The Hawley Appliance: Advantages, Disadvantages, Indications, Components, Fabrication, Adjustments

June 16, 2012 | By | Reply More

The Hawley Appliance: Advantages, Disadvantages, Indications, Components, Fabrication, Adjustments


  • It is a removable wire and acrylic palatal appliance.


  • A Hawley appliance can be used both as a passive retainer (for retaining or stabilizing teeth in their new position following orthodontic treatment) and as an active appliance in order to achieve minor tooth movements.


  • As the Hawley is a removable appliance, it can be removed for brushing, flossing and special social occasions.
  • The palatal acrylic offers a significant anchorage.


  • Like any other removable appliance, the success or failure depends entirely on patient compliance.
  • Speech might be affected.
  • Only tipping movements can be achieved.
  • Rotated teeth are extremely difficult to correct.


  • To hold teeth in a new position after orthodontic correction and to prevent relapse until bone fill around the moved teeth is achieved.
  • To move teeth mesio-distally and buccally (minor, tipping movement)à can be used to correct simple anterior crossbites

Components of the Hawley Appliance

Acrylic base

  • Supports all the elements of the appliance

Adam clasp

  • Assures the retention of the appliance
  • Fabricated with 0.7 mm wire engaging the mesio-buccal and disto-buccal undercuts of the posterior teeth
  • Do not tend to separate teeth it is clasping

Labial bow

  • Provides some anterior stabilization for the appliance
  • Controls the position of incisors that are not meant to move

Finger-spring: only for active Hawley appliance

  • Active component of the Hawley appliance
  • Not included in Hawley appliance if used as a retention appliance (a passive appliance)
  • Only tipping movement can be achieved by the spring
  • The design must ensure adequate springiness and range while retaining acceptable strength
  • Spring must be guided so that its action is exerted only in the appropriate direction

Fabrication of the Hawley Appliance:

  • Alginate impression of the maxillary arch (impression of the mandibular arch may also be required if a Hawley appliance is being fabricated for retention purposes)
  • Pour up alginate impression
  • Lab Prescription- include:
  • Date
  • Student’s name
  • Patient’s name
  • Orthodontist’s signature
  • Instructions to laboratory:
    • Example: Fabricate a maxillary Hawley appliance with Adams clasps on 1.6 and 2.6, labial bow in anterior region, loops in area of tooth 1.3 and 2.3
    • Include instructions for placement of a fingerspring if it is required

Insertion & Adjustments:

  • The posterior of the appliance should be inserted first, then the anterior
  • The appliance should be placed by pressing on the occlusal surfaces of the teeth
  • To remove the appliance, a simple pull with a fingernail on the back clasps is sufficient.
  • NEVER pull on the springs or the labial bow (front wire)à this will bend the wires and result in undesired tooth movements.
  • If the appliance does not seat properly upon insertion, some acrylic surrounding the teeth may be removed. A straight handpiece with acrylic burs should be used.

Finger spring activation (when Hawley used as an active appliance)

  • The fingerspring is activated 1.5 to 2 mm per month for a tooth movement of approximately 1 mm (within that time frame)
  • Greater activation will slow the tooth movement due to excessive force being exerted on the tooth.
  • Treatment is aimed at a slight over-correction of the crossbite until overbite is adequate is adequate to retain the corrected tooth position
  • One or two months of retention with a passive appliance should follow the crossbite correction

Instructions to the Patient:

  • Wear the appliance day and night (while sleeping)
  • Remove the appliance while eating
  • To avoid breakage, place the container in a protective container
  • After each meal and before bedtime, clean teeth and the appliance with a toothbrush and toothpaste.
  • Do not rinse the appliance under hot water
  • Avoid chewing gum, candy or anything hard such as crusty bread or nuts
  • Once the teeth are in the desired correct position, the appliance is only worn at night.
  • If the appliance is broken or becomes uncomfortable, an appointment should be made to fabricate a replacement.

Recall Schedule and Adjustments

  • Recall visits of 4 to 6 week intervals are indicated to assess the tooth movement and to perform the required adjustments.
  • The following adjustments may be necessary:
    • Tightening of the clasps
    • Activation of the spring
    • Removal of material from the baseplate
      • Trim away baseplate material to complete the activation of a spring
      • Baseplate must not be removed near a clasp since this may jeopardize the retention (due to possible movement of the anchor teeth)


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Category: Dental, Orthodontics

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