To conduct a preliminary investigation on the establishment of a three-dimensional measurement database of upper lip-related indicators in the normal young Han population in Chengdu, and to establish reference values.

A simple random sampling method was used to recruit 150 volunteers who visited Sichuan Provincial People’s Hospital between September 2012 and December 2019. The facial multi-slice spiral CT (MSCT) data were collected, and the image data was obtained to generate a three-dimensional model, which was analyzed by applying 3-matic Medical 13.0 software. The linear and proportional indices of upper lip correlation were measured including the crista philtra, right side point-the crista philtra, left side point (CphR-CphL), the right cheilion point- the left cheilion point (ChR-ChL), the middle point of crista philtra, right side point-the middle point of crista philtra, left side point (MphR-MphL), the apex of philtral column, right side point-the apex of philtral column, left side point(SbalR-SbalL), the stomion point-the sublabiale point (Sto-Sl)], ratio index [Ls-Sto/Sto-Li, MphR-MphL/ChR-ChL, MphR-MphL/CphR-CphL, Ls-Sto/Sn-Sto, Sto -Li/Sto-Sl]. In addition, the angle of the nasolabial angle was measured, and the radian of the upper lip was measured by the lip bead-bilateral angle three-point fitting circle method. The t test was used to compare the differences of the above indicators in different genders and ages (18-24, 25-30 years old). For the ChR-Ls-ChL, the Mphr-the middle point of subnasale and labrale-mphl(MphR-A-MphL), the SbalR-Sn-SbalL different radian position indexes were compared by ANOVA and SNK-q method.

A total of 150 volunteers were included in this study, including 68 males (45.3%) and 82 females (54.7%), ranging in age from 18 to 30 years old, with an average age of 24 years. Between different genders: the differences in linear indicators Ls-Sto, Sto-Li, Sn-Sto, Sn-Ls, Ls-Li, CphR-CphL, ChR-ChL, SbalR-SbalL, Sto-Sl were statistically significant (P<0.05), there was no significant difference in MphR-MphL (P>0.05); there were significant differences in Ls-Sto/Sn-Sto, Sto-Li/Sto-Sl in the ratio indicators (P<0.01), Ls -Sto/Sto-Li, MphR-MphL/ChR-ChL, MphR-MphL/CphR-CphL had no significant difference (P>0.05). There was no significant difference in nasolabial angle (P>0.05); the difference in radian index ChR-Ls-ChL was statistically significant(P<0.05), there was no significant difference in MphR-A-MphL, SbalR-Sn-SbalL in radian index (P>0.05). Between different age groups: there was no significant difference in each linear index, proportional index, angle index and radian index. (P>0.05) Between different radian positions: the radian values of 3 different radian positions were significantly different (P<0.01). ChR-Ls-ChL was compared with MphR-A-MphL, SbalR-Sn-SbalR the difference in SbalL was statistically significant (P<0.01), but there was no significant difference between MphR-PoinA-MphL and SbalR-Sn-Sbal (P>0.05).

Based on the MSCT image data, this paper completed the preliminary survey of the three-dimensional measurement database of the upper lip-related indexes of the normal young Han population in Chengdu area, and established the reference value. The obtained data set can provide an intuitive reference for clinical evaluation and design. In addition, evaluating the upper lip by measuring the curvature of the upper lip is a new measurement method that can effectively reflect the physiological curvature of the upper lip.

Lamiaceae; Tomography; Anthropometry; Imaging, Three-dimensional; Organ size; Dimensional measurement accuracy