Study Of The Hemifacial Microsomia With Distraction Osteogenesis

Objective: Apply distraction osteogenesis to treat children with Hemifacial Microsomia,explore the improvement of osseous structure of maxillofacial bone by distraction osteogenesis.Methods: A total of 6 children with hemifacial microsomia who had completed distraction osteogenesis surgery in the Burn & Plastic Unit of Children’s Hospital of ChongQing Medical University.4 males and 2 females,with a median age of 2 years(mean 2.85±2.53 years).The postoperative follow-up time ranged from 3 to 5 months.Using three-dimensional CT reconstruct the maxillofacial skull.Measure the landmark as followed when preoperative(T1),complete distraction(T2),and remove distractor(T3).Mandibular: distance from gonion(GO)to condyle process(CP),GO-CP,distance from gonion(GO)to pogonion(Pog),GO-Pog,altitude difference of two side gonion(AL-AR),distance from gonion to sagittal plane(GO-SP),Maxilla: distance from Orbitale(Or)to sagittal plane(Or-SP)and between two infraorbital rim(OrL-OrR),distance from infraorbital foramen(IF)to sagittal plane(IF-SP)and between two infraorbital foramen(IFL-IFR).Facial soft tissue: Make the horizontal reference line(HRL)and Vertical reference line(VRL)on the face.Make a vertical line of the HRL from the both side angulus oris,measure the length of the line,the affected side marked as LA,the unaffected side marked as LA’,measure the angle between the lip plane and HRL,marked as ∠α.Measure the length of facial contour,the affected side marked as LB while the unaffected side marked as LB’.The satisfaction degree of parents and surgeons was calculated,the differences between different periods were compared.Result: All the included children successfully completed the surgery.1 child has pin tunnel infection after 3 months of hospital discharge and remove the distractor immediately.1 child had mouth numbness and droop after remove the distractor,recovered in 1 month by itself without special treatment.And the other children had no abnormality.All children had no tooth germ damage and mandibular bone nonunion.6 cases,three period of maxillofacial osseous tissue and facial soft tissue data were analysis by SPSS22.0 software.Go-CP at T1&T2 and T1&T3 have statistical significance(p < 0.05),and LB/LB’ at T1&T2 and T1&T3 have statistical significance(p < 0.05).Go-SP,IF-SP,Or-SP and ∠α have no statistically significant in each period.The satisfaction degree of the parents and doctors to the children’s facial contour was statistically significant in T1&T2 and T1&T3.Conclusion: Distraction osteogenesis surgery has a good effect on the improvement of the affected mandible by hemifacial microsomia,without affecting the maxilla bone structure,and also improves the asymmetry of the facial soft tissue.Parents and doctors were satisfied with the improvement of facial asymmetry.Early surgery may be the factor of no significant relapse in a short time,but the long-term effect still needs longer follow-up.