General considerations of Stage II in Begg Technique.
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Introduction Objective of ortho trt is to correct malocclusion of teeth and those deformities of the jaws and face associated with it . 1954 Dr. Begg published – “Stone Age Man’s Dentition” – “Round wire Technique”. This later evolved into the light wire technique. www.indiandentalacademy.com
Changes. Finished cases with detail and precision. 3 distinct stages. Root torquing auxiliaries Mesiodistal uprighting springs. Emphasised imp. Of free tipping. Stage models. www.indiandentalacademy.com
Second Stage of Trt. Complete closure of what still remains of the extraction spaces – carried out. Space closure carried out - elastics www.indiandentalacademy.com
Objectives Of Second Stage. 1. Maintain all corrections achieved during first stage. M-D molar relationship maintained – Cl II or Cl III elastics. Original spaces b/w ant. teeth prevented from recurring – tying IM circles to cuspid brackets www.indiandentalacademy.com
Over rotations of cuspids maintained – engaging
brackets – offset on the teeth. of bicuspids held – replacing elastic threads with steel ligature ties.
of Central and lateral incisors – maintained – continued use of bayonet bends in the archwires. www.indiandentalacademy.com
Bite opening maintained – continued use of bite opening bends & Cl II or Cl III elastics. Correction of post. Crossbite maintained – modifying archwire or cross elastics.
2. Close any remaining post. spaces. Wearing of horizontal elastics.
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Malocclusion of 2nd stage – not same as at the beginning of trt. Most malocclusions – similar appearance – conclusion of first stage mechanics. Edge to edge or mild open bite reln. Spaces b/w cuspids & 2nd bicuspids. Class II Class I or Class III. Class III mild Class II www.indiandentalacademy.com
Class II elastics – relieved of correcting overjet. used to attain or maintain overcorrected positions of ant. & post. teeth.
Molars – relieved of correcting overbite. if necessary anchorage bend www.indiandentalacademy.com
Reasons for a second stage of treatment. Prevent posterior teeth from being moved too far mesially. Insufficient space to move ant. teeth back onto basal bone upper & lower dental arches – too far anteriorly in the jaws BMP. Anchorage failure does not occur – 1 st stage www.indiandentalacademy.com
completed before 2nd stage.
Commencement of stage II – Lateral ceph & stage models. Intraoral photographs.
Lateral Ceph. compared with that of original M.O
antero posterior tooth movements in ref to each other & to face & cranium. anchorage maintained properly. inclination of the anterior teeth. www.indiandentalacademy.com
Importance of stage models.
Check arch contour and width. Inclination of upper and lower anterior teeth.
Self discipline to complete each stage before proceeding. www.indiandentalacademy.com
Following through to overcorrections in trt. – rotations, overbite corrections
and mesio-distal relns.
Better insight how anchorage – maintained in trt.
Better conception of how the technique progresses.
Visual aid for the patient and parents. www.indiandentalacademy.com
ď ŹElastics Used to effect changes in length, breadth and depth of dental arches. Elastic force should signify measured force for the individual patient. Elastic – exert only traction force. www.indiandentalacademy.com
Size of elastics – dist . stretched. Large dia molar extn. cases. Small Class II elastics Bicuspid extn.(small teeth). Smaller horizontal elastics later 2nd stage.
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Reactivation cycles. Natural rubber Begg elastics (1960’s) – 5 – 8Oz force on insertion, in two days, constant at 2 Oz – next 2 days – Elastic force reactivated in 4 days. Latex elastics – lower force initially, less wear off over 24 hr span, Elastic force reactivated daily
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ď Ź Space closing elastics – horizontal or intramaxillary elastics.
Necessary to maintain anteroposterior relation of buccal teeth & edge to edge to relation of incisors - Cl II intermaxillary elastics. Six elastics worn simultaneously. www.indiandentalacademy.com
Problems encountered with elastic wear.
Space closing elastic – irritating the gingiva Seat it occlusally to the PM bracket b/w ligature wire & band.
Horizontal elastic from buccal surface of molars – rotational force. Distal ends – toe in ( more in maxillary than mandibular.) Horizontal elastics – engaged on lingual hooks rather than on buccal.www.indiandentalacademy.com
Lingual elastics. Used as a supplement or a counterbalancing agent to buccal elastic force - efficiency of force distribution. Help in obtaining desired movements and preventing or arresting undesired movements of teeth – until needed archwire changes are made. Can be used for retraction of ant. segment. Half strength horizontal elastics – on both buccal and lingual surfaces.
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Advantages in using half strength elastics. Better positional control over the anchor molar – obviating the need for a mandatory compensatory ‘toe in’. Closure of extn spaces easier. Improves anchorage potentialof molar – simpler mechanics. Additional adaptational demands on patient’s tongue Greater patient co-operation – elastic wear. www.indiandentalacademy.com
Archwires. Initially 0.018 inch archwire used. Trt. Proceeds smoothly – 0.020” arch wires used. Only function – to maintain the corrections – achieved. ( bite opening, arch form & tooth alignment.) Stabilize the teeth against – adv. Reciprocal forces – application of elastics or auxiliaries.
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Anchorage bend.
in comparison with that given – 0.018” wire.
Variation in location. Stage of trt. – 2nd stage. Far enough forward – spaces close before anchorage bends reaches molar tube.
Rate of progress & amount of space remaining. If rapid – bends placed farther forwards Little space – tooth contact before anchorage bend reaches molar tube. www.indiandentalacademy.com
Inserting and activating archwires. Insert and check. Degree of anchorage bend – adequate to resist forward pull of elastics. rest passively – halfway b/w brackets & mucolabial fold. Distal ends of the archwires – 1 – 2 mm beyond the distal end of the tubes. Anchorage bends sufficiently forward - too far or too less.
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Tooth movements carried out during the second stage of trt. Spaces in the buccal segment to be closed. Extn. Space of four first premolars. Congenital absence of 2nd P.M. Lost buccal teeth due to caries. Spaces b/w teeth in Non-Extn cases.
Exception. Extreme tooth spacing – small tooth size. www.indiandentalacademy.com
Closure of spaces by retracting upper and lower incisors OR moving post. segments mesially to lose anchorage. Decision depends on Torquing requirements anticipated in 3rd stage, apical base diff. Profile requirements of the patient. www.indiandentalacademy.com
Large apical base diff. at start of trt. – lingual root torque in third stage - SNA. Upper and lower incisors tipped lingually with horizontal elastics. Profile good at start – small ANB diff. – spaces closed moving post segments mesially- to avoid flattening of profile. Stronger elastics One point contact bracket of cuspid 2 point contact – passive uprighting spring. www.indiandentalacademy.com
Correction of midline discrepancies. Usually corrected in stage I with Class II elastics. Horizontal elastics in Stage II – diff. in amnt. of extn. space remaining – corrected. Severe discrepancies – anterior intermaxillary cross elastics. www.indiandentalacademy.com
Corrective movements of bicuspids – performed easily and quickly tight intercuspation of bicuspids prior to trt. Due to correction of overjet and overbite.
Note existing rotational status of molars & cuspids Horizontal elastic – buccal or lingual as necessary. No rotation – half strength horizontal elasticsbuccal & lingual. www.indiandentalacademy.com
Braking mechanics. spaces to be closed by mesial movement of the posteriors.
C &B.C
one point contact bracket of cuspids 2 point contact bracket. braking type paralleling auxiliary on cuspids. Aux: - usually a passive spring – arm and stem at an angle of 120°. ( 0.018 or 0.020” wire)
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LI
passive
Passive spring – misconception – enough force to hold – cuspid upright. Pin incisors tightly – intentional binding of archwire – limit tipping. Extreme cases – torque arch aux. Heavier elastic forces – 4-6 Oz. (113 – 170 gm). www.indiandentalacademy.com
Engaging bicuspid with caution. Bracket too far gingivally – extrusion of this tooth and intrusion of the anchor molar & cuspid. Absence of bayonet bends – bicuspid overexpansion and molar overcontraction. Bicuspids – not to be pinned in until archwire changes are made at the commencement of the third stage. www.indiandentalacademy.com
Shortening of doubled back archwires. Straight back archwires – cut distally. For shortening doubled back archwire & to reposition its anchor bend – small vertical take up loops in the buccal sections of the archwire. 1st made distal to the cuspid bracket. just mesial to the anchor bend www.indiandentalacademy.com
Teeth positions at the end of Stage II. Extraction spaces – closed. Anteroposterior occlusal relations – maintained. crowns of upper and lower ant. teeth – tipped back or ‘dished in’ - most favorable state – in success of trt. evidence- upper & lower dental arches – not brought anteriorly. www.indiandentalacademy.com
Crowns of CI
tipped back lingually.
Crowns of LI
tipped lingually & distally, root apices farther mesial than crown.
Crowns of Caninetipped distally not lingually
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Summary Started after achieving stage I objectives. Maintain all corrections achieved – A-P occlusal relations. Overjet & overbite.
Major tooth movement – space closure in post.buccal segments. Achieved – elastics – Intramaxillary – space closure. Intermaxillary – maintanence. www.indiandentalacademy.com
Archwire – 0.020” base wire – maintain corrections. Closure of spaces – Retraction of ant. Mesial movement of molars.
End of stage II. Completed closure of spaces. Maintanence of corrections achieved in stage I www.indiandentalacademy.com
Conclusion ď ą Through the use of the optimum orthodontic force ie, one that moves the teeth most rapidly, with least discomfort to the patient and with least damage to the teeth and their investing tissues, effective space closure is achieved with minimum taxation of anchorage. ď ą Teeth are left in the proper position to be uprighted and put into good axial relation in the third stage. www.indiandentalacademy.com
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