Establishment of a three-dimensional digital model based on multi-source craniofacial profile / 中华医学美学美容杂志

Objective To establish a three-dimensional digitized visible model to meet the clinical and research needs.Methods The head of the volunteer was scanned by a cone beam CT (CBCT).The bone tissue,the facial soft tissue and the teeth were extracted from the cone beam CT raw data according to the different Houns field values.The 3D digital craniofacial model was reconstructed from the three tissues extracted from the CBCT original data.The 3D dental model with high resolution was acquired by scanning the dental cast with the laser scanner.The 3D facial model with texture was acquired by scanning the volunteer's face directly by other laser scanner.With the regis tration algorithm in 3D graphics,the 3D facial model with texture and the 3D dental model with high resolution were transformed to the same coordinate which was of the 3D digital craniofacial model.Results We acquired a complicated 3D craniofacial digital model which combined the teeth model with high resolution,the bone model and the face model with texture.Conclusions The method is able to accurately establish the craniofacial digital model.

Computer Generated Three-Dimensional Reconstruction of the Auditory Pathway Structures of Brainstem

OBJECTIVE: The purpose of the study is to draw the three-dimensional reconstructions of nuclei and tracts of the auditory pathway structures of drainstem. METHOD: The drawings of 1 mm sections of the brainstem were scanned with a computer scanner into AUTOCAD program. All lines of structures except for the auditory pathway structures and outlines were removed. Each layer was plotted to a x, y, and z coordinated plotting reference to the corresponding points on the mid-sagittal plane and reconstructed to a three-dimensional drawing. Center point of the auditory pathway structures of all cross section layers were connected with a line in succession and that was thought to be a imaginary pathway of auditory pathway through the brainstem. RESULTS: This auditory pathway has several turning points, at the cochlear nucleus, superior olivary nucleus, and inferior colliculus which correspond with known generation sources of the peak of brainstem evoked potentials. CONCLUSION: This study presents a method for the conversion of the two-dimensional transverse sections into a three-dimensional format, to allow the visualization of the auditory pathway structures from multiple directions.

THREE-DIMENSIONAL COMPUTER RECONSTRUCTION OF NUCLEUS ISTHMUS OF FROG / 解剖学报

Based on the principle of binocular stereopsis, three-dimensional reconstruction of the nucleus isthmus (NI) in the frog (Rana nigromaculata) has been realized by using a microcomputer system. The histological techniques used were somewhat different from conventional ones in that two pin holes, which were regarded as fiducial points to ensure an accurate alignment of the outlines of microstructures in the serial sections during three-dimensional computer reconstructing, were made in the tissue block with a micropipette before it was cut. All operations such as collection of outline-data of the microstructures, data processing and drawing output were all under control of the software. Three-dimensional morphology of NI and its location in the midbrain have been demonstrated by the stereopairs. Its dimensions measured on the basis of the reconstruction is 500 (caudorostal)?810 (dorsoventral)?810 (mediolateral)?m. The significance of three-dimensional computer reconstruction for accurately measuring the dimensions of NI and other biological microstructures and for the study of histological morphology are discussed.