Extraction patterns for begg treatment in orthodontics /certified fixed orthodontic courses by Indian dental academy

Extraction patterns for
Begg Treatment
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INDIAN DENTAL ACADEMY
Leader in continuing dental education

Introduction

Since the beginning of orthodontics, mechanical
therapy has been used to create space for
crowded teeth.
Space - created in three ways:
expansion of the dental arch,
lengthening of the dental arch, and
extraction of teeth or any combination of the three.

‘to extract or not to extract’ – key qn.- planning
ortho trt.
2 major reasons for extraction:


Severe crowding – provide space – remaining teeth.



protrusion or camouflage Sk Cl II or Cl III.


Historical Background
Great Extraction controversy – 1920’s.
Occlusal concepts  def. of normal occlusion.
Potential complications:
Facial esthetics.
Stability of results.

Angle influenced by:
Philosophy of Rousseau & biologic concepts of his
time.
Rousseau  perfectibility of man

Extn. for ortho trt. – inappropriate.
Inherent capability – perfect dentition.
Ideal relation of 32 natural teeth.

 Angle impressed by discovery
Bone architecture  stresses placed.
1900’s – German Physiologist – Wolff
“Wolff’s law of bone” – bone trabeculae arranged in
response to stress lines on the bone.

Two Key Concepts.
Skeletal growth – infl. by external pressures.
Class II or Class III  problem – abnormal
stress on jaws.
Difft. pressure patterns – with trt – change
growth  overcome problem.

Proper fn.  Key – maintain teeth in correct
position.
teeth in proper occl. – force transmitted to teeth
– stimulate bone growth – stabilize teeth in new
position.
Edgewise appl. – “Bone growing appliance” –
capable of controlling root posn. – bodily
movement.

Dentofacial Esthetics:
Professor Wuerpel – tremendous variety – impossible to
specify – ideal.

Angle’s insight:
Reln. of dentition to face
&

VARY

esthetics of lower face
Ideal esthetics for each individual – teeth in ideal
occlusion


Calvin Case’s challenge:
arches expanded – teeth aligned – neither esthetics nor
stability satisfactory – long term.

Re-introduction of extraction.
1930’s – relapse observed.
Charles Tweed – retreated with extrn. – four 1st PM’s 
stable results.
Reintroduction – 1940’s.
Raymond Begg, Australia – Non extn – unstable  Extn.
Trt. with Begg appliance.

Stockards breeding experiments – crossbreeding
dogs
Malocclusion – inherited.

Begg’s – Attritional occlusion studies.

Extraction – necessary.
Recent Trends.
decline in extraction rates.
PM extn – no guarantee of stability.
Public preference – more prominent lips.

“Neo – Angle” school of Treatment planning.

Rational contemporary view:
majority – trtd without removal of teeth.
some require extn. – compensate for:
Crowding, incisor protrusion  facial esthetics
or jaw discrepancy.
Contemporary Extn. Guidelines. –
Cl I crowding & protrusion.
<4mm discepancy –extn. Indicated.
 5- 9mm – extn.or non. extn.
>10mm – Extn. Almost always.

Extraction trt. & Begg technique.
Dr. Begg’s studies – Stone Age Man’s dentitionAttritional occlusion.
Natural wearing away of tooth – not seen in modern
man – dietary refinements.
Evolutionary progress – Smaller jaw bones.


Primary cause of Malocclusion.
Reduction in tooth str. – extn. & stripping 
modern substitute for attrition.

Five factors – considered – case requiring extn.
Arch length problems:
tooth size to jaw discrepancy – civ. Man.
tooth extn.- in tooth sub. – fnly. stable occlsn.
Anchorage values.
rate of tooth movement α total root surface area.
force kept constant.
Growth tendencies.
assess adult size of tooth bearing parts of the jaws.
Relative to – total M-D width – full complement of
teeth.

Soft tissue analysis.
extn – influence – relative posn. of upper lip, lower
lip; nasolabial angle & prominence of chin.
Organized occlusion.
impt. role in selection of teeth for extn
Esp. in cases with missing laterals & mandibular
2nd PM’s.

Choice of Extraction.
essential to discard – automatic or routine
decision – which teeth to extract.
Refinement in diagnostic aids,
Changes in
Sophistication in mechanotherapy,
Understanding of growth & Dev.
objectives
of trt.

ability of the orthodontist to move teeth
 variety of choices other than Ist bicuspids.

Four first Premolars.
Dr. Begg  when indicated, all 4 1st PM’s – teeth
chosen.
Reasons:
1st PM’s – closer to ant. region – crowding seen.
Ease of appl. Therapy – teeth close to the crowding
region.

Smallest occlusal surface – masticatory fn.
not hampered.
Cuspids – good proximal contact – 2nd PM.
maintain – normal physiologic fns.
Esthetic appearance – not ruined – when
extd.
Approx.7.5 mm space gained on each side.


Study – Raliegh Williams & Fred
Hoslla ( AJO 1976).
Amount of incisor retraction – difft.
extns.
4 1st PM extn. –
66.5% of extn space – ant. retraction.
Mean distal movement – ant.
10.3mm.
Post. Anchor unit – 5.2mm

1st

PM,
34.50%

1st PM,
66.50%


ant. retraction
post . Movmt.

Controversial issues:
Etiologic factor in TMJ disorders –
over retraction – displ. of condyle post.
 vertical dimension of occlusion.
 Julie Ann Staggers ( 1994 AJO )– proved
wrong.
Changes in V.D – Not difft. – occuring in nonextn. cases.


Four Second Premolars
Orthodontic trt. with Begg – border line cases –
good facial profile & mild crowding – challenge.

In 1965, Henry gave two basic criteria for extraction of
second bicuspids:
1. A mild degree of crowding and a good profile.
2. No crowding and a fullness of the lips.

De Castro - mammalian dentition arrangement of three independent segments—
an anterior segment ending at the canines & two
posterior segments.
Second premolar extracted –
middle of the posterior segment, - this segment
is shortened.
first premolars extracted,
posterior segments & transitional areas are
disturbed

The indications for second premolar extraction are:
 Good profile + mild crowding.
 Flat profile + moderate crowding.
 Class II division 1 arch relation on Skeletal I base
with mild mandibular crowding .
 Mild Class III arch relationship with mild
crowding in maxillary arch.

The advantages of this approach :
Original facial contours - maintained, without
reduction of lip profile.
Maxillary first premolar - esthetic tooth
alongside a canine.
less tendency for extraction spaces to reopen in
the mandibular arch.

 buccal or lingual bone furrows in the
extraction area,  rapid space closure.
Maintain – correct mand. canine width.
Proper axial position of canines.
Canine protection – better – canine 1st PM
combination.

Begg – 2nd PM extn -

likelihood of relapse.
Extract – when carious or faulty – formation.

De Castro (1974 AJO). – findings:
Deliberate molar movement - > 2.5 mm on each side,
requd.
Average extn case – no change in facial profile.
> 5mm disc.- good profile at start of trt.
Post. Crowding – 2nd or 3rd molars / impactions .

Upper first & lower second PM’s
Indications:
Lower cuspids & ant. well placed.
To correct MO – protract molars. Eg; Class II reln.
Pathology ( Caries , malformed etc. )

Advantages:
Contact b/w cuspid & 1st PM – lower arch undisturbed.
Good occlsn. Upper 2nd PM & lower 1st PM &
Molar.

Disadvantages:
Mechanotherapy – difficult[ distalization of 1st PM –
lower arch.]
Narrow distal surface of 1st PM. – Contact not as
desirable as with 2nd PM.


Willliams & Hoslla ( ’76
AJO)

–

 Mean forward movmnt. –

43.70%
56.30%

anchor unit  7.2mm.
 Actual mean rtrcn.  9.3 mm.
Space utilized for retrcn. – 56.3%


ant.
post.

Maxillary & Mandibular first molars
Indication:
Any form of pathology – necessitating – extn.
Endodontically treated teeth / multifilled teeth.
Missing molars ( premature extn.)

Disadv:
Site of extn. – far from site of crowding.
necessary to move 10 teeth in each arch.
Mechanics – complicated.
Relapse – mesial migration of 10 teeth – greater amt.
of ant. translation.

Williams & Hoslla:Forward movement of post. teeth – 13.9 mm.
Ant segment – 6.3mm.
Space used for retraction – 31%


Maxillary & Mandibular 2nd molars.
Extd. very rarely for orthodontic purposes.
Indications:
 Severely carious, ectopically erupted or severely rotated.
 Mild discrepancies, good facial profiles.
 To facilitate molar distal movt.
 Class II Sk.cases – mild mandibular crowding.

Prerequisites:
Third molars present – normal size & shape.
No congenitally missing teeth.
Third molar inclination – 15 – 30° - long axis of 1st molar.

Advantages
 amount and duration of appliance therapy
 Disimpaction & Faster eruption of third molars
 Prevention of "dished-in'' appearance of the face
 Prevention of "late" incisor imbrication
 1st molar distal movement


Distal movement of the dentition only as
needed to correct the overjet
"residual" spaces – less - end of orthodontic
treatment
 relapse
Good functional occlusion
Good mandibular arch form
 incisal overbite


Disadvantages.
Extraction site - far - in moderate-to-severe
anterior crowding
 patient cooperation - wearing appliances moving the dentition to the distal ''en mass"
Possible impaction of third molars even with
second molar extraction
 Frequently unacceptable positions of erupted
third molars
second, late stage of fixed-appliance therapy.

Staggers (1990 AJO):
compared results – 1st PM & 2nd Molar extn.
Not much diff. in findings.
Amount of ant. retraction
Protraction of first molars
in PM gp.
Retraction of lower lip
Facial profile change
- in 2nd molar gp.
Not statistically sig.
Third molar angulation – OPG – not stat. sig.

Eight tooth Extraction
Incidence – 0.5% of cases – Lyman Wagers ( JCO 1977)
Rationale.
Goals in trt. –
mand incisor - + 2° AP Line.
interincisal angle - 130°.
1 – Sn =100°
In severe discrepancy cases – to achieve – goals.
High mand. plane angle – no room – post. roots –
moved back.

Problems:
Lack of proper molar control – tipping
mesiolingually.
Biting archwire – unwanted bends.
Williams & Hoslla:
Mean forward movement – 18.6 mm.
Ant. retraction
- 18.3 mm.
50% space utilized for retraction of ant. segments.


Single Arch Extractions
Indications:
Class II div I- perfect lower arch alignment & incisor
position.
Growth expectations – inadequate – non extraction.
Non – extn. – tried.
Class II div I with mild openbite.


Upper first premolars
Choice of extn. – amount of space requd. –
region.
Good molar interdigitation,
Space requirement – 15 mm ant to 2nd PM’s.

Profile improved.
Esthetics improved.
Masticatory fn. optimum.


Problems encountered:
Molar reln. Still in class II.
Reopening – space behind canine.
Partial relapse of upper incisor protrusion.
Mesial tipping of upper 1st molar – lingual cusp
plunging b/w lower first molar & 2nd PM.

Upper first molars
Adv. over 1st PM extn: ( Raliegh Williams AJO 1979)
Space behind canine – does not reappear.
Buccal interdigitation normal – U 2 PM’s x L 2 PM’s
2nd molar – Class I reln. with lower 1st molar.
cusp fossa reln. normal.
Upper 3rd molars – can erupt succesfully.


Other Adv.
Tuberosity – not crowded – distal movmnt. of
molars.
Min. patient co-operation.
results stable in A-P dimension.
No retention in lower arch.
Post trt. profile excellent – upper and lower lips
balanced.
Ultimate appearance – no extns.

Precautions:
Strap lower arch alsoLevel the lower arch.
Minor interarch adjustments – Class II or Class III
elastics

Not even slightest crowding in lower arch.
Curve of spee – should not be significant
Upper 3rd molars – present.

Upper 2nd molars.
Recommended by Graber ( AJO 1969).
In class II div I (1) there is excessive labial inclination of the
maxillary incisors, with no spacing;
(2) overbite is minimal; and
(3) third molars are present in the maxilla, in good
position and of proper size and shape.

3rd molar
erupting


Advantages:
 in trt. time and appl. use.
Molar distalization easier.
Bite opening effective.
Less adverse effect on profile.

Disadv.
More loss of tooth subs.
 dist form site of crowding.
Overeruption of L 2nd molars.
Uncertainty of third molar eruption

Lower first molars or 1st PM’s.
Trt. Of Class III MO –
Problem –
large lower arch & jaw.
Space analysis – if extn. Requd – L 1st Molars or L 1st PM’s.
Teeth ant to extn site retracted.

Unilateral Extractions.
Very seldom.
Single lower incisor extn. – in this category
Well formed arches, major midline shift,
Class II on one side, Class III on other.
Extn. ltd. to – class II side.
Lower arch, Class II side – protracted.
Class III side – retracted


Class I

Single lower incisor.
Indications:
Periodontally involved incisor.
Widening of mand. Intercanine width – prevented.
narrow arch forms, severe crowding
non extn – incisors finish forwards – “prow of a
boat” – ( Riedel )

Advantages:
Maintains or


intercanine width.

retention period.

Ant. segments - retracted readily.
Anchorage loss
 overbite – readily accommplished.
Co-op.- wearing of elastics
Mechanotherapy simplified.

Disadvantages:
Tendency – space opening.
Danger of tooth size disc.
eg. In extn of mand incisors with max. PM’s.
Color diff. b/w – lateral & canine.
Incising impaired.

Conclusion
A particular malocclusion can be treated with
more than one approach. The astute and the
learned clinician will treat each individual
patient with the approach that provides him
with the best results.
The success or failure of of orthodontic treatment
is not often the result of the teeth extracted. It is
dependent on the ability of the clinician to
properly diagnose the malocclusion and
skillfully use the appropriate appliance to
provide optimal functional and esthetic results

Leader in continuing dental education


Extraction patterns for begg treatment in orthodontics /certified fixed orthodontic courses by Indian dental academy

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