Optimum orthodontics – how to move teeth without

Optimum orthodontics – how to
move teeth without root resorption
?
www.indiandentalacademy.com

INTRODUCTION
The main goal of orthodontic treatment is to
improve the form and function of orofacial
complex. Optimally , efforts to reach this goal
should be performed efficiently causing no
discomfort to patient and without long lasting
tissue damage .

Optimum orthodontic force is defined by NICOLAI as
that which produces a maximun of desirable biologic
response with minimum tissue damage , resulting in
rapid tooth movement with little or no clinical
discomfort .
Optimal Orthodontics is a mode of treatment whereby
malocclusions are treated efficiently, producing
excellent results without causing any permanent
tissue damage .

ROOT RESORPTION
• Apical root resorption is a common idiopathic
problem associated with orthodontic treatment
and has recently received considerable
attention because of medicolegal exposure.
Loss of apical root material is unpredictable
and, when extending into the dentin it is
irreversible.

• Histologic studies report a high incidence,
whereas clinical studies reveal a more varied
incidence. Extensive postorthodontic root
resorption compromises the benefits of an
otherwise successful orthodontic outcome.
However, most root loss resulting
from orthodontic treatment does not decrease
the longevity or the functional capacity of the
involved teeth.

• Although most root resorption studies
attempt to investigate the etiologic factors
and predictability of this phenomenon, its
origins remain obscure. *Individual
susceptibility,* hereditary predisposition,
*systemic,* local, and *anatomic factors
associated with orthodontic
mechanotherapy are commonly cited
components

• Bates, in 1856, was the first to discuss root
resorption of permanent teeth.
• Ottolengui, in 1914, related root resorption
directly to orthodontic treatment.
• In 1927 Ketcham, demonstrated, with
radiographic evidence, the differences between
root shape before and after orthodontic
treatment. This was followed by a wide range of
histologic, clinical, and physiologic research on
root resorption and orthodontic treatment.

Root resorption of the permanent teeth is a complex
biologic process of which many aspects still remain
unclear.
Phillips, Reitan, and Shafer et al enumerated the various
major factors causing root resorption of permanent teeth:
• physiologic tooth movement,
• adjacent impacted tooth pressure,
• periapical or periodontal inflammation,
• tooth implantation or replantation,
• continuous occlusal trauma,
• tumors or cysts, metabolic or systemic disturbances,
• local functional or behavioral problems,
• orthodontic treatment,
• idiopathic factors

Andreasen(1988) defines three external root
resorption types:
• surface resorption, is a self-limiting process,
usually involving small outlining areas followed
by spontaneous repair from adjacent intact parts
of the periodontal ligament.
• inflammatory resorption, here initial root
resorption has reached dentinal tubules of an
infected necrotic pulpal tissue or an infected
leukocyte zone.
• replacement resorption, here bone replaces
the resorbed tooth material that leads to
ankylosis.

• According to Tronstad,(1988) inflammatory resorption is
related to the presence of multinucleated cells that
colonize the mineralized or denuded cemental surface.
He characterizes two kinds of inflammatory resorption.
• Transient inflammatory resorption occurs when the
stimulation to the damage is minimal and for a short
period. This defect is usually undetected radiographically
and is repaired by a cementum-like tissue. When
stimulation is for a long period, he suggests the term
progressive inflammatory resorption.

• Ankylosis is the result of an extensive necrosis of the
periodontal ligament with formation of bone onto a
denuded area of the root surface. Since the tooth
becomes a part of the bone, normal remodeling process
will gradually lead to a complete destruction of the tooth
by the bone, replacement resorption.
• Root resorption after orthodontic treatment is surface
resorption, or transient inflammatory resorption.
Replacement resorption is rarely if ever seen after
orthodontic treatment.

• Orthodontic forces applied to the biologic system
act similarly on bone and cementum, which are
separated by the periodontal membrane. If there
are no differences in the biologic behavior of
these two organs, both would resorb equally.
Since cementum is more resistant to resorption
compared with the more vulnerable bone,
applied forces usually cause bone resorption,
which leads to tooth movement. However,
resorption of the cementum and dentin may also
occur.

• It is documented that the uncalcified
mineral tissues, osteoid, precementum,
and predentin are resistant to resorption
and may initially prevent loss of root
tissue. However, continuous pressure will
eventually lead to resorption of these
areas.

FACTORS AFFECTING ROOT
RESORPTION
• Biologic factors
• Mechanical factors
• Combined biologic and mechanical factors

Biologic factors
• Individual susceptibility is considered a major factor
in determining potential root resorption with or
without orthodontic treatment.(Reitan AO 1974) This
potential exists in the deciduous and permanent roots
of all persons, and in varying degrees in different
teeth.
Studies show that asians are less prone to root
resorption than white or hispanic (AJO 2001 Glenn)

• Genetics.
• Several studies strongly suggest a genetic component
for shortened roots. Although no definite genetic
conclusion was found, autosomal dominant,
autosomal recessive, and polygenic modes of
inheritance are possible. (Newman AJO 1975)
• AJO 2003 Riyad Found that polymorphism of IL-1
cluster genes is found in the periodontium during
tooth movement has a role in tissue resorption . So
they found linkage disequlibrium of IL-1b
polymorphism which clinically manifest as EARR

Systemic factors.
According to Becks, endocrine problems including
*hypothyroidism,* hypopituitarism,
*hyperpituitarism, and other diseases are related to
root resorption. This hypothesis, based on basal
metabolic rates, has not been examined by updated
blood analyses.
Hyperparathyroidism, *hypophosphatemia, and *Paget
disease have been linked to root resorption in a few
case reports. It has been suggested that hormonal
imbalance does not cause but influences the
phenomenon.(Linge and Linge 1983 EJO)www.indiandentalacademy.com

AJO1988 Engstrom et al,
• A controlled animal study did not support the
hypothesis that secondary hyperparathyroidism
is primarily responsible for increased root
resorption.
• A further study(AJO 1984 Goldie and King) suggested
that the parathyroid hormone plays a major role
in bone metabolism, but that low calcium levels
are necessary for root resorption to occur.
Calcium ions are reputed to play an important
role in mediating the effects of external stimuli
(force, hormones) on their target cells.

Nutrition.
Marshall advocated that malnutrition can cause root
resorption.
Becks demonstrated root resorption in animals deprived of
dietary calcium and vitamin D.
It (EJO 1983 Linge and Linge) was later suggested that
nutritional imbalance is not a major factor in root resorption
during orthodontic treatment.

Chronologic age.
All tissues involved in the root resorption process show
changes with age.
• The periodontal membrane becomes less vascular,
aplastic, and narrow,
• the bone more dense, avascular, and aplastic, and
• the cementum wider.
These changes are reflected by a higher susceptibility to root
resorption seen in adults.
The relationship between root resorption,
orthodontic treatment and patient age was investigated. A
positive relationship between these parameters was often
reported, showing that root resorption is more prevalent
in adults (Linge and Linge).

AJO 2000 April they found that as age increases the
center of resistance moves apically , due to the marginal
bone loss and idiopathic root resorption, but its relative
distance from the alveolar crest decrease at the same
time and the center of rotation moves cervically . The
moment to force ratio has to be increased for bodily
movement .

• Linge and Linge showed that less resorption was
seen in patients treated before the age of 11, due to
preventive effect of thick layer of pre dentine in
young developing roots . They suggested that root
resorption could be avoided if tooth movement is
completed before the roots were fully developed .
• Only a few studies showed no relationship
between apical root loss and patient age at
orthodontic treatment. Massler and Malone claimed
that even without orthodontic treatment, the incidence
of root resorption increases with age.

Gender.
Treated and untreated random samples showed no
correlation between gender and root
resorption.According to other studies females are more
susceptible to root resorption (Newman AJO1975)
Habits.
Nail-biting, tongue thrust associated with open bite.
(BJO1985 Odernick) and increased tongue pressure
have been statistically related to increased root
resorption (AJO1992 Harris and Butler)

Tooth structure:
Deviating root form is more susceptible to postorthodontic root
resorption (AJO 1975Newman). The degree of root resorption
in teeth with blunt- or pipette-shaped roots was significantly
higher than in teeth with normal root form. The pipette-shaped
root was shown to be the most susceptible root form to root
resorption (Levander EJO1988)
Previously traumatized teeth:
Traumatized teeth can exhibit external root resorption without
orthodontic treatment. Orthodontically moved traumatized
teeth with previous root resorption are more sensitive to
further loss of root material. The average root loss for trauma
patients after orthodontic therapy was 1.07 mm compared
with 0.64 mm for untraumatized teeth.(Linge and Linge
EJO1983) Traumatized teeth without signs of resorption are
not resorbed more than nontraumatized teeth (AJO1982
Goldson)

Endodontically treated teeth
During orthodontic treatment ,a higher frequency
and severity of root resorption of endodontically
treated teeth was reported (AO1974 Wickwire).
However, it has also been suggested that
endodontically treated teeth are more resistant
to root resorption because of an increased
dentin hardness and density (AJO-1989 Riedel)

Alveolar bone density
Several investigators found that the more dense
the alveolar bone, the more root resorption
occurred during orthodontic treatment.
(AJO1984 Goldie) In a less dense alveolar bone,
there are more marrow spaces. Tooth
movement, as a result of bone resorption, is
facilitated by the formation of active resorptive
cells, the number of which increases according
to the number of marrow spaces.

• According to Reitan,a strong continuous force on
less dense alveolar bone causes the same root
resorption as a mild continuous force on highly
dense alveolar bone. Lamellar bone is more
difficult to resorb with orthodontic pressure than
bundle bone. Direct contact between roots and
cortical bone can precipitate root resorption,
especially during Begg treatment as a result of
high stress pattern at the apex.(1976 JCO
Tenhoeve and Mulie)

Specific tooth vulnerability to root
resorption.
Different teeth have different tendencies to root
resorption. All examined teeth after orthodontic
treatment showed evidence of root resorption.
• (AJO 1989 Mc Fadden ) reported that maxillary
teeth are more sensitive than mandibular teeth.
Converse incidences were shown in conflicting
reports.

• (EJO 1980 Thilander) The maxillary incisors are the
teeth most affected by root resorption. The extent of
movement in these teeth is usually greater than in others
because of malocclusion, function, and esthetics. Their
root structure and relationship to bone and periodontal
membrane tend to transfer the forces mainly to the apex.
• Others have found the mandibular incisors to be more
affected.
• It is believed that if there is no apical root resorption
seen in the maxillary and mandibular incisors, then
significant apical resorption in other teeth is less likely to
occur (AJO 1975 Goldson)

The most frequently affected teeth,
according to severity, are
Maxillary laterals
Maxillary centrals
Mandibular incisors
Distal root of mandibular first molars
Mandibular second premolars
Maxillary second premolars

Mechanical factors
Orthodontic appliances should be designed to
satisfy goals for of the patient and the doctor .
Appliances that are able to achieve these goals
more closely approaches the ideal treatment
system . It is often stated that the degree of root
damage is a function of the appliance
used..Analysis of appliances of the different
systems has significant advantages and that the
advantages of one system frequently are the
disadvantages of the other .

Fixed versus removable
• (Linge and Linge 1983 EJO) Study compared root
resorption resulting from fixed and removable
appliances, concluding that the use of fixed appliances is
more detrimental to the roots.
• Ketcham claimed that normal function is disturbed by the
splinting effect of orthodontic fixed appliances over a
long period that can cause root resorption.
• Stuteville, suggested that the jiggling forces caused by
removable appliances are more harmful to the roots.

Magnets
(AJO1987) Kawata, suggested that the increase in force as space
closes with time (attraction) can stimulate a more physiologic tissue
response, and thus decrease the potential for root resorption.
Intermaxillary elastics
Linge and Linge(EJO 1983) found significantly more root resorption on
the side where elastics were used and suggested that jiggling forces
the result of function combined with elastics are responsible for the
incisors' root resorption.
Extraction versus nonextraction
McFadden and VonderAhe found no difference in the extent of root
resorption in patients treated with or without extractions.

Orthodontic movement type -There is no safe
tooth movement.
• Intrusion is probably the most detrimental to the roots
involved (AJO 1989 Mc Faden), but tipping, torque,
bodily movement, and palatal expansion can also be
implicated. Reports on resorption during bodily
movement are controversial.
• According to Reitan, the stress distribution along the
roots during bodily movement is less than the stress
concentration at the apex resulting from tipping.
Therefore risk of root resorption that is due to bodily
movement should be less than that of tipping.

Orthodontic force
Review of literature:
The exact magnitude of force that is most ideal for
physiologic tooth movement has been a subject of
controversy for many years among the members of the
orthodontic specialty.
Farrar, in 1876, indicated that forces of lighter magnitude
were more desirable for tooth movement, but did not
give exact force values
In 1929 McKeag, was one of the earliest investigators to
propose a specific force value for the orthodontic
movement of teeth. He claimed that the initial pressure
should be 2 ounces for each tooth.
Schwarz, in 1932, experimented on the teeth of dogs and
evaluated various magnitudes of orthodontic force.www.indiandentalacademy.com

• In 1942 Oppenheim critically described the effect of
continuous forces. He claimed that intermittent light
forces administered over long periods of time constituted
the best orthodontic treatment.
• Moyers and Bauer suggested in 1950 that the ideal
orthodontic appliance should operate over a distance of
less than 0.2 mm. with a force of 15 to 25 grams.
• Smith and Storey, in 1952, found that there was an
optimum range of pressure on the tooth-bone interface
which produced the maximum rate of tooth movement.
This range of force extended approximately from 150 to
200 grams. For pressure below this "optimum range"
there was practically no movement of the cuspid tooth.

• The different forces advocated for cuspid movement are
250 gms REITAN(1957 AJO)
150- 260 gms LEE (1965 AJO)
75gms by RICKETS .
• Degree of force: Harry and Sims(AO 1982) found the
distribution of resorbed lacunae was directly related to
the amount of stress on the root surface and the rate of
lacunae development was more rapid with increasingly
applied forces. They concluded that higher stress causes
more root resorption.
• According to Schwartz, applied force exceeding the
optimal level of 20 to 26 gm/cm2 causes periodontal
ischemia, which can lead to root resorption

EJO1996 Owman
The clinical and histological study was designed to
investigate the effect on tooth movements on root
resorption when a fixed orthodontic appliance was
activated with a controlled, continuous force of 50 gms or
with a four-fold larger force of 200 gms.
• The magnitude of the mean horizontal crown movement
increased 50 per cent when a force of 200 gms was
applied compared with a 50 gms force.
• Root resorptions were registered in histological sections
of the extracted test teeth with no significant difference in
frequency or severity between the two forces used.
• Individual variations were large regarding both tooth
movement and root resorption.

Continuous versus intermittent forces
The pause in treatment with intermittent forces allows the
resorbed cementum to heal and prevents further
resorption. On the other hand, intermittent forces have
been linked in their detrimental effects to jiggling forces
(BJO 1978 Hall)
• AO-1999 April Study was done to find out the effect of
continous and discontiinous forces.
• Results showed that discontinous force show less root
resorption

• Kee- Joon- Lee(AJO 2004) found that there was
no significant difference in the tooth movement
between the continious and intermittent forces.
• Maltha JC et al (Cranial facial research 2004)
found that continious forces cause significantly
more root resorption than intermittent forces .

Jiggling and occlusal trauma:
(Linge and Linge EJO 1983) Jiggling forces causing
occlusal trauma and implicated in root resorption can
result from the use of intermaxillary elastics or active
removable appliances. Occlusal forces on poorly aligned
dental inclined planes can be a contributing factor in root
resorption during orthodontic treatment , but Newman
however, did not find a relationship between root
resorption and occlusal trauma or heavy occlusal forces.

Combined biologic and mechanical
factors
Treatment duration.
• Most studies report that the severity of root resorption is directly
related to treatment duration. (AO 1974 Reitan , AJO 1987
Subttelny)
• Though there were a few studies did not support this finding
(AO1973 VonderAhe)
• Rudolph reported that 40%, 70%, 80%, and 100% of the patients in
treatment demonstrated some root resorption after 1, 2, 3, and 7
years of active treatment, respectively.

• Levander and Malmgren(EJO 1988) found that 34% of
examined teeth showed root resorption after 6 to 9
months of treatment, whereas at the end of active
treatment, lasting 19 months, root resorption increased
to 56%. Histologically, 34% and 56% of the examined
teeth showed resorbed lacunae after 15 and 20 days of
tooth movement, respectively.
• Though investigators have suggested that the length of
active treatment is not related to the chance of severe
resorption; others have shown that the longer the active
treatment time, the greater the chance of severe
resorption McFadden, AJO1989.

• Goldin (AJO1989) reported that the amount of
root loss during treatment is 0.9 mm/year.
• AJO 2005 JonArtun reported that root resorption
can begin in the early stage of orthodontic
treatment ( leveling ) , he found that 4.8%
patient had 1.5 mm root resorption and 15.5%
had 2mm root resorption .

Root resorption detected radiographically
during orthodontic treatment.
Minor resorption or an irregular root contour seen after 6 to
9 months indicates an increased risk of further root
resorption. Levander and Malmgren (EJO 1988) No
severe resorption was detected at the end of treatment
in teeth without resorption after 6 to 9 months.

ROOTS OF 29 YR OLD
FEMALE PATIENT SHOWING
EXTENSIVE ROOT
RESORPTION OF MAXILLARY
CENTRAL INCISORS

Relapse.
• Reitan(AO1974) claims that forces of relapse are not
strong enough to cause root resorption.
• However, Ten Hoeve and Mulie believe that the teeth
are prone to additional root loss during relapse as a
result of light muscles forces.
• Sharpe et al (AJO 1987) found a higher frequency of
root resorption in patients demonstrating relapse
compared with patients without relapse because of the
loss of overall bone support.

Root resorption after appliance removal.
• Reitan claimed that additional active resorption lasts for about a
week after appliance removal followed by cementum repair that
lasts 5 to 6 weeks of orthodontic inactivity.
• Only a few publications report on active root resorption during
retention. (AJO 1983 Gholston) One case of active root resorption
lasted 3 years after appliance removal
• This could explain the 0.1 mm of apical root loss seen in the study
of Copland and Green.(ALO 1986) (Root resorption in maxillary
central incisiors following active orthodontic treatment)
• Clinically, root resorption associated with orthodontic treatment
usually ceased once the active treatment terminated.This is
expected since progressive root resorption is tissue-pressure
related.. Remodeling of the sharp, rough edges of the resorbed root
surfaces may occur.(AJO 1989 Remington).

Teeth vitality:
Teeth vitality and color do not change even in
cases of extensive root resorption. According to
Stenvik and Mjor, orthodontic movement can
cause pulp blood flow disturbances,
vacuolization and, rarely, pulp necrosis that are
not related to root resorption.

Loss of crestal bone and tooth stability:
Loss of marginal attachment is more detrimental
than loss of an equivalent amount of root length
by apical resorption. The resulting decrease of
tooth stability according to Goldin is explained
by the presence of large amounts of periodontal
fibers in the crestal area compared with the
apical zone.

• .(AO 1974 )Zachrisson found that during orthodontic
treatment, crestal bone loss is about 0.2 to 0.5 mm.
• According to Kalkwarf et al., 3 mm of root resorption is
approximately equivalent to 1 mm of crestal bone loss.
• The most significant diagnostic aid in predicting root
resorption is radiographic evidence of root resorption
before orthodontic treatment. This is especially true for
the maxillary incisors. Other predicting factors are root
shape and the stage of root development. Pipette-
shaped rootsand fully developed roots are more
susceptible to resorption.

DRUGS USED IN REDUCING ROOT
RESORPTION
AO1994 Thyroid function and root resorption, Eric Loberg,
Christer Engström.
• Root resorption was induced in the maxillary incisors of rats in
the normal and thyroxine groups when the teeth were
subjected to an orthodontic force. The amount of force-
induced root resorption lesions was less in the thyroxine group
than in the control group. The alkaline phosphatase activity in
serum was significantly different in the normal and control
groups, the results indicate that thyroxine administration might
affect bone metabolism. The decrease of resorptive lesions in
the thyroxine group may be correlated to a change in the bone
modeling process, especially resorption activity.

EJO2003 Saffar Effect of PG E2 and calcium gluconate on OTM and root
resorption in rats.
• The results showed that Ca ions working in
assosiation with PG E2 helps in stabilising root
resorption while significantly increasing OTM.
EJO2005 Selvig. Effect of systemic doxycycline.(study in rats)
• The restults showed significant reduction in root
resorption .
• Decreased osteoclast and odontoclast.
• A slight reduction in tooth movement also was
observed.

Clinical considerations related to root
resorption(AJO)
1. The patient or his parents must be informed that apical root
shortening (root resorption) may be a consequence of
orthodontic treatment. Its incidence is highly unpredictable.
2. Perapical radiographs:
(a.) Periapical radiographs are an important part of complete
orthodontic records as any pretreatment record, and are
particularly useful to compare pretreatment and
posttreatment root resorption.
(b.) since it is impossible to predict the onset of root resorption,
periodic control radiographs are indicated. Periapical
radiographs of the incisors should be taken at least every
year after appliance placement.

(c.) Posttreatment radiographs are an essential part of
complete records to assess the bone/root integrity after
treatment, of which the patient must be informed.
3. Computed tomography.
Studies have shown that the sensitivity of intra oral
radiography was low in diagnosing root resorption.
CTscanning detects rootsresorption in the early stage
4. Orthodontic treatment timing. Orthodontic treatment
should begin as early as possible since there is less root
resorption in developing roots and young patients show
better muscular adaptation to occlusal changes. Adults
have poorer adaptive ability and need more rigid and
longer lasting mechanical forces.
5. The orthodontic force should be intermittent and light.

6. When root resorption is detected during active treatment,
final goals must be reassessed. A decision should be
made to terminate the treatment or to arrive at a
treatment compromise. When necessary, applied forces
should be stopped and/or a bite plane used to
disocclude the teeth.
7. Habits such as nail biting or tongue thrust should be
stopped, since it was shown that root resorption is more
severe in such orthodontic patients.
8. All types of tooth movement can cause root resorption. It
seems that intrusion is the most detrimental.

9. Occlusal traumatism and jiggling are potentially
detrimental to the roots, and it is suggested to finish
treatment with a correct occlusion.
10. It is essential to recognize that routine orthodontic tooth
movement can have anatomic and physiologic
limitations. If the objectives of treatment are beyond
these limitations, surgical intervention may be required.
11. Teeth with resorbed roots can serve as abutments to
bridges only when their root length exceeds the clinical
crown length.
12. Orthopedic effect in the early treatment phase has less
destructive potential on the roots compared with the
dentoalveolar effect at a later treatment phase.

13. In choosing treatment appliances, the risk of root
resorption should be weighed against appliance
efficiency and individual treatment objectives.
14. Treatment time should be as short as possible while
adhering to other important principles.
15. Traumatized teeth should be treated cautiously since
they are more prone to root resorption during orthodontic
treatment.

16. Medical examination and familial tendency records are
of value especially in cases of severe or extensive root
resorption.
17. If root resorption continues after appliance removal or
during retention, seqeuntial root canal therapy with
calcium hydroxide is advisable. Gutta-percha filling is the
definitive therapy only after root resorption ceases.
18. It is advisable to take full-mouth radiographs when
receiving a transfer case.

DIFFERENT TECHINIQUES AND THEIR
PREDISPOSITION TO ROOT RESORPTION
BEGGS STRAIGHTWIRE
EDGEWISE

BEGG TECHINIQUE
In Beggs technique initial tipping and subsequent torquing
of anteriors in the 3rd stage lead to “round tripping”,is
harmful to the roots.
The use of pin and tube brackets used in begg techinique
facilitates one point contact,which has virtually no
capability of controlling rotations or tipping.
The use of continious small wires, elastics , the force
system is designed to provide tipping movement .
The Anchor bend with class II elastics could have a
extrusive and clockwise rotation on the incisors .

Apical root resorption during Begg Treatment
1985 JCO L’ABEE
A study was done to investigate root resorption of maxillary
incisor during begg treatment
• They found significantly more resorption in the first stage of
the Begg technique than in the second stage or in the
retention period , and less resorption in the second stage than
in the third stage
• The amount of resorption in stage I did not differ significantly
from that found in stage III.
• However, when average values are compared, there appears
to be more resorption in stage I than in stage III.

• Labial movement of the root apices of the
maxillary incisors during the early stage of begg
mechanics induces new bone formation ,
subsequent lingual root torqing of incisors in the
III stage is impeded by this new bone , which
has greater resistance to resorption ,
consequently the incisors extrude and the
crown move labially in response to torquing
auxillary , since the desired lingual root torque is
resisted

EDGEWISE TECHINIQUE
In edgewise, extraoral appliance and rectangular
archwire lead to heavy forces from the beginning.
• EJO 2000 dec – Maria and Andrea
Conducted a study to compare the severity
of apical root resorption occuring in patients treated with
standard edgewise and straightwire edgewise
technique . The sample consisted of 80 patients of which
40 were treated with standard edgewise and 40 with
straightwire edgewise . both had 0.018 slot bracket .
They found that there was a significant apical root
resorption of both central incisior in standard edgewise
than in straightwire edgewise group.

• Journal of Orofacial Orthopaedics-1998
Study was done to compare the rate of root resorption with
Partially programmed appliance and Fully programmed
appliance.In Fully programmed appliance there was
8.2% resorption and in Partially programmed 7.5%
resorption was seen.
• AJO-1995July
Speed and Edgewise appliance were compared.Speed
provides continous rotatory and torquing actions through
its spring clip mechanism in contrast with Edgewise
appliance that may provide an interrupted force.No
stastitically significant root resorption between the two
was found.

• AJO-2000Sep Comparision between Bio-efficient therapy,Standard
Edgewise and straight wireEdgewise
Bio-efficient therapy had less resorption than
others.Factors responsible for less resorption
were Heat activated NiTi,Superelastic wires
and .018 x .022 wire in .022 x .028 slot during
retraction and finished stage.

Begg versus edgewise:
• It is often stated that the light wire Begg technique
causes less root resorption than edgewise, although
maxillary incisor root resorption during the Begg third
stage has been documented.(JCO 1984 Remmelnick).
• Malmgren et al.(1982 AJO) suggested that there is no
difference between these techniques, but found that the
frequency of root resorption was signficantly higher
(48%) in traumatized maxillary incisors when intruded by
the Begg technique compared with edgewise technique
(43%).

• AO-2000 June ,A study was done to find the
incidence of root resorption between edgewise
and begg techinique and they concluded that the
incidence of root resorption was 2.3 times higher
for Beggs when compared with Edgewise and it
was 3.72 times higher when extraction was
performed.

AMALGAMATED TECHINIQUE
• The Amalgamated technique was `introduced in
1976 which combines biomechanical principles
of both Begg and Edgewise techniques on
controlled tooth movement.
• Techniques demonstrated the controlled tipping
with an Edgewise bracket and a round wire .
Light wire edgewise system provided an
effective mechanism for correction of
malocclusion.

This technique was based upon avoidance of potentially
harmful tooth movement, such as
• uncontrolled tipping,
• round tripping,
• displacements of root into and through compact plates of
alveolar bones,
• torque with the bracket slot filling rectangular wire.
Several other factors like duration of treatment, length of
time in rectangular arch-wire that fully engage the
edgewise bracket slot could implicate irreversible
change, which detracts from otherwise successful
treatment out come.

Correction of Over-jet without displacement of the root
apices in the opposite direction , which is a desirable and
the fundamental objective in the Orthodontic mechano
-therapy and can be achieved by the Amalgamated
technique.
Controlled tipping
In amalgamated technique ,undesirable clock wise rotation
of the maxillary incisors are largely avoided, because the
teeth are retracted only to their optimal angulation
relative to the line nasion-point A .There after, they are
translated palataly. In classical Begg treatment free
tipping stops only after an edge to edge incisor relation is
achieved.

Biological consideration:
• In second stage Begg technique, the roots of the
canine and the 2nd premolars are hyper
divergent relative to each other and require
extensive uprighting to gain parallelism at the
extraction site The incisal angle is marginally
obtuse and requires considerable lingual root
torque for normalisation .Anchorage taxation
accompanies lingual torque and uprighting via
the torquing and uprighting springs of the third
stage mechanics.

This forces directed to the labial and the inter
proximal alveolar crest around the teeth with the
possibility of causing irreversible damage to
these sites.torquing and uprighting are not only
mechanically inefficient,but also potentially
harmful biologically.the potential for the root
resorption following round tripping (supported by
lamino grapic findings of ten hoeve and mulie
JCO1976)

The amalgamated technique incorporates edgewise
brackets, which are strategically positioned, angulated
and have zero degree torque.
• A series of light round stainless steel arch wires are
used to resolve overbite and overjet by controlled tipping.
• Accentuated reverse curve of spee arch wire design,
combined with judicious class-2/3 elastics force where
indicated to produce controlled labio lingual tipping the
maxillary incisors are retracted only to their optimal
angulation relative to the line nasion-point A .there after,
they are translated palataly with Warren Spring fasten
to light rectangular wire.

An arch wire with warren spring engaged in the
bracket

Force calibration of warren spring torque mechanics (this is
not possible with intra slot torque)

• The use of undersized archwire with warren spring that
applies a second moment to the more gingival level is
more efficient and versatile in obtaining root torque than
torque incorporated in the arch wire which could have a
reverse effect on the adjusant teeth .
• Root uprighting are virtually achieved owing to seating of
successive archwire thicknesses into pre-angulated
brackets.torque is attended with the warren spring,never
with full archwire slot engagement.

• The lower load deflection rates afforded by
warren spring auxiliary torque provide
biologically desirable light continuous force than
full slot archwire torque
• .Force generated by Warren springs are
approximately 1/7 of those generated by full slot
arch wire torque.Warren spring system is also
advantageous since the adjacent teeth does not
under go reverse torque.

• A series of archwires of progressive thickness
are utilized.A commonly utilized adjunct to
amalgamated technique is the headgear.The
head gear type is dictated by the skeletal
pattern.The extra oral force disrupts the
intercuspation, inducing the patient to more
comfortable intercuspation by posturing the
mandible forward.This phenomenon,combined
with the application of class II elastics,is
responsible for inducing favorable mandibular
growth in class II skeletal pattern.

• Another advantageous feature of amalgamated
technique is that mild constriction/expansion of
the light edgewise archwire along the
masticatory forces allow for excellent bucco
lingual settling as treatment progresses.rigid
rectangular archwires that engages the bracket
slot seriously inhibit this desirable ongoing
physiological process.

CONCLUSION
The concept of optimal orthodontics translates
into attaining excellent, stable occlusal and functional
results while subjecting the roots and the parental
tissues to the most comfortable and shortest duration of
the force application.
The unpredictability and widespread incidence
of the root resorption phenomenon in light of the
orthodontists's liability calls for the specialty to define this
uncertainty and establish criteria of diagnosis, records,
and informed consents to protect its members against
unnecessary and unjustified litigation.

Optimum orthodontics – how to move teeth without

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