Methods of ligation

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  • Methods of Ligation

    Metal ligationBy Prof. Dr

  • In orthodontics, ligation method refers to themeans by which an archwire is held inside thebracket. Conventionally, elastic or metallic tieswere used to hold the archwire in place; howevermore recently ligating methods have been designedand built directly into brackets.

  • Currently the three most common ligation systems are active- and passive self ligation and conventional elastic ligation.

  • Research has shown that different ligation types produce different force and moment systems along the orthodontic arch; specifically, passive self-ligation has been found to decrease the forces and moments produced when compared to elastic ligation, which may lead to increased patient comfort .

  • This is because elastic ligation actively holds

    The wire in place against the bracket, whereas passive ligation simply guides the wire while leaving room for movement.

  • Variable Force Orthodontics Delta Force Bracket Features The Delta Force Bracket A Change for the Better The Delta Force Bracket System incorporates an advanced design that allows you to control the friction between the archwire, bracket and ligatures.

  • The advanced technology and variations in ligature placement provide full control over the sliding mechanics offering the ability to easily increase or decrease friction for better treatment planning and results

  • Delta Force Brackets have unique features to achieve variable force ligation throughout the treatment stages. Early in treatment: Light force can be attained for excellent sliding mechanics and low friction. Intermediate stage of treatment: Medium force can be utilized for anchorage and stabilization, as well as initial torquing forces.

  • Delta Force Ligation Options

    Minimum Force Start your treatment with passive ligation for minimum force. Rapid leveling and aligning can be attained as the ligation is configured to prevent the ligature from directly contacting the archwire. The free sliding mechanics created result in low friction and more patient comfort during this early phase of treatment

  • Maximum Force You may finish your treatment with maximum force by locking the archwire in for full expression of the straight arch bracket. Tie the ligature to lock the archwire in the tip, torque and rotational control

    Minimum Force Maximum Force

  • Medium Force In the next stage, medium force is achieved through limited contact of the ligature and the archwire. This configuration uses a standard ligation, full tip, torque and rotational control through lightly seating a rectangular archwire

    Minimum Force Maximum Force

    Medium Force

  • Maximum + Force If needed, for full expression of the straight arch bracket system, you can apply maximum + force, by placing an inverted V elastic ligation

  • Optional Step Rotation Control and Force If necessary, extra rotation can be created by ligating behind one tie wing on one side. Please note, rotation will occur towards the non-ligated wing

  • Metal ligatureShort Twisted Preformed Ligature Ties Short Twisted Kobayashi Ligature Wires 008" PRE-FORMED SHORT


  • The vast majority of fixed orthodontic appliances have stored

    tooth-moving forces in archwires, which are deformed within their

    elastic limit. For this force to be transmitted to a tooth, wires need a

    form of connection to the bracket.

  • Elastomeric ligatures and self-ligating brackets are firmly

    established orthodontic terms.

  • Elastomeric modules are adversely affected by oral

    environment, demonstrates stress relaxation with time and exhibit great individual variation in properties.

  • The normal force exerted by the ligature

    has been estimated to be between 50 to

    300 g.

  • Bazakidou showed that there was no significant

    differences between frictional resistance offered

    by the conventional tied stainless steel ligature

    and elastomeric module.

  • Frictional forces can be reduced by

    stretching the elastomeric modules prior

    to placement on the brackets or by tying

    stainless steel ligatures loosely around

    the brackets .

  • On the other hand stainless steel ligatures

    can be too tight or too loose , depending

    upon the technique and needs of the clinician.

  • Stainless Steel Ligatures

    When stainless steel became available, this was universally

    adopted as the method of ligation. Stainless steel ligatures

    have several beneficial inherent qualities. They are cheap,

    robust, and essentially free from deformation and

    degradation, and to an extent they can be applied tightly or

    loosely to the arch wire.

  • Stainless Steel Ligatures

    They also permit ligation of the archwire at a distance from

    the bracket. This distant ligation is particularly useful if the

    appliance tends to employ high forces from the archwires,

    because this high force prevents sensible full archwire

    engagement with significantly irregular teeth.

    Kobayashi Ties

    Add an auxiliary hook to any bracket

    Available in .010", .012", or .014"

  • Composite ligature Fabricated from the acrylic monomer n-

    butyl methacrylate and drawn poly

    ethylene fibers.

    Due to stress relaxation properties

    within an hour it loss 98% of ligation

    forces( not used in sliding mechanism)

  • Specially formulated almond color coating

    will not peel. For use with ceramic or

    plastic brackets.

    Teflon coated Ligature No discoloration.

    The coating wears off after 2-3 weeks and the metal is


    Produces less friction when compared with elastomeric

    ligatures & stainless steel ligatures.

    It generates lighter forces of engagement of the arch

    wire into bracket slot.

  • Ligation materials: 0.010 stainless steel ligature wire (G & H wire Company) 0.010 Teflon coated stainless steel ligatures (G & H wire Company) 0.12 elastomeric ligature ties (American Orthodontics).

    Effects of Different Ligature Materials on Friction in Sliding Mechanics Aparna Khamatkar1 , Sushma Sonawane2 , Sameer Narkhade3 , Nitin Gadhiya2 , Abhijit Bagade1 , Vivek Soni4 , Asha Betigiri3

  • Teflon coated stainless steel ligatures produced the least friction amongst the materials tested in both dry and wet conditions, and there was no significant effect on friction in this group caused due to lubrication

  • Artificial saliva produced increased friction in elastomeric modules, but does not cause any significant difference in friction when stainless steel or Teflon coated stainless steel ligatures are used


  • Despite these good qualities and their widespread use over

    many decades, wire ligatures have substantial drawbacks,

    and the most immediately apparent of these are the length

    of time required to place and remove the ligatures.

    Preformed Ligature Ties

    Preformed in dead soft temper

    Available in long or precut

    Stainless Steel Ligatures

  • One typical study found that an additional 11 minutes was

    required to remove and replace two archwires if wire

    ligatures were used rather than elastomeric ligatures.

    Bulk Ligature Spools

    1 pound spools

    Bright finish with soft temper for

    ease of use

    Stainless Steel Ligatures

  • Stainless Steel Ligatures

    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.

  • The use of stainless steel ligature ties has been shown to

    increase friction through a dual mechanism. There is a

    higher engagement force between the archwire and bracket,

    and additional friction is generated by the contact of the

    ligature surface with the archwire; however, elastomeric

    ligatures can induce the same effects.

  • A practical conclusion from these studies

    was that self- ligating brackets showed

    less frictional forces, while the figure-of-

    eight ligature configuration increased

    friction significantly.

  • Conventional brackets received metallic ligatures used to tie

    the arch to the slots (A), always carefully bending them

    perpendicular to the leveling arch (B) in order to reduce

    plaque retention

  • Comparative Thickness of MPA

    A Multi-Purpose Attachment -MPA can be used in different conditions . The

    thickness of an MPA is very less as compared to the conventional brackets

    and tubes. It has a body that is very thin - 0.4 mm and a lumen through

    which a ligature wire or an 0.016" arch wire can pass. Curved MPAs are for

    the canines, premolars and molars and the flat ones are for the incisors.

    Multi-Purpose Attachment



    Easily bonded to any tooth. Specially designed base provides

    a firmer bonding strength. 10 per package

  • Stainless Steel Ligatures

    Single Tie

    One end of a small piece of ligature wire is passed through the

    lumen of the attachment. It is then passed under the arch wire on

    the other side, twisted around the oth