Abstract: Crown contour is the most protruding part of each axial plane of crown，which forms the height of the crown，and it is closely related to the health of the surrounding periodontal tissue. Establishing a suitable protrusion so as to restore the shape of the prosthesis matched with the natural teeth is of great significance in maintaining the health of periodontal tissue，prolonging the life of the prosthesis and achieving good repairing effect. In this paper，we will define the crown contour，and explore whether there is a quantitative mathematical relationship between the crown contour and the soft and hard tissue around it，so as to guide the aesthetic effect of natural and harmonious soft and hard tissue around the restoration and reconstruction of the restoration body，and it will provide theoretical evidence for oral technicians to prepare prosthesis.

Key words: crown contour, emergence profile, periodontal health, soft tissue aesthetics

摘要： 牙体外形突度是牙冠各轴面上最突出的部分，其形成了牙冠外形的高度，与周围牙周组织的健康息息相关。如何建立合适的外形突度，从而恢复与天然牙相匹配的修复体外形，对维护牙周组织健康、延长修复体寿命、达到良好修复效果有着重大意义。文章将科学地定义牙体外形突度，探究其与周围软硬组织之间是否具有可定量分析的数学关系，从而指导恢复与重建修复体周围自然、和谐的软硬组织美学效果，为口腔技师进行修复体制作提供理论依据。

关键词: 牙体外形突度, 穿龈轮廓, 牙周组织健康, 软组织美学