Transverse maxillary deficiency and constricted maxillary dental arch resulting to posterior crossbite can be genetic in origin or could be caused by environmental influences such as digit sucking and mouth breathing. In pre-adolescent patients, correction of the posterior crossbite, whether unilateral or bilateral, as soon as diagnosed is important to avoid further worsening of the transverse maxillary deficiency and maxillary arch constriction, prevent functional problem and mandibular shift on closure and at the same time provide more space for the eruption of the permanent teeth.
An appliance called quadrihelix, originally developed by Herbst can be used for expansion of a constricted maxillary arch to correct posterior crossbite in a pre-adolescent child. The combination of a posterior crossbite and a finger sucking habit is the best indication for this appliance.
It is an adjustable lingual arch with loops fabricated from 36 mil stainless steel wire and soldered to molar bands. When activated, the quadrihelix should deliver proper force level that produces some opening of the mid-palatal suture by slow expansion aside from buccal tipping of the posterior teeth.
Clinical management of the Quadrihelix Appliance for correction of posterior crossbite in pre-adolescent children – http://www.costbraces.org/quadrihelix-appliance/
by: Dr. Damri Thongnoi