OBJECTIVETo investigate the application of three-dimensional CT(3D-CT) in the treatment of oblique facial clefts with mandibular outer cortex, including the surgical design and results assessment.

METHODSFrom Jan. 2003 to Dec. 2013, 22 cases with oblique facial cleft, who underwent mandibular outer cortex onlay bone graft were retrospectively studied. 3D images from CT data were reconstructed before operation for design. Then the mandibular outer cortex onlay bone transplant was performed to reconstruct the bone defect and cleft. 3D CT was performed 5-10 days postoperatively and 6- 12 months postoperatively to assess the facial symmetry.

RESULTSAccording to the results of CT measurement, the average volume of the orbital bone defects on the affected side decreased by(64. 6 ± 14. 4)% 5 to 10 days after operation. The average volume of the maxillary and zygomatic bone defects on the affected side decreased by(71.4 ± 15.7)% after surgery. After 6 to 12 months,the average recovery of the mandibular donor site was (57. 9 ± 13. 9)% of the removed mandibular outer cortex. The average absorption of grafted bones was(24.7 ± 25.6 )%. The average height difference between the centre of pupils on both sides before surgery was(3.76 ± 1.27) mm,which decreased to( 1. 15 ± 1.00) mm 5 to 10 days after surgery(P =0. 000) , and( 1.35 ± 1. 13) mm 6 to 12 months after surgery(P = 0. 003). The relapse may be caused by the absorption of the grafted bones.

CONCLUSIONS3D-CT can be used for preoperative design and postoperative assessment in the treatment of oblique facial cleft with mandibular outer cortex.