A Note on Anterior cross bite

Anterior cross bite

Possible causes

Class III skeletal pattern

Crowding

Retained primary teeth and roots

Presence of supernumerary teeth

Trauma

Clinical features

• Instanding maxillary incisor occluding behind the corresponding lower incisors.
• Over bite which can vary from nothing to excessive depth.
• Gingival recession of the lower incisor involved.
• Forward displacement of the  mandible-  instanding tooth comes into premature contact along the normal path of closure.
•      mobility of the lower incisor involved in the cross bite.

Methods available for correction

Spoon handle biting.

Removable appliance with either cantilever spring or screw.

Lower inclined bite plane.

     

Spoon handle biting

Instruct the child to bite on a spoon handle to guide the incisor which is erupting into cross bite.

 Do not attempt this on an erupted incisor which has a positive over bite.

Once cross bite established,

Identify predisposing factors and remove them to prevent development of the cross bite

Once the cross bite is established, identify and remove aetiological factors responsible and select appropriate method for correction.

Removable appliance

Selection of appliance and the spring design depend on,

      Axial inclination of the tooth

Depth of the over bite.

Amount of forward movement required

Number of teeth involved in the cross bite

Appliance design

Select the best active component which should be used depending on the above factors discussed.

Adequate number of clasps

Add adequate number of clasps to the appliance to resist the reaction of the vertical component of the active force.

Appliance design

Add posterior bite plane to disocclude teeth

Instruction to the technician

Adams clasps on 6/6 d /d

Double cantilever spring(Z spring) on /1

Posterior bite plane (half molar capping)

Management of patient

Fit the appliance and give adequate instructions to the patient to wear it regularly including meal time.

Activate the spring by the correct amount.

Adjust clasps and check the thickness of the molar capping.

Give adequate instruction to the parents as well.

Monitor progress of treatment

If cross bite is corrected and depth of the over bite adequate to ensure the stability of the occlusion discontinue appliance

Monitor the development of the occlusion until the occlusion of the permanent dentition is established.

Incisors cross bite before and after correction

Incisor cross bite not corrected early lead to a severe malocclusion