The purpose of this study was to determine the effect of the
T4K, a prefabricated functional appliance, on the transverse
and anterior-height dimensions of the maxillary and mandibular
dental arches. Dimensions before and after treatment were measured
on the sample, then, natural growth was subtracted from the
treatment effects and compared with twice the error of the method.
A clinically significant increase of both dimensions was observed
in the maxilla and mandible when Class II malocclusion patients
were treated with the T4K. Therefore, this retrospective study
demonstrates that T4K is a valid treatment choice at an early
age when transverse expansion is part of the treatment goal.
Key words: Dentofacial orthopedics, transverse expansion,
functional appliance