Design And Manufacture Of Fillers In Hemifacial Local Dent Patients With Rapid Prototyping Technique

Objective:To design and manufacture fillers for the patients with hemifacial local dent to correct the deformity with computer assisted design (CAD) and rapid prototyping (RP) technique.Methods:Computer tomography scanning was performed on heads of seven patients with hemifacial local dent, and then the transaxial second-dimensional image data were converted into digitized second-dimensional contour data with CT image processing software of Magic RP 9.0. The three-dimensional images of cranifacial bone contour were achieved when the vector graph (digitized contour data) were superimposeded by the way of vector. On the basis of mirror-image relation, point cloud data of normal side bone were converted into the opposite side, and then a three-dimensional model of filler came into being between the atrophied bone surface and the mirror image of normal side. The three-dimensional model data were stratified again. It is necessary to transform model data format into stereo lithography (STL) which rapid prototyping machine acquiesces. After being converted into STL format, the design data were imported into rapid prototyping machine, and then the substantial filler or reference model of filler for operation was obtained. The material called Medpor was carved according to the size and shape of the reference model, and then the substantial Medpor filler was achieved.Results:The data of abnormal position contour of craniofacial bone and three-dimensional model of filler were obtained by using computer tomography scanning, three-dimensional reconstruction and computer assis-ted design, and then the substantial filler or reference model of filler for operation was produced by rapid prototyping machine. The material called Medpor which was implanted into the dent position to complete the operation was carved or pliced according to the size and shape of the reference model.After the swelling of operation part disappeared, original deformities of patients are corrected completely and the operation effects are wonderful.Conclusions:The shape and size of abnormal craniofacial bone and filler can truly reappear with application of CAD and RP technique. Because of lifelike shape and individuality, RP technique is a promising technique in the field of customised manufacture of prosthesis in cranio-facial plastic and cosmetic surgery.