| Usually skeletal craniofacial deformities are diverse in the structural features, and the compensation mechanism of craniofacial skeletal structure is complex and various.The discussions of the structural features and the compensation mechanism are suitable for orthodontic treatment as well as orthognathic surgery planning, and beneficial to long time functional and esthetic stability.The theory of architectural balance of the cranio-maxillo-facial set appeared in 1960s and based on the integrate cranio-maxillo-facial structure of human-being and the development of congenital cranio-maxillo-facial deformities.The theoretic Delaire cephalometric analysis can obtain the cranio-maxillo-facial deformities accurately and quantitatively. Maybe this method was more effectively than the conventional cephalometric analysis when analyze the skeletal compensation mechanism. Although Delaire cephalometric anlysis method has been used in clinical for several years, limited in language obstacle, the complicated manual analysis methods was used by most orthognathic surgeon. Since now, there has been no report about the comparison between normal occlusion population and other malocclusion population through Delaire methods in Chinese people.In order to reduce the inadequate of manual Deliare cephalometric analysis, the research will establish the computer-assisted Deliare cephalometric analysis system and obtain the measurement items accurately and quickly as early as possible.Based on the theory of Deliare cephalometric analysis and the function of user-defined landmark points, the auxiliary lines, the program modules etc and to write the measurement and analysis program with WinCeph8.0, then establish the computer-assisted Deliare cephalometric analysis system.Computer-assisted Deliare cephalometric analysis system was convenient and accurate to trace the landmark points and the auxiliary lines completed the measurement and calculation and showed analysis results automatically.We chose 40 cephalometric radiographs to carry both computer-assisted and the manual Deliare cephalometric analysis, and the results were analyzed through paired t-test and dispersion analysis.Statistical analysis showed that computer-assisted analysis was more accurate than manual analysis.This research was the first time to combine Delaire cephalometric analysis method with commercial software and this will provide a stable platform for further use.Delaire cephalometric analysis is a sagittal direction and individual method, the normal reference standards will help us to analyze the cranio-maxillo-facial structure character of different races and areas.The cranio-maxillo-facial tissue marks of 95 radiographs were measured with computer assistant Delaire cephalometric analysis to analyze the architectural features of cranio-maxillo-facial hard tissues of normal occlusion in Chongqing region (44 males and 51 females, 18-23 years old). The data from corresponding indexes were processed with SAS 9.0 statistics analysis. The Delaire cephalometric analysis normal reference standards of normal occlusion population in Chongqing region are obtained.Furthermore, we compared the normal reference standards of Chongqing region with French area, which can provide reference to the further research of different races and the compensate mechanism of other skeletal malformation.Based the above research, we chosen 48 cephalometric radiographs of skeletal classⅢocclusion (18-39 years old, ANB<-4°) and measured with computer assistant Delaire cephalometric analysis. The data were deal with ANOVA analysis through SAS9.0 statistical software. The research divided the cranio-maxillo-facial hard tissue structure feature of skeletal classⅢinto four classifications through Delaire cephalometric analysis including hypo-divergent, hyper-divergent, maxilla normal and glenoid fossa retrocession, nine parameters of four groups have significantly variability through ANOVA analysis(P<0.05),for example, anterior cranial base angle, sphenoidal angle, percentage of craniospinal area to cranial depth ,percentage of craniofacial area to cranial depth and so on. The conventional cephalometric analysis chosen SNA, SNB, ANB, NA-PA etc to reflect the protrusion or retrusion of maxillary and Mandible, but they can't reflect this extent quantitatively. The Delaire cephalometric analysis can analyze the protrusion or retrusion of maxillary and Mandible quantitatively through Me-F1,Me-Met,Np-F1 etc. This method combine with conventional methods can evaluate accurately, quantitatively and directly. Secondly, 56 cephalometric radiographs of young ClassⅡmalocclusion (mandibular retrusion type) patients were measured with traditional cephalometric analysis and the Delaire cephalometric analysis respectively. Most traditional cephalomertric analysis results were qualitative, such as point B retrocess, the height of mandibular ramus decrease, the lower incisor and alveolar bone lip incline compensatory. The Delaire cephalometric analysis not only describe qualitatively but also measure quantity of vertical direction and sagittal direction by F1-Me,Me-Met etc.In conclusion, our study provided a convenient, simplified and accurate computer-assisted analysis application platform for the Delaire cephalometric analysis and obtained the Delaire cephalometric analysis reference standards of normal occlusion population in Chongqing region, which is very helpful to orthodontic treatment and research work.Meanwhile we measured the skeletal classⅢocclusion and mandibular retrusion patients by traditional cephalometric analysis and the Delaire cephalometric analysis. We discovered the Delaire cephalometric analysis was more accurately and conveniently. This method can help us to understand the cranio-maxillo-facial structure compensatory mechanism of the skeletal classⅢocclusion and mandibular retrusion patients, which can provide reference for diagnosis, project and orthodontic treatment. |
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