Clinical Study On Operation Design Of Zygomatic Maxillary Complex Fracture Using Bone Standard Anatomy Points In Three Dimensional CT Images Of Zygomatic Maxillary Complex

ObjectiveSpecial anatomic landmarks of zygomatic maxillary complex (ZMC) were selected, toestablish a reliable CT measuring method for quantitative diagnosis of unilateral ZMCfractures. Using these surface anatomic landmarks of ZMC, to approach prediction methodfeasibility to guide ZMC operation. Thus we can provide a efficient reference for clinicaltreatment of ZMCF.Method(1) A retrospective chart review was conducted of534patients treated at XinqiaoHospital Three Military Medical University, Department of Stomatology from January2005to December2009.205patients were identified with a diagnosis of soft tissues injuries,134patients were determined to have mandible fractures, and75patients were have ZMCfractures,68patients were have Maxillary fractures,8patients were have nasal bonefractures. The radiological records of these patients were then reviewed; exclusion criteriawere bilateral ZMC fractures, a total of29patients with ZMC fractures were analyzed inthis study.(2)29cases of unilateral zygomatic Maxillary complex (ZMC) fractures wereexamined by three dimensional CT, Three dimensional CT databases of29cases wasestablished, then database were analyzed and remodeled by the Mimics software. DuplicateZMC and adjacent bone standard anatomy points were selected, and then the distance ofselected same two points and the angle of selected same three points were measured byMimics software. Measuring results showed that the the degree displacement of thezygomatic to backward inward and downward. To summarize the law of the displacementafter ZMC fractures, to provide a reference for surgical reduction.(3) Based on the previousstudy, from January2010to September2011,20ZMC fracture patients needed operation were collected, three dimensional CT images of all patients anatomic landmarks weremeasured and analyzed. Compared to uninjured side. The different value of the distanceand the angle of injured side ZMC were acquired, ZMC fractures were operated based onthe different value. At the same time, according to the angle of uninjured side ZMC,preexisting micro miniature bone plate set to ensure intraoperative reduction form. Toimprove the precision of the unilateral ZMC reduction. All patients were examined by threedimensional CT postoperation, and the different value of the distance and the angle of bothside were measured identical to preoperation. Therapy effects were analysed based on thedatabase of different value of the distance and the angle.Results(1) We selected a total of11points (fmo, oz, zm, mp, ju, Ms, A, zy, tp, B, C) toanalyzed in this study.29patients with unilateral ZMC fractures were measured, and thenthe digital measurement system of ZMC fracture was established. The processes of thezygomatic and zygomatic arch were measured specially. Measuring results showed that thedisplacement of the zygomatic of most patients was backward and inward.(2) Higherfracture scores, and/or severe displacement in one or more dimensions were more likely torequire repair. Severe displacement in the medial-lateral dimension was most stronglycorrelated with need for surgical repair.(3)20ZMC fracture patients needed operation byanatomic landmarks assisted reduction, The different value of the distance＜2mm，and thedifferent value of the angle＜1°. Postoperation can acquire a satisfactory operation effects.20patients reached the three dimensional nearly symmetric, surgical results weresatisfactory in recovery of occlusion and mouth opening.。Conclusion(1) We selected a total of11points (fmo, oz, zm, mp, ju, Ms, A, zy, tp, B, C) toanalyzed in this study. Use these anatomic landmarks we selected, and the3D CT data, athree-dimensional digital model created, and then the digital measurement system of ZMCfracture was established.(2) Use the displacement of distance and angle measuring method,can accurately located the fractured ZMC; multi-angle demonstrated the severity of thefracture.(3) Compared to uninjured side. The different value of the distance and the angleof injured side ZMC were acquired, before the operation, we can prediction reduction of thefracture direction, distance and angle.(4) A prospective study of the results shows that the study on the screening of anatomic landmarks and the measurement method, can improvethe precision of the unilateral ZMC reduction.