The basic characteristics of aesthetics of appearance (1) Chen Shuo, Department of Maxillofacial Surgery, Peking University Stomatological Hospital The word aesthetics originates from the Greek word aesthesis, which originally means the inner feeling of the sense organs towards the external world. It can be seen that “beauty or not” includes both objective external existence and subjective internal feelings. So let’s talk about how objective beauty exists. The basis of beauty is the coordination, symmetry, harmony and unity between the hard and soft tissues of the face, which is usually evaluated from the front and side. First of all, let’s introduce the evaluation indicators of the frontal view. The positive evaluation of the harmony of the frontal view can be summarized as “three stops and five eyes”, “three stops” refers to the proportional relationship of the length of the face, which can be divided into “big three stops” and The “three stops” refers to the proportional relationship between the length of the face, which can be divided into “big three stops” and “small three stops” (Figure 1). The “big three stops” refers to the hairline to the chin is divided into three equal parts, that is, the hairline point to the point between the eyebrows, the point between the eyebrows to the point under the nose, the point under the nose to the point under the chin of approximately equal length. The lower 1/3 of the face can be divided into three equal parts, i.e., from the point under the nose to the upper edge of the lower lip, from the upper edge of the lower lip to the middle point of the chin-lip groove, and from the middle point of the chin-lip groove to the point under the chin, which is approximately equal. Figure 1 Figure 2 “Five eyes” means that the width of the face is equal to the width of five eye fissures on the horizontal line of the eye fissures, i.e., the spacing between the left and right outer canthus to the left and right ear, the spacing between the two inner canthus and the spacing between the inner and outer canthus of the two eyes are nearly equal (Figure 2). The vertical line through the outer canthus coincides with the angle of the mandible, the vertical line through the inner canthus coincides with the lateral point of the nose, and the vertical line through the iris coincides with the angle of the mouth (Figure 3). Figure 3 Figure 4 Symmetry of frontal view In fact, the face of normal people is not absolutely symmetrical, and there are objectively a lot of small asymmetries in appearance, but these small asymmetries are within the range of people’s visual errors. Some scholars have analyzed the appearance of beautiful people, and the asymmetry rate can be regarded as symmetry within 10%. The midline of the face is usually determined by the point between the eyebrows, the tip of the nose and the middle of the chin (Figure 4). This is used as a reference to observe whether the zygomatic prominence is consistent, the mandibular angle is symmetrical, the angle of the mouth is horizontal, and the midline of the upper and lower dentition is consistent with the midline of the face. Here, the correction of the inclined occlusal plane needs to be emphasized as it is very important to correct the facial asymmetry. Note: The images in this article are taken from Johan P. Reyneke. Essentials of orthognathic surgery. 2nd.