Rapid and slow maxillary expansion: a posteroanterior cephalometric study

The purpose of this study was to evaluate and compare the dental and orthopaedic effects of rapid and slow maxillary expansion in a sample of young patients with transversal maxillary deficiency by using a postero-anterior cephalometric analysis.

Two groups of patients were considered: 10 patients (3 males, 7 females) with an average age of 8.9 years were treated with a rapid maxillary expansor (RME); 10 patients (7 males, 3 females) with an average age of 12.2 years were treated with a new slow maxillary expansion appliance (ELA). Postero-anterior cephalometric analyses were made at the beginning of the therapy (T0) and at the end of expansion (T1) using a computerised cephalometric programme. Four parameters were measured: Nasal width, maxillary width, mandibular width, upper molars width.

Transversal average width increased 5.435 mm (SD 3.31 mm) between the upper molars in the RME group and 5.547 mm (SD 3.49 mm) in the SME group. Maxillary average width increased 4.254 mm in the first group and 2.845 mm in SME group. Discussion An orthopaedic result was reached with both treatments. These results are in agreement with the orthodontic literature.

This work confirms the effectiveness, efficiency and usefulness of this new ELA appliance in the correction of transversal deficiency with orthopaedic results, if used in growing patients.