Comparison of differential and conventional rapid maxillary expansion on upper airway dimensions in children with bilateral complete cleft lip and palate: A CBCT-based secondary analysis of a clinical trial

Abstract

Aim

This study aimed to compare the changes in upper airway dimensions produced by conventional expanders (CE) and differential expanders (DE, which display two parallel jackscrews) in children with bilateral cleft lip and palate (BCLP).

Materials and methods

The initial clinical trial sample included 50 patients with complete BCLP who were treated with RME before the secondary bone graft procedure at a single centre—Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo (HRAC-USP). The patients were divided into two groups. Group DE were treated with differential expanders, while Group CE received Hyrax expansion during pre-bone graft orthodontics. Pre-expansion (T1) and six months post-expansion (T2) cone-beam computed tomography (CBCT) images were analysed to assess upper airway dimensions, including the nasal cavity, nasopharynx, oropharynx, and total pharyngeal space. Intergroup comparisons were performed using independent T-tests (α = 0.004).

Results

Of the initial 50 patients, the final Group DE consisted of 20 patients with a mean age of 9.07 years while the CE group included 19 patients (13 males and 6 females), with a mean initial age of 9.19 years. No statistically significant differences were observed between the changes of the two groups in the analysed variables, indicating that both expanders had similar effects on increasing upper airway dimensions.

Conclusion

Both CE and DE effectively increase upper airway dimensions in BCLP patients. These findings support that the choice of expander should be guided by the dental upper arch shape and the clinician's preferences.