Some dialogs like ParagraphPropertiesDialog and SectionColumnsDialog have dependency properties for defining the width of the numerics. When creating implicit style, the value of these custom properties results in 0 and they are invisible in the UI.

Workaround: Set the value of the property in the custom style. For paragraph properties dialog:

<Style TargetType="rtb:RadParagraphPropertiesDialog" BasedOn="{StaticResource CustomStyle}" >
    <Setter Property="NumericWidth" Value="85"/>
</Style>