Rapid Palatal Expansion in Mixed Dentition Using a Modified Expander: a Cephalometric Investigation

Abstract

The aims of this investigation were to cephalometrically study the short-term skeletal and dental modifications induced by rapid palatal expansion in a sample of 20 patients (10 male, 10 female), aged 6–10 years (mean age 8 years) in mixed dentition with a uni- or bilateral posterior crossbite, a mild skeletal Class II malocclusion, and an increased vertical dimension (FMA, SN^GoGn), and to compare them with an untreated matched control group of 20 subjects (10 male and 10 female), mean age 8 years.

Cephalometric analysis showed that the maxilla displayed a tendency to rotate downwards and backward, resulting in a statistically significant increase of the SN^PP angle (T0 = 9•95 degrees, T1 = 11•60 degrees, P < 0•01) and the SN–ANS linear value (T0 = 49•50 mm, T1 = 51•10 mm, P < 0•05).

Table 1. Method error coefficients

In addition, there was a statistically significant alteration of the anterior total facial height N–Me (T0 = 113•15mm, T1 = 114•15 mm, P < 0•05) and for the dental upper molar measurement U6–PP (T0 = 19•70 mm, T1 = 20•30 mm, P < 0•05).

The small alterations found in the anterior total facial height and in the sagittal angles agree with previous studies, and suggest that RPE can be also used in subjects with a tendency to vertical growth and a skeletal Class II malocclusion.

Keywords:

• Maxillary expansion
• Mixed dentition
• Cephalometric investigation