| Objective:Hemifacial microsomia(HFM) is one kind of congenital malformations with facial asymmetry which is the primary clinical manifestation because of the unilateral dysplasia of maxillary and mandible. Some researchers considered that distraction osteogenesis only had good short-term effects. Furthermore, lower surface asymmetry deformity were not seen obviously improved. So they even doubted that this technique was an effective procedure to correct the heimifacial mirosomia for the reason of its high relapse rate in the long-term follow-up. Nevertheless, some scholars drew an opposite conclusion and they insisted that the shape of the mandible and deformity of the lower face could be improved using the technique. In order to solve this issue, the data of three-dimensional CT of patients were measured and analyzed on three observation-points including before and after operations and follow-up. According to the statistical analysis, the morphology of mandible, facial symmetry of patients and effect of this procedure were evaluated.Methods:6 children diagnosed with HFM in Plastic Surgery Hospital, Chinese Academy of Medical Sciences Centre, Maxillofacial Plastic Surgery from May 2011 to March 2014 were selected in the study.The data of three-dimensional CT reconstruction on three observation-points were adopted to analyze by Mimics. The observation-points were pre-operation, post-operation of DO and follow-up (the follow-up periods range from half a year to three years), respectively. According to the mimic software, the alteration of line distance, space angle and anatomical plane, according to bony landmark, which contains the height of mandible ramus, the length of mandibular body, the distance from pogonion to sagittal plane and the angle between horizontal plane and occlusal plane, were measured. Then all the results mentioned were statistically analyzed by SPSS.Results:Both the lower facial symmetry and occlusal plane of the 6 HFM patients were significantly improved. These 6 HFM patients 3D CT results of pre-and post-DO, as well as the long-term post-operation follow-up were analyzed. The height of mandible ramus in the affected side to that in the healthy side ratio were 65.84+/-10.71%,101.80+/-8.28%,81.83 +/-11.90% among pre-DO, post-DO and the follow-up respectively. The difference among them was considered statistically significant. For the length of mandibular body ratio were 76.56+/-8.24%,76.47+/-6.98% and 76.57+/-6.46% in these there time points.And no statistical significance was observed among them.The angle between occlusal plane and horizontal plane were 18.60+/-3.27°,15.16+/-3.19° and 15.03+/-3.13° for pre-, post-DO and long-term post-operation follow-up. There was no statistical significance between follow-up and post-DO group. Statistical significance is also obtained among these three groups of the distance from pogonion to sagittal plane. And the results were -9.01+/ 4.02mm,-0.77+/-3.97mm and -2.71+/-3.15mm respectively.Conclusion:According to the analysis of pre-operation, post-operation and follow-up radiographs, we conclude that the distraction osteogenesis surgery is effective and the operation could correct the lower facial asymmetry significantly.The mandibular ramus may relapse to some degree after mandibular DO. However, lower facial asymmetry has been improved significantly. Hence, we draw a conclusion that the mandibular Distraction Osteogenesis Sugery is an effective treatment for children with HFM and it could correct facial asymmetry. |
PDF Full Text Request