[Objectives] To analyze pars orbitalis symmetry of UCLP patients in mixed dentition period, ad provide better theoretical basis for studying craniofacial shape and clinical treatment. [Methods] 3D reconstruction of CBCT images of 20 UCLP patients in mixed dentition period was conducted, and 13 mark points were selected from 3D image for fixed-point measurement to analyze 3D shape of pars orbitalis. [Results] (i) Horizontal symmetry of pars orbitalis. The width of pars orbitalis of UCLP patients at sites So, Lo, Oi, Or, SoF, Z of fracture side was all equa to that at nonfracture side, and there was not statistical difference (P>0.05). (ii) Sagittal symmetry of pars orbitalis. Sagittal development of pars orbitalis of UCLP patients at sites So, Lo, Oi, Or, SoF, Z of fracture side was equal to that at nonfracture side, and there was not statistical difference (P>0.05). (iii) Vertical symmetry of pars orbitalis. The height of pars orbitalis of UCLP patients at sites So, Lo, Oi, SoF, Z of fracture side was higher than that at nonfracture side, and there was not obvious statistical difference (P > 0.05). [Conclusions] There was not significant asymmetry in par orbitalis of UCLP patients in mixed dentition period. [ABSTRACT FROM AUTHOR]