Three-dimensional Evaluation Of Upper Airway In UCLP Patients Following SME-a CBCT Study

[Objectives]The aim of this study was to use cone-beam computed tomography to assess the dimensional changes of maxilla and the upper airway in unilateral complete cleft lip and palate patients treated by slow maxillary expansion.[Materials and methods]16 orthodontic UCLP patients who were about to get congenital alveolar process cleft grafting were recruited.The patients were divided into two groups according to the extension of the maxillary deficiency.Group 1 were treated with SME using removable occlusal pad appliance with expansion screw(RPE)and group 2 were treated with SME(slow maxillary expansion)using removable occlusal pad appliance with expansion screw—Fan-type(RPE-F).CBCT images were taken immediately before(T0)and three months after expansion(T1).All CBCT data were processed with the software Dolphin Imaging.After orienting the CBCT images,a set of linear,area and volumetric parameters of the maxilla and upper airway were measured and calculated,including premolar to premolar width(PW)and molar to molar width(MW)of upper arch;the lateral width of the anterior,middle and posterior part of lower nose(Ln-pa,Ln-p,Ln-m);the cross airway area of middle and posterior part of lower nose(Nca-p,Nca-m);the volume of nasal airway and oropharyngeal airway(NPV,OPV);the minimal cross area of oropharyngeal airway(MCA).All CBCT data were analyzed in the software SPSS13.0.[Results]There were significant changes in upper arch of 16 patients treated with SME using PRE or RPE-F and the posterior crossbites were well corrected.After expanding,the PW increased more significantly than MW in group 2.But in group 1,there were no difference between them.After expansion,nasal lateral width increased from anterior to the posterior part,Ln-pa,Ln-p,Ln-m increased significantly.At the same time,Nca-p and Nca-m also increased significantly.The NPV increased 1289.2mm~3 in average.All the increasing of above are statistically significant.The OPV and MCA showed no positive change after SME.[Conclusions]1?SME can expand upper arch of UCLP effectively.2?The cross airway area and the volume of nasal airway were increased after expansion since nasal lateral width increased.3?The influence of SME on the oropharyngeal airway is limited.