Use of computed tomography to determine correlation between maxillary expansion and appliance opening after surgically assisted rapid palatal expansion

Surgically assisted rapid palatal expansion (SARPE) is indicated as one of the procedures of choice for maxillary expansion in adults. Limited information is available regarding the correlation between the amount of appliance opening and the pattern of skeletal expansion. The purpose of the present study was to evaluate the correlation between the appliance opening and skeletal changes after SARPE, using Computed Tomography as a tool. In 15 adults (10 females and 5 males) submitted to SARPE without pterygoid plate separation, linear and angular measurements were performed on multislice computed tomography. The correlation between maxillary expansion and appliance opening was evaluated. Transverse skeletal expansion achieved through SARPE without pterygoid plate separation was less than uniform. Even with a constant and predictable pattern of maxillary skeletal expansion, a linear correlation between appliance opening and regional maxillary expansion was not obtained.