Objective: To observe the differences in normal facial skin thickness and echo density by different ages and sites of healthy adults of the same sex using 50 MHz high-frequency ultrasound. Methods: From January to June 2019, 200 healthy adult volunteers with normal facial skin who were from Sichuan, Yunnan, Guizhou, and Chongqing and met the inclusion criteria were recruited by the Affiliated Hospital of Southwest Medical University with simple random sampling method, and then were included in this cross-sectional investigation study. Then 50 MHz high-frequency ultrasound was used to obtain skin ultrasonogram of volunteers' forehead, canthus, eyelid, and cheek. According to the ages, 100 female volunteers were divided into 20-29 years old (30 females), 30-39 years old (25 females), 40-49 years old (20 females), and 50-70 years old (25 females) groups; 100 male volunteers were divided into 20-29 years old (30 males), 30-39 years old (25 males), 40-49 years old (20 males), and 50-70 years old (25 males) groups. The thickness of full-skin, the upper dermal echo density, and the lower dermal echo density of the female and male volunteers'forehead, canthus, eyelid, and cheek were recorded respectively. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Bonferroni correction. Results: (1) The thickness of full-thickness skin in forehead, canthus, eyelid, and cheek of female and male volunteers in 20-29 years old group were (1.86±0.26), (1.36±0.11), (1.24±0.25), and (1.90±0.21) mm, (2.45±0.37), (1.64±0.19), (1.44±0.16), and (2.53±0.26) mm, respectively, in 30-39 years old group were (1.98±0.24), (1.43±0.13), (1.15±0.15), and (2.12±0.13) mm, (2.34±0.27), (1.63±0.27), (1.50±0.38), and (2.43±0.40) mm, respectively, in 40-49 years old group were (1.90±0.21), (1.43±0.18), (1.24±0.27), and (1.98±0.12) mm, (2.14±0.24), (1.54±0.25), (1.28±0.14), and (2.39±0.36) mm, respectively, in 50-70 years old group were (1.64±0.25), (1.36±0.19), (1.16±0.12), and (1.89±0.29) mm, (2.28±0.27), (1.73±0.25), (1.58±0.18), and (2.38±0.32) mm, respectively. There were no statistically significant differences between female volunteers in the 4 groups and male volunteers in the 4 groups in thickness of full-thickness skin in canthus, eyelid, and cheek (F=0.677, 0.666, 0.136, 0.697, 0.294, 0.888, P>0.05). The thickness of full-thickness skin in forehead and cheek of the female volunteers in the 4 groups and male volunteers in the 4 groups was similar (P>0.05), and was significantly higher than that of canthus and eyelid (P<0.05). The thickness of full-thickness skin in canthus and eyelid of female volunteers in 20-29 years old, 40-49 years old, and 50-70 years old group was similar (P>0.05), while thickness of full-thickness skin in canthus and eyelid of male volunteers in the 4 groups was similar (P>0.05). (2) The upper dermal echo density of forehead, canthus, eyelid, and cheek of female volunteers in 50-70 years old group was significantly lower than that in 20-29 years old and 30-39 years old groups (P<0.05). The upper dermal echo density of forehead, canthus, eyelid, and cheek of male volunteers in 50-70 years old group was significantly lower than that in 20-29 years old group (P<0.05). The upper dermal echo density of forehead, canthus, eyelid, and cheek of female and male volunteers in 20-29 years old and 30-39 years old groups was similar (P>0.05). The upper dermal echo density of forehead and cheek of female volunteers in 20-29 years old, 40-49 years old, and 50-70 years old groups was significantly lower than that of canthus and eyelid (P<0.05). The echo density of upper dermis of cheek of male volunteers in the 4 groups was significantly lower than that of canthus and eyelid (P<0.05). The upper dermal echo density of canthus and eyelid of female volunteers in the 4 groups and male volunteers in the 4 groups was similar (P>0.05), the upper dermal echo density of forehead and cheek was similar (P>0.05). (3) The lower dermal echo density of forehead, canthus, eyelid, and cheek of female volunteers in 50-70 years old group was significantly higher than that in 20-29 years old and 30-39 years old groups (P<0.05). The lower dermal echo density of forehead, canthus, eyelid, and cheek of male volunteers in 50-70 years old group was significantly higher than that in 20-29 years old group (P<0.05). The echo density of the lower dermis of forehead, eyelid, and cheek of female and male volunteers in 20-29 years old, 30-39 years old, and 40-49 years old groups was similar (P>0.05). The lower dermal echo density of forehead and cheek of female volunteers in the 4 groups was significantly lower than that of canthus and eyelid (P<0.05). The lower dermal echo density of forehead and cheek of male volunteers in 30-39 years old, 40-49 years old, and 50-70 years old groups was significantly lower than that of canthus and eyelid (P<0.05). The lower dermal echo density between canthus and eyelid and between forehead and check of female volunteers in the 4 groups and male volunteers in the 4 groups was similar (P>0.05). Conclusions: The 50 MHz high-frequency ultrasonography shows that the thickness of full-thickness skin of canthus, eyelid, and cheek is similar in all age groups of female and male adult volunteers with normal facial skin. In the same age group, the thickness of full-thickness skin of forehead and cheek of male and female volunteers is significantly higher than that of canthus and eyelid. The upper dermal echo density of forehead, canthus, eyelid, and cheek of female and male volunteers shows a decreasing trend with age, while the lower dermal echo density shows an increasing trend with age. In addition, the echo density of upper and lower dermis of canthus and eyelid was significantly higher than that of cheek in all the four age groups.
目的： 采用50 MHz高频超声观察同一性别成人的不同年龄和部位面部正常皮肤的厚度和回声密度的差异。 方法： 2019年1—6月，西南医科大学附属医院采用简单随机抽样法招募符合入选标准的川滇黔渝区域面部皮肤正常的健康成人志愿者200名，纳入本横断面调查研究。使用50 MHz的高频超声采集所有志愿者额头、眼外角、眼睑和脸颊的皮肤声像图。根据年龄将100名女性志愿者分为20～29岁组30名、30～39岁组25名、40～49岁组20名、50～70岁组25名，100名男性志愿者分为20～29岁组30名、30～39岁组25名、40～49岁组20名、50～70岁组25名，分别统计女性4组和男性4组志愿者的额头、眼外角、眼睑与脸颊的全层皮肤厚度、真皮上层回声密度和真皮下层回声密度。对数据行单因素方差分析、重复测量方差分析、LSD检验、Bonferroni校正。 结果： (1)女性、男性20～29岁组志愿者额头、眼外角、眼睑、脸颊全层皮肤厚度分别为(1.86±0.26)、(1.36±0.11)、(1.24±0.25)、(1.90±0.21)mm，(2.45±0.37)、(1.64±0.19)、(1.44±0.16)、(2.53±0.26)mm；30～39岁组分别为(1.98±0.24)、(1.43±0.13)、(1.15±0.15)、(2.12±0.13)mm，(2.34±0.27)、(1.63±0.27)、(1.50±0.38)、(2.43±0.40)mm；40～49岁组分别为(1.90±0.21)、(1.43±0.18)、(1.24±0.27)、(1.98±0.12)mm，(2.14±0.24)、(1.54±0.25)、(1.28±0.14)、(2.39±0.36)mm；50～70岁组分别为(1.64±0.25)、(1.36±0.19)、(1.16±0.12)、(1.89±0.29)mm，(2.28±0.27)、(1.73±0.25)、(1.58±0.18)、(2.38±0.32)mm。女性4组和男性4组志愿者眼外角、眼睑和脸颊全层皮肤厚度组间总体比较，差异均无统计学意义(F＝0.677、0.666、0.136，0.697、0.294、0.888，P>0.05)。女性4组和男性4组志愿者额头和脸颊全层皮肤厚度均相近(P>0.05)，且均明显高于眼外角和眼睑(P<0.05)。20～29岁组、40～49岁组、50～70岁组女性志愿者眼外角与眼睑全层皮肤厚度相近(P>0.05)，4组男性志愿者眼外角与眼睑全层皮肤厚度均相近(P>0.05)。(2)50～70岁组女性志愿者额头、眼外角、眼睑和脸颊真皮上层回声密度均明显低于20～29岁组和30～39岁组(P<0.05)，50～70岁组男性志愿者额头、眼外角、眼睑和脸颊真皮上层回声密度均明显低于20～29岁组(P<0.05)，20～29岁组与30～39岁组女性、男性志愿者额头、眼外角、眼睑及脸颊真皮上层回声密度均相近(P>0.05)。20～29岁组、40～49岁组和50～70岁组女性志愿者额头和脸颊真皮上层回声密度均明显低于眼外角和眼睑(P<0.05)，4组男性志愿者脸颊真皮上层回声密度均明显低于眼外角和眼睑(P<0.05)；女性4组和男性4组志愿者眼外角与眼睑真皮上层回声密度相近(P>0.05)，额头与脸颊真皮上层回声密度相近(P>0.05)。(3)50～70岁组女性志愿者额头、眼外角、眼睑及脸颊真皮下层回声密度均明显高于20～29岁组与30～39岁组(P<0.05)，50～70岁组男性志愿者额头、眼外角、眼睑及脸颊真皮下层回声密度明显高于20～29岁组(P<0.05)，20～29岁组、30～39岁组和40～49岁组女性、男性志愿者额头、眼睑及脸颊真皮下层回声密度均相近(P>0.05)。4组女性志愿者额头与脸颊真皮下层回声密度均明显低于眼外角与眼睑(P<0.05)，30～39岁组、40～49岁组和50～70岁组男性志愿者额头与脸颊真皮下层回声密度均明显低于眼外角与眼睑(P<0.05)，且女性4组和男性4组志愿者额头与脸颊、眼外角与眼睑真皮下层回声密度相近(P>0.05)。 结论： 50 MHz高频超声显示女性、男性所有年龄组面部皮肤正常成人志愿者眼外角、眼睑和脸颊的全层皮肤厚度均相近；而在同一年龄组里，男性和女性志愿者额头和脸颊全层皮肤厚度均明显高于眼外角与眼睑。女性与男性志愿者额头、眼外角、眼睑及脸颊部位真皮上层回声密度随年龄增加呈降低趋势，真皮下层回声密度随年龄增加呈增加趋势；且4个年龄段均表现为眼外角和眼睑真皮上层与真皮下层回声密度明显高于脸颊。.
Keywords: Echo-density; Face; High-frequency ultrasound; Skin; Skin sonogram; Skin thickness.