Combined patterns of soft and hard tissue structure in mandibular prognathism

目的建立下颌前突患者软、硬组织结构的自组织映射网络(SOM)，对下颌前突患者的软、硬组织结构进行直观分类，揭示下颌前突患者的典型特征。16个软硬组织结构标记被数字化。将所有点转换为X-Y值，得到SOM的输入向量。采用自组织算法，计算出包含4个加工单元的下颌前突轮廓图。结果经过1万次学习，计算出2×2个单元的下颌前突侧貌图，生成4个虚拟侧貌。每个虚拟配置文件都由…进行了字符调整面部凸度、面部高度、下颌前突、上颌骨缺失、上下唇前突、鼻唇角。第一单元：硬组织特征：下颌平面角低，上颌骨轻度缺失，下颌前突。软组织特征为轻度面中部发育迟缓和下颌前突。单位2：硬组织特征为下颌升前倾和下颌前突，软组织内鼻唇角变窄。单位3：硬组织特征为下颌平面角偏高，下颌前突。软组织特征表现为面部下部高度增加和下颌前突。单位4：硬组织特征为上颌骨缺失、下颌平面角偏高、上下切牙轻度脱牙槽代偿。软组织特征特征增加，面部高度降低，面中部轻度迟缓。结论该图可用于建立基于虚拟轮廓的下颌前突软硬组织结构组合模式的视觉分类。较少

Combined patterns of soft and hard tissue structure in mandibular prognathismObjectiveThe purpose of this study was to create a self-organizing map (SOM) for visual classification of soft and hard tissue structure in mandibular prognathism, and to demonstrate the typical profiles in mandibular prognathism cases.MethodsThe lateral cephalometric radiographs of 90 female patients (mean age 22.6±3.8 years) with malocclusion were examined. Sixteen soft and hard tissue structurelandmarks were digitized. All points were converted into X-Y values to obtain input vectors for the SOM. By self-organization algorithm, a mandibular prognathism profile map with 4 processing units was calculated. After represent inputting process of vectors, the soft and hard tissue profiles of all the subjects were entered in the map.ResultsAfter ten thousand learning events, the mandibular prognathism profile map with 2× 2 units was calculated, producing 4 virtual profiles. Each virtual profile was character zed by … More the degree of facial convexity, facial height, mandibular protrusion, maxillary deficiency, upper and lower lip protrusion, and nasolabial angle.Unit 1 : Hard tissue characteristic features were low mandibular plane angle, mild maxillary deficiency and mandibular protrusion. Soft tissue characteristic features were mild mid-face retardation and protrusion of the chin.Unit 2 : Hard tissue characteristic features were anterior inclination of the mandibularramus and mandibular protrusion with narrowing of nasolabial angle in soft tissue. Unit 3 : Hard tissue characteristic features were high mandibular plane angle and mandibular protrusion. Soft tissue characteristic features were increased lower facial height and protrusion of the chin.Unit 4 : Hard tissue characteristic features were maxillary deficiency, high mandibular plane angle and slight deto-alveolar compensation of upper and lower incisors. Soft tissue characteristic features were increased lower facial height and mild mid-face retardation.ConclusionThe results suggest that this map is useful in establishing visual classification of combined patterns of soft and hard tissue structure based on virtual profiles in mandibular prognathism. Less