self ligation,brackets

2. “Brackets that incorporate a locking mechanism (such as a ring,
spring, or door mechanism) that holds the archwire in the bracket
slot”

3. Historical Aspects and
Evolution of Ligation
and Appliances
• Archwire ligation
• Stainless steel ligatures
• Elastomeric ligatures
• Begg pins
• Self ligation

4.  They are cheap, robust,
 essentially free from deformation
and degradation and
 to an extent they can be applied
tightly or loosely to the archwire.
 They also permit ligation of the
arch-wire at a distance from the
bracket.
 This distant ligation is
particularly useful if the
appliance tends to employ high
forces from the archwires,
The length of time required to
place and remove the ligatures.
additional 11 minutes was
required to remove and replace two
archwires
Additional potential hazards
include those arising from puncture
wounds from the ligature ends and
trauma to the patients’ mucosa if the
ligature end becomes displaced.

5. fail to fully engage an archwire
‘figure of 8’
substantial degradation of their mechanical
proper-ties in the oral environment.
more than 50% degradation in force in the first
24 hours5
The higher temperature in the mouth,
enzymatic activity and lipid absorption by
polyurethanes are all cited as in vivo sources of
force relaxation.
loss of rotational control
Lam et al. reported substantial variation in the
range and tensile strength of elastomerics from
different manufacturers and for different colours of
elastomeric from the same manufacturer.
much higher friction between bracket and
archwire in vitro with elastomeric ligation
compared to wire ligatures. Hain et al.8
 greatly reduced time required
to place and remove them
when compared with steel
wire ligatures.
 It was also easier to learn the
skills required to place these
ligatures,
 Intermaxillary elastics-
Calvin S. Case and H.A.
Baker.

6. • Faster ligation
• Secure archwire engagement
• Low friction
• Assistance to good oral hygiene?
• More comfortable treatment?
• Secure archwire engagement and low friction as a
combination

7. Have a slide that
opens and closes vertically and
creates a passive labial surface
to the slot with no intention to
invade the slot.
Have a sliding spring clip,
which encroaches on the slot
from the labial aspect,
potentially placing an active
force on the archwire.
e.g: Damon,
Smartclip,
Praxis Glide,
Carriere LX,
vision LP,
Lotus.
e.g: Speed,
In-Ovation,
Nexus,
Quick, Time

8. Year Developer/company Name Ligation principle Design
1935 Stolzenberg Russell Passive Metal
1972 Wildman/Ormco EdgeLok Passive Metal
1973 Sander/Forestadent Mobil-Lock Passive Metal
1980 Hanson/Strite Industries SPEED Active Metal
1986 Plechtner/A-Company Activa Passive Metal
1994 Heiser/Adenta Time Active Metal
1996 Damon/A-Company Damon Passive Metal
1997 Voudouris/GAC In-Ovation Active Metal
1998 Wildman/Ormco TwinLock Passive Metal
1999 Damon/A-Company/Ormco Damon 2 Passive Metal
2002 Voudouris/GAC In-Ovation R Active Metal
2004 Abels/Ultradent Opal Passive Aesthetic
2004 3M Unitek SmartClip Passive Metal
2004 Damon/Ormco Damon 3 Passive Aesthetic
2005 Adenta Flair Active Metal
2005 Forestadent Quick Active Metal
2005 American Orthodontics Vision LP Passive Metal
2007 Abels/Ultradent Opal M Passive Metal
2007 GAC In-Ovation C Active Aesthetic
2007 3M Unitek Clarity SL Passive Aesthetic
2008 Dentaurum Discovery SL Passive Metal
2008 Forestadent QuicKlear Active Aesthetic

9. Try to treat without extractions in all cases which appear to
have the necessary potential
• If treatment objectives cannot be accomplished without
extractions, extract second bicuspids to minimize any tendency
toward unattractive reduction in the prominence of the
dentition
• Use preliminary functional appliances to favorably alter jaw
growth patterns wherever it is desirable and feasible
• Employ intra-oral distalization mechanics instead of headgear
when conditions permit
• Expand arches which have failed to develop to their full
potential
• Intrude upper anterior teeth in patients who exhibit a lot of
gingival tissue
• Correct tooth rotations to ideal alignment without any over-
correction and rely upon interproximal reshaping and
circumferential supracrestal fiberotomies to enhance retention
• Overcorrect class II or class III buccal segment relationships
where a strong relapse tendency is expected
Treatment should be planned to optimize facial appearance as
maturation and aging occur
• Treat non-extraction where biologically possible and
compatible with dental and facial treatment goals
• Use light forces, in an appliance where direct transmission of
archwire energy to bracket can be achieved without modifi
cation or absorption by ligatures, in order to move teeth with
adaptation of the alveolar bone by ensuring the orthodontic
forces do not impede blood supply in the periodontium
• Use functional appliances to obtain anteroposterior
correction of class II malocclusions
• Do not use rapid palatal expansion appliances or headgear
• Utilize the oral musculature to assist in correction of the
malocclusion by:
Allowing the orbicularis oris and mentalis muscles to provide a
‘lip bumper’ effect which minimizes anterior movement of the
incisors during non-extraction treatment
Expanding the posterior buccal segments with light archwires
thus allowing the tongue position to elevate and move forward
producing a new force equilibrium between it and the facial
muscles
Dr Hanson’s
treatment
philosophy
for the SPEED
appliance
Dr Dwight
Damonfor
the Damon
System
appliance
Treatment philosophies

10. Active clip or passive slide ?
• with thin aligning wires smaller then 0.018" diameter
• The potentially active clip will be passive
• For teeth which were initially placed lingual to their
neighbours, the active clip can bring the tooth more
labially (up to a maximum of 0.027 - 0.018 = 0.009
inches) with a given wire.
• Pandis et al (2010) found no difference in the rate of
alignment when comparing the passive Damon MX
with the active In-Ovation R brackets.

11. for wires > 0.018" diameter
• The active clip will place a continuous lingual force on the wire even when the
wire has gone passive.
• On teeth which are in whole or in part lingual to a neighbouring tooth, the
active clip will again bring the tooth (or part of the tooth if rotated) slightly more
labial than would have been the case with a passive clip at 0.027" slot depth.
• The maximum difference will be the difference between the labiolingual
dimension of the wire and 0.027".
• 0.016" x 0.022" -maximum difference of 0.005".
• 0.016" x 0.025" or 0.014” x 0.025” nickel titanium wires are recommended as
the intermediate aligning wire for Damon and this wire reduces this potential
difference to 0.002".
• Lingually placed teeth would have a slightly higher initial force with an active
clip and wires of this intermediate size.
• With an active clip, an active lingually-directed force will remain on the wire
even when it is passive

12. with thick rectangular wires
• An active clip will probably make a labiolingual
difference in tooth position of 0.002" or less which
is very small.
• An active clip places a lingually directed force on
the wire in all circumstances which results in a
higher friction and resistance to sliding.

13. Torque effectiveness and active vs.
passive brackets

14. Archambault et al 2010-concluded that the
reduced slop angle with an active clip ( 5 degrees
less) did not in fact produce a clinically significant
difference in torque forces.
Exploring this in more detail Major et al, 2011
again concluded that from a clinical perspective
the torque plays were essentially identical for
Damon Q, In-Ovation R and SPEED brackets.
The torque plays for these three bracket types
were 11.3°, 11.9°, and 10.8°, respectively.
These conclusions support the finite element
analysis work by Huang et al.

15. Major et al 2011-has reinforced the conclusion that the delivery of torquing
forces is very similar for Damon, Speed and In-Ovation brackets.
They found that all brackets had torque play between approximately −12° and
10.5°.
Brauchli et al (2012) found that the range of ‘slop’ (zero torquing force) was
larger - from minus 15 to plus degrees for a number of brackets.
They too found no difference in the torque performance of passive and active
self-ligating brackets.
By measuring brackets with the clip open and shut, they found that the
contribution to torque from the active clip was 1Nmm which is a small
percentage of the torquing force thought to be clinically effective.
Key point: Active and passive self-ligating brackets do not inherently differ in
their ability to apply torquing forces. An active clip contributes little to torquing
force. Play or ‘slop’ in the torque dimension is greater than frequently
appreciated and should influence our choices of prescription accordingly.

16. Hisham Badawi and the team at the
University of Alberta.
The resulting friction and binding produced a
labially directed force on the central incisors
which was reduced by between 73% and
82% when Damon 3MX brackets with their
passive slide were used instead of In-Ovation
brackets with an active clip.
These results agree with those of Baccetti et
al (2009) and (Franchi et al 2009)

18. Pandis et al (2007) who retrieved spring
clips from SPEED and In-Ovation R
brackets following a course of treatment
and compared the stiffness and range of
action of these spring clips with unused
spring clips.
The two types of bracket had spring clips
of very different initial stiffness and the
In-Ovation clips lost an average of 50% of
their stiffness during the treatment,
whilst the SPEED clips had very little
change in their performance.

19. • alignment: in theory, it is probable that with an active clip, initial
alignment is more complete for a wire of given size to an extent which is
potentially clinically useful.
• friction: overall, an active clip will generate higher forces and higher
friction. The increased clearance between a given wire and a passive slide
will generate lower forces and may facilitate dissipation of binding forces
and the ability of teeth to push each other aside as they align. It may also
lead to qualitative differences in the direction and amount of tooth
movement but this is yet to be established.
• robustness and ease of use: in any specific bracket these factors are
frequently related to the type of clip or slide.
• torque control: there is good evidence that the presence of an active clip
does not contribute significantly to torque control.

20. (Harradine 2001), (Eberting et al 2001), (Tagawa 2006), found that self-ligation with earlier versions
of Damon brackets was quicker, with less visits and good or better final alignment and occlusion than
with conventional appliances used by the same operator/s.
A retrospective study by Vajaria et al (2011) also found a reduction of two months in treatment time.
Several other (but not all) presented but unpublished consecutive case series have also found more
efficient treatment with self-ligation, whilst Ong (2010) compared alignment, arch widths and
spontaneous extraction space closure after 20 weeks of treatment in a retrospective study and found
no difference in these parameters between Damon MX and conventional brackets.
Ollivere (2012) published the results of two studies of consecutively treated premolar extraction
cases and in both instances, found no significant difference in treatment time with his switch to
active self-ligation and changes in treatment protocol.

21. (Miles 2005), (Miles et al 2006), (Pandis et al 2007b), (Scott et al 2008),
(Fleming et al 2009), (Fleming 2009b), (Fleming et al 2010) have not found
any overall benefit in the alignment phase, although Pandis et al found
that mild crowding was eliminated 2.7 times more rapidly with Damon 2
than with conventional brackets. Only one of these studies has to date
reported data for the whole of the treatment period.
Another study by Miles (2007), found no improvement in the rate of en
masse space closure with SmartClip self-ligating brackets.
Two prospective split mouth studies (Burrow 2010) and (Mezomo 2011) of
the rate of canine retraction on 0.018” stainless steel wires have also failed
to find faster retraction with self-ligation, in fact Burrow found that with
conventional brackets, the rate averaged 0.17 mm per month faster than
with Damon 3 or Smartclip. The better rotational control with self-ligating
brackets in the study by Mezomo has already been noted.
Two systematic reviews (Fleming and Johal 2010) and Chen et al (2010),
have concluded that there is insufficient evidence to support the view that
treatment with self-ligating brackets is more or less efficient than with
conventional ligation.

22. (Scott et al 2008b) found no difference between Damon 3 and Synthesis in the first
week of treatment and
(Fleming 2009c), found no difference in pain levels comparing SmartClip and
conventional brackets and also that the actual process of archwire changes with
SmartClip brackets was significantly more uncomfortable than with conventional
ligation.
Tagawa (2006) in a case series found a substantial reduction in reported pain with Damon SL brackets.
Miles (2006) in a split mouth study found lower pain levels with Damon 2 brackets during the alignment
phase, although opening the brackets was more uncomfortable than removing elastomerics.
Pringle et al (2009) in an RCT found significantly less pain during the initial 7 days of treatment with Damon 3
brackets when compared with elastomerics tied in an ‘O’ configuration.
The systematic review by (Fleming and Johal 2010) concluded that the balance of evidence from the three
publiched RCTs on this topic just favoured a reduction of pain with self-ligation.
A very interesting paper by Yamaguchi et al (2009) examined the question via a different measure of pain.
They measured the level of the neuropeptidase substance P in gingival crevicular fluid. This substance is a
marker of the inflammation and associated pain resulting from orthodontic forces. They found that treatment
with Damon brackets significantly lowered the levels of this marker of pain and inflammation when compared
with conventional ligation at 24 hours after archwire placement.

24. self-ligation – and particularly passive self-ligation – enables tooth-moving
forces to be sufficiently light that forces from the soft tissues can compete
with them.
It has been proposed that the lips can restrain labial movement of the
incisors and that the alignment of crowded teeth on a non-extraction basis
will result in more lateral arch expansion and less labial incisor movement
than would be the case with heavier forces and higher resistance to sliding –
the “lip bumper” concept.
Further, it has been claimed that expansion brought about by such light
forces is more likely to achieve an archform which is in balance with the
tongue and cheeks and can establish a wider arch which will be relatively
stable because of altered tongue position.

25. • wider arches which may be more
aesthetic
• wider arches which have better periodontal
health than those resulting from more rapid
and forceful expansion
• wider arches which may be more
stable
• less incisor proclination for a given
amount of crowding
• less need for extractions
• easier class 2 correction through a
‘lip-bumper’ effect

26. Self - ligation Conventional
Esthetics Some designs permit significant miniaturization Limited miniaturization
Force level Permits use of lighter forces Require heavier force level
Force density Limited initial force Higher initial force
Friction Predictable, very low S/s: high
Elastomeric: very high
Infection control Significantly reduced risk of percutaneous injury Increased risk of percutaneous injury
Instrumentation Fewer instrument required during arch wire change Many instruments
Ligation Movable,integral part creates outer fourth wall S/s or elatomeric ligatures
Ligation stability Retains original throughout t/t Loses initial shape & tightness
Office visit Shorter, less frequent Longer more frequent
Oral hygiene Wingless designs easy to clean Difficulty to treat food straps
Patient comfort Slight discomfort Teeth usually sore after ligation
Sliding mechanics Ideally situated for tooth translation slow
t/t time Reduced by 4 months Longer esp. in extraction cases

27. • Self ligation systems have been gaining popularity in recent years with a host of claimed
advantages over conventional appliance systems relating to reduced overall treatment
time, less associated subjective discomfort, promotion of periodontal health, superior
torque expression, and more favorable arch -dimensional change.
• Other claimed advantages include possible anchorage conservation, greater amounts of
expansion, less proclination of anterior teeth, less need for extractions, and better
infection control.
• However, many of these claims were based on retrospective studies which are potentially
biased as there are many uncontrolled factors which may affect the outcome.
• These include greater experience, differing archwires, altered wire sequences, changes in
treatment mechanics, and modified appointment intervals.
• While Advocates claim that low-friction SL brackets coupled with light forces enhance the
treatment efficiency and address the clinical superiority of self-ligating brackets, other
team believes that bracket type does not appear to have a significant influence on
treatment efficiency.