Fig. 1.

Measurement of maxillary (a) and mandibular width (b) with a digital caliper on the stone models. The frontal view of maxillary (blue line) and mandibular width (red line) is shown in (c). In this patient, the maxillary width is 55.0 mm, the mandibular width is 59.6 mm, and the maxillary transverse deficiency is 4.6 mm (59.6 − 55.0). The amount of maxillary skeletal expansion required for the patient is equal to the maxillary transverse deficiency (4.6 mm)