Learn Orthodontics

Adjustment of Labial Bows

Labial bows are adjusted using either adams or round/flat pliers. Adams are good for 'flattening' loops and flat/rounds for tightening loops.

adams halfrounds

There are two options to adjust a labial bow - always adjust both sides equally to achive the force required. The bow height should be about 13 up of the crown from the incisal edge of the central incisors. The bow should be firm and not over tight.

REMEMBER to adjust the acrylic of the baseplate to allow the teeth to move.

  1. To tighten
    • a) U loop labial bow
    • Using flat/round pliers grip across the opening of the U and squeeze. This closes the loop and tightens the labial bow, BUT it also drops the height of the bow, moving it towards the incisal edge and you then have to adjust the height of the bow at the distal of the U loop.

      Labial adjust 3 adjust 17

      Labial adjust 4 adjust 2

    • b) Reverse loop labial bow
    • Using adams pliers grip the top of the loop and squeeze to 'flatten' it, this tightens the labial bow, again this results in the height of the bow dropping, but usually less than occuring with a conventional U loop labial bow. Again adjust the height of the bow.

      Labial adjust 5 adjust 22

  2. To Loosen
    • a) U loop labial bow
    • Labial adjust 2 adjust 16

    • b) Reverse loop labial bow
    • Labial adjust 6 adjust 9

  3. To adjust the baseplate
  4. Use a staright handpiece and large acrylic trimming bur. Remove acrylic palatal to the tooth so there is approx 1-2mm clearance between tooth and baseplate. NOTE trim as in diagram A and not as in diagram B, otherwise the acrylic plate will contact the tooth and stop any movement occuring.

    acrylic rem 2 acrylic remove 1