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Current application of Begg mechanics
Current application of Begg mechanics William J. Thompson, Bmdentm, Fla.
D.D.S.,
M.S.
A
patient’s care and well-being and an orthodontist’s happiness and security depend on efficient and effective utilization of an orthodontic appliance, regardless of its type, design, or origin. This article will discuss the current application of the Begg appliance as it is presently being used in the correction of malocclusion. Obviously, a brief discussion cannot be thorough enough to teach the complete technical utilization of such a complex multibanded appliance. The intent of this presentation, therefore, is to provide a summary of the various principles, objectives, and problems involved in the various stages of Begg treatment. Enough basic information will be presented to develop confidence and understanding in the appliance by orthodontists who are undecided about using the technique or who are uninformed about its operation and effectiveness. Current technical procedures and recent modifications of technique are also incorporated into the discussion. Several specific teaching philosophies have developed concerning the Begg technique. Many modifications, some slight and some extensive, are evident in the various schools of thought. Those illustrated in this article are the interpretations of the currently accepted principles and applications of the Begg philosophy. The procedures shown are based on pure Begg mechanics. Modifications in technique are presented as the exception rather than the rule; they should be utilized only to enhance the technique, not to alter the differential force system or to mix different theories of mechanotherapy. The four basic areas to be discussed are (1) clinical terminology on what the Begg technique is and how it works, (2) the actual mechanical stages of Begg treatment, (3) problems and pitfalls that may occur and discourage the use of Begg treatment procedures, and (4) why, when, and where the Begg technique should be utilized as a part of a total orthodontic treatment approach. The
Begg
technique:
A
description
The Begg technique can be described as a series of special stages of orthodontic mechanics designed as a system to obtain dentofacial harmony. Begg 245
246
Thompson.
Fig.
1A.
Routine
Class
II treatment.
mechanotherapy has been discussed by its discoverer, Haymond P. Begg, and various other authors as a differential force syst.em.4-7’ 16,I8 The concept demands that the clinician change some of his older ideas of force, anchorage, and speed in treatment, for the technique very nearly approaches an optimum physiologic system. Forces are light and continuous; this is due to a long interbracket distance, a small-diameter wire size, a complex wire design, light elastic forces, and a reduction of friction because of bracket design. Muscle physiology and tooth size and shape become important concerns in the differential movement system, since there is no real attempt to create static or fixed anchorage. Anchor teeth are held in position by occlusal forces, muscular forces, and tooth mass. It is a dynamic type of system; it is controlled by the force vectors established in the design of the arch wire, the Begg attachment
Begg mechanics
Fig. lg. For legend,
see
opposite
247
page.
mechanism, and the intermaxillary forces. Excellent articles by Begg,4-7 Williams,25 McDowell,lO* I1 Kesling,g and others have thoroughly described differential anchorage. An understanding of this phenomenon, of the basic physiology of occlusion, of force vectors, of vertical dimension, of interocclusal space, and of muscular physiology is essential if the clinician is to be fully aware of the complexity of Begg mechanotherapy. One of the great problems with acceptance of Begg mechanics has been the unfortunate implication that it is a simple technique or an automatic appliance. Nothing can be farther from the truth; the Begg appliance and technique are complex and require absolute understanding and precise manipulation. Any appliance so dependent upon a complex dynamic system must be completely controlled or rapid breakdown of the system occurs. In turn, this can only lead to failure and disastrous results, A critical analysis of the appliance and forces must be reviewed continuously throughout treatment. Most tooth movement with Begg mechanics is of a tipping nature-physiologic in character and, therefore, very rapid. Any loss of control obviously leads to a serious misdirection of tooth movement. it must be Pact No. 1: The technique is dynamic, complex, and intricate; thoroughly understood and precisely manipulated or control is lost.
Fig. Indications
for
Begg
2A,
Routine
Class
II treatment.
treatment
Clinical experience with the Begg appliance indicates that it can be used to treat any type of occlusal disharmony-eitllel~ as a. system itself, with certain specific modifications, or in conjunction with surgical or palatal expansive procedures. It can be used effectively in either extra&ion or nonextraction cases if the pretreatment diagnostic evaluation is properly determined and if the The technique has proved principles of the technique are precisely followed. effective in all areas of orthodontic treatment. Very likely, its greatest potcntial is in severe, deep-bite, Class II, discrepancy-type malocclusions (Figs. 1 and 2). Two of the greatest clinical contributions of the technique are its ability to open the bite and its early ~duction of the prot.rusioI~ and crowding. Such
Begg mechanics
Fig.
2B.
For
legend,
see
opposite
249
page.
accomplishments in the first few months of treatment are great advantages. Bite opening reduces occlusal interference; this increases tooth movement and decreases the trauma of intermittent occlusal forces on the teeth and supporting tissues. Reduction of protrusions early in treatment stimulates the patient’s enthusiasm because of the immediate esthetic improvements. The early retraction of incisors and the elimination of crowding also enhance muscular and periodontal reorientation. Early correction means longer perio’ds in the corrected position; it also may be one reason for the decrease in posttreatment retention in many of the cases in which pure Begg mechanotherapy was utilized. Such findings indicate an additional benefit of Begg treatment to both orthodontist and patient, for stability of result is one of the chief requirements in every omrthodontic correction. Many antagonistic theories and opinions have been brought forth condemning the technique for its “round-trip ride,” its tipping action, its occlusal plane changes, and its use of elastic forces. 14px5>I7 Each of these criticisms is gradually being answered by astute research.2r 13, 21,22 Clinically, there is little reason to be plagued by all the apparent problems related to the physiologic changes pro-
250
Thompson
Fig. 3.
The
An
incisally
aid
bite
appliance placed
must anterior
be
constructed
band
and
as
accurately
a gingivally
as placed
all molar
multibanded tube
are
appliances. suggested
to
opening.
duced by tho technique. In fact, clinically, tht! impression is that the results consistently look better, consistently work out with greater ease, and consistently appear to hold up as well as or better than in GISCSt,hat have been finished with other techniques, In a recent evaluation of 100 random cases, it was extremely gratifying to observe the consistent skeletomuscular findings after treatment.‘” The occlusion, the skeletodental patterns, and the faces were most. pleasing-to the orthodontist as well as to the patient; that, in itself, is an additional benefit of the technique. It appeared that these 100 cases were actually treated with an appliance that was being favorably influenced, directed, and limited by the child’s facial pattern rather than by an arbitrary ideal which had been determined from previous training ,averages, and experience. Fact No. 2: When evaluating the appliance, believe what you, see, not what you expect to occur, because the principles do not agree with historical views and opinions. Keeping in mind the idea that the technique is a complex system of moving, reciprocal forces, let us now look at the Begg technique in operation. It is first suggested that in the clinical application of the technique several important things should be accepted as fact and not altered or modified without proper analyses of the effects on the total force system. Experience has shown that
Begg mechanics
Fig. 4. Anchorage occlusal surface and bite opening. before treatment
251
depends upon elimination of the freeway space. Interlocking the of the molars provides the stability of the molar during incisor retraction (After McDowell: Angle Orthod. 37: 109-l 31, 1967.) A, Freeway space is normal. B, Freeway space during treatment has disappeared.
“hodge podge” modification of the appliance or its manipulation leads very quickly to disaster because of the rate of movement in this technique. Modification after due analysis may lead to beneficial refinement, but in Begg treatment, modification on the whim of the operator because he thinks it will help, because it worked with the old system, or because he has not the time to do it as reeommended will lead to immediate problems. Fact No. 3: Listen to those who have gone before; use the appliance and technique as described for the best results; modify it only after complete analysis and understanding. Begg
Stage
I
The objectives of Stage I in the Begg treatment procedure are (I) to open the bite, (2) to correct the anteropoaterior molar relationship to Class I, (3) to unravel anterior teeth, and (4) to begin overcorrections. The Begg appliance must be constructed, as well as other multibanded techniques (Fig. 3). Proper bracket placement is important, and bands must fit soundly. Poor bracket placement and poor band construction produce many difficulties with Begg treatment. The Begg force system depends upon differential forces with free tipping. It is essential that friction not be produced by unnecessary distortion of the arch wire caused by improperly placed brackets or bands. Poor bracket placement also encourages loose bands and distorted arch wires during those periods when the bite is being opened. During bite-opening procedures the molars and premolars are elevated into their anchor positionll (Fig. 4). If the posterior brackets are too high oeclusally, they are constantly being smashed by the occlusion from above. In addition, the anchor bend in these high tubes is subject to distortion by the opposing occlusion. Raleigh Williams”’ and others continuously stress the cervical placement of molar tubes to reduce these traumatic problems and also to assist bite opening. Dr. Williams believes that incisally placed anterior bands and gingivally placed molar bands assist the bite-opening mechanics by setting up more effective depressive forces on the incisors. The fit of bands is important-not only during the bite-opening mechanics, but also during the torque procedures on the incisors. Bands of poor quality or
252
Fig.
Thompson
5.
A,
bends,
and
in the
molar
Anchor
Stage
I archwires
active areas.
bends
deep
into
[After
Kesling,
the
should
anchor
bends.
6, Anchor
should
be The
bends
sufficient
mucobuccal P. C.:
fold Begg
have They
should to
before Journal
all
necessary
should place they 1:47-53,
be be
overcorrections,
coordinated
definite
the
and
round
are July,
but the
0.016
activated
premolar have
arch Stage
by
pinning
slight
wires
bayonet expansion
symmetrical.
I and into
Stage the
C, II
wires
brackets.
1962.)
poor fit frequently are pulled away from the surfaces of the incisors by the torque auxiliaries. Such disappointmc>nts only decrease the extreme effectiveness of a well-designed Begg system. Stage I arch wire formation is also important, since the greatest activation of the arch wire occurs during this time (F’ig. 5). Movement is rapid and cxtreme, and any asymmetry in the wire produces rapid and extreme aberrant changes. Anchor bends should bc adjust,ed to have positive anterior depressive forces on the incisors; the degree of force is determined by placing the 0.016 inch wire so that the anterior srgmcnt is tlccp to the mucobuccal fold when the wire is in the tubes posteriorly. The wire should be adjusted for anterior symmetry before it is placed. Approximately I/$ inch expansion is placed in the wire to assist molar control; canine width must be maintained to keep the tooth in the alveolar trough as the tooth tips distally.
Begg mechanics
253
Fig. 6. Loops
are placed to reduce the forces, increase the range of action of the wire, and produce gentle unraveling of teeth. They must be removed as soon as possible to get better wire mechanics for bite opening. Use the minimum number of loops that will accomplish the task.
Care should be taken not to distort bracket. Such a procedure changes the and constricts the molars into improper areas to increase the action of the wire the teeth or gingiva, and they should
the wire by pinning it into a rotated position of the ends of the arch wire position. Loops are placed in anterior (Fig. 6). The loops must not bind on be overactivated so that the wire will
254
Thompson
Fig. 7. Anchor bends must come out of the buccal tube straight after the wire is activated. A, Incorrect. 8, Correct. C, Toe-in or toe-out bends may be incorporated into the anchor bend
to keep
its position
straight
and
vertical.
overcorrect all rotations and buccolingual malpositions. It may be impossible to pin all teeth with the first wire; ligatures are used until the wire can be pinned with little resistance or distortion of the arch wire. To facilitate bite opening, the highly flexible looped arches should be removed as soon as possible; they are replaced with routine, overcorrected, straight 0.016 or 0.018 inch wires. The wires are adjusted to overcorrect all rotations and labiolingual displacements. The design of the anchor bend is also important in controlling the loop positions (Fig. 7). If the anchor bend does not come out of the tube straight, the wire rolls and the loops move gingivally or labially. The movement causes impingement of the loop on the gingira. The rolled wire may permit the molar to rotate or go lingually, which also reduces bite-opening forces. Toe-in or toeout bends may be necessary to change the arch wire form to compensate for molar roll produced by the anchor bend9 (Fig. 7, C) BertrandS and Barre? have written a great deal about molar control with Begg treatment. Their
Volume Number
62 3
Begg mechanics
255
Fig. 8. Simple aids such as the bayonet bends at the premolars, the sliding lock pins on the canines, and by-pass clamps on the premolars reduce binding and increase efTiciency. A, Proper bayonet bend mesial to the premolars keeps the premolar in good buccolingual position and reduces friction. B, Premolar by-pass clamps reduce friction and eliminate irritating tie wires. C, The sliding lock pin controls anterior spacing but permits free canine tipping. The lock pin slides through the loop as the canine uprights.
articles show conclusively why, when, and how not to be a “molar roller” by using correct anchor-bend design and other controlling adjustments. After the control of bite-opening mechanics, the next important consideration in Stage I is free tipping. All friction areas must be minimized. Three current means used to reduce friction and increase free tipping are bayonet bends to keep the premolar positioned in the arch, sliding canine lock pins, and premolar bypass clamps (Fig. 8). The bayonet bend relieves the lingual constriction force on the premolar which is normally seen when a
256
Thompson
straight wire passes from the molar tube.1 The sliding lock pin ant1 the l)yIlirss clamp merely eliminate troublesome, frequently binding, and Gssuc-irritating tie wires. The three tipping aids-bayonet, bend, sliding lock pin, and bypass clamp-are used throughout Stages I and IT. Elastic pressure is the final consideration to be discussed in Stage I. Elastics are the keys to anchorage, to retraction, and to bite opening. They must be worn 24 hours per day during Stages I and II. The magnitude of the force must be a,ccurately gauged since the light action of the force is the controlling influence on molar and incisor movement or stability. The usual elastic force values for Stages I and II are 11/! to 2M ounces. Hca.vicr forces ctnc*ouragc forward momment of molars, molar tip, molar roll, extrusion of upper incisors, and forward movement of lower incisors. Elastic forces must be light and they must be contjinuous if the differential force mechanics are to function. Cooperation by the patient is essential; in instructions to patients, great emphasis is placed on the importance of elastics. Elastics are never prescribed without tension gauge readings (Fig. 9). Such action confirms the force control while it reinforces the importance of elastics to the patient at each visit. Elastic quality may vary. Bulk elastic supplies should be checked periodically for conformity in size, shape, and cut,. Poorquality elastics mean improper force control. Such a condition can lead to loss of anchorage or poor bite opening. An accurate magnit,ude of force from elastics is of great importance in the differential force system. In summarizing Sta.ge :I, we have arranged ten problem areas that require constant analysis in Stage I : 1. If appliance design is poor, binding, loose bands, and poor hitc opening will result (Fig. 10). 2. If an arch wire is bent or distorted, the anchor bend may be too far forward, molar tubes may be too high, or the wire is of poor quality Fig. 11). 3. When anchor bends are caught in the molar tube, the tipping and retraction of incisors stop (Fig. 12). 4. If loops are impinging on tissue, it may be that the arch wire form is incorrect, anchor bends are wrong, or the loops are too long. One should get the loops out early! 5. Molar rolling. (See Bertrand’s work.8) (Fig. 13.) 6. If the arch wire is hitting the upper second molars or gingival tissue, the resulting binding stops the retraction and tipping of the inincisors (Fig. 14). 7. Canines may be drifting distally unequally. If so, the bracket position may be incorrect, and the canine is extruded ; the sliding lock pin is not used, and the canine is binding ; the canine is interfering with occlusion on the lingual button or the bracket (Fig. 15). 8. If elastics are too light or are not being worn, the orthodontist should check lower first molar tipping (Fig. 16). 9. If premolars look constricted, bayonet bends should be used to keep them positioned buccally. (See Fig. 8, A.)
Fig.
9.
Elastil c t’ ension
should
not
exceed
1112 to
21/2
Inadequate
number
of
ounces
ar lchor
unless
we!
10s s
is
desil .ed. Fig.
10.
pin9
ing
Fig. vor
Poor aF jpliance design. on te eth and tissue.
11 . Poor
)er.
Bite
a fJpliance c ve ning has
design. Band been adversely
height too affected.
low,
bands, molar
loops tubes
too too
long 1ligh,
I Iclops
im-
ela sties
im-
258
Fig. fort
Fig.
Thompson
12.
And
es in cisors
13.
Mola
lor
Am. J. Orth,od. 8eptenzber 3972
bend
or
wire
end
caught
in
the
molar
tube
stops
tiF )pin
lingual
‘9 and
labially. r roll
occurs
extending Fig. 14. Arch wire all Ilingu lal rei .raction.
with
improper through
anchor the
molar
bend
design
tube
may
or too hit
the
strong second
an
el asti ic p\ J/I.
mo lar
an ,d si ‘OP
Begg mechanics
Fig. 15. Occlusal desi red tipping Fig. 16. elm itics.
interference as with the
Panorex
Fig. 17. Open-bites tion . To ngue spurs
shows
due to poor lower canine.
adverse
bracket
tipping
of molar
and tongue-thrust are helpful in these
can hold cases.
height roots back
on
arch
as a result Class
form of
II correction
poor
may
,K
coope and
259
uce
un-
ratic 3n \ Nith
inc :isor
ret rac-
260
Thompson
Fig.
18.
Stage II space
closure
may
involve
six
elastics.
10. When a tongue-thrust is evident, the bite may have been opened excessively and the anterior protrusion will not reduce. A tongue-control device may be needed’” (Fig. 1’7). Stage
II
After the objectives of Stage I have been completed, the clinician can start Stage II. At this point another principal rule should be stated: “Do not mix stages.” One should bring each stage to completion and accomplish each of that stage’s objectives before progressing to the next stage. The appliance is designed to accomplish specific duties with specific force systems, Altering or mixing the stages thereby changes the force system and ca,n lead to serious difficulty with control of anchorage, bite opening, or retraction of incisors. The objectives of Stage II are (1) closure of extraction spaces, (2) retraction of incisors, (3) continuation of bite opening, (4) continuation of anteroposterior correction to slight Class III, and, (5) overcorrection. In Stage II mechanics little change occurs in the arch wire form or force values. The principal difference in the mechanics is that in Stage II, for the first time, anteriorly directed forces are applied to the molar teeth with horizontal elastics (Fig. 18). Anchor molars are now used as the retraction anchorage for space closure and incisor retraction. A properly designed appliance having 2 to 21/ ounce elastic force, good arch form, proper anchor bends, and freedom from binding should permit routine lingual movement of incisors with
Begg mechanics
Fig. 19. Formation in elastics should
of a Class III incisor be used to eliminate
bite is contraindicated, this problem.
and
compensatory
261
changes
little mesial movement of the molars. If anchorage loss is desired, as in borderline space problems or cases requiring minimal anterior retraction, adjustments are made in the appliaace to reduce anchorage. Although mesial movement of molars is usually not desired, it can be accomplished readily with such procedures as placing uprighting springs on canines, tying ligatures tightly to produce binding of canines, and increasing the elastic forces to 4 ounces or more on the molars. Stage II space closure is continued until all spaces are closed. Occasionally it is necessary to stop the use of one or more elastics when one space closes earlier than another. In late Stage II one occasionally will see a Class III type of incisor bite form (Fig. 19). In these instances elastic forces and direction may obviously have to be altered to correct the problem. It is not considered improper technique to alter a basic elastic pattern in any stage to accomplish a specific movement or correct an unforseen problem. Cross-bite elastics, vertical elastics, triangular, or diagonal elastics may be necessary to get an end-to-end incisor bite, to correct a midline, or finally to get the posterior teeth settled into a solid occlusion for starting Stage III (Fig. 20). During the final periods of Stage II it will become easier to see discrepancies in band height or bracket placement. Such findings become more evident POW since the teeth are relatively more even and the severe distortions and
262
Fig. to
Thompson
20.
prevent
Many
elastic
combinations
or eliminate
a problem
may or carry
be
used out
temporarily
a necessary
at
any
time
during
treatment
correction.
irregularities seen in Stage I arc about gone. 11 clear view of the appliance is possible, and any defects should he corrected immediately since this is the final period of change before the complex Stage III is inserted. The appliance and the occlusion should be as ideally set up for Stage III as is possible. Occasionally it is necessary to place a. series of pre-Stage III wires to ensure a truly good base for Stage III (Fig. 21). In our office we routinely place preStage III wires which we label as “base Stage 111.” It is our intent to get the best base possible for the uprighting mechanics. The pre-Stage III wires may simply be routine Stage II 0.016 inch wires re-adapted and pinned to all teeth. Usually, however, they are new 0.01s or 0.020 inch ideal arch wires with rotations overcorrected and wires adapted to seat the premolars and get a solid occlusion. They are left 4 to 6 weeks after which they continue as the base wires for Stage III springs. The pre-Stage III procedure provides a good base for the appliance, because it permits settling to occur which enhances the action of the uprighting and torquing springs. It also reduces the discomfort associated with the placement of the complex Stage III appliance because after the settling has occurred the wire is less rigid in the brackets and placement of the ties and springs is less difficulty. At the completion of Stage II and of pre-Stage III the occlusion should be end to end in the incisor segment and slightly Class III in the molar area, premolars and molars should intercuspate, all spaces should be closed, and the anterior bite should be recessive or “dished in” (Fig. 22). Good anchorage control and good cooperation should produce a moderate to severe lingual inclination of
Begg mechanics
Fig. 21. Pre-Stage Stage auxiliary
III.
Note spring
Ill arch wires the additional on the mandibular
are used to prepare the occlusion movements being initiated with a right central and lateral incisors.
263
for the complicated Sain reverse torque
the incisors. Proper lingual inclination of incisors and good interlock of premolars help to hold the crowns as the roots are uprighted. Lack of tipping and occlusal interlock permits crowns of the uprighting teeth to move and encourages loss of anchorage in Stage III. In passing through Stage II six areas of concern should be watched : 1. If the bite is closing, the clinician should continue elastics and use proper bit-opening bends in the wire. 2. If retraction has stopped (one side or both sides), the tip-back bend may be binding in the molar tube. 3. Retraction may have stopped because the wire is hitting the upper second molars or the tissue distal to the upper first molars. 4. If tipping is stopped on one tooth or generally, a pin is hitting the arch wire, in which case they should be bent mesially, or a bracket slot is pinched or binding, and it should be opened with the T.P. No. 133 pliers. 5. If incisors are locked in Class III, the clinician should stop Class II elastics or go to Class III elastics. 6. If the bite is open and retraction is stopped, an squired tonguethrust has developed, and a tongue spur should be used. The bite should not be allowed open excessively in any stage.
Volume Number
Begg mechanics
62 3
Fig. 23. paralleling arch wire
A slight 5 degree bend between canines and in Stage III. The bend should be very slight is pinned into place because of the pressures
Fig. 24. Alastics also
Stage
convenient
are aids
good auxiliaries in other areas
to aid to control
265
premolars aids retention of and is often not visible after of the uprighting levers.
in space control and molar incisor spaces and rotations.
control.
They
root the are
Ill
Stage III is the final and most complex period of treatment. In this stage all occlusal harmony, functional harmony, and esthetic harmony are established. Uprighting, torquing, and intricate finishing must be done in Stage III. It normally will require as much time as Stage I and II combined, but if the appliance and dentition are properly set up, the entire stage is one of few adjustments and few problems. Some arch wire changes are recommended in Stage III. It is not desirable to have a severe anchor bend. Arch wires should be contoured with only a passive anchor bend. Severe anchor bends tend to affect the molar adversely during root torque mechanics and produce buccal roll of upper molars. The wire may have a slight V bend between the canine and premolar (Fig. 23). It should be 5 to 10 degrees, and it is used to compensate for the depressive force of the uprighting springs, to hold the bite open, and to facilitate holding of the uprighted and overcorrected premolar and molar roots. The bend tends to align the wire with the flat base of the bracket and thus encourages the teeth to stay upright. With heavier arch wires it is not necessary to constrict the maxillary arch wire extensively to compensate for the torque forces. Molar position can be controlled with the heavier 0.018 or 0.020 inch base wire with only slight constriction and very little anchor bend. The windlass ties are thought by some to be unnecessary; our findings indicate that if a molar-to-canine tie is not
to
use
the
Occasionally
in control
aid
III
may
elastics
be
may
width
proper
as
long
arch
as
both
maintaining in
relationships.
eliminated
while
be
as necessary.
arch
control
of
elastics
to
Stage
25.
elastics
Fig.
of Stage
III
A, overbite
Stage
if
Class
crossbite
Stage
overbite
and
Note
I and
elastic and
overjet
are
B,
from
Occasionally,
I occlusion.
Il.
it
is
routine
without
Class
second
necessary lower maintained
Note
the
to
alter
the
The
elastics them.
II
premolars
keep
the patient
to
to
number,
size,
can
the
upper be
instructed
bite
open.
direction canines
or
to
k -21. 2: k+r E\ :o *,
Begg ~nechalzics
267
used, one must continuously check for molar rotations (Fig. 24). Alastik links are used to hold the molar from rotating and to aid in keeping the extraction sites closed. These are easily placed, they hold adequately, and they provide the advantages of the old-style windlass tie with none of its disadvantages. Stage III arch wires are tied with ligatures before springs are placed as a safety control, even though the newer springs are self-locking. A tooth that gets away from the wire during uprighting can be seriously affected by the free spring force. The premolars are tied to the distal, and the canine and lateral incisor are tied to the mesial. The ends must be short, so as not to bind on the arch wire and prevent uprighting. Usually 0.014 inch springs with a double or triple helix are used to make insertion easy and prolong the helix action. The springs should be placed so as to permit free movement of the lever arm during uprighting. The springs must be checked so that they do not hit each other, torquing loops, brackets, or bends in the arch wire. It is also necessary to be sure the action is not taken out of the loop as the spring is activated. The torquing arch is formed from 0.014 or 0.016 inch wire. Preformed 0.016 inch arch wires are selected from preformed kits according to size. Several styles of anterior torquing wires are now accepted. Some are believed to provide less distortion o’f the wire at the canine area. Others are designed as additional add-on auxiliaries. Clinically, it appears that any will provide effective torque, and the degree of success depends primarily on the freedom of the auxiliary, the degree of action of the loop, and the length of time it is acting. Most error seems to be the tendency to stop torquing too early. Head films are recommended at Stage III to check torque by the SN 1 angle. An average of 103 degrees is suggested. In 100 random cases the average torque value at the end of treatment was 98.5 degrees, and this was found to be quite cosmetic and functional in appearance.ls Many cases require only a two-finger torque spring; this is especially true when lateral incisors are flared. In such cases, a twofinger torque will be adequate, since the uprighting spring tends to keep the lateral incisor in position. The degree of torque force is controlled by the form of the torque wire, including the angle of the torque loop and the constriction of the arch wire. Forty-five degrees of angulation of the loops is a good standard. The arch wire itself can be contoured to form a circle about the size of a fivecent piece. Stage III is by far the longest and most intricate of stages (Fig. 25). Usually it will last 4 to 6 months, and it may be double that in some cases. Six-week intervals between visits is the desired interval, since the springs are continuousaction springs and do not require or need frequent adjusting. As the teeth are uprighted, it is desired to overcorrect the action so that some of the rebound will be compensated for when the springs are removed. As teeth reach their desired position, the springs can be deactivated; usually their removal is contraindicated until both the adjacent springs can be removed together. During Stage III several areas must be observed closely for problems : 1. If the base wire is bent from occlusal trauma in the first molar areas, arch form is destroyed and the occlusion is distorted.
260
Thompson
Fig.
26.
duration square with D,
Finishing
movements
but
add
to
for
final
wire torque
Ideal
arch tionals
wire
changes
in buccal
C,
form
of
arch
auxiliary. arch
may
quality
with to
double
the
be
necessary
result.
alignment
A,
and
after
Stage
Coordinated seating
of
Anterior
torque upper
anterior
root
molar
leveling.
F, Auxilliary
tubes
second to control
second
molar
using
They 0.018
cusps.
additional
control
correction
III. ideal
are
usually
inch,
B, Anterior Sain
control.
root
reverse
torque
E, Auxiliary 0.016
or
of
0.020
or
positioning springs. bands
0.018
short
inch,
inch
and sec-
position.
2. If uprighting arms are not free, the lever arm must be freed t,o move as tooth uprights. 3. Springs must be active. They must be checked at each visit to be sure that they have not become passive. 4. If molar rotation occurs, a windlass map uot have been used, arch form may be poor, or the anchor bend may be excessive. 5. If molars are flared, excessive torque was used. It is necessary t,o control the molar with elastics and proper arch wire form immediately.
Begg mechanics
269
Fig. 27. Debanding is done in sections to provide good opportunity for natural settling of occlusion before final retention is placed. A, Finishing appliance. B, Segmented band removal has been completed and impressions taken for the positioner. The appliance now acts as a retainer until the positioner is placed. C, Occasionally, only a Hawley and a canine-to-canine retainer are utilized. D, Retained result.
6. If space develops between the upper central incisors, elastics, tie wires or Alastik should be used to control the drift of the incisors. 7. Arch wire distortion or poor form may be due to constricted prcmolars, poor arch symmetry, and improper arch coordination. 8. If a broken arch wire or wire end occurs, it may cause the torque and uprighting springs to force the incisors labially, producing spaces and aberrant distortion of arch form. Theoretically, at the end of Stage III the occlusion is such that the case can be disbanded. In an ideal situation this is true. Practically, however, it is occasionally necessary to make some detailed refinements after Stage III. Although a fourth stage in treatment is not recommended, if it will discipline the operator to evaluate the case thoroughly before he disbands, then Stage IV is a necessity. In reality, few cases will require any advanced postStage III treatment. If the occlusion is not ideal, however, then it is recommended that ideal arches be placed and the finishing touches be undertaken in Stage IV. In this phase of treatment 0.018 or 0.020 inch wires, round wire, square wire, or sectional wire may be used to obtain small movements. Various elastic combinations are utilized to seat cusps. Many simple movements can be accomplished which greatly enhance the final result in a very few weeks or visits at the termination of treatment (Fig. 26). These minor corrections are what tend to reduce the need for positioners in finishing.
270
Thompson
In final phases of treatment, segmented band removal is recommended to permit as much natural settling as possible. Because of the tendency t,o achieve good muscular and skeletal harmony7 with the Begg appliance, it is very desirable to permit as much physiologic settling in retention as possible. A tooth positioner is used to encourage settling in about one half of the cases, This is made from an impression taken with incisor and molar bands in place (Fig. 27, B). The occlusion is then held with arch wires and elastics until the positioner is delivered. At the delivery appointment the bands arc removed and the positioner is placed. The technique permits good response to the positioner since it acts as an immediate posit,ioner. It also permits some free settling of premolars, even before the positioner is placed, and it compensates for the frequent laboratory time delays. The positioner is used 3 to 4 months or less and is t,hen replaced with a lower canine-to-cailin~~ fixed retainer and an upper Hawley retainer. In cases in which no positioner is rcquirtd, the. customary procedure is to deband in segments, allow the teeth to settle naturally, and then place the upper and lower retainers. An upper Hawley and a lower canine-to-canine retainer are routinely utilized ; occasionally, no lower retention is necessary. These retainers permit desirable settling of thr posterior teeth while holding the incisors in their proper position. The upper r&iner is worn at night for varied periods of time from 6 months to indefinitely, depending upon tongue action and severity of original rotations. During t,his time the acrylic along the teeth is removed to free the teeth to settle naturally. Occl~~~l adjustment is done judiciously to stabilize the occlusion and establish centric and functional harmony. Conclusion
Having reached retention, the mechanics of Begg treatment has about been covered. Certainly, it is agreed that basic knowledge is essential to undertake any adventure if it is to be successfully completed, and the Begg treatment is no exception. The purpose of this presentation has not been to persuade anyone to take up the Begg appliance as an answer to all problems in orthodontics. The purpose has been to show the current application of a technique that has revolutionized the thinking of many orthodontists, has made their days easier, their worries less, and their orthodontic practice more satisfying. If an orthodontist decides to use this appliance, he must give it a chance. A suggestion is to treat twenty-five consecutive cases and stay with them. Most men who are dissatisfied or disappointed with Begg treatment became discouraged too easily or complicated the technique with modifications. It works as it was designed; use it that way, have faith in its effectiveness, and the Begg technique will then be a wonderful aid in the total spectrum of orthodontics. REFERENCES
1. Baldridge, Doyle W. : Begg technique clinic, American Begg Society, 1968. 2. Barrer, Harry C.: An evaluation of the Begg technique five years later, Begg 1964. 3. Barrer, Harry C.: Treatment problems-source and elimination, Begg J. 4:
J. 3: 29-34, 59-64,
1968.
Begg mechanics
Volume 62 Nu?7sbev 3
271
4. Begg, P. R.: Differential force in orthodontic treatment, AM. J. ORTHOD. 42: 481-510, 1956. 5. Begg, P. R.: Light wire technique, Ax J. ORTHOD. 47: 30-48, 1961. 6. Begg, P. R.: Begg orthodontic theory and technique, Philadelphia, 1965, W. B. Saunders Company. 7. Begg, P. R.: The origin and progress of the light wire force technique, Begg J. 4: 9-34, 1968. Molar control with the Begg technique, Begg J. 5: 25-33, 1969. 8. Bertrand, J. L.: 9. Kessling, P. C.: A consideration of the first stage of Begg treatment, Begg J. 1: 47-53, 1962. 10. McDowell, C. Stewart: The hidden force, Angle Orthod. 37: 109-131, 1967. 11. McDowell, C. Stewart: Static anchorage in the Begg technique, Angle Orthod. 39: 162-170, 1969. 12. Meeks, James E., Jr.: Begg technique clinic, American Begg Society, 1968. 13. Newman, George V.: A biomechanical analysis of the Begg light wire technique A&r. J. ORTHOD. 49: 721-740, 1963. 14. Parker, William 8.: A consideration of pure Begg technique, Angle Orthod. 39: l-10, 1969. 15. Salzmann, J. A.: Begg orthodontic theory and technique (B. rev.), AM J. ORTHOD. 51: 547-548, 1965. 1G. Sims, M. R.: The Begg philosophy and treatment technique, Begg J. 4: 9-34, 1968. 17. Strang, Robert H.: The value of precision technique, AM. J. ORTHOD. 50: 113-124, 1964. 18. Swain, B. F.: Iw Graber, T. M. : Current orthodontic concepts and techniques, Philadelphia, 1969, W. B. Saunders Company, vol. 2, p. 720. 19. Thompson, W. J.: A critical appraisal of incisor positioning with the Begg technique (unpublished). Presented to Midwestern Component of the Angle Society, Chicago, 1969. 20. Thompson, W. J.: Begg Stage IV, Begg J. 5: 17-24, 1969. 21. Weber, Faustin N.: Clinical investigations related to the use of the Begg technique at the University of Tennessee, AM J. ORTHOD. 59: 24-36, 1971. 22. Williams, Raleigh T.: In Begg, P. R. : The Begg orthodontic theory and technique, Philadelphia, 1965, W. B. Saunders Company. 23. Williams, Raleigh T:. Begg treatment in high angle cases, AM J. ORTHOD. 57: 573-589, 1970. 24. Wiliams, Raleigh T. : Personal communication, 1969. 25. Williams, Raleigh T.: The diagnostic line, AM. J. ORTHOD. 55: 458-476, 1969. 4008
Ninth
Ave..
W.
D.D.S.,
M.S.
A
patient’s care and well-being and an orthodontist’s happiness and security depend on efficient and effective utilization of an orthodontic appliance, regardless of its type, design, or origin. This article will discuss the current application of the Begg appliance as it is presently being used in the correction of malocclusion. Obviously, a brief discussion cannot be thorough enough to teach the complete technical utilization of such a complex multibanded appliance. The intent of this presentation, therefore, is to provide a summary of the various principles, objectives, and problems involved in the various stages of Begg treatment. Enough basic information will be presented to develop confidence and understanding in the appliance by orthodontists who are undecided about using the technique or who are uninformed about its operation and effectiveness. Current technical procedures and recent modifications of technique are also incorporated into the discussion. Several specific teaching philosophies have developed concerning the Begg technique. Many modifications, some slight and some extensive, are evident in the various schools of thought. Those illustrated in this article are the interpretations of the currently accepted principles and applications of the Begg philosophy. The procedures shown are based on pure Begg mechanics. Modifications in technique are presented as the exception rather than the rule; they should be utilized only to enhance the technique, not to alter the differential force system or to mix different theories of mechanotherapy. The four basic areas to be discussed are (1) clinical terminology on what the Begg technique is and how it works, (2) the actual mechanical stages of Begg treatment, (3) problems and pitfalls that may occur and discourage the use of Begg treatment procedures, and (4) why, when, and where the Begg technique should be utilized as a part of a total orthodontic treatment approach. The
Begg
technique:
A
description
The Begg technique can be described as a series of special stages of orthodontic mechanics designed as a system to obtain dentofacial harmony. Begg 245
246
Thompson.
Fig.
1A.
Routine
Class
II treatment.
mechanotherapy has been discussed by its discoverer, Haymond P. Begg, and various other authors as a differential force syst.em.4-7’ 16,I8 The concept demands that the clinician change some of his older ideas of force, anchorage, and speed in treatment, for the technique very nearly approaches an optimum physiologic system. Forces are light and continuous; this is due to a long interbracket distance, a small-diameter wire size, a complex wire design, light elastic forces, and a reduction of friction because of bracket design. Muscle physiology and tooth size and shape become important concerns in the differential movement system, since there is no real attempt to create static or fixed anchorage. Anchor teeth are held in position by occlusal forces, muscular forces, and tooth mass. It is a dynamic type of system; it is controlled by the force vectors established in the design of the arch wire, the Begg attachment
Begg mechanics
Fig. lg. For legend,
see
opposite
247
page.
mechanism, and the intermaxillary forces. Excellent articles by Begg,4-7 Williams,25 McDowell,lO* I1 Kesling,g and others have thoroughly described differential anchorage. An understanding of this phenomenon, of the basic physiology of occlusion, of force vectors, of vertical dimension, of interocclusal space, and of muscular physiology is essential if the clinician is to be fully aware of the complexity of Begg mechanotherapy. One of the great problems with acceptance of Begg mechanics has been the unfortunate implication that it is a simple technique or an automatic appliance. Nothing can be farther from the truth; the Begg appliance and technique are complex and require absolute understanding and precise manipulation. Any appliance so dependent upon a complex dynamic system must be completely controlled or rapid breakdown of the system occurs. In turn, this can only lead to failure and disastrous results, A critical analysis of the appliance and forces must be reviewed continuously throughout treatment. Most tooth movement with Begg mechanics is of a tipping nature-physiologic in character and, therefore, very rapid. Any loss of control obviously leads to a serious misdirection of tooth movement. it must be Pact No. 1: The technique is dynamic, complex, and intricate; thoroughly understood and precisely manipulated or control is lost.
Fig. Indications
for
Begg
2A,
Routine
Class
II treatment.
treatment
Clinical experience with the Begg appliance indicates that it can be used to treat any type of occlusal disharmony-eitllel~ as a. system itself, with certain specific modifications, or in conjunction with surgical or palatal expansive procedures. It can be used effectively in either extra&ion or nonextraction cases if the pretreatment diagnostic evaluation is properly determined and if the The technique has proved principles of the technique are precisely followed. effective in all areas of orthodontic treatment. Very likely, its greatest potcntial is in severe, deep-bite, Class II, discrepancy-type malocclusions (Figs. 1 and 2). Two of the greatest clinical contributions of the technique are its ability to open the bite and its early ~duction of the prot.rusioI~ and crowding. Such
Begg mechanics
Fig.
2B.
For
legend,
see
opposite
249
page.
accomplishments in the first few months of treatment are great advantages. Bite opening reduces occlusal interference; this increases tooth movement and decreases the trauma of intermittent occlusal forces on the teeth and supporting tissues. Reduction of protrusions early in treatment stimulates the patient’s enthusiasm because of the immediate esthetic improvements. The early retraction of incisors and the elimination of crowding also enhance muscular and periodontal reorientation. Early correction means longer perio’ds in the corrected position; it also may be one reason for the decrease in posttreatment retention in many of the cases in which pure Begg mechanotherapy was utilized. Such findings indicate an additional benefit of Begg treatment to both orthodontist and patient, for stability of result is one of the chief requirements in every omrthodontic correction. Many antagonistic theories and opinions have been brought forth condemning the technique for its “round-trip ride,” its tipping action, its occlusal plane changes, and its use of elastic forces. 14px5>I7 Each of these criticisms is gradually being answered by astute research.2r 13, 21,22 Clinically, there is little reason to be plagued by all the apparent problems related to the physiologic changes pro-
250
Thompson
Fig. 3.
The
An
incisally
aid
bite
appliance placed
must anterior
be
constructed
band
and
as
accurately
a gingivally
as placed
all molar
multibanded tube
are
appliances. suggested
to
opening.
duced by tho technique. In fact, clinically, tht! impression is that the results consistently look better, consistently work out with greater ease, and consistently appear to hold up as well as or better than in GISCSt,hat have been finished with other techniques, In a recent evaluation of 100 random cases, it was extremely gratifying to observe the consistent skeletomuscular findings after treatment.‘” The occlusion, the skeletodental patterns, and the faces were most. pleasing-to the orthodontist as well as to the patient; that, in itself, is an additional benefit of the technique. It appeared that these 100 cases were actually treated with an appliance that was being favorably influenced, directed, and limited by the child’s facial pattern rather than by an arbitrary ideal which had been determined from previous training ,averages, and experience. Fact No. 2: When evaluating the appliance, believe what you, see, not what you expect to occur, because the principles do not agree with historical views and opinions. Keeping in mind the idea that the technique is a complex system of moving, reciprocal forces, let us now look at the Begg technique in operation. It is first suggested that in the clinical application of the technique several important things should be accepted as fact and not altered or modified without proper analyses of the effects on the total force system. Experience has shown that
Begg mechanics
Fig. 4. Anchorage occlusal surface and bite opening. before treatment
251
depends upon elimination of the freeway space. Interlocking the of the molars provides the stability of the molar during incisor retraction (After McDowell: Angle Orthod. 37: 109-l 31, 1967.) A, Freeway space is normal. B, Freeway space during treatment has disappeared.
“hodge podge” modification of the appliance or its manipulation leads very quickly to disaster because of the rate of movement in this technique. Modification after due analysis may lead to beneficial refinement, but in Begg treatment, modification on the whim of the operator because he thinks it will help, because it worked with the old system, or because he has not the time to do it as reeommended will lead to immediate problems. Fact No. 3: Listen to those who have gone before; use the appliance and technique as described for the best results; modify it only after complete analysis and understanding. Begg
Stage
I
The objectives of Stage I in the Begg treatment procedure are (I) to open the bite, (2) to correct the anteropoaterior molar relationship to Class I, (3) to unravel anterior teeth, and (4) to begin overcorrections. The Begg appliance must be constructed, as well as other multibanded techniques (Fig. 3). Proper bracket placement is important, and bands must fit soundly. Poor bracket placement and poor band construction produce many difficulties with Begg treatment. The Begg force system depends upon differential forces with free tipping. It is essential that friction not be produced by unnecessary distortion of the arch wire caused by improperly placed brackets or bands. Poor bracket placement also encourages loose bands and distorted arch wires during those periods when the bite is being opened. During bite-opening procedures the molars and premolars are elevated into their anchor positionll (Fig. 4). If the posterior brackets are too high oeclusally, they are constantly being smashed by the occlusion from above. In addition, the anchor bend in these high tubes is subject to distortion by the opposing occlusion. Raleigh Williams”’ and others continuously stress the cervical placement of molar tubes to reduce these traumatic problems and also to assist bite opening. Dr. Williams believes that incisally placed anterior bands and gingivally placed molar bands assist the bite-opening mechanics by setting up more effective depressive forces on the incisors. The fit of bands is important-not only during the bite-opening mechanics, but also during the torque procedures on the incisors. Bands of poor quality or
252
Fig.
Thompson
5.
A,
bends,
and
in the
molar
Anchor
Stage
I archwires
active areas.
bends
deep
into
[After
Kesling,
the
should
anchor
bends.
6, Anchor
should
be The
bends
sufficient
mucobuccal P. C.:
fold Begg
have They
should to
before Journal
all
necessary
should place they 1:47-53,
be be
overcorrections,
coordinated
definite
the
and
round
are July,
but the
0.016
activated
premolar have
arch Stage
by
pinning
slight
wires
bayonet expansion
symmetrical.
I and into
Stage the
C, II
wires
brackets.
1962.)
poor fit frequently are pulled away from the surfaces of the incisors by the torque auxiliaries. Such disappointmc>nts only decrease the extreme effectiveness of a well-designed Begg system. Stage I arch wire formation is also important, since the greatest activation of the arch wire occurs during this time (F’ig. 5). Movement is rapid and cxtreme, and any asymmetry in the wire produces rapid and extreme aberrant changes. Anchor bends should bc adjust,ed to have positive anterior depressive forces on the incisors; the degree of force is determined by placing the 0.016 inch wire so that the anterior srgmcnt is tlccp to the mucobuccal fold when the wire is in the tubes posteriorly. The wire should be adjusted for anterior symmetry before it is placed. Approximately I/$ inch expansion is placed in the wire to assist molar control; canine width must be maintained to keep the tooth in the alveolar trough as the tooth tips distally.
Begg mechanics
253
Fig. 6. Loops
are placed to reduce the forces, increase the range of action of the wire, and produce gentle unraveling of teeth. They must be removed as soon as possible to get better wire mechanics for bite opening. Use the minimum number of loops that will accomplish the task.
Care should be taken not to distort bracket. Such a procedure changes the and constricts the molars into improper areas to increase the action of the wire the teeth or gingiva, and they should
the wire by pinning it into a rotated position of the ends of the arch wire position. Loops are placed in anterior (Fig. 6). The loops must not bind on be overactivated so that the wire will
254
Thompson
Fig. 7. Anchor bends must come out of the buccal tube straight after the wire is activated. A, Incorrect. 8, Correct. C, Toe-in or toe-out bends may be incorporated into the anchor bend
to keep
its position
straight
and
vertical.
overcorrect all rotations and buccolingual malpositions. It may be impossible to pin all teeth with the first wire; ligatures are used until the wire can be pinned with little resistance or distortion of the arch wire. To facilitate bite opening, the highly flexible looped arches should be removed as soon as possible; they are replaced with routine, overcorrected, straight 0.016 or 0.018 inch wires. The wires are adjusted to overcorrect all rotations and labiolingual displacements. The design of the anchor bend is also important in controlling the loop positions (Fig. 7). If the anchor bend does not come out of the tube straight, the wire rolls and the loops move gingivally or labially. The movement causes impingement of the loop on the gingira. The rolled wire may permit the molar to rotate or go lingually, which also reduces bite-opening forces. Toe-in or toeout bends may be necessary to change the arch wire form to compensate for molar roll produced by the anchor bend9 (Fig. 7, C) BertrandS and Barre? have written a great deal about molar control with Begg treatment. Their
Volume Number
62 3
Begg mechanics
255
Fig. 8. Simple aids such as the bayonet bends at the premolars, the sliding lock pins on the canines, and by-pass clamps on the premolars reduce binding and increase efTiciency. A, Proper bayonet bend mesial to the premolars keeps the premolar in good buccolingual position and reduces friction. B, Premolar by-pass clamps reduce friction and eliminate irritating tie wires. C, The sliding lock pin controls anterior spacing but permits free canine tipping. The lock pin slides through the loop as the canine uprights.
articles show conclusively why, when, and how not to be a “molar roller” by using correct anchor-bend design and other controlling adjustments. After the control of bite-opening mechanics, the next important consideration in Stage I is free tipping. All friction areas must be minimized. Three current means used to reduce friction and increase free tipping are bayonet bends to keep the premolar positioned in the arch, sliding canine lock pins, and premolar bypass clamps (Fig. 8). The bayonet bend relieves the lingual constriction force on the premolar which is normally seen when a
256
Thompson
straight wire passes from the molar tube.1 The sliding lock pin ant1 the l)yIlirss clamp merely eliminate troublesome, frequently binding, and Gssuc-irritating tie wires. The three tipping aids-bayonet, bend, sliding lock pin, and bypass clamp-are used throughout Stages I and IT. Elastic pressure is the final consideration to be discussed in Stage I. Elastics are the keys to anchorage, to retraction, and to bite opening. They must be worn 24 hours per day during Stages I and II. The magnitude of the force must be a,ccurately gauged since the light action of the force is the controlling influence on molar and incisor movement or stability. The usual elastic force values for Stages I and II are 11/! to 2M ounces. Hca.vicr forces ctnc*ouragc forward momment of molars, molar tip, molar roll, extrusion of upper incisors, and forward movement of lower incisors. Elastic forces must be light and they must be contjinuous if the differential force mechanics are to function. Cooperation by the patient is essential; in instructions to patients, great emphasis is placed on the importance of elastics. Elastics are never prescribed without tension gauge readings (Fig. 9). Such action confirms the force control while it reinforces the importance of elastics to the patient at each visit. Elastic quality may vary. Bulk elastic supplies should be checked periodically for conformity in size, shape, and cut,. Poorquality elastics mean improper force control. Such a condition can lead to loss of anchorage or poor bite opening. An accurate magnit,ude of force from elastics is of great importance in the differential force system. In summarizing Sta.ge :I, we have arranged ten problem areas that require constant analysis in Stage I : 1. If appliance design is poor, binding, loose bands, and poor hitc opening will result (Fig. 10). 2. If an arch wire is bent or distorted, the anchor bend may be too far forward, molar tubes may be too high, or the wire is of poor quality Fig. 11). 3. When anchor bends are caught in the molar tube, the tipping and retraction of incisors stop (Fig. 12). 4. If loops are impinging on tissue, it may be that the arch wire form is incorrect, anchor bends are wrong, or the loops are too long. One should get the loops out early! 5. Molar rolling. (See Bertrand’s work.8) (Fig. 13.) 6. If the arch wire is hitting the upper second molars or gingival tissue, the resulting binding stops the retraction and tipping of the inincisors (Fig. 14). 7. Canines may be drifting distally unequally. If so, the bracket position may be incorrect, and the canine is extruded ; the sliding lock pin is not used, and the canine is binding ; the canine is interfering with occlusion on the lingual button or the bracket (Fig. 15). 8. If elastics are too light or are not being worn, the orthodontist should check lower first molar tipping (Fig. 16). 9. If premolars look constricted, bayonet bends should be used to keep them positioned buccally. (See Fig. 8, A.)
Fig.
9.
Elastil c t’ ension
should
not
exceed
1112 to
21/2
Inadequate
number
of
ounces
ar lchor
unless
we!
10s s
is
desil .ed. Fig.
10.
pin9
ing
Fig. vor
Poor aF jpliance design. on te eth and tissue.
11 . Poor
)er.
Bite
a fJpliance c ve ning has
design. Band been adversely
height too affected.
low,
bands, molar
loops tubes
too too
long 1ligh,
I Iclops
im-
ela sties
im-
258
Fig. fort
Fig.
Thompson
12.
And
es in cisors
13.
Mola
lor
Am. J. Orth,od. 8eptenzber 3972
bend
or
wire
end
caught
in
the
molar
tube
stops
tiF )pin
lingual
‘9 and
labially. r roll
occurs
extending Fig. 14. Arch wire all Ilingu lal rei .raction.
with
improper through
anchor the
molar
bend
design
tube
may
or too hit
the
strong second
an
el asti ic p\ J/I.
mo lar
an ,d si ‘OP
Begg mechanics
Fig. 15. Occlusal desi red tipping Fig. 16. elm itics.
interference as with the
Panorex
Fig. 17. Open-bites tion . To ngue spurs
shows
due to poor lower canine.
adverse
bracket
tipping
of molar
and tongue-thrust are helpful in these
can hold cases.
height roots back
on
arch
as a result Class
form of
II correction
poor
may
,K
coope and
259
uce
un-
ratic 3n \ Nith
inc :isor
ret rac-
260
Thompson
Fig.
18.
Stage II space
closure
may
involve
six
elastics.
10. When a tongue-thrust is evident, the bite may have been opened excessively and the anterior protrusion will not reduce. A tongue-control device may be needed’” (Fig. 1’7). Stage
II
After the objectives of Stage I have been completed, the clinician can start Stage II. At this point another principal rule should be stated: “Do not mix stages.” One should bring each stage to completion and accomplish each of that stage’s objectives before progressing to the next stage. The appliance is designed to accomplish specific duties with specific force systems, Altering or mixing the stages thereby changes the force system and ca,n lead to serious difficulty with control of anchorage, bite opening, or retraction of incisors. The objectives of Stage II are (1) closure of extraction spaces, (2) retraction of incisors, (3) continuation of bite opening, (4) continuation of anteroposterior correction to slight Class III, and, (5) overcorrection. In Stage II mechanics little change occurs in the arch wire form or force values. The principal difference in the mechanics is that in Stage II, for the first time, anteriorly directed forces are applied to the molar teeth with horizontal elastics (Fig. 18). Anchor molars are now used as the retraction anchorage for space closure and incisor retraction. A properly designed appliance having 2 to 21/ ounce elastic force, good arch form, proper anchor bends, and freedom from binding should permit routine lingual movement of incisors with
Begg mechanics
Fig. 19. Formation in elastics should
of a Class III incisor be used to eliminate
bite is contraindicated, this problem.
and
compensatory
261
changes
little mesial movement of the molars. If anchorage loss is desired, as in borderline space problems or cases requiring minimal anterior retraction, adjustments are made in the appliaace to reduce anchorage. Although mesial movement of molars is usually not desired, it can be accomplished readily with such procedures as placing uprighting springs on canines, tying ligatures tightly to produce binding of canines, and increasing the elastic forces to 4 ounces or more on the molars. Stage II space closure is continued until all spaces are closed. Occasionally it is necessary to stop the use of one or more elastics when one space closes earlier than another. In late Stage II one occasionally will see a Class III type of incisor bite form (Fig. 19). In these instances elastic forces and direction may obviously have to be altered to correct the problem. It is not considered improper technique to alter a basic elastic pattern in any stage to accomplish a specific movement or correct an unforseen problem. Cross-bite elastics, vertical elastics, triangular, or diagonal elastics may be necessary to get an end-to-end incisor bite, to correct a midline, or finally to get the posterior teeth settled into a solid occlusion for starting Stage III (Fig. 20). During the final periods of Stage II it will become easier to see discrepancies in band height or bracket placement. Such findings become more evident POW since the teeth are relatively more even and the severe distortions and
262
Fig. to
Thompson
20.
prevent
Many
elastic
combinations
or eliminate
a problem
may or carry
be
used out
temporarily
a necessary
at
any
time
during
treatment
correction.
irregularities seen in Stage I arc about gone. 11 clear view of the appliance is possible, and any defects should he corrected immediately since this is the final period of change before the complex Stage III is inserted. The appliance and the occlusion should be as ideally set up for Stage III as is possible. Occasionally it is necessary to place a. series of pre-Stage III wires to ensure a truly good base for Stage III (Fig. 21). In our office we routinely place preStage III wires which we label as “base Stage 111.” It is our intent to get the best base possible for the uprighting mechanics. The pre-Stage III wires may simply be routine Stage II 0.016 inch wires re-adapted and pinned to all teeth. Usually, however, they are new 0.01s or 0.020 inch ideal arch wires with rotations overcorrected and wires adapted to seat the premolars and get a solid occlusion. They are left 4 to 6 weeks after which they continue as the base wires for Stage III springs. The pre-Stage III procedure provides a good base for the appliance, because it permits settling to occur which enhances the action of the uprighting and torquing springs. It also reduces the discomfort associated with the placement of the complex Stage III appliance because after the settling has occurred the wire is less rigid in the brackets and placement of the ties and springs is less difficulty. At the completion of Stage II and of pre-Stage III the occlusion should be end to end in the incisor segment and slightly Class III in the molar area, premolars and molars should intercuspate, all spaces should be closed, and the anterior bite should be recessive or “dished in” (Fig. 22). Good anchorage control and good cooperation should produce a moderate to severe lingual inclination of
Begg mechanics
Fig. 21. Pre-Stage Stage auxiliary
III.
Note spring
Ill arch wires the additional on the mandibular
are used to prepare the occlusion movements being initiated with a right central and lateral incisors.
263
for the complicated Sain reverse torque
the incisors. Proper lingual inclination of incisors and good interlock of premolars help to hold the crowns as the roots are uprighted. Lack of tipping and occlusal interlock permits crowns of the uprighting teeth to move and encourages loss of anchorage in Stage III. In passing through Stage II six areas of concern should be watched : 1. If the bite is closing, the clinician should continue elastics and use proper bit-opening bends in the wire. 2. If retraction has stopped (one side or both sides), the tip-back bend may be binding in the molar tube. 3. Retraction may have stopped because the wire is hitting the upper second molars or the tissue distal to the upper first molars. 4. If tipping is stopped on one tooth or generally, a pin is hitting the arch wire, in which case they should be bent mesially, or a bracket slot is pinched or binding, and it should be opened with the T.P. No. 133 pliers. 5. If incisors are locked in Class III, the clinician should stop Class II elastics or go to Class III elastics. 6. If the bite is open and retraction is stopped, an squired tonguethrust has developed, and a tongue spur should be used. The bite should not be allowed open excessively in any stage.
Volume Number
Begg mechanics
62 3
Fig. 23. paralleling arch wire
A slight 5 degree bend between canines and in Stage III. The bend should be very slight is pinned into place because of the pressures
Fig. 24. Alastics also
Stage
convenient
are aids
good auxiliaries in other areas
to aid to control
265
premolars aids retention of and is often not visible after of the uprighting levers.
in space control and molar incisor spaces and rotations.
control.
They
root the are
Ill
Stage III is the final and most complex period of treatment. In this stage all occlusal harmony, functional harmony, and esthetic harmony are established. Uprighting, torquing, and intricate finishing must be done in Stage III. It normally will require as much time as Stage I and II combined, but if the appliance and dentition are properly set up, the entire stage is one of few adjustments and few problems. Some arch wire changes are recommended in Stage III. It is not desirable to have a severe anchor bend. Arch wires should be contoured with only a passive anchor bend. Severe anchor bends tend to affect the molar adversely during root torque mechanics and produce buccal roll of upper molars. The wire may have a slight V bend between the canine and premolar (Fig. 23). It should be 5 to 10 degrees, and it is used to compensate for the depressive force of the uprighting springs, to hold the bite open, and to facilitate holding of the uprighted and overcorrected premolar and molar roots. The bend tends to align the wire with the flat base of the bracket and thus encourages the teeth to stay upright. With heavier arch wires it is not necessary to constrict the maxillary arch wire extensively to compensate for the torque forces. Molar position can be controlled with the heavier 0.018 or 0.020 inch base wire with only slight constriction and very little anchor bend. The windlass ties are thought by some to be unnecessary; our findings indicate that if a molar-to-canine tie is not
to
use
the
Occasionally
in control
aid
III
may
elastics
be
may
width
proper
as
long
arch
as
both
maintaining in
relationships.
eliminated
while
be
as necessary.
arch
control
of
elastics
to
Stage
25.
elastics
Fig.
of Stage
III
A, overbite
Stage
if
Class
crossbite
Stage
overbite
and
Note
I and
elastic and
overjet
are
B,
from
Occasionally,
I occlusion.
Il.
it
is
routine
without
Class
second
necessary lower maintained
Note
the
to
alter
the
The
elastics them.
II
premolars
keep
the patient
to
to
number,
size,
can
the
upper be
instructed
bite
open.
direction canines
or
to
k -21. 2: k+r E\ :o *,
Begg ~nechalzics
267
used, one must continuously check for molar rotations (Fig. 24). Alastik links are used to hold the molar from rotating and to aid in keeping the extraction sites closed. These are easily placed, they hold adequately, and they provide the advantages of the old-style windlass tie with none of its disadvantages. Stage III arch wires are tied with ligatures before springs are placed as a safety control, even though the newer springs are self-locking. A tooth that gets away from the wire during uprighting can be seriously affected by the free spring force. The premolars are tied to the distal, and the canine and lateral incisor are tied to the mesial. The ends must be short, so as not to bind on the arch wire and prevent uprighting. Usually 0.014 inch springs with a double or triple helix are used to make insertion easy and prolong the helix action. The springs should be placed so as to permit free movement of the lever arm during uprighting. The springs must be checked so that they do not hit each other, torquing loops, brackets, or bends in the arch wire. It is also necessary to be sure the action is not taken out of the loop as the spring is activated. The torquing arch is formed from 0.014 or 0.016 inch wire. Preformed 0.016 inch arch wires are selected from preformed kits according to size. Several styles of anterior torquing wires are now accepted. Some are believed to provide less distortion o’f the wire at the canine area. Others are designed as additional add-on auxiliaries. Clinically, it appears that any will provide effective torque, and the degree of success depends primarily on the freedom of the auxiliary, the degree of action of the loop, and the length of time it is acting. Most error seems to be the tendency to stop torquing too early. Head films are recommended at Stage III to check torque by the SN 1 angle. An average of 103 degrees is suggested. In 100 random cases the average torque value at the end of treatment was 98.5 degrees, and this was found to be quite cosmetic and functional in appearance.ls Many cases require only a two-finger torque spring; this is especially true when lateral incisors are flared. In such cases, a twofinger torque will be adequate, since the uprighting spring tends to keep the lateral incisor in position. The degree of torque force is controlled by the form of the torque wire, including the angle of the torque loop and the constriction of the arch wire. Forty-five degrees of angulation of the loops is a good standard. The arch wire itself can be contoured to form a circle about the size of a fivecent piece. Stage III is by far the longest and most intricate of stages (Fig. 25). Usually it will last 4 to 6 months, and it may be double that in some cases. Six-week intervals between visits is the desired interval, since the springs are continuousaction springs and do not require or need frequent adjusting. As the teeth are uprighted, it is desired to overcorrect the action so that some of the rebound will be compensated for when the springs are removed. As teeth reach their desired position, the springs can be deactivated; usually their removal is contraindicated until both the adjacent springs can be removed together. During Stage III several areas must be observed closely for problems : 1. If the base wire is bent from occlusal trauma in the first molar areas, arch form is destroyed and the occlusion is distorted.
260
Thompson
Fig.
26.
duration square with D,
Finishing
movements
but
add
to
for
final
wire torque
Ideal
arch tionals
wire
changes
in buccal
C,
form
of
arch
auxiliary. arch
may
quality
with to
double
the
be
necessary
result.
alignment
A,
and
after
Stage
Coordinated seating
of
Anterior
torque upper
anterior
root
molar
leveling.
F, Auxilliary
tubes
second to control
second
molar
using
They 0.018
cusps.
additional
control
correction
III. ideal
are
usually
inch,
B, Anterior Sain
control.
root
reverse
torque
E, Auxiliary 0.016
or
of
0.020
or
positioning springs. bands
0.018
short
inch,
inch
and sec-
position.
2. If uprighting arms are not free, the lever arm must be freed t,o move as tooth uprights. 3. Springs must be active. They must be checked at each visit to be sure that they have not become passive. 4. If molar rotation occurs, a windlass map uot have been used, arch form may be poor, or the anchor bend may be excessive. 5. If molars are flared, excessive torque was used. It is necessary t,o control the molar with elastics and proper arch wire form immediately.
Begg mechanics
269
Fig. 27. Debanding is done in sections to provide good opportunity for natural settling of occlusion before final retention is placed. A, Finishing appliance. B, Segmented band removal has been completed and impressions taken for the positioner. The appliance now acts as a retainer until the positioner is placed. C, Occasionally, only a Hawley and a canine-to-canine retainer are utilized. D, Retained result.
6. If space develops between the upper central incisors, elastics, tie wires or Alastik should be used to control the drift of the incisors. 7. Arch wire distortion or poor form may be due to constricted prcmolars, poor arch symmetry, and improper arch coordination. 8. If a broken arch wire or wire end occurs, it may cause the torque and uprighting springs to force the incisors labially, producing spaces and aberrant distortion of arch form. Theoretically, at the end of Stage III the occlusion is such that the case can be disbanded. In an ideal situation this is true. Practically, however, it is occasionally necessary to make some detailed refinements after Stage III. Although a fourth stage in treatment is not recommended, if it will discipline the operator to evaluate the case thoroughly before he disbands, then Stage IV is a necessity. In reality, few cases will require any advanced postStage III treatment. If the occlusion is not ideal, however, then it is recommended that ideal arches be placed and the finishing touches be undertaken in Stage IV. In this phase of treatment 0.018 or 0.020 inch wires, round wire, square wire, or sectional wire may be used to obtain small movements. Various elastic combinations are utilized to seat cusps. Many simple movements can be accomplished which greatly enhance the final result in a very few weeks or visits at the termination of treatment (Fig. 26). These minor corrections are what tend to reduce the need for positioners in finishing.
270
Thompson
In final phases of treatment, segmented band removal is recommended to permit as much natural settling as possible. Because of the tendency t,o achieve good muscular and skeletal harmony7 with the Begg appliance, it is very desirable to permit as much physiologic settling in retention as possible. A tooth positioner is used to encourage settling in about one half of the cases, This is made from an impression taken with incisor and molar bands in place (Fig. 27, B). The occlusion is then held with arch wires and elastics until the positioner is delivered. At the delivery appointment the bands arc removed and the positioner is placed. The technique permits good response to the positioner since it acts as an immediate posit,ioner. It also permits some free settling of premolars, even before the positioner is placed, and it compensates for the frequent laboratory time delays. The positioner is used 3 to 4 months or less and is t,hen replaced with a lower canine-to-cailin~~ fixed retainer and an upper Hawley retainer. In cases in which no positioner is rcquirtd, the. customary procedure is to deband in segments, allow the teeth to settle naturally, and then place the upper and lower retainers. An upper Hawley and a lower canine-to-canine retainer are routinely utilized ; occasionally, no lower retention is necessary. These retainers permit desirable settling of thr posterior teeth while holding the incisors in their proper position. The upper r&iner is worn at night for varied periods of time from 6 months to indefinitely, depending upon tongue action and severity of original rotations. During t,his time the acrylic along the teeth is removed to free the teeth to settle naturally. Occl~~~l adjustment is done judiciously to stabilize the occlusion and establish centric and functional harmony. Conclusion
Having reached retention, the mechanics of Begg treatment has about been covered. Certainly, it is agreed that basic knowledge is essential to undertake any adventure if it is to be successfully completed, and the Begg treatment is no exception. The purpose of this presentation has not been to persuade anyone to take up the Begg appliance as an answer to all problems in orthodontics. The purpose has been to show the current application of a technique that has revolutionized the thinking of many orthodontists, has made their days easier, their worries less, and their orthodontic practice more satisfying. If an orthodontist decides to use this appliance, he must give it a chance. A suggestion is to treat twenty-five consecutive cases and stay with them. Most men who are dissatisfied or disappointed with Begg treatment became discouraged too easily or complicated the technique with modifications. It works as it was designed; use it that way, have faith in its effectiveness, and the Begg technique will then be a wonderful aid in the total spectrum of orthodontics. REFERENCES
1. Baldridge, Doyle W. : Begg technique clinic, American Begg Society, 1968. 2. Barrer, Harry C.: An evaluation of the Begg technique five years later, Begg 1964. 3. Barrer, Harry C.: Treatment problems-source and elimination, Begg J. 4:
J. 3: 29-34, 59-64,
1968.
Begg mechanics
Volume 62 Nu?7sbev 3
271
4. Begg, P. R.: Differential force in orthodontic treatment, AM. J. ORTHOD. 42: 481-510, 1956. 5. Begg, P. R.: Light wire technique, Ax J. ORTHOD. 47: 30-48, 1961. 6. Begg, P. R.: Begg orthodontic theory and technique, Philadelphia, 1965, W. B. Saunders Company. 7. Begg, P. R.: The origin and progress of the light wire force technique, Begg J. 4: 9-34, 1968. Molar control with the Begg technique, Begg J. 5: 25-33, 1969. 8. Bertrand, J. L.: 9. Kessling, P. C.: A consideration of the first stage of Begg treatment, Begg J. 1: 47-53, 1962. 10. McDowell, C. Stewart: The hidden force, Angle Orthod. 37: 109-131, 1967. 11. McDowell, C. Stewart: Static anchorage in the Begg technique, Angle Orthod. 39: 162-170, 1969. 12. Meeks, James E., Jr.: Begg technique clinic, American Begg Society, 1968. 13. Newman, George V.: A biomechanical analysis of the Begg light wire technique A&r. J. ORTHOD. 49: 721-740, 1963. 14. Parker, William 8.: A consideration of pure Begg technique, Angle Orthod. 39: l-10, 1969. 15. Salzmann, J. A.: Begg orthodontic theory and technique (B. rev.), AM J. ORTHOD. 51: 547-548, 1965. 1G. Sims, M. R.: The Begg philosophy and treatment technique, Begg J. 4: 9-34, 1968. 17. Strang, Robert H.: The value of precision technique, AM. J. ORTHOD. 50: 113-124, 1964. 18. Swain, B. F.: Iw Graber, T. M. : Current orthodontic concepts and techniques, Philadelphia, 1969, W. B. Saunders Company, vol. 2, p. 720. 19. Thompson, W. J.: A critical appraisal of incisor positioning with the Begg technique (unpublished). Presented to Midwestern Component of the Angle Society, Chicago, 1969. 20. Thompson, W. J.: Begg Stage IV, Begg J. 5: 17-24, 1969. 21. Weber, Faustin N.: Clinical investigations related to the use of the Begg technique at the University of Tennessee, AM J. ORTHOD. 59: 24-36, 1971. 22. Williams, Raleigh T.: In Begg, P. R. : The Begg orthodontic theory and technique, Philadelphia, 1965, W. B. Saunders Company. 23. Williams, Raleigh T:. Begg treatment in high angle cases, AM J. ORTHOD. 57: 573-589, 1970. 24. Wiliams, Raleigh T. : Personal communication, 1969. 25. Williams, Raleigh T.: The diagnostic line, AM. J. ORTHOD. 55: 458-476, 1969. 4008
Ninth
Ave..
W.