Objective three-dimensional assessment of lip form in patients with repaired cleft lip

Abstract

Objectives: To measure and compare three-dimensional lip form in participants with a repaired cleft lip and noncleft control participants.

Design: Retrospective study. Three-dimensional facial images of each participant were obtained.

Participants: The sample consisted of two groups: a repaired cleft lip group (n = 57) and a noncleft "normal" group (n = 28).

Main outcome measures: Thirty-four variables that described the features of each participant's lip form were extracted from the image data. A t test was used for each variable to test for significant differences between the groups, and a mathematical technique was used to categorize the lip forms in both groups.

Results: Seventeen variables showed significant between-group differences. The differences were focused on the free edges of the upper and lower lip vermilion borders, upper and lower lip protrusion, and lip symmetry. Lip forms were described by seven categories. Participants with cleft lip were represented in all categories but fell mainly into two categories at one extreme. Noncleft participants were represented in five categories but also exclusively in two categories at the other extreme from participants with a repaired cleft lip. The findings show greater variation in lip form for the participants with a cleft lip.

Conclusion: Three-dimensional lip form in participants with a repaired cleft lip was found to have greater variation and to be significantly different from that in noncleft participants. This method can be used to assess surgical outcomes of lip form.

Figures

Figure 1

3D camera systems. a. Rainbow 3D camera model 250 system, Genex Technologies Inc, Kensington, MD. b. MU-4 camera system, 3dMD Inc, Atlanta, GA.

Figure 1

3D camera systems. a. Rainbow 3D camera model 250 system, Genex Technologies Inc, Kensington, MD. b. MU-4 camera system, 3dMD Inc, Atlanta, GA.

Figure 2

The coordinate system. a. 3D sagittal reference plane. Defined as a plane perpendicular to a line passing through the midpoint of rex & ren and lex & len, and midway between rex & lex. b. 3D axial reference plane. On the 2D photograph, angle rex-sn-tr was defined and transferred to the 3D image by superimposing on rex & sn to produce a virtual line connecting sn & tr on the 3D image. The axial plane was defined as a plane passing through se at a 7.5° upward rotation from se-tr. c. 3D coronal reference plane. Defined as the plane passing through se and perpendicular to both the axial and the sagittal planes.

Figure 2

The coordinate system. a. 3D sagittal reference plane. Defined as a plane perpendicular to a line passing through the midpoint of rex & ren and lex & len, and midway between rex & lex. b. 3D axial reference plane. On the 2D photograph, angle rex-sn-tr was defined and transferred to the 3D image by superimposing on rex & sn to produce a virtual line connecting sn & tr on the 3D image. The axial plane was defined as a plane passing through se at a 7.5° upward rotation from se-tr. c. 3D coronal reference plane. Defined as the plane passing through se and perpendicular to both the axial and the sagittal planes.

Figure 2

The coordinate system. a. 3D sagittal reference plane. Defined as a plane perpendicular to a line passing through the midpoint of rex & ren and lex & len, and midway between rex & lex. b. 3D axial reference plane. On the 2D photograph, angle rex-sn-tr was defined and transferred to the 3D image by superimposing on rex & sn to produce a virtual line connecting sn & tr on the 3D image. The axial plane was defined as a plane passing through se at a 7.5° upward rotation from se-tr. c. 3D coronal reference plane. Defined as the plane passing through se and perpendicular to both the axial and the sagittal planes.

Figure 3

Diagram illustrating a lip surface inclination (LSI) map. Two vertically adjacent voxels (b1, b2) on the 3D lip data were projected on the Y–Z plane (b1’, b2’), and the angle between the Y-axis and a line connecting the voxels (b1’, b2’) was calculated. The procedure was repeated for all voxels, and the angular 39 differences (LSI values) were stored in an LSI map (Light gray in a LSI map indicates larger LSI values; black and dark gray, smaller LSI values).

Figure 4

Diagram illustrating variables v1, v2, …, v7 (see Table 3 for definitions). The sto was defined as the origin with the x-axis as a line parallel to the X-axis passing through the origin, and the y-axis as a line parallel to the Y-axis passing through the origin. The dotted line is the FELVB line contour (curving line); The solid line: approximated straight lines rcm-sto, sto-lcm, and rcm-lcm generated by applying a linear square fitting algorithm to the FELVB curving line between rcm and sto, sto and lcm, and rcm and lcm, respectively; p1, p2: intersections of the approximated rcm-lcm line and the FELVB line contour.

Figure 5

Diagram illustrating variables v8, v9, …, v21 (see Table 3 for definitions). At each point on the FELVB line contour, the LSI values in the middle two-thirds of the distance between ls & sto, and sto & li were averaged to generate a projected LSI value for the upper lip & lower lip, respectively.

Figure 6

Diagram illustrating variables v22, v23, …, v34 (see Table 3 for definitions). a, d, e, & f. Origin, rcm that projected on the sagittal plane; x’-axis, a line parallel to the X-axis passing through the origin; and z’-axis, a line parallel to the Z-axis passing through the origin. Gray lines indicate 3D surface data of the lip vermilion on the sagittal plane. b. Origin, sto that projected on the sagittal plane; u-axis, a line connecting sto and ls that projected on the sagittal plane; and v-axis, a line perpendicular to the u-axis that passes through the origin on the sagittal plane. Gray lines indicate 3D surface data of the upper lip vermilion on the sagittal plane; p3, a point that showed the maximum v value of the upper lip contour at midline; L1, v value of the p3; and L2, u value of the p3. c. Origin, sto that projected on the sagittal plane; u’-axis, a line that connects sto and li that projected on the sagittal plane; v’-axis, a line perpendicular to the u’-axis that passes through the origin on the sagittal plane. Gray lines indicate 3D surface data of the lower lip vermilion on the sagittal plane; p4, a point that showed the maximum v’ value of the lower lip contour at midline; L3, v’ value of the p2; and L4, u value of the p4. (Modified from Tanikawa et al., 2009).

Figure 7

Mean FELVB line contours, mean lip profiles, and mean 3D lip form for each category.

Figure 8

Significant differences between categories (y-axis) for each of the 17 feature variables (y-axis=magnitude of feature variable). The circle points represent the estimated mean values for the variable. Error bars represent Tukey-Kramer comparison intervals: non-overlap between bars for any two categories indicates a significant difference (p ≤ .05) between the two categories.

Figure 9

Percentages of participants with and without a cleft lip in each of the seven categories. a. Bar graph with Categories (y-axis) and participants % (x-axis). b. Pie chart of the percentages of the entire sample within each category.

Figure 9

Percentages of participants with and without a cleft lip in each of the seven categories. a. Bar graph with Categories (y-axis) and participants % (x-axis). b. Pie chart of the percentages of the entire sample within each category.

Figure 10

The example pictures of the lip vermilions within each category.