Means and standard deviations were computed for each group for overbite, overjet, sagittal and transverse relationships, arch dimension and crowding.
Dental casts were obtained, and the sagittal and transverse relationships, overbite, overjet, arch dimension and crowding were evaluated.
Although previous clinical studies failed to provide a measurable benefit, our results show that lack of expansion could promote worsening of transverse relationships.
Antero-posterior, vertical and transverse relationships in face shape analysis were determined using the following soft tissue parameters: exR exL (inter-eye distance) and al al (nose width) allows transverse analysis, pg g, pg men (total face height), sn men, Is men, n sn (mid-face height) allows vertical relationship analysis, s sn pg (face convexity) relate to antero-posterior features.
Twenty Caucasian subjects (nine males and 11 females; mean age 28.05 years; SD 8.34) were randomly selected according to the following inclusion criteria: normal occlusal sagittal, vertical and transverse relationships, as characterised by Angle Class I molar and cuspid relations, absence of cross-bites and well-set interincisal relations without major crowding.
All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1 CS2).
The hypothesis is that IO has no effect on the transverse dental arch relationship.
The mean differences in the transverse dental arch relationship are significant at 12 years of age.
