ABSTRACT
Objective @# A titanium personalized orthodontic bracket is designed and manufactured using the technology of computed tomography (CT), computer aided design (CAD), finite element analysis (FEA), and selective laser melting (SLM) to well match the patient tooth so as to realize mold-free manufacturing. @*Methods@#A model of a titanium personalized orthodontic bracket which is built by CT scanning machine and Pro/E software, is imported into Ansys software to carry out finite element simulation analysis with nonlinear contact method. Then, the titanium personalized orthodontic bracket is proposed after the model data above is imported to SLM molding equipment via titanium powder melted with layer by layer using a high-speed scanning galvanometer. @*Results @#The maximum equivalent stress of the titanium personalized orthodontic bracket is distributed uniformly and reasonably, the titanium personalized orthodontic bracket formed by SLM molding equipment can provide high accuracy and there is a high similarity between the bottom of the orthodontic bracket and the tooth surface shape.@*Conclusion @#The combination of CT, CAD, FEA, SLM technology can fulfill model-free manufacturing of the personalized orthodontic bracket and thus shorten the manufacturing cycle.
ABSTRACT
Objective @#To explore an efficient method for the establishment of three-dimensional (3-D) digital models of maxillofacial region including muscle tissue based on CT and MRI images fusion on a personal computer, integration of CT and MRI data, and provide accurate 3D model for biomechanical analysis. @*Methods @#A male volunteer was scanned on maxillofacial region by spiral CT and MRI. Two kinds of data obtained were imported into Mimics 15. In the three sections, namely the transverse, sagittal, coronal sections, two kinds of data were adjusted to the same anatomical layers. The most obvious anatomical points on each layer were selected as registration points. Then, the multi-points registration was implemented for data fusion. Then the bone and facial skin were segmented and 3D reconstructed using CT data, the main facial muscles were segmented and 3D reconstructed using MRI data. @*Results@#The 3D model including 3 pairs of masticatory muscles, 12 pairs of facial expression muscles, facial skin and jaw tissues were established. @*Conclusion @# The efficient registration and fusion of CT and MRI datas were accomplished. Moreover, this method can be used for further segmentation and reconstruction of other important structures in craniofacial area, such skin, blood vessel, fat, lymph node and the brain tissues.