOLAR STOPS Molar stops are placed on the archwire in order to limit the extent to which the wire can slide into the molar tube. They are not used expect when it is necessary to preserve space. Molar stops may be bent into the archwire or may consist of removable lock placed on it.
Double back archwire Flat oval molar tubes and double back archwires are used when second permanent molars are the anchor teeth; second permanent molars require more arch wire support than first molars. Archwires with double back ends and flat molar oval tubes are also used on mandibular dental arch when lower second premolars are absent because archwire spanning the space between the first premolars and first molars are likely to be bent by patients when they are masticating food. Flat oval tubes are better for double back archwire, because double back round archwires fit more accurately into flat oval tubes.
Molar anchorage bends: The anchorage bend, formerly called the tip back bend is a bend whose vertex faces occlusally. Placed immediately posterior to the 2nd premolar bracket Bent opposite so that when inserted into the buccal tubes the anterior section of the archwire lies in the buccal sulci Amount of bend varies from case to case Greater force tend to eventually cause lingual rolling and distal tilting of molars Increase of excessive leverage the mesial marginal ridge of the molars are is seen to raise above the occlusal level
the purpose of anchor bend in upper arch is to prevent mesial migration of the molars; In lower is to supply bodily control of the lower molars as these are moved forward by action of Class II elastics
Anchorage bend opposite to molar premolar contact point
Labial portion lying in buccal sulci.
The degree of anchor bend is influenced by the following factors The stage of treatment- the anchor bend is usually greater in the first stage than for second stage and little if any for the third stage The depth of overbite- the degree of anchor bend in the initial archwire should be such that the archwire lies passively at the mucobuccal fold when the wire is inserted into the buccal tubes The location of extraction space- greater for 2nd bicuspid than for first bicuspid. Inclination of the anchor molar- if one or both the molars are inclined then the anchor bend should be reduced so that the wire will rest evenly and passively in the mucobuccal fold The hazard of occlusal impingement The type of archwire used –in looped archwire it is placed far enough forward so that this bend does not slide back into the buccal tube before the looped archwire is discarded.
Commonly used passively to retain overrotation brought about via previously looped arch. It is inadvisable to use bayonet bends for active correction, because of the tendency for round archwire to rotate within bracket slots causing the bayonet bend to become ineffective or supply movement in wrong plane They should be small and offset section is 5 degrees to the line of main arch.
Use of Lock pins and ligation on arch wires: The pins used in the opening stages of treatment should be super safety lock design and safety lock pin in the second stage which will automatically obviate friction between pinhead and archwire. In the Stage I of treatment of Class II all the teeth are pinned except The second premolars Teeth initially so far displaced Upper laterals which are lingual to centrals Rotated buccal teeth.
CANINE TIE They are steel ligature ties (0.008-0.009 inch) from the intermaxillary hook to the canine bracket. If there are no restraints between the intermaxillary hook and the cuspid bracket the cuspid will continue to tip distally away from the lateral. In order to prevent this and to maintain and move the six anterior teeth as a unit the canine ties are given.
ELASTICS Elastics are used to effect changes in the length, depth and breadth of the dental arches. All anteroposterior tooth movements, including anterior retraction, mesial molar movements, correction of class II or class III occlusion and closure of spaces are entirely due to elastics. In extraction cases, the class II, horizontal, vertical and crossbite elastics average 2-4 ounces (57-113 ) gm In non extraction cases the class II and horizontal elastics average 1 ½ -2 ½ ounces (4271) grams Larger diameter elastics exert lighter force and smaller diameter exert heavier force Reactivation cycle The natural rubber Begg elastics used in the early 1960’s exerted 5-8 ounces (142-227) gms and the elastic force was reactivated in four day cycle. Currently, latex elastics are preferred that exert much lower force initially but show less drop off over a 24 hour span. Placement of Elastics: It is impossible for the arch wire to function properly without the proper elastics. In order to determine the size of the elastics the tension gauge is used. The Class II elastics are engaged around the distal ends of the molar tubes or molar hooks and stretched anteriorly to engage the maxillary Intermaxillary hook mesial to the maxillary cuspid. In Class III elastics are worn from the maxillary molars to the intermaxillary hook mesial to the mandibular cuspid bracket. No horizontal (intramaxillary) elastics are applied during stage I.
Class II elastics pulling 2 to 3 ounce at the beginning
Class III elastics
Horizontal (intramaxillary) elastic
Check list for stage I: Check for desired movements Overbite and over jet improvement Anterior alignment progressing Dental arch width particularly the molar width Dental arch form being maintained
Antero - posterior relation of cuspids and molars being maintained Individual molar positions being maintained
Check for undesired movements or manifestations Failure to wear elastics at all times Poor hygiene Vertical loops impinging on tooth or tissues Arch wire distortion contraction or expansion of arch width
Stage II: (usually 1 to 4 months) Maintenance of all anterior and posterior overcorrection achieved in stage I Completion of extraction space closure 1. By continuing retraction of anterior teeth 2. Correction of premolar rotations Completion of correction of midline discrepancies Continued correction of Open Bite
Arch wire: The Archwire pattern is basically that of Stage I treatment 0.016” gauge of wire is used 0.018” is used when there is frequent arch wire distortions or unilateral space closure Anchor bend is made 1mm mesial to the molar, premolar contact point. The pressure supplied by the anchor bends to the molars and incisors is slightly reduced from that employed during Stage I. Because Intermaxillary elastics tend to rotate molars slight toe in bends are made in the molar areas to prevent molar rotation. Intermaxillary hooks are incorporated in both archwire immediately mesial to the cuspid brackets and in contact or very near contact with them.
The hooks in upper arch have to bear two elastics which is somewhat difficult for ring pattern. A ‘Z’ shaped hook makes it easier for the patient to apply two rubbers to the hook.
The 2nd premolar is bypassed from pinning as in Stage I, The wire is held in position by bypass clamp or steel ligature.
The bypass clamp in position of the bracket in premolar
Slight horizontal offsets are formed distal to canines to maintain correct buccolingual position of the premolars and canines-they are the premolar offsets
TOE IN AND TOE OUT BENDS They are horizontal offset bends that are often combined with the anchor bends If the wire is bent lingually it is a toe in bend and if it is bent buccally it is a toe out bend Functions Corrective for rotation of molars when required. After insertion, the toein or toe-out bend exerts light force so that the molar tends to rotate and the wire and the tube gradually become parallel. Preventive- preventing the rotation of molars due to elastic force. Passive- to prevent the rotation of anchor molars already in normal alignment.
Inter & Intramaxillary elastics: Lateral Cephalogram is taken and from cephalometric evaluation it is determined whether the anteriors are to be retracted or posteriors are moved for closure of space. The Space – closing elastic ( esp. the maxillary) stretching from the Intermaxillary hook to the molar hook against molar lies against the gingiva and irritates the gingiva, to overcome this elastic is twisted one half turn when it is placed Wearing of horizontal elastics tries to rotate the molars distobuccally and this should be counteracted by the toe – in bends of the arch wire. If rotation aggravates after giving toe in bends the elastics can be engaged on the lingual hooks. Care should be taken of the second premolar so it doesn’t tip when elastic crosses it occlusally.
Correction of Midline discrepancy: Midline must be determined by reference to the center of face, whether the discrepancy is confined to one arch or in both If one arch is involved shifts more than 2mm is major; less than 2mm is a minor problem. The application of intramaxillary elastic will complete closure on the side to which midline is shifted; The intramaxillary elastic on the side which closes first can be discontinued Minor discrepancies are self correcting
Diagonal elastics for correction of midline in both the arches
Correction by movement of individual units or small group after distal tipping of canine Auxiliaries in stage II: The auxiliaries used are passive mesio distal root uprighting springs on the mandibular canines and the lower anterior braking arches. The function of these types of auxiliaries is to establish two point contact between teeth and archwire and prevent free tipping movement of the anteriors.
Lower braking auxiliary on the four anteriors
Changes observed at the end of stage II All extraction spaces are closed The crowns of the upper and lower anteriors are tipped back further than the first stage The anteroposterior occlusal relations attained in the first stage are maintained The overcorrections of rotations done in the first stage are maintained
Check list for stage II: Check the teeth and appliances before treatment progress for
Loosened bands Loosened brackets Patient co-operation in elastic wearing Compare the positions of the teeth on the second stage model with those in mouth Check for desired movements Check for undesired movements or manifestations such as
Failure to wear elastics at all times
Poor oral hygiene
Arch wire projecting out and causing impingement, Contraction or expansion of the arch
Asymmetry of dental arch
Molars rotating mesiolingually due to use of single elastic on the buccal
Anterior class III relation developing
Excessive anterior open bite
Anchorage bend coming into close proximity
Teeth Position at the Start of stage III
“Tipping back” or “Dishing in” of the six upper and lower anterior teeth is most favorable state of affair as far as the success of the final result of treatment is concerned.
STAGE III OBJECTIVES: 1. Maintain all corrections achieved during first and second stages. 2. Achieve desired axial inclinations of all teeth. - Posterior spaces kept closed by bending the distal ends of the arch wires around the buccal tubes. - Arch form and overbite corrections maintained by using heavier (0.018 to 0.025) main arch wires. - Changes in the mesiodistal inclinations of teeth are accomplished by the use of individual root – tipping springs. - Lingual or labial root torque is applied to anterior teeth through the application of torqueing auxiliaries.
STAGE THREE UPPER ARCH WIRE
Made by 0.20 s.s
Constricted in distal ends to counteract the widening effect of max torqueing auxillary.
Gingival bend distal to cuspid bracket to counteract the occlusal vectors of force created by anterior lingual root torqueing auxillary.
STAGE III LOWER ARCH WIRE
Made by 0.20 round s.s.
Expansion in distal to combat tendency of molars to tip lingually from wearing class II elastics.
Molar offset bend
Mild anchor bend maintained
Mild bend distal to canine bracket to reduce any tendency for recurrence of an anterior overbite
Slight vertical step in the anchor bend area.
AUXILIARIES USED IN STAGE III UPRIGHTING SPRING:
Used to correct the axial angulation of teeth in mesio – distal direction.
Upper and lower canines and premolars- 0.016 inch with two coil
Upper lateral 0.014 inch with two coil
Lower lateral- 0.014 with three coils
Helix of spring face towards tooth surface and lie on the gingival aspect of arch wire.
TYPES OF UPRIGHTING SPRING
A combination safety lock pin and uprighting spring that eliminates the need for ligating the arch wire to the bracket. Locked in place by bending the tail of the spring around the body of bracket.
Available as two coil and three coil from .014
PLAIN UPRIGHTING SPRING
Made of 0.014 for uprighting canine and premolars, 0.012 for incisors.
The angulation of the active arm and retentive arm is 135 degree.
The helix with retentive arm should face the tooth surface.
The base arch wire is ligated, otherwise the action of uprighting spring will extrude the tooth.
Made of thinner diameter (0.009) high resilient supreme grade wire.
The coil of springs is only twice the size of the wire.
The activation is 100%, the stem and active arm are in one line.
TORQUING AUXILLARY Torques the root of the maxillary incisors lingually
FOUR SPUR TORQUEING AUXILLARY
Most popularly used for torqueing the upper anterior teeth palatally
The constricted arch form of the auxillary counteracts reciprocal forces applied to the arch wire when the auxillary is engaged ,which tend to widen the dental arch
0.016 or 0.014 inch diameter wire used
Preformed available TWO SPUR TORQUEING AUXILLARY
Used when lateral incisors do not require palatal root torque, as in extraction cases when upper laterals were displaced slightly palatally.
RECIPROCAL TORQUEING AUXILIARY -
Indicated when the upper lateral incisors were blocked out palatally before treatment. Their root apices must be torqued labially to reduce the tendency for the crowns to relapse lingually.
Lever arms on laterals pass incisally for labial root torque.
SHORT FOUR – SPUR TORQUEING AUXILIARY
Indicated for torqueing of upper anteriors.
Does not engage cuspid bracket
Easy to fabricate.
REVERSE TORQUEING AUXILIARY
Indicated if lower anterior teeth are becoming too proclined.
Acts as a source of intra oral mandibular anchorage to inhibit forward movement of mandibular dental arch.
ONE TO ONE TORQUEING AUXILIARY
Indicated when two adjacent teeth require root torque in opposite directions.
Tends to deliver excessive force therefore degree of activation between lever arms should be low
PROBLEMS ENCOUNTERED DURING STAGE III Maxillary Molars Widening: a. Anchor bends present in maxillary arch wire.
b.Too much bite – opening bend between cuspid and bicuspid c. maxillary arch wire too small in diameter. d. Maxillary arch wire too wide. e. Torqueing auxillary not constricted adequately. Mandibular molars narrowing a. Lower arch wire not wide enough b. class II elastics exerting too much force c presence of steel ligature tie from the lingual of the mandibular cuspid to the lingual of the mandibular molar d. lack of support through occlusion of molars- use cross elastics, check symmetry of both arch wires Anterior bite deepening: a. Too much power in the torqueing auxillary b. Maxillary arch wire too thin. c. Patient not wearing class II elastic Teeth not uprighting mesiodistally: A. springs not active B. Arch wire caught on the edge of the bracket - Tighten spring – pin to draw arch wire in bracket - Draw arch wire into bracket with a steel ligature tie C. Occlusal interference caused by an elevated tooth. - reposition the bracket. D. Springs placed in backwards Maxillary anterior teeth not torqueing palatally 1. Not enough force from maxillary torqueing auxiliary 2. Maxillary incisal edges caught lingual to lower anterior teeth
Lower anterior teeth labially inclined Normal mesial migration of teeth during third stage. If in middle of third stage give reverse torquing auxillaries Rotation of teeth other than molars 1. Lack of complete bracket engagement 2. Arch wire slot too large. Improper bracket placement Positions of teeth at the end of stage III End of Stage III with perfect parallelism of canine and premolar roots.