Problem shooting /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


Problem Shooting
in
Begg
&
its Management



Begg technique – Unique Approach



Dominating specialty since it’s introduction
 Simplicity
 Versatility
 Modifiability
 Affordability
 Ability to resolve serious MO



However Begg appliance is not without any
problems.



A thorough knowledge of
 Basic mechanics involved
 Manifestations of various problems
 Causes
 Remedies

highly essential for succ.
completion of each and every case.

Problem Encountered During Begg Trt.
Problems can occur in any stage or can either
be
 Poor tissue response
 Lack of patient cooperation
 Poor mechanics
Identification of problem is imp. for
producing successful results.

Extra dia. aids – valuable in analyzing trt.
results
A large mirror can reflect occ. surface of
either arch , Sym.
 A tongue blade or base plate sheet for
checking defi. in level of ind. teeth
 Study models
 Caliper or various gauges

Stage I (Objectives)
Vertical plane
Opening of ant. overbite (closure in ob)
A-p plane
 Overcorrect md relationship of buccal segment
 Proper overjet relationship
Transverse plane
 Correction of existing cross bite & Mid line deviation
Individual tooth abnormalities
 Correction of spacing & crowding
 Overcorrection of rotation

Problems encountered during first stage and
their remedies.
1.Bite not opening.
 Poor elastic cooperation.
 Educate patient and the parents.
 Lack of co-operation can be discovered
 Purposely not providing enough elastics
 Making it impossible for patient to hook
elastics
 Discovering the patient without elastics on

school or other places

Orthodontist has responsibility in seeking pt.
cooperation with elastics
 Should be worn conti. except brushing
Instruct patient carefully where to attach elastics,
after inst., have him place E himself
 Make sure patient can place elastic easily &
remain in place without slipping off & undue
breakage
 Caution the patient not to allow lower jaw to
come forward in response to pulling forces

exerted by class II elastics

 Patient biting out bite opening bends.
 Remove aw, restore bite opening bends.
 Check eating habits.
 Lower the level of mandibular molar tubes.
 Move the anchor bends closer to the molar
tubes

 Over retention of looped archwire
 Replace looped AW with plain AW as soon
as possible

Inadequate anchor bend force
 Remove AW, place proper AB
 Use stiffer 0.018” pr +p.s wire with adeq. AB

 ↓of AB force by toein bend or buccal
offset bend
 MD tubes should be at proper position (toein bend tends to rotate in tube  vertex of
AB displaced buccally & vertical force 

Anchor molars out of occlusion.
 Vertical elastics from U-m to L-m.
 Horizontal elastics from most pos. place molar
 molar mesially  occ.

 Poor quality AW or that has become weaker
 Use stiffer 0.018” pr +p.s wire with adeq. AB

 Loose molar band.
 Readapt and recement (same band if fit
proper) band.

 Improper angulation of buccal tube or
entire molar band.
 Remove molar band, correct angulation
(tube II to occ.& buccal surface of molar)


 A W binding due to bicuspid ligature or
clamp which is too tight
 Make sure PM are not ligated tightly

 Binding & friction among anterior teeth
due to pinning or ligating too tightly
 make sure pins or ligatures are loose
enough


 Use of elastics that are too loose
 Exert insufficient retraction force to keep lin.
surface of U-I in contact with incisal edge
of L-I stepping up process is weak
 Assure class II force is adequate

 Use of elastics that are too tight
 Mesial tipping of lower molars (if AB force
inadequate)
 Assure class II force is adequate

 Binding of archwire in tube
 If wire does not extend through distal of tube,
may catch on inside wall & gouge sufficiently
 ant. teeth forward & excessive distal
tipping of molars. The end of wire can move
forward not backward when forces are released
”Ratchet & Pawl” or ‘Trammel” effects
 Replace with longer arch wire
 Bend distal end of wire


 Grinding & clenching
 Palpate teeth for undue mobility
 Depress molar with blunt instrument, for sign
of loosening or extrusion pumping of molar or
trumpet valve effect for their tendency to rise
again after depressed.
Reciprocal movement reflects influ. of
excessive class II force & clenching.
 Prescribe sugar less gum
 Patient education ”keep lips together &
teeth apart”


 Excessive force due to habitual biting of
lip & tongue
 Prevents retraction U-ant. teeth stepping
up process
 Patient education

 Patients habit of holding jaw forward in class
I
 To ↓ discomfort & self cons. about facial esth.
 Caution the patient not to allow lower jaw to
come forward in response to pulling forces
exerted by class II elastics

2. Molar width narrowing (usually L – M)
 Vertical component of Class II elastic
 Considerable AW expansion in molar region.
 Expansion auxiliary in 0.018 SS.

 Prolonged wearing of cross elastics
 Discontinue cross elastics
 Correct cross bite by other means- doubled
back wire, vertical elastics or finger springs.

 Distolingually rotated cuspids.
 Engage wire in cuspid bracket after derotation.

 PM rotational elastic tie on the lingual from

bicuspid to the molar.
 Extend archwire to the 2nd molar.
 Toe out bends on the distal end of the arch wire.

 Retie elastic thread from the PM to the arch wire.

 Rolling of the distal ends of the AW.
 Place toe in or toe out bends.

3. Adverse tipping of anchor molars .
 No AB ( if tipped mesially )
 Too much AB ( if tipped distally )
 Proper AB in place for too long. (tipped distally )
 Place bracket on first molar and band second molar

 Improper placement of M tube or band.
 Loose molar band. (m mes.)
 Excessive elastic force. (m mes.)
 Use sensitive tension gauge, if force delivered
proper, see whether pt. is wearing more elas.

 Improper placement of elastics on tooth.
 instruct patient proper placement, provide
hooks in desired areas

 Oversize archwire (m dis)
 Replace with 0.016 hard aus. wire.

4. No appreciable changes.
 Not wearing elastics.
 Archwire bent out of shape.
 Oral habits that counteract forces of
appliances.
 Identify & eliminate the habit ,if possible

 Patient seen too soon.
 Dismiss pt. for at least 6 weeks

5. Vertical loops buried in the gingiva .
 Looped archwire left too long.
 Replace it with plain archwire with
bayonet bends.

 Misjudgment in proper direction of
loops.
 If ant. are still crowded or irregular
modify direction of loops.


6. Elastics which break or do not stay on.
 Excuse for not wearing elastics.
 Educate patient

 Elastic not staying on Intermax. circle .
 Instruct pt. to pull elastic distally into circle.
 Open I.M circle vertically.


 Distal end of archwire too short or
imbedded in the gingiva.
 Make new archwire or bend the wire.
 Elastic hook on the molar band.

7. Lock pins lost.
 Occlusal – incisal forces.
 Use steel pins, if brass pins previously
 Check AB to facilitate opening the bite.

 Patient picking out them.
 Patient education.
 Bend tails of pins tightly.
 Use ligature wires.

8. Extremely mobile molars.
 Clenching of teeth.
 Prescribe sugar less gum

 Intermittent wearing of elastics.


 Pathology.
 Take IOPA x-ray, check med.-dental
history, refer to periodontist, general dentist
or physician.

 Excessive force applied to the molar.
 Reduce archwire to 0.016 inch.
 Reduce elastic force to 21/2 oz.
 Reduce anchor bends.

 No apparent cause.
 Remove AW and elastics for 8-10 weeks,
molar should tighten. Resume trt.

9. Lower anterior teeth tipping labially.
 Optical illusion with roots moving ling.
 Education of both pt. & orthodontist

 Binding of archwire in bicuspid brackets.
 Use bypass clamps.
 Remove bicuspid band temporarily.

 Binding of ends of AW inside buccal
tubes.
 Replace with wires of sufficient length.

 Poor diagnosis
 Reconsider the need for extn of teeth.

10.Anterior open bite not closing.
 Patient not wearing ant. vertical elastics .

 Persistent tongue thrust or other adverse
habits.
 Placement of lingually directed spurs on lower
anterior teeth.
 Refer to speech and swallowing therapy spec .

 Too much anchor bend.
 Reduction of anchor bends.

11. Tooth not rotating.
 Not enough space.
 Check diagnosis or archwire design.

 Not enough activation in the bracket
area of the archwire.
 Remove AW and activate bracket area
between vertical loops

 Elastic threads slipping over the top of
the tooth.
 Use bypass clamp to lower the level of AW
 Lower the lingual button.

12. Midline discrepancy.
 Asymmetrical tipping of anterior teeth.
 Do nothing, study situation carefully to
confirm that space closure & ultimate
uprighting of teeth in 3rd stage will correct
midline.

Stage II (Objectives)

 Maintain all corrections achieved during 1st
stage

 Closure of remaining posterior space
Problems encountered during second stage
and their remedies.
1.Ant. bite closing
 Lack of bite opening bends
 Remove AW, place proper bite-opening bends

 Bitten out bite opening bends, arch wire
distorted
 Pt. edu. for proper diet
 Remove, correct & replace archwire

 Anchor molar out of occlusion
 Discontinue Class II or Class III elastics
 Horizontal elastics from most pos. place
molar  molar mesially  occ.
 Vertical elastics from U-m to L-m

 Patient not wearing I.M elastics properly
 Educate patient

2. Ant. teeth assuming class III relationship
Excessive wearing of class II elastics
 Discontinue Class II elastics till teeth are in edge
to edge relation
 place class III elastics, discontinue class III
elastics when ant. teeth are edge to edge


 Pseudo bite opening
 When AB are insufficient & pt. wears class
II elas. properly,  edge to edge bite of ant.
but post. teeth will not occlude, Ant. will
assume class III with under bite.

 Place proper bite opening bends
 Place class III elastics, until ant. teeth are
edge to edge & pos. teeth are in occlusion

3. Spaces dev. between ant. teeth.
 Failure to give cuspid tie
 Intermax. circles formed too far apart
 Roll one or both circles mesially, tie with steel lig.
 if space is too large, close space with hor. elastic
from 3-3

4. Anchor molars rotating distobuccally
 Toe-out on arch wire
 Remove arch wire & place toe in bend

 Too much force from horizontal elastics
 Use lighter hor. Elastics
 Tie elastic thread from 3 lingual button to
lingual hook on molar.

 Elastics pulling on distal of molar tube
 Place the hook properly
 Edu. pt. to place elastic on hook rather than
around tube.

5. Canine roots bulging on labial plate of
alv. bone
 Normal distal tipping of canine crown slig.
mesial movement of apices, ( canine is
corner tooth) bulging of labial plate of alv.
bone. will disappear during stage III
 Do nothing

 Poor arch form
 Poor bracket placement
 if bracket is to far gingival tooth will supra
erupt. Inclined plane relationship with opposing
teeth  rotate mand. cuspid crowns lingually
 roots labially


6. Posterior space not closing
 Poor elastic cooperation.
 Educate the patient
 Make sure that pt. can hook the elastics

 AW not free to slide distally through tube
 Remove source of resistance
 End of wire striking 2nd molar
 AB in molar tube
 Arch wire short & caught on burr inside tube

 A W pinned or caught in PM bracket slot
 Unpin archwire, remove from slot
 Place bypass clamp

 Pt. placing tongue or pencil in space
 Educate patient

 Occlusal interference
 ↑ AB to open bite
 Check bracket level

 Ant. teeth not free to tip distally
 Use proper brackets
 Make sure AW is not pinned too tightly
 Make sure AW is seated in bracket slot, not
caught on flange of bracket
 If tongue habit, place spurs on lingual
surface of teeth, refer to speech and
swallowing therapy spec.

7. Mesial tipping of 2nd PM
 Slight, expected mesial movement of
anchor molar
 proceed with stage II, conti. to guard anchorage

 Abnormal loss of anchorage
 Remove AW, ↑ AB
 ↓ elastic force
 Check for loose molar band or tubes

8. Mand. ant. teeth achieving desired
lingual inclination before space closure
 Careful preservation of anchorage
 Apply braking mechanics
 Apply 6- 10 oz. horizontal elastics with braking
mechanics

 Excess space present at beginning of trt.
(Cong. small or missing teeth or space from
trauma or caries)
 Clinical experience & education of patient

9. Relapse of crowding
 Intermax. circles not abutting to canines
 Pins dislodged from brackets


10. Too much retraction of U –incisors
resulting in gummy smile
 Uncontrolled tipping of incisors
 Use MAA

 Not attaining proper intrusion of U - incisors
 Use of Power arms or TPA for wearing class I
elastics


Anchorage loss during stage I & stage
II
 Vertical loop touching the labial surface
of the teeth

 Proper arch wire fabrication
 Proper location of loops & limitation of the
number of loops
 Slightly labial inclination of loops in severe
crowding cases

 Vertical loop impinging on the gingival
tissue
(If impinge on gingiva become imbedded by next
visit, Prolong stage I & II)

 Careful modification of loops
 Slightly labial inclination of loops when arch first
applied
 Do not modify the loop without removing from
mouth

 Intermaxillary hooks not cranked out
(Vertical portion of I.M.H resting snugly against
the canine  +ve braking mechanism)

 I.M.H should be cranked out before arch wire is
applied

 Use horizontal circle

 Distal leg of I.M.H sliding against the lock
pin & becoming engaged in canine bracket
(Prevents free and simple tipping of canine crown
Usually happen when loop arch wire are used to
unravel ant. crowding)

 I.M.H should be cranked far enough labially,
engage against the mesial surface of bracket


 Elastic over the I.M.H engaging the labial
surface of canine
(Due to using thick elastics or two elastics)
 Modify I.M.H so that elastic not
produce undesirable pressure


 Lock pin binding the arch wire in bracket
(prevent free tipping of teeth)

 Use special safety lock pins
 If conv. pins, tails should be bend before head
strike the arch wire

 Cuspid forced out into buccal plate
(Improper arch wire form, Causes drag teeth
can not tip freely)

 Place the distal ends of arch wire in molar
tubes, see if wire lies so far labially in canine
region

 Too strong elastic force
 Use proper intermaxillary elastic force
 2-2½ ounce

 Wearing more than one elastic
 Pt. must be properly educated in
Function of elastics
Danger of wearing more elastics

 Elastics not worn continuously
(Intermittent wearing causes anchor tooth to
become loose, Ant. teeth hardly move, Prolong
Rx  anchorage loss)

 Proper patient education


 Arch wire accidentally engaged in the
slot of second premolar
(Increases friction, In mes.ling molar rotation wire
may acci. engage)

 Use of bypass clamp
 Remove the premolar band for first 6 weeks

 Arch wire binding in buccal tube
(If arch wire too short to protrude through the
distal end of molar tube,
When cut to proper length, cause internal burring
(not removed by ordinary polishing)

 Make always slightly longer than necessary
 Do not cut the end of wire until all modifications
and bends

 End of arch wires striking the second
molar
(Retards and sometimes stops the distal sliding
of arch wire (usually in upper molar)

 Extend the arch wire farther distally
buccal to 2nd molar

 If impossible, cut it short enough to
allow it to slide freely until next visit

 End of arch wire penetrating gingival tissue
(Usually distal end of lower arch
Gingival tissue (bone) prevent free sliding)

 instruct pt. to visit orthodontist if they feel
discomfort or can not engage elastics

 Anchorage bends engaging buccal tube
(Once entered in molar tube free sliding is prevented
due to three point contact)
 Check the situation every visit
 If necessary remove the arch wire, st. it and, make
new AB mesially


 Ligating premolar too tightly to arch wire
Arch wire can not slide distally
 Ligate the arch wire lightly so that arch is free to
slide


 Insufficient anchorage bend in first arch
wire when first applied
 Incorporate enough AB to cause the ant.
section to lie against the floor of mucobuccal
fold when distal ends of arch wire is threaded
into molar tubes.


 Distorted anchorage bend
(Seen in negligent pt. mesial to lower molar tube,
esp. when lower 2nd premolars are not present)

 Examine the arch wire closely
 If distorted ,remove from mouth, eliminate the
distortion


 Too much anchorage bend
 May cause distortion of arch wire
 May cause arch wire to rotate in molar tubes
rotate the molars  failing to depress molars

 Improper toe in
 Results in loss of control of anchor teeth &
failure to reduce ant. deep bite.

 Proper amount of toe in or toe out  by
placing the AW in molar tubes & in ant.
brackets

 The wire should pass st. forward & occlusally
as it leaves the tube by action of AB.


 Arch wire too soft
 AW material must have higher resiliency
 Other wise Rx time will increase  more
anchorage loss

 Starting stage II too soon
 If ant. teeth are not in genuine end to end
contact, not free to tip under the forces of
horizontal elastics

 Overactivated expansion loops or
improperly bent arch wires
 Cause rapid initial labial tipping and spacing of
ant. teeth

 More force & time spend to recover original
lab.ling. inclination of ant. teeth

 Loss of anchorage


 Wrong type of bracket
 Do not use edge wise bracket
 May allow ample tipping labiolingually but
it restricts mesiodistal tipping and causes loss
of anchorage


 Bend – over free end of lock pin
impinging on arch wire
 Use short lock pin
 Cut the lock pin tail off flush with the side of
bracket
 Bend all pins tail to mesial


 Arch wire rolling in buccal tube
 Avoid too much anchorage bend
 and/or too much toe in bend


 Improper arch wire form
 Arch wire should keep all teeth in the cancellous
through of alveolar bone

 Arch wire must be bilaterally similar in form or
should be so shaped as to eliminate any
asymmetry of arch

 Upper and lower arch wire forms not
coordinated
 Teeth will assume faulty relationship
 Ant. or pos. cross bite  cuspal interference 
prolonged Rx time


 Internal diameter of buccal tube too
small or large
 Best internal diameter 0.036” for 0.016” wire
 If less free sliding will reduced
 If more  molar control lessen, depression
force on ant. lessen


 Length 0.20” – 0.25”
 Shorter tube  lessens molar control & force of
anchor bend,

 Longer tube  more control, reduces the
distance of arch wire between mesial end of
molar tube and premolar bracket operational
difficulties during stage 3.

 Retaining looped arch wire longer than
necessary

 Danger of

loops moving into such positions that
they press against labial surface of ant. teeth

 Not transmit tooth depressing force as accurately
as an arch wire without loop

 Cuspid will depress more than incisors

 Binding of doubled-back arch wire in flat
oval tube
 Binding will occur by having the legs too far
apart

 May be due to too large a radius where the
arch wire returned on itself, or too long a
vertical section extending from the hook that is
wound around the arch.

 Legs of double back are not ll.

 Curving arch wires between expansion
loops
 Make the arch wire st. between the loops
 If need to modify the form make bends in the loops
 When engaged, loops become distorted 
rotations of the sections of archwire

 If curved three point contact  inhibit free lab.ling.
tipping

 Improper ligature tie at canine
 do not pass ligature ties on canines over the
incisal of brackets  prevents free tipping

 It should pass directly distally across the labial
surface of canine


 Anchorage bend too far mesially
 Ideal location at the mesial of anchor molar
 It may become restricted by ligature tie on
bicuspid, preventing free distal sliding

 Arch wire will be projected towards the occlusal
plane and be deformed by occlusal forces.


 Anchorage curves instead of bends
 Gently curved anchor bend can be initially
placed so far mesially in the arch wire that it is
unnecessary to remove the arch wire from
mouth in order to make a new bend farther .


 Using 0.014” instead of0.016” wire
 insufficient force from its AB to prevent the
anchor molars from being tipped mesially .
 Ant. Deep bite will also not open

 Thumb or finger sucking, lip sucking,
tongue thrusting and abnormal sleeping
habits
 Habit breaking measures

 Loosening of anchor molar bend
 Pull the affected molar forward
 Anterior teeth are not depressed


Stage III (Objectives)

 Maintain all corrections achieved during 1st
& 2nd stage

 Achieve desired axial inclination of all teeth
Problems encountered during third stage and
their remedies.
1. Max. molars widening
 AB present in max. AW
 Remove max. AW, eliminate or ↓ AB bends

 Too much bite opening bend between
cuspid & bicuspid
 Remove AW, reduce the degree of bend

 Max. AW too flexible (small in diameter)
 use stiffer archwire (0.020” premium p.s)

 Max. AW too wide
 Remove & modify AW

 Torquing auxiliary not constricted adequately
or extended too far distally
 Remove & modify, narrow in post. region,
shorten so that ends between cuspid & bicuspid

2. Mand. molars narrowing
 Mand. AW not wide enough
 Remove & widen distal ends of AW

 Class II elastics exerting too much force
 use lighter elastics ( 2- 2 ½ oz.)

 Presence of s.s lig. tie from lingual of 3 to
lingual to molar
 Remove lig. tie, hold space by bending the
ends of AW around distal end of buccal tube.

 Lack of support through occlusal contact
with max. molars
 Use posterior cross elastics
 Check sym. of both arch wires

3. Ant. bite deepening
 Overactivated torquing auxiliary
 lessen activation
 Make with smaller wire (0.012”pr + p.s)

 Max. AW too thin
 use heavier (stiffer) AW (0.020” premium p.s)

 Patient not wearing class II elastics

 Bite opening bend not placed between
canine & premolar
 Place necessary bend

 Bite not truly open at beginning of stage III
 Remove all torquing mechanism, return to stage I

4. Teeth not uprighting
 Springs not active
 Remove & activate spring
 use 0.010” supreme for incisors & 0.012”pr+p.s
for canines & PM


 AW caught on the edge of bracket
 Tighten spring pin to draw AW in bracket
 Draw AW into bracket with ss lig. Tie(0.009” –
0.010”), before placing uprighting springs

 Occlusal interference due to elevated tooth
 Review bracket position & correct it

 Lack of room mesiodistally
 St. AW distal to tube, or remove ligature tie

 Residual deciduous root fragment against
root being upright
 Reevaluate situation, either remove surgically,
or settle for present amount of uprighting

 Improper placement of spring
 Remove & replace properly

 ligature tie on wrong side
 Always use lig. tie on the side toward which
crown is to be tipped


 Intermax. hook butting on mesial end of
canine bracket
 leave 1 mm space ant. to canine bracket

 Lack of alv. bone between cortical plates
due to prolonged resorption of ridge or
loss of cortical plate during extn. of tooth
 Remove uprighting springs
 Achieve best occlusion possible with tooth in
present inclination

5. Max. ant. teeth not torquing palatally
 Not enough force from torquing auxiliary
 Remove & reactivate
 Make new aux. from heavier wire
 Fashion different type of torquing auxiliary

 U-incisal edge caught lingual to L ant. teeth
 Open bite, by AW modification or bracket
repositioning
 Consider incisal reduction with diamond stone

 Not enough time
 Be patient & wait

6. Mand. ant. teeth labially inclined
 Normal mesial migration during stage III
 If near end, do nothing
 If in middle, place reverse torquing auxiliary


7. Rotation of teeth other than molars
 Lack of complete bracket engagement
 Seat AW completely in bracket slot using
spring pins, ss ligature or lock pin

 Arch wire slot too large (labiolingually)
 Replace bracket with proper size slot
 Remove AW, place bayonet bends to
compensate for lack of proper fit

 Bracket off center on buccal surface of
tooth
 Observe carefully, may be maintenance of
overcorrection achieved during stage I
 Reposition bracket

8. Extn. space opening
 Improper cinching of AW
 Improper ligated lingual attachments
 use at least 0.011” ligature wire

 Interference from hooks of opposing
uprighting spring
 Use short arm uprighting springs

 Brackets of opposing tooth located too far
gingivally, resulting in plunger cusp action
 Reposition brackets

9. Canine rotate mesiolingually
 Intermax. circles tied too tightly
 lingual attachments ligated too tightly
 Incorrect bracket placement
 Incorrect base AW form in canine area
 Bracket slot enlarged

10. Canine rotate distolingually
 Incorrect bracket placement

 Distortion or incorrect placement of uprighting
spring, with helix distal to bracket & exerting
pressure lingually
 Arm of uprighting not II to AW
 Incorrect base AW form in canine area
 Bracket slot enlarged
 Intermax. circles in contact with canine bracket
at beginning of stage

11. Buccolingual torque of molars is not
possible
 Use of round wire in round wire
 Use of 0.018” x 0.022” or 0.020” sq. alpha
titanium wires (torque incorporated in wire) with
combination tubes (Consist of gingival round
tube 0.036”diametre x 6.2mm long &
rectangular (ribbon) occlusal tube 0.025”x
0.018” dia x 5.5 mm ) in stage IV

Anchorage loss in stage III
one of the main problem of stage III
 In stage III, Begg used eq. resistance i.e high
resistance slow response movements of ant.
torquing & IIing against high resistance slow
response movements of PM & molars.
 Although resistance & response are eq. type,
seldom equal in magnitude considered main cause
of anchor loss in stage III
71.2% anchorage loss in 3rd stage (Swain)

 Anchorage loss by II ing auxiliaries
 when ever possible the ii ing aux. should be
opposed to one another
 Even though forces exerted by springs equal,
II ing may not occur at same rate (cuspid root
is often larger)
 In 2nd PM cases complete reciprocity not
possible because more II ing spring in front of
extn. space than behind

 Anchorage loss due to rectangular wire for
torquing
 Force exerted by rectangular wire so great roots
resist being move lingually  more crown labial
movement.
 Class II elastics also can not prevent forward
movement due to use of rect. wires

 Anchorage loss due to lack of elastic
wearing
 If class II elastics are not worn, U –arch as a whole
move too forward while roots of teeth of dental
arches are uprighted.

Chair side vector analysis of trt. problems
 Employs direct measurement & observation
to differentiate between causes of trt.
problems
 Question pt. about elastic cooperation, use tongue
blade
 Measure elastic force with strain gauge
 Measure AB force by disengaging lock pins
 Observe pt. cheek & temples for periodic bilateral
muscular contraction of clinching

 Measure changes in arch width

 Also employs inferences to differentiate
between causes of trt. problems
(Inferential diagnosis is form of reasoning in which the
presence or absence of causative factor is
assumed from presence or absence of equal &
opp. reaction force.)
 Orthodontist can use inference to detect the pres.
of abnormal force when trt. is unsatisfactory.


 When seeking cause of problem in trt.
 It is helpful to know typical signs of abnormal force,
such as distal tipping of L- molar due to poor elastic
cooperation
 It is imp. to know other causes of problem & how to
diff. between them
 To acknowledge that imposition of orthodontic force
may augment some existing forces &resistance for
others
 Complex problem may arise, & analysis of many
variables in each indiv. req. observation,
measurement & differential deduction

Conclusion
A thorough knowledge of basic principles
involved in Begg mechanotherapy is
essential to avoid any form of problems
during treatment.
An awareness of all possible problems help
us in every stage of treatment, leading to
excellent treatment results.


Problem shooting /certified fixed orthodontic courses by Indian dental academy

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