Three-dimensional evaluation of soft tissue changes after mandibular setback surgery in class III malocclusion patients according to extent of mandibular setback, vertical skeletal pattern, and genioplasty

Three-dimensional evaluation of soft tissue changes after mandibular setback surgery in class III malocclusion patients according to extent of mandibular setback, vertical skeletal pattern, and genioplasty Minji Kim, DDS, MSD, PhD,a Dong-Yul Lee, DDS, MSD, PhD,b Yong-Kyu Lim, DDS, MSD, PhD,b and Seung-Hak Baek, DDS, MSD, PhD,c Seoul, Korea KOREA UNIVERSITY AND SEOUL NATIONAL UNIVERSITY

Objective. To investigate the 3-dimensional (3D) changes in the soft tissue after mandibular setback surgery (MSS). Study design. Thirty-three skeletal class III malocclusion (SCIII) patients treated with MSS (bilateral sagittal split ramus osteotomy) were subdivided according to extent of MSS, vertical skeletal pattern (VP), and vertical-reduction genioplasty. Lateral cephalograms and 3D facial scan images were taken before and 6 months after surgery. Linear and angular variables were measured with Rapidform 2006 (Inus Technology). Results. After MSS, there were significant increases in the upper lip length and decreases in the lower lip length in the large setback, hypodivergent, and genioplasty groups. The mentolabial fold deepened less in the genioplasty group than in other groups. Although there was no skeletal advancement of the maxilla, the soft tissue convexity in the paranasal area increased more in the hyperdivergent group than in the hypodivergent group after MSS. Conclusion. The extent of MSS, VP, and genioplasty could be used as guidelines for 1- and 2-jaw surgeries in SCIII borderline cases. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e20-e32)

Improvement in facial esthetics is one of the most important goals of orthodontic treatment and orthognathic surgery. Traditionally, cephalometric analysis has been used to evaluate and predict changes in facial profile after orthodontic treatment and orthognathic surgery.1-6 However, this conventional 2-dimensional (2D) method can only evaluate the soft tissues of the midsagittal area.2,3 To analyze and evaluate the soft tissues in the paranasal, zygomatic, cheek, and other facial areas, 3-dimensional (3D) imaging methods such as 3D computerized tomography (CT)7-9 and 3D facial scan images (3D-FSI)10-15 are needed. Furthermore, several studies16,17 have reported that 3D methods are more accurate than 2D methods. The majority of Asian patients seeking orthodontic treatment and orthognathic surgery are class III malocclusion patients.18,19 Clinicians sometimes experience good improvement in facial esthetics in the midface a

Fellow, Department of Dentistry, College of Medicine, Korea University. b Professor, Department of Dentistry, College of Medicine, Korea University. c Associate Professor, Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University. Received for publication Oct 16, 2009; returned for revision Dec 23, 2009; accepted for publication Jan 3, 2010. 1079-2104/$ - see front matter © 2010 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2010.01.002

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area with the mandibular setback surgery (MSS) only in the class III malocclusion borderline cases (Fig. 1).19 The purpose of the present study was to investigate, using 3D-FSI, changes in the soft tissue after mandibular setback surgery. Our hypotheses were that soft tissue changes due to mandibular setback surgery would be seen not only in the upper and lower lips, but also in other areas remote to the midsagittal area, such as the zygomatic, cheek, and paranasal areas, and that these changes would be influenced by the extent of mandibular setback, the vertical skeletal pattern, and genioplasty. MATERIALS AND METHODS Thirty-three skeletal class III malocclusion patients (11 male and 22 female; mean age 25.23 ⫾ 7.44 years; SNA 80.48 ⫾ 3.64°; SNB 82.91 ⫾ 4.07°; Wits appraisal ⫺11.20 ⫾ 4.14 mm; A to N perpendicular ⫺1.10 ⫾ 3.17 mm; Pog to N perpendicular 4.08 ⫾ 7.49 mm; SN-GoGn 35.27 ⫾ 6.21°; ⬍3 mm facial asymmetry at the soft tissue pogonion point) who had undergone mandibular setback surgery (bilateral sagittal split ramus osteotomy, average amount of mandibular setback 8.16 ⫾ 3.74 mm at point B) by a single surgeon were included in this study. Patients were subdivided according to the extent of MSS, the vertical skeletal pattern, and vertical-reduction genioplasty (Table I). Approval for this study was granted by the Institutional Review Board of Korea University Medical Center (IRB no. GR0791).

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Fig. 1. An example of a skeletal class III malocclusion patient who had good results in terms of facial soft tissue changes in the midface area after mandibular setback surgery only. Comparison of facial profiles (A) and lateral cephalograms (B) before (left) and after (right) treatment.

Table I. Demographic data of the subgroups according to the extent of mandibular setback, vertical pattern, and vertical-reduction genioplasty Variable

Subgroup (mean ⫾ SD)

Extent of the mandibular setback Small setback group (n ⫽ 14; ⬍7 mm) 4.81 ⫾ 2.08 mm Vertical pattern (SN-GoGn) Hypodivergent group (n ⫽ 18; SN-GoGn ⬍35°) 31.28 ⫾ 5.46° Vertical-reduction genioplasty Genioplasty group (n ⫽ 12) 4.50 ⫾ 2.58 mm upward and 0.58 ⫾ 2.19 mm forward movements at pogonion

Lateral cephalograms, taken immediately before (T1) and 6 months after surgery (T2), with centric occlusion, natural head position,20 and reposed lip, were traced and digitized using the program V-Ceph 5.0 (Osstem, Seoul, Korea) by a single operator. To scan the whole face without shadows,21 3D-FSIs were taken from 3 different horizontal angles and from 2 different vertical angles. Patients sat with centric occlusion, a natural head position,20 reposed lips, a hair band, and slightly closed eyes. Optotop-SE (Breuckmann, Meersburg, Germany; white-light scanner; 30-40 ␮m accuracy according to the manufacturer; scanning time ⬍3 s) was used by a single operator. The 3D-FSIs were reconstructed using Rapidform 2006 and Rapidform XO scanning software (Inus Technology, Seoul, Korea). We chose a period 6 months after surgery as the T2 stage because we reasoned that after this period the facial soft tissue would be stable and any subsequent changes would be small enough to be ignored.22 Landmarks for superimposition of T1 and T2 images12,23-25 and the reference axes15,26 are defined in Figs. 2 and 3, respectively. The differences between the T1 and T2 images were expressed with 2 color-mapping methods: absolute color and signed color.

Large setback group (n ⫽ 19; ⬎7 mm) 10.63 ⫾ 2.57 mm Hyperdivergent group (n ⫽ 15; SN-GoGn ⬎35°) 40.06 ⫾ 2.62° Nongenioplasty group (n ⫽ 21) —

The extent and direction of changes in landmarks and the linear and angular variables between the T1 and T2 stages (Table II and Figs. 4 and 5) were measured by a single operator using Rapidform 2006 software (Inus Technology). Inter- and intraexaminer reliability tests showed that the Cronbach coefficient ␣ of all 52 coordinate values of the 66 images were 0.9972 and 0.9984, respectively. Because a Cronbach coefficient ␣ close to 1 indicates high reliability, the inter- and intraexaminer reliabilities in this study were excellent. Therefore, the first set of measurements was used in this study. Pearson correlation analysis and independent t tests were performed for statistical analysis. RESULTS Correlations and ratios of the horizontal and vertical changes between the hard and soft tissues in cephalometric analysis Correlations between hard and soft tissues in Li, B=, and Pog= (the lower lip and chin, respectively) were higher and the values were less diverse in the anteroposterior direction than in the vertical direction (Table III). However, correlation between hard and soft tissues in Ls (the upper lip) was low in the anteroposterior

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Fig. 2. Reference points (blue) for superimposition of T1 (yellow) and T2 images (green): forehead area (glabella, 1), nasion area (2), exocanthion (3/4), and endocanthion (5/6).

Fig. 3. Reference axes established on the original point (nasion): a midsagittal line (Y coordinate, vertical axis), a parallel line to the floor (Z coordinate, anteroposterior axis), and a parallel line to a line connecting both exocanthions (X coordinate, transverse axis).

direction, and diverse values were obtained in the vertical direction (Table III). Comparison of changes in soft tissue landmarks, linear variables, and angular variables between T1 and T2 according to the amount of mandibular setback Although the landmarks in the cheek area and upper lip did not show significant differences between the small and large setback groups, there was a greater downward movement of landmarks in the stomion and lower lip (landmarks 20, 28, and 34; P ⬍ .05) and more backward movement of the chin (landmark 31, B; P ⬍ .001; landmark 35, Pog; P ⬍ .01) in the large setback group than in the small setback group (Appendix A). There were significant increases in the lengths of the upper vermilion (landmarks 17-20, 23-25, and 24-26;

P ⬍ .05) and the upper lip (14-20; P ⬍ .05) and a decrease in the length of the lower lip (20-35 and 34-35; P ⬍ .05) in the large setback group (Table IV). However, the other linear and angular variables did not show significant differences between the 2 groups (Tables IV and V). Comparison of changes in soft tissue landmarks, linear variables, and angular variables between T1 and T2 according to the vertical skeletal pattern In the hyperdivergent group, lengthening of the upper lip (landmarks 14-15; P ⬍ .05) and shortening of the lower lip (20-35 mm; P ⬍ .05; 18-31 mm; P ⬍ .01) were significantly larger than in the hypodivergent group (Table IV).

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Table II. Definitions of the soft tissue landmarks used in the study Soft tissue landmarks 1 2 3/4 5/6 7/8 9/10 11/12 13 14 15/16

Glabella Nasion Exocanthion (Rt/Lt) Endocanthion (Rt/Lt) Nasal ala (Rt/Lt) Alar curvature point (Rt/Lt) Subalare (Rt/Lt) Pronasale Subnasale

17 18/19 20 21 22 23/24

Upper lip point (crista philtri) (Rt/Lt) Labrale superius Cheilion (Rt/Lt) Stomion Upper lip prominent Lower lip prominent Upper lip boarder (Rt/Lt)

25/26

Stomion (Rt/Lt)

27/28 29/30 31 32/33 34 35 36/37

Lower lip boarder (Rt/Lt) Ac-cheilion midpoint (Rt/Lt) B point B-cheilion midpoint (Rt/Lt) Labrale inferius Pogonion Ac-exocanthion (Rt/Lt)

38/39 40/41

Mid Ac-endocanthion (Rt/Lt) Midpoint of upper cheek (Rt/Lt)

42/43 44/45

Mid Ac-Ac-exocanthion (Rt/Lt) Zygomatic point (Rt/Lt)

46/47 48/49

Cheilion-exocanthion (Rt/Lt) Midpoint of lower cheek (Rt/Lt)

50 51/52

Menton Lateral point of lower cheek (Rt/Lt)

Definition The most prominent midline point between the eyebrows The point in the midline of both the nasal root and the nasofrontal suture The point at the outer commissure of the eye fissure The point at the inner commissure of the eye fissure The most lateral point on each alar contour The most lateral point in the curved base line of each ala, indicating the facial insertion of the nasal wing base The point at the lower limit of each alar base,where the alar base disappears into the skin of the upper lip The most protruded point of the apex nasi The midpoint of the angle at the columella base where the lower border of the nasal septum and the surface of the upper lip meet The point on each elevated margin of the philtrum on the vermilion line The midpoint of the upper vermilion line The point located at each labial commissure The point at the midline of labial fissure between gently closed lips The point most prominent from lateral view on the upper lip The point most prominent from lateral view on the lower lip The point located laterally from the labrale superius, located on the upper vermilion line vertically beneath the right and left subalare points The point located laterally from the Stomion, on the labial fissure between gently closed lips, beneath the right and left subalare points The point located on the lower vermilion line, beneath the right and left Subalare points The midpoint between Alar curvature point and cheilion The most deepest point from lateral view, on the facial midline, between the lower lip and chin The midpoint between B point and cheilion The midpoint of the lower vermilion line The most anterior midpoint of the chin The point where a vertical line from exocanthion and a horizontal line from ala curvature point meet The midpoint between alar curvature point and endocanthion The point where two diagonal lines meet, one from exocanthion to alar curvature point, and the other endocanthion to Ac-exocanthion The midpoint between alar curvature point and Ac-exocanthion The most lateral point of each zygomatic arch, viewed from an angle where exocanthion is slightly seen The point where a vertical line from Exocanthion and a horizontal line from Cheilion meet The point where two diagonal lines meet, one from alar curvature point to cheilionexocanthion, and the other Ac-exocanthion to cheilion The lowest median landmark on the lower border of the mandible The midpoint between Ac-exocanthion and cheilion-exocanthion

There were significant increases in the convexities of the angular variables in the midcheek area (38-9-29 and 37-52-47; P ⬍ .01) and lower cheek area (43-49-47 and 45-41-39; P ⬍ .05) in the hyperdivergent group compared with the hypodivergent group (Table V). Also see Appendix B. Comparison of changes in soft tissue landmarks, linear variables, and angular variables between T1 and T2 according to genioplasty Downward movement of the upper lip (landmarks 15 and 25; P ⬍ .05) and lower lip (32 and 33; P ⬍ .001) and upward movement of menton (50 mm; P ⬍ .05)

were significantly greater in the genioplasty group than in the nongenioplasty group, owing to vertical-reduction genioplasty and eventual relief of soft tissue stretching (Appendix C). However, vertical-reduction genioplasty induced less posterior movement of menton (landmark 50; P ⬍ .05; Appendix C) than was seen in the nongenioplasty group. The genioplasty group showed significant decreases in the lengths of the lower vermilion (landmarks 22-34; P ⬍ .05; Table IV) and lower lip (20-35; P ⬍ .05; Table IV) and less deepening of the mentolabial sulcus (18-32-31 and 19-33-31; P ⬍ .05; Table V) than the nongenioplasty group.

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Fig. 4. Soft tissue landmarks: 7/8, nasal ala; 9/10, alar curvature point; 11/12, subalare; 13, pronasale; 14, subnasale; 15/16, upper lip point (crista philtri); 17, labrale superius; 18/19, cheilion; 20, stomion; 21, upper lip prominent; 22, lower lip prominent; 23/24, upper lip border; 25/26, stomion; 27/28, lower lip border; 29/30, Ac-cheilion midpoint; 31, B point; 32/33, B-cheilion midpoint; 34, labrale inferius; 35, pogonion; 36/37, Ac-exocanthion; 38/39, mid-Ac-endocanthion; 40/41, midpoint of the upper cheek; 42/43, mid-AcAc-exocanthion; 46/47, cheilion-exocanthion; 48/49, midpoint of the lower cheek; 51/52, lateral point of the lower cheek.

Changes in 3D images between the T1 and T2 stages Changes in 3D images from each subject due to mandibular setback surgery were examined by absolute- and signed-color mapping methods (Fig. 6). The soft tissue of the cheek area moved mostly backward after surgery with an increasing gradient from the upper to the lower cheek area as well as from the midline to the lateral area (Fig. 6). Although the greatest change in the chin area was seen after mandibular setback surgery, several patients, especially those in the hyperdivergent group, showed significant soft tissue changes in the paranasal area, as illustrated by the top left case in Fig. 6.

™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™3 Fig. 5. Changes in linear (A) and angular variables (B and C) after mandibular setback surgery. A red line indicates an increase in values and a blue line indicates a decrease in values.

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Table III. Correlations and ratios between the anteroposterior (AP) and vertical (V) changes in the hard and soft tissues Ls

L1 Point B Pog

Li

B=

Pog=

AP

V

AP

V

AP

V

AP

V

0.37* (7.4%) 0.38* (7.9%) 0.42** (8.0%)

0.61*** (⫺47.1%) 0.52** (⫺101.2%) 0.26 (⫺29.6%)

0.90*** (81.0%) 0.88*** (86.6%) 0.86*** (87.7%)

0.38* (⫺71.6%) 0.52** (⫺154.0%) 0.28 (⫺39.5%)

0.90*** (83.0%) 0.95*** (88.7%) 0.92*** (89.8%)

0.79*** (49.2%) 0.74*** (105.8%) 0.43** (28.0%)

0.78*** (81.7%) 0.88*** (87.3%) 0.91*** (88.4%)

0.51** (78.0%) 0.68*** (167.6%) 0.67*** (44.4%)

From the cephalometric measurements, correlations and ratios of the anteroposterior and vertical changes between the hard and soft tissues in the midsagittal plane were examined. Pearson correlation analysis was done. Ratio means amount of change in the soft tissue/amount of change in the hard tissue (%); positive (⫹) value, the change with the same direction; negative (⫺) value, the opposite direction; AP, anteroposterior change; V, vertical change; *P ⬍ .05; **P ⬍ .01; ***P ⬍ .001.

DISCUSSION Correlations and ratios of horizontal and vertical changes between hard and soft tissues in cephalometric analysis Changes in the soft tissue thicknesses of the upper and lower lips and the chin area are known to be influenced by the initial preoperative thickness of the corresponding area1 and are closely correlated with the amount and direction of hard tissue movement after mandibular surgery.2 In the present study, the ratios of Pog-Pog= and point B-B= in the horizontal direction were 88.4% and 88.7% (Table III), which are similar to the values reported by McCance et al.7 and Chew27 but lower than those reported by Gjørup and Athanasiou1 and Hu et al.2 The finding that the vertical movements of the landmarks in the hard and soft tissues had low correlations compared with those of the horizontal movements (Table III) is consistent with earlier studies.4,5,9,27 Comparison of changes in soft tissue landmarks, linear variables, and angular variables between T1 and T2 according to the amount of mandibular setback, the vertical skeletal pattern, and genioplasty The upper lip moved downward and backward and the upper lip length increased after mandibular setback surgery (Tables IV and V; Appendices A-C). These results are similar to other cephalometric studies that reported backward movement of the upper lip1,2 and a decrease in the upper lip thickness after mandibular setback surgery.1,4,28 In the present study, upper lip length increased after surgery, especially in the large setback group and the hypodivergent group (P ⬍ .05 [both]; Table IV). Because the lower incisors in the prognathic mandible squeeze the upper lip upward and forward, the upper lip

is shortened and thickened before surgery.1 Therefore, the upper lip can lengthen to a greater extent in individuals with hypodivergence or a large setback. With increase in the upper lip length after surgery, the stomion moved downward and backward (Table IV; Appendices A-C), which is in accordance with earlier studies.1,4,28 When a normal incisor relationship is achieved, the soft tissue overlying the incisors can normalize the lip posture. The cheilion moved toward the midline, resulting in a decrease in the intercheilion width after surgery (Table IV; Appendices A-C). Stretching of the soft tissue of the chin area in the prognathic mandible can pull the lower lip downward. When normal lip posture is achieved after surgery, the original convexity of the lower lip can be restored. Therefore, the convexity of the lower lip decreased after surgery (Tables IV and V). The finding that lengths of the lower vermilion and lower lip decreased after surgery (Table IV) is consistent with Gjorup and Athanasiou.1 A greater decrease was observed in the genioplasty group because vertical reduction genioplasty was performed. In addition, the lower lip length decreased in the large setback and hypodivergent groups. Because the mandible moved upward and backward according to the inclination of upper occlusal plane by surgery, a larger mandibular setback could decrease the lower face height and the lower lip length to a greater extent than could less setback of the mandible (Table IV). Patients with a hypodivergent skeletal pattern have a tendency to overclose the mandible before surgery, which can make the soft tissue in the chin area redundant. As the mandible moves to its normal position, the lower lip length in the hypodivergent group recovered to a greater extent than in the hyperdivergent group. In this study, the mentolabial sulcus became deeper after surgery (Table V), as reported in previous stud-

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Table IV. Comparison of the change (from T1 to T2) in the 3-dimensional linear variables between subgroups according to the extent of mandibular setback, the vertical pattern, and vertical-reduction genioplasty Small setback group Variable ⌬ Upper lip length (mm) 14-15 14-16 14-17 14-18 14-19 14-20 ⌬ Cheilion (mm) 9-18 10-19 ⌬ Upper vermilion length (mm) 17-20 23-25 24-26 17-21 21-20 ⌬ Lower vermilion length (mm) 25-27 20-34 26-28 20-22 22-34 ⌬ Horizontal lip width (mm) 15-16 18-19 15-18 16-19 ⌬ Lower lip length (mm) 20-31 20-35 34-31 18-31 19-31 34-35 ⌬ Nasal width (mm) 9-10 11-12 ⌬ Zygomatic width (mm) 44-45

Large setback group

Hypodivergent group

Mean

SD

Mean

SD

Sig.

⫺0.04 0.20 0.45 0.43 0.62 1.36

0.78 0.68 0.80 1.03 2.05 0.89

0.55 0.37 1.00 0.93 1.71 2.50

0.88 0.96 1.18 1.12 1.68 1.37

0.43 0.15

1.08 1.72

0.88 1.22

1.73 1.61 1.52 0.63 1.35

0.94 0.89 1.19 0.72 1.24

⫺2.07 ⫺2.65 ⫺2.29 ⫺2.14 ⫺1.01

Hyperdivergent group

Nongenioplasty

Mean

SD

Mean

SD

Sig.

.0570 .5842 .1399 .1925 .1023 .0110*

0.01 0.23 0.56 0.39 0.98 2.16

0.73 0.69 1.18 1.02 1.47 1.44

0.64 0.37 1.02 1.11 1.56 1.83

0.94 1.02 0.87 1.09 2.32 1.14

1.37 1.59

.3188 .0737

0.62 0.48

1.21 1.49

0.77 1.11

2.83 2.45 2.53 0.98 2.19

1.54 0.93 1.23 0.94 1.32

.0248* .0142* .0241* .2576 .0740

2.82 2.10 2.04 1.07 2.05

1.58 1.13 1.46 0.98 1.55

1.85 1.34 1.45 1.22 1.12

⫺3.02 ⫺2.94 ⫺2.81 ⫺2.00 ⫺1.43

1.92 2.14 2.07 1.71 1.25

.1662 .6641 .4225 .8003 .3252

⫺2.57 ⫺2.89 ⫺2.38 ⫺1.95 ⫺1.44

⫺0.18 ⫺3.19 0.93 0.74

0.92 2.13 1.14 2.04

⫺0.52 ⫺3.38 1.12 1.91

1.09 2.53 1.27 1.79

.3453 .8141 .6588 .0903

⫺2.48 ⫺2.25 ⫺1.41 ⫺3.00 ⫺2.82 ⫺1.10

1.45 2.49 1.78 1.33 1.56 2.84

⫺2.75 ⫺4.97 ⫺1.20 ⫺3.87 ⫺3.32 ⫺3.55

1.93 3.17 1.96 1.93 2.19 3.47

0.34 ⫺0.02

0.54 0.26

0.72 ⫺0.08

0.22

4.24

⫺0.04

Genioplasty

Mean

SD

Mean

SD

Sig.

.0367* .6421 .2199 .0611 .3815 .4826

0.21 0.22 0.78 0.67 1.12 1.92

0.73 0.80 1.02 0.95 2.03 1.58

0.45 0.42 0.74 0.80 1.47 2.18

1.10 0.93 1.18 1.35 1.68 0.59

.4657 .5251 .9291 .7492 .6178 .4998

1.34 1.94

.7469 .3026

0.68 0.68

1.15 1.79

0.70 0.93

1.48 1.62

.9673 .6950

1.82 2.08 2.18 0.54 1.58

0.97 0.84 1.12 0.60 1.00

.0395* .9386 .7691 .0738 .3211

2.18 1.94 2.04 0.91 1.52

1.44 1.09 1.50 0.94 1.19

2.68 2.36 2.21 0.70 2.37

1.36 0.77 0.91 0.72 1.44

.3322 .2429 .7145 .5121 .0770

2.00 1.72 1.67 1.34 1.28

⫺2.67 ⫺2.73 ⫺2.85 ⫺2.20 ⫺1.03

1.89 1.99 2.02 1.71 1.09

.8939 .8107 .4746 .6328 .3417

⫺2.49 ⫺2.59 ⫺2.35 ⫺2.11 ⫺0.93

2.16 1.83 1.91 1.70 1.01

⫺2.84 ⫺3.22 ⫺3.01 ⫺1.99 ⫺1.82

1.47 1.82 1.64 1.14 1.33

.6233 .3486 .3211 .8262 .0395*

⫺0.47 ⫺3.95 0.91 1.07

1.08 2.49 1.41 1.76

⫺0.26 ⫺2.52 1.18 1.83

0.98 1.94 0.91 2.16

.5798 .0790 .5273 .2776

⫺0.09 ⫺3.37 0.98 1.33

0.85 2.36 1.18 2.11

⫺0.87 ⫺3.18 1.13 1.56

1.15 2.40 1.28 1.74

.0340* .8284 .7334 .7510

.6631 .0121* .7538 .1570 .4775 .0385*

⫺3.10 ⫺4.95 ⫺1.65 ⫺4.21 ⫺3.21 ⫺3.49

1.58 3.54 1.61 1.64 2.17 3.64

⫺2.09 ⫺2.46 ⫺0.86 ⫺2.66 ⫺2.98 ⫺1.32

1.79 2.03 2.09 1.48 1.68 2.75

.0955 .0177* .2262 .0081** .7445 .0671

⫺2.48 ⫺2.95 ⫺1.16 ⫺3.54 ⫺3.39 ⫺1.78

1.78 2.46 1.93 1.85 1.87 2.86

⫺2.92 ⫺5.35 ⫺1.51 ⫺3.43 ⫺2.61 ⫺3.78

1.66 3.76 1.80 1.58 2.03 4.00

.4910 .0339* .6086 .8707 .2739 .1044

2.09 0.34

.4532 .5677

0.99 ⫺0.04

2.03 0.33

0.04 ⫺0.07

0.63 0.28

.0729 .8129

0.66 ⫺0.04

1.93 0.31

0.39 ⫺0.08

0.85 0.32

.5840 .7865

3.11

.8404

⫺0.18

3.42

0.37

3.85

.6681

0.67

3.59

⫺0.99

3.44

.2031

Independent t test was done. *P ⬍ .05; **P ⬍ .01.

ies.1,3,28 However, less deepening was observed in the genioplasty group compared to the other groups (Table V). Because we performed vertical reduction genioplasty in this study, the vertically redundant soft tissue in the chin area might have resulted in less deepening of the mentolabial sulcus. Although there are some reports that the nasolabial angle increased after mandibular setback surgery,3,9,28 we could not observe any significant changes in the nasolabial angle in the present study (Table V). The soft tissue of the cheek area generally moved backward after surgery with an increasing gradient from the upper to the lower cheek area as well as from

the midline to the lateral area (Appendices A-C). These findings are similar to those of McCance et al.7 who reported greater changes in the lateral areas than in the midline of the chin and mentalis regions after MSS. The finding that changes in the facial soft tissue occurred in the paranasal area after MSS despite no actual advancement of the maxilla (Tables IV and V; Appendices A, B and C; Figs. 1 and 6) is similar to that reported by Jung et al.9 They reported soft tissue changes in the upper lip and philtrum after asymmetric mandibular setback surgery and hypothesized that this was due to muscle and soft tissue tension. After assessing hard and soft tissue changes, they concluded that

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Table V. Comparison of the change (from T1 to T2) in the 3-dimensional angular variables between subgroups according to the extent of mandibular setback, the vertical pattern, and vertical-reduction genioplasty

Variable

Small setback group

Large setback group

Mean

SD

Mean

SD

Sig.

Mean

SD

Mean

SD

2.62 2.90 1.49 1.47 2.18 2.39 1.76 1.79

⫺1.70 ⫺0.09 1.20 ⫺0.04 ⫺3.15 ⫺1.98 0.16 1.47

3.35 3.33 1.29 1.12 3.64 2.86 1.68 1.90

.3673 .9709 .1316 .7084 .0109* .1788 .3899 .0438*

⫺1.18 ⫺0.56 0.68 ⫺0.15 ⫺2.46 ⫺1.70 0.40 0.44

3.73 3.25 1.51 1.13 3.98 3.04 1.92 1.86

⫺1.41 0.44 1.12 ⫺0.06 ⫺1.20 ⫺1.10 0.36 1.43

2.09 2.95 1.28 1.44 2.53 2.31 1.49 1.98

3.57 4.37 2.92 3.91 4.77 6.83 3.61 4.56

3.29 5.53 ⫺1.83 ⫺3.29 ⫺0.79 ⫺5.16 ⫺7.42 ⫺7.31

3.52 6.68 2.99 3.26 7.50 6.26 5.78 7.84

.8710 .1922 .5929 .8907 .3910 .1064 .9034 .5836

4.82 4.70 ⫺2.45 ⫺4.16 ⫺1.18 ⫺0.61 ⫺6.54 ⫺7.16

3.19 6.91 3.44 3.86 7.96 4.18 5.60 6.58

1.65 3.97 ⫺0.57 ⫺2.10 ⫺2.17 ⫺7.06 ⫺8.68 ⫺6.28

3.34 3.95 3.42 1.15 5.15 4.79 2.02 2.90 2.45 3.46 2.34 3.25 1.90 2.24

1.81 1.58 0.99 1.29 ⫺6.24 ⫺5.47 ⫺0.96 ⫺1.43 1.05 0.67 ⫺0.21 2.34 1.46 0.86

4.21 4.23 4.30 3.25 6.48 7.39 2.99 2.63 1.88 2.49 5.94 3.56 3.56 3.84

.5555 .6398 .9543 .1816 .9770 .5808 .5568 .1512 .3962 .5209 .4872 .1330 .8117 .6985

2.41 3.19 1.88 1.34 ⫺6.41 ⫺6.20 ⫺1.11 ⫺0.66 0.40 ⫺0.07 ⫺0.06 1.82 1.30 0.31

4.12 4.40 3.67 3.37 6.47 6.01 2.89 3.22 2.37 2.39 6.05 4.08 3.69 3.40

10.01 8.44 5.61 3.53 2.51 7.75 2.90 10.29 4.81 3.53

⫺14.87 13.34 5.05 ⫺4.14 ⫺0.28 ⫺6.32 0.85 2.71 ⫺12.70 4.42

15.02 10.19 6.58 5.10 3.54 10.31 5.53 13.27 6.16 5.67

.4018 .9078 .0750 .5423 .6319 .4923 .1037 .3411 .2931 .7717

⫺14.53 13.87 4.05 ⫺3.38 ⫺0.85 ⫺5.19 1.99 4.14 ⫺11.11 4.22

7.71 5.19 5.21 7.61 12.76

⫺8.50 ⫺7.09 ⫺7.07 2.30 4.35

11.29 6.64 7.43 8.70 7.69

.1372 .7718 .7630 .4472 .6309

2.36

6.11

5.94

.8779

⌬ Upper cheek angle (°) 5-38-9 ⫺0.72 6-39-10 ⫺0.13 5-40-42 0.45 6-41-43 ⫺0.21 5-40-36 ⫺0.18 6-41-37 ⫺0.68 3-40-9 0.68 4-41-10 0.10 ⌬ Midcheek angle (°) 38-09-29 3.50 39-10-30 2.79 40-42-48 ⫺1.27 41-43-47 ⫺3.12 36-51-46 ⫺2.78 37-52-47 ⫺1.35 9-29-18 ⫺7.64 10-30-19 ⫺6.01 ⌬ Lower cheek angle (°) 42-48-46 1.00 43-49-47 2.27 9-48-46 1.07 10-49-48 0.18 36-48-18 ⫺6.18 37-49-19 ⫺4.20 29-48-46 ⫺0.42 30-49-47 ⫺0.01 44-40-38 0.41 45-41-39 1.34 36-42-9 0.85 37-43-10 0.48 51-48-29 1.23 52-49-30 0.41 ⌬ Lip angle (°) 17-21-20 ⫺10.93 20-22-34 13.73 25-20-26 1.03 18-20-19 ⫺5.12 23-17-24 ⫺0.82 15-17-16 ⫺4.04 27-34-28 3.35 21-20-22 6.84 18-21-19 ⫺10.58 18-22-19 3.92 ⌬ Lower lip angle (°) 34-31-35 ⫺3.16 27-31-35 ⫺6.46 28-31-35 ⫺6.36 18-32-31 0.06 19-33-31 2.48 ⌬ Nasolabial angle (°) 13-14-17 5.88

Hypodivergent group

Hyperdivergent group

Nongenioplasty Sig.

Genioplasty

Mean

SD

Mean

SD

Sig.

.8305 .3665 .3848 .8408 .2956 .5296 .9445 .1479

⫺1.93 ⫺0.33 0.96 0.07 ⫺2.33 ⫺1.93 0.42 0.98

2.63 3.14 1.60 1.11 3.30 3.01 1.73 2.19

⫺0.15 0.28 0.74 ⫺0.42 ⫺1.12 ⫺0.55 0.31 0.73

3.52 3.16 1.04 1.50 3.62 1.88 1.74 1.54

.1073 .5977 .6626 .2895 .3358 .1648 .8650 .7230

3.08 4.60 1.77 2.72 4.25 7.52 3.79 6.81

.0070** .7314 .0527 .0920 .6542 .0075** .2165 .7086

2.55 3.56 ⫺1.57 ⫺3.30 ⫺1.57 ⫺4.28 ⫺7.30 ⫺6.31

3.75 5.76 3.26 4.18 5.42 7.72 4.89 5.09

4.83 5.78 ⫺1.64 ⫺3.09 ⫺1.74 ⫺2.25 ⫺7.88 ⫺7.53

2.48 6.12 2.36 1.93 8.26 4.32 5.13 8.85

.0706 .3055 .9525 .8442 .9435 .4093 .7514 .6170

0.33 0.29 0.00 0.19 ⫺5.98 ⫺3.41 ⫺0.28 ⫺1.02 1.24 2.18 0.59 1.23 1.44 1.10

3.21 3.05 4.02 0.98 5.26 6.64 2.22 2.27 1.77 3.07 2.53 2.79 1.76 3.06

.1210 .0390* .1693 .1804 .8379 .2156 .3704 .7165 .2674 .0250* .6840 .6419 .8855 .4900

1.36 2.24 1.03 1.21 ⫺6.97 ⫺5.41 ⫺0.34 ⫺0.45 1.34 1.18 ⫺0.14 1.16 1.37 0.57

4.01 4.16 4.23 3.08 6.21 5.02 2.79 2.75 2.05 3.25 5.57 3.25 3.28 3.14

1.65 1.22 1.02 0.13 ⫺4.91 ⫺4.10 ⫺1.42 ⫺1.48 ⫺0.19 0.56 0.89 2.23 1.37 0.84

3.65 3.98 3.40 1.29 5.20 8.41 2.16 2.87 1.98 2.26 2.81 3.98 2.32 3.50

.8334 .4938 .9943 .1730 .3388 .6310 .2581 .3164 .0454* .5630 .4899 .4120 .9968 .8229

13.71 8.99 7.20 4.53 2.77 8.87 5.85 10.40 5.79 4.20

⫺11.60 13.08 2.50 ⫺5.96 ⫺0.11 ⫺5.55 1.82 4.86 ⫺12.63 4.20

12.61 10.06 5.47 4.11 3.53 9.99 3.03 14.25 5.56 5.63

.5303 .8127 .4969 .0996 .5077 .9139 .9158 .8681 .4516 .9907

⫺11.42 11.85 3.40 ⫺5.56 ⫺0.75 ⫺6.71 3.11 5.39 ⫺11.85 3.47

14.99 10.36 6.20 4.29 3.32 9.10 4.31 14.04 5.69 5.42

⫺16.30 16.41 3.25 ⫺2.78 ⫺0.10 ⫺2.98 ⫺0.19 2.85 ⫺11.72 5.50

8.60 6.68 7.08 4.38 2.80 9.41 4.82 7.92 5.83 3.35

.3114 .1816 .9481 .0853 .5685 .2714 .0516 .5706 .9497 .2495

⫺6.87 ⫺7.25 ⫺7.83 0.60 2.29

10.67 6.30 5.36 9.42 10.07

⫺5.47 ⫺6.31 ⫺5.50 2.24 5.07

9.81 5.77 7.64 6.68 10.08

.6992 .6592 .3119 .5757 .4366

⫺8.12 ⫺7.89 ⫺6.82 ⫺0.92 0.59

10.63 6.12 5.81 7.12 8.93

⫺2.94 ⫺4.97 ⫺6.67 5.31 8.74

8.69 5.50 7.82 8.78 10.04

.1611 .1816 .9497 .0337* .0220*

6.11

5.66

5.90

3.41

.9013

5.09

5.44

7.63

2.46

.0766

Independent t test was done. *P ⬍ .05; **P ⬍ .01.

the soft tissues in the upper lip, mouth corner, and paranasal areas also changed in relation to the lower lip and chin area.9

Angular variables in the cheek area indicated an increase in convexity, and this increase was greater in patients with a hyperdivergent skeletal pattern com-

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CONCLUSIONS 1. By comparing 3D-FSIs before and after MSS surgery, soft tissue changes were confirmed in the upper and lower lips as well as in other areas remote from the midline, such as the zygomatic, cheek, and paranasal areas. These changes were influenced by the amount of mandibular setback, vertical skeletal pattern, and genioplasty, confirming our hypotheses. 2. These variables can be used as guidelines to determine whether 1- or 2-jaw surgery should be performed for skeletal class III malocclusion borderline cases. REFERENCES

Fig. 6. Examples of different patterns of change in 3D images between T1 and T2 using absolute color (A) and signed color (B). Absolute color expresses the absolute amount of deviation between the 2 images (blue color indicates almost no deviation, and color changes toward red indicate larger deviations). Signed color is expressed with a “⫹” and “⫺” to show the direction of deviation. Blue indicates backward (⫺) movement and red indicates forward (⫹) movement. Although the greatest change occurred in the chin area after mandibular setback surgery, several patients showed significant changes in their paranasal area, as illustrated in the case in the top left of the figure.

pared to those with a hypodivergent pattern (Table V). This may be due to midfacial soft tissue laxity and alterations in the general drape of the soft tissues, especially in patients with hyperdivergent skeletal patterns. To determine changes in hard and soft tissue more precisely after surgery, 3D surface scanning data and 3D CT data should be combined. Furthermore, examination of soft tissue changes after 2-jaw surgery is important to enable clinically accurate predictions of cosmetic outcomes.

1. Gjørup H, Athanasiou AE. Soft-tissue and dentoskeletal profile changes associated with mandibular setback osteotomy. Am J Orthod Dentofac Orthop 1991;100:312-23. 2. Hu J, Wang D, Luo S, Chen Y. Differences in soft tissue profile changes following mandibular setback in Chinese men and women. J Oral Maxillofac Surg 1999;57:1182-6. 3. Enacar A, Taner T, Torog˘lu S. Analysis of soft tissue profile changes associated with mandibular setback and double-jaw surgeries. Int J Adult Orthod Orthognath Surg 1999;14:27-35. 4. Mobarak KA, Krogstad O, Espeland L, Lyberg T. Factors influencing the predictability of soft tissue profile changes following mandibular setback surgery. Angle Orthod 2001;71:216-27. 5. Koh CH, Chew MT. Predictability of soft tissue profile changes following bimaxillary surgery in skeletal class III Chinese patients. J Oral Maxillofac Surg 2004;62:1505-9. 6. Johnston C, Burden D, Kennedy D, Harradine N, Stevenson M. Class III surgical-orthodontic treatment: a cephalometric study. Am J Orthod Dentofac Orthop 2006;130:300-9. 7. McCance AM, Moss JP, Fright WR, James DR, Linney AD. A three dimensional analysis of soft and hard tissue changes following bimaxillary orthognathic surgery in skeletal III patients. Br J Oral Maxillofac Surg 1992;30:305-12. 8. Cavalcanti MG, Rocha SS, Vannier MW. Craniofacial measurements based on 3D-CT volume rendering: implications for clinical applications. Dentomaxillofac Radiol 2004;33:170-6. 9. Jung YJ, Kim MJ, Baek SH. Hard and soft tissue changes after correction of mandibular prognathism and facial asymmetry by mandibular setback surgery: three-dimensional analysis using computerized tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:763-771.e8. 10. McCance AM, Moss JP, Wright WR, Linney AD, James DR. A three-dimensional soft tissue analysis of 16 skeletal class III patients following bimaxillary surgery. Br J Oral Maxillofac Surg 1992;30:221-32. 11. Da Silveira AC, Daw JL Jr, Kusnoto B, Evans C, Cohen M. Craniofacial applications of three-dimensional laser surface scanning. J Craniofac Surg 2003;14:449-56. 12. Soncul M, Bamber MA. Evaluation of facial soft tissue changes with optical surface scan after surgical correction of class III deformities. J Oral Maxillofac Surg 2004;62:1331-40. 13. Kau CH, Zhurov A, Bibb R, Hunter L, Richmond S. The investigation of the changing facial appearance of identical twins employing a three-dimensional laser imaging system. Orthod Craniofac Res 2005;8:85-90. 14. Holberg C, Schwenzer K, Mahaini L, Rudzki-Janson I. Accuracy of facial plaster casts. Angle Orthod 2006;76:605-11.

OOOOE Volume 109, Number 5 15. Baik HS, Jeon JM, Lee HJ. Facial soft-tissue analysis of Korean adults with normal occlusion using a 3-dimensional laser scanner. Am J Orthod Dentofacial Orthop 2007;131:759-66. 16. Ghoddousi H, Edler R, Haers P, Wertheim D, Greenhill D. Comparison of three methods of facial measurement. 1. Int J Oral Maxillofac Surg 2007;36:250-8. 17. Ozsoy U, Demirel BM, Yildirim FB, Tosun O, Sarikcioglu L. Method selection in craniofacial measurements: advantages and disadvantages of 3D digitization method. J Craniomaxillofac Surg 2009;37:285-90. 18. Im DH, Kim TW, Nahm DS. Current trends in orthodontic patients in Seoul National University Dental Hospital. Korean J Orthod 2003;33:63-72. 19. Chew MT. Spectrum and management of dentofacial deformities in a multiethnic Asian population. Angle Orthod 2006;76:806-9. 20. Solow B, Tallgren A. Natural head position in standing subjects. Acta Odontol Scand 1971;29:591-607. 21. Kusnoto B, Evans CA. Reliability of a 3D surface laser scanner for orthodontic applications. Am J Orthod Dentofac Orthop 2002;122:342-8. 22. Kau CH, Cronin AJ, Richmond S. A three-dimensional evaluation of postoperative swelling following orthognathic surgery at 6 months. Plast Reconstr Surg 2007;119:2192-9. 23. McCance AM, Moss JP, Fright WR, Linney AD, James DR, Coghlan K, Mars M. Three-dimensional analysis techniques— part 4: three-dimensional analysis of bone and soft tissue to bone ratio of movements in 24 cleft palate patients following Le Fort

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24.

25.

26.

27. 28.

I osteotomy: a preliminary report. Cleft Palate Craniofac J 1997; 34:58-62. Kau CH, Richmond S, Savio C, Mallorie C. Measuring adult facial morphology in three dimensions. Angle Orthod 2006;76: 773-8. Miller L, Morris DO, Berry E. Visualizing three-dimensional facial soft tissue changes following orthognathic surgery. Eur J Orthod 2007;29:14-20. Ferrario VF, Sforza C, Schmitz JH, Santoro F. Three-dimensional facial morphometric assessment of soft tissue changes after orthognathic surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:549-56. Chew MT. Soft and hard tissue changes after bimaxillary surgery in Chinese class III patients. Angle Orthod 2005;75:959-63. Naoumova J, Söderfeldt B, Lindman R. Soft tissue profile changes after vertical ramus osteotomy. Eur J Orthod 2008; 30:359-65.

Reprint requests: Dr. Seung-Hak Baek Department of Orthodontics School of Dentistry Dental Research Institute Seoul National University Yeonkun-dong #28 Jongro-ku, Seoul 110-768 Korea [email protected]

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Appendix A. Comparison of the changes in the coordinate values (X, Y, and Z) of the soft tissue landmarks between small setback group and large setback group (mm) X

Variable Upper lip 15 Upper lip point (Rt) 16 Upper lip point (Lt) 17 Labrale superius 21 Upper lip prominent 23 Upper lip border (Rt) 24 Upper lip border (Lt) 29 Ac-cheilion midpoint (Rt) 30 Ac-cheilion midpoint (Lt) 18 Cheilion (Rt) 19 Cheilion (Lt) Stomion 20 Stomion 25 Stomion (Rt) 26 Stomion (Lt) Lower lip 22 Lower lip prominent 27 Lower lip border (Rt) 28 Lower lip border (Lt) 32 B-cheilion midpoint (Rt) 33 B-cheilion midpoint (Lt) 34 Labrale inferius Chin area 31 B point 35 Pogonion 50 Menton Cheek area 36 Ac-exocanthion (Rt) 37 Ac-exocanthion (Lt) 38 Mid-Ac-endocanthion (Rt) 39 Mid-Ac-endocanthion (Lt) 40 Midpoint of upper cheek (Rt) 41 Midpoint of upper cheek (Lt) 42 Mid-Ac-Ac-exocanthion (Rt) 43 Mid-Ac-Ac-exocanthion (Lt) 44 Zygomatic point (Rt) 45 Zygomatic point (Lt) 46 Cheilion-exocanthion (Rt) 47 Cheilion-exocanthion (Lt) 48 Midpoint of lower cheek (Rt) 49 Midpoint of lower cheek (Lt) 51 Lateral point of lower cheek (Rt) 52 Lateral point of lower cheek (Lt)

Y

Small setback

Large setback

Mean

SD

Mean

SD

0.19 0.02 0.12 0.21 0.13 0.04 ⫺0.04 0.18 1.76 ⫺1.42

0.69 0.84 0.67 0.76 0.29 0.62 0.31 0.12 0.92 1.74

0.24 ⫺0.29 0.05 0.01 ⫺0.07 ⫺0.08 0.16 0.16 1.86 ⫺1.50

0.16 ⫺0.07 0.22

0.74 0.37 0.29

0.32 ⫺0.11 0.32 0.21 0.33 0.22

Z

Small setback

Large setback

Small setback

Large setback

Sig.

Mean

SD

Mean

SD

Sig.

Mean

SD

Mean

SD

0.67 0.70 0.64 0.41 0.27 0.36 0.54 0.46 1.32 1.84

.8455 .2476 .7735 .3809 .0439* .5119 .2104 .8723 .8071 .8895

⫺0.39 ⫺0.48 ⫺0.88 ⫺1.33 ⫺1.21 ⫺1.25 ⫺0.19 0.01 ⫺0.88 ⫺0.50

0.76 0.97 0.87 1.09 0.75 0.86 0.50 0.45 1.17 1.88

⫺0.91 ⫺0.70 ⫺1.44 ⫺2.26 ⫺1.35 ⫺1.48 ⫺0.30 ⫺0.34 ⫺1.32 ⫺1.65

1.25 1.33 1.49 1.73 1.27 1.34 0.73 1.14 1.27 1.72

.1790 .6009 .2164 .0884 .7274 .5699 .6228 .2305 .3172 .0770

⫺0.78 ⫺0.93 ⫺1.13 ⫺1.48 ⫺0.93 ⫺1.32 ⫺0.79 ⫺1.19 ⫺4.04 ⫺3.95

0.77 0.88 0.91 1.37 0.86 1.02 0.92 0.81 1.83 1.82

⫺0.94 ⫺1.01 ⫺1.33 ⫺1.93 ⫺1.24 ⫺1.39 ⫺1.08 ⫺1.14 ⫺5.07 ⫺5.36

1.01 1.22 1.35 1.93 1.33 1.81 0.95 1.27 1.92 2.45

.6182 .8239 .6384 .4682 .4541 .8856 .3859 .9071 .1334 .0784

⫺0.01 ⫺0.11 0.22

0.33 0.46 0.41

.4232 .7709 .9947

⫺1.43 ⫺1.69 ⫺1.44

0.97 0.96 1.57

⫺2.59 ⫺2.41 ⫺2.44

1.50 1.25 1.40

.0168* .0793 .0637

⫺3.28 ⫺2.89 ⫺3.47

1.15 1.18 1.51

⫺4.66 ⫺3.93 ⫺4.23

2.03 1.58 2.23

.0192* .0475* .2816

0.87 0.34 0.69 0.41 0.98 0.56

⫺0.19 ⫺0.22 0.22 0.13 ⫺0.23 ⫺0.30

0.73 0.51 0.68 0.62 1.55 0.98

.0806 .4914 .6762 .6666 .2423 .0669

⫺0.75 ⫺1.11 ⫺0.50 0.13 0.16 0.27

1.51 1.62 1.76 1.45 1.36 1.44

⫺2.34 ⫺1.71 ⫺1.94 ⫺0.67 ⫺0.57 ⫺1.02

1.81 1.30 1.45 1.44 1.38 1.67

.0119* .2421 .0148* .1264 .1399 .0273*

⫺6.03 ⫺6.31 ⫺6.78 ⫺6.03 ⫺6.78 ⫺6.63

1.84 1.68 2.20 1.99 2.70 1.78

⫺7.66 ⫺8.59 ⫺9.16 ⫺8.65 ⫺9.13 ⫺8.58

2.63 2.75 3.14 1.63 2.88 2.61

.0564 .0099** .0214* .0002*** .0232* .0217*

0.15 0.35 ⫺0.10

0.87 0.64 1.14

⫺0.35 ⫺0.47 ⫺0.79

1.01 1.40 2.40

.1491 .0325ⴱ .2819

1.57 1.08 0.94

1.94 2.77 3.35

0.70 2.58 2.45

2.13 3.13 3.62

.2405 .1621 .2316

⫺5.87 ⫺5.54 ⫺7.38

1.64 1.79 4.07

⫺9.04 ⫺8.70 ⫺10.49

2.88 4.03 6.21

.0004*** .0054** .1128

⫺0.06 0.20 0.12 0.12 ⫺0.01 0.06 ⫺0.11 ⫺0.03 ⫺0.23 ⫺0.01 ⫺0.46 0.23 ⫺0.20 0.23 ⫺0.15 0.48

0.27 0.43 0.21 0.28 0.28 0.27 0.26 0.28 2.73 1.77 0.54 1.38 0.17 0.29 0.35 0.40

⫺0.31 0.30 0.16 ⫺0.01 0.07 0.11 ⫺0.12 0.10 0.08 0.01 ⫺0.46 0.50 ⫺0.13 0.31 ⫺0.38 0.45

0.50 0.47 0.23 0.25 0.28 0.24 0.29 0.26 2.23 2.14 1.41 1.57 0.27 0.31 0.52 0.61

.0695 .5372 .6629 .2015 .4276 .5759 .9295 .1833 .7219 .9786 .9943 .6175 .4231 .4619 .1685 .8765

⫺0.02 0.13 0.06 0.01 ⫺0.04 0.03 ⫺0.01 ⫺0.03 ⫺0.19 ⫺0.50 ⫺0.32 ⫺0.58 ⫺0.15 ⫺0.14 ⫺0.11 ⫺0.27

0.28 0.24 0.26 0.23 0.19 0.33 0.20 0.17 0.70 0.89 0.53 0.64 0.21 0.30 0.30 0.34

⫺0.08 ⫺0.03 ⫺0.09 0.00 ⫺0.02 ⫺0.04 ⫺0.02 0.02 ⫺0.24 ⫺0.33 ⫺0.76 ⫺0.68 ⫺0.05 ⫺0.16 ⫺0.34 ⫺0.22

0.35 0.20 0.21 0.35 0.25 0.21 0.25 0.21 0.85 0.68 0.90 0.80 0.21 0.26 0.25 0.30

.5498 .0420* .0780 .9117 .7666 .4615 .9191 .4545 .8625 .5387 .1104 .6918 .2010 .8617 .0223* .6091

⫺0.44 ⫺0.76 0.09 ⫺0.02 ⫺0.15 ⫺0.24 ⫺0.28 ⫺0.43 ⫺0.47 ⫺0.29 ⫺2.39 ⫺4.50 ⫺0.99 ⫺1.63 ⫺0.43 ⫺2.21

1.09 1.57 0.30 0.30 0.57 0.49 0.72 0.64 2.91 1.44 3.44 5.39 0.99 0.95 1.73 2.84

⫺1.67 ⫺1.28 0.20 0.17 ⫺0.21 ⫺0.18 ⫺0.65 ⫺0.56 ⫺0.69 ⫺0.57 ⫺4.65 ⫺6.02 ⫺1.94 ⫺2.07 ⫺2.76 ⫺2.99

1.77 2.26 0.85 0.86 0.96 1.07 1.55 1.68 2.20 2.08 6.09 6.84 1.87 1.81 3.36 3.99

.0286* .4671 .5922 .3762 .8418 .8254 .4119 .7515 .8022 .6712 .1868 .4961 .0687 .3756 .0151* .5372

Sig.

The reference axes are established on the original point (nasion) as follows: a midfacial line (Y coordinate, vertical axis), a parallel line to the floor (Z coordinate, anteroposterior axis), and a parallel line to a line connecting both exocanthions (X coordinate, transverse axis). Independent t test was done. *P ⬍ .05; **P ⬍ .01; ***P ⬍ .001.

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Kim et al. e31

Appendix B. Comparison of the changes in the coordinate values (X, Y, and Z) of the soft tissue landmarks between hypodivergent group and hyperdivergent group (mm) X

Variable Upper lip 15 Upper lip point (Rt) 16 Upper lip point (Lt) 17 Labrale superius 21 Upper lip prominent 23 Upper lip border (Rt) 24 Upper lip border (Lt) 29 Ac-cheilion midpoint (Rt) 30 Ac-cheilion midpoint (Lt) 18 Cheilion (Rt) 19 Cheilion (Lt) Stomion 20 Stomion 25 Stomion (Rt) 26 Stomion (Lt) Lower lip 22 Lower lip prominent 27 Lower lip border (Rt) 28 Lower lip border (Lt) 32 B-cheilion midpoint (Rt) 33 B-cheilion midpoint (Lt) 34 Labrale inferius Chin area 31 B point 35 Pogonion 50 Menton Cheek area 36 Ac-exocanthion (Rt) 37 Ac-exocanthion (Lt) 38 Mid-Ac-endocanthion (Rt) 39 Mid-Ac-endocanthion (Lt) 40 Midpoint of upper cheek (Rt) 41 Midpoint of upper cheek (Lt) 42 Mid-Ac-Ac-exocanthion (Rt) 43 Mid-Ac-Ac-exocanthion (Lt) 44 Zygomatic point (Rt) 45 Zygomatic point (Lt) 46 Cheilion-exocanthion (Rt) 47 Cheilion-exocanthion (Lt) 48 Midpoint of lower cheek (Rt) 49 Midpoint of lower cheek (Lt) 51 Lateral point of lower cheek (Rt) 52 Lateral point of lower cheek (Lt)

Y

Hypodivergent

Hyperdivergent

Mean

SD

Mean

SD

0.43 ⫺0.04 0.18 0.10 0.05 0.02 0.18 0.19 2.28 ⫺1.66

0.74 0.85 0.76 0.72 0.32 0.60 0.54 0.46 1.22 1.88

⫺0.03 ⫺0.30 ⫺0.04 0.07 ⫺0.04 ⫺0.09 ⫺0.05 0.14 1.26 ⫺1.23

0.14 ⫺0.11 0.29

0.68 0.46 0.37

0.07 ⫺0.07 0.27 0.04 ⫺0.20 ⫺0.08

Z

Hypodivergent

Hyperdivergent

Hypodivergent

Hyperdivergent

Sig.

Mean

SD

Mean

SD

Sig.

Mean

SD

Mean

SD

Sig.

0.48 0.65 0.46 0.37 0.26 0.31 0.32 0.15 0.80 1.66

.0433ⴱ .3315 .3381 .8787 .4007 .5213 .1671 .7045 .0092** .4994

⫺0.48 ⫺0.49 ⫺1.01 ⫺1.88 ⫺1.33 ⫺1.41 ⫺0.22 ⫺0.17 ⫺1.13 ⫺0.85

0.83 0.92 1.31 1.68 1.06 1.30 0.71 0.97 1.13 1.70

⫺0.94 ⫺0.75 ⫺1.44 ⫺1.85 ⫺1.25 ⫺1.35 ⫺0.29 ⫺0.23 ⫺1.13 ⫺1.53

1.31 1.45 1.24 1.43 1.11 0.99 0.55 0.88 1.38 2.01

.2283 .5266 .3483 .9608 .8322 .8883 .7615 .8553 .9975 .2964

⫺1.10 ⫺1.22 ⫺1.51 ⫺2.11 ⫺1.41 ⫺1.66 ⫺1.00 ⫺1.02 ⫺4.75 ⫺4.89

0.96 1.23 1.40 2.02 1.24 1.77 0.93 1.16 1.87 2.43

⫺0.61 ⫺0.69 ⫺0.92 ⫺1.29 ⫺0.74 ⫺1.00 ⫺0.91 ⫺1.32 ⫺4.49 ⫺4.61

0.79 0.79 0.73 1.14 0.94 1.05 0.96 1.00 2.03 2.17

.1228 .1605 .1343 .1540 .0937 .2143 .7734 .4409 .6977 .7314

⫺0.03 ⫺0.07 0.14

0.31 0.38 0.34

.3406 .7559 .2351

⫺2.25 ⫺2.10 ⫺1.79

1.53 1.10 1.66

⫺1.91 ⫺2.11 ⫺2.29

1.28 1.31 1.37

.5050 .9669 .3556

⫺4.55 ⫺3.83 ⫺4.39

2.01 1.66 2.27

⫺3.50 ⫺3.08 ⫺3.33

1.43 1.19 1.38

.1000 .1530 .1230

1.07 0.46 0.70 0.54 1.65 1.07

⫺0.02 ⫺0.30 0.24 0.31 0.26 ⫺0.08

0.38 0.39 0.68 0.51 0.86 0.54

.7456 .1424 .8857 .1589 .3438 .9950

⫺1.92 ⫺1.65 ⫺1.43 ⫺0.46 ⫺0.48 ⫺0.57

2.16 1.60 1.82 1.45 1.29 2.04

⫺1.36 ⫺1.22 ⫺1.20 ⫺0.17 0.01 ⫺0.36

1.39 1.28 1.65 1.54 1.52 1.18

.3936 .4036 .7062 .5862 .3289 .7178

⫺7.36 ⫺7.99 ⫺8.62 ⫺7.77 ⫺8.34 ⫺8.15

2.55 2.95 3.21 2.23 3.05 2.69

⫺6.50 ⫺7.19 ⫺7.59 ⫺7.27 ⫺7.89 ⫺7.28

2.29 2.10 2.70 2.20 3.02 2.16

.3196 .3850 .3346 .5270 .6739 .3206

⫺0.26 ⫺0.22 ⫺0.64

1.09 1.17 1.54

0.01 ⫺0.01 ⫺0.33

0.82 1.26 2.43

.4280 .6347 .6641

1.31 2.75 2.10

1.88 3.27 4.27

0.79 0.97 1.45

2.30 2.50 2.49

.4816 .0941 .5919

⫺7.92 ⫺7.58 ⫺10.03

3.18 4.09 6.53

⫺7.43 ⫺7.10 ⫺8.14

2.57 3.03 4.08

.6310 .7099 .3382

⫺0.23 0.15 0.18 0.02 0.05 0.07 ⫺0.07 ⫺0.04 0.03 ⫺0.16 ⫺0.30 0.37 ⫺0.13 0.30 ⫺0.28 0.34

0.54 0.48 0.25 0.28 0.30 0.19 0.30 0.20 2.25 1.70 1.42 1.42 0.28 0.28 0.51 0.61

⫺0.17 0.38 0.10 0.08 0.01 0.11 ⫺0.18 0.15 ⫺0.16 0.20 ⫺0.64 0.41 ⫺0.19 0.24 ⫺0.29 0.61

0.27 0.39 0.17 0.25 0.26 0.31 0.23 0.32 2.68 2.28 0.57 1.58 0.18 0.34 0.42 0.37

.6373 .1343 .2856 .5677 .6737 .6325 .2544 .0484 .8230 .6100 .3628 .9428 .4797 .5468 .9772 .1518

⫺0.07 ⫺0.01 ⫺0.02 0.04 ⫺0.05 ⫺0.05 ⫺0.01 0.01 ⫺0.24 ⫺0.27 ⫺0.56 ⫺0.37 ⫺0.04 ⫺0.12 ⫺0.28 ⫺0.16

0.35 0.22 0.28 0.30 0.19 0.28 0.27 0.16 0.86 0.51 0.91 0.55 0.22 0.28 0.25 0.31

⫺0.04 0.10 ⫺0.04 ⫺0.05 0.00 0.03 ⫺0.02 ⫺0.01 ⫺0.20 ⫺0.56 ⫺0.60 ⫺0.96 ⫺0.15 ⫺0.19 ⫺0.20 ⫺0.34

0.29 0.24 0.21 0.30 0.27 0.26 0.17 0.23 0.71 0.99 0.64 0.79 0.20 0.27 0.34 0.30

.8348 .1894 .8632 .4059 .4858 .4305 .8542 .8339 .8779 .3165 .8908 .0160ⴱ .1531 .5199 .4112 .1145

⫺1.17 ⫺0.43 0.31 0.31 ⫺0.03 0.15 ⫺0.28 ⫺0.09 ⫺0.79 ⫺0.06 ⫺3.13 ⫺4.07 ⫺1.52 ⫺1.65 ⫺1.80 ⫺1.89

1.86 2.14 0.83 0.78 1.00 0.93 1.59 1.61 2.19 1.61 5.85 6.67 2.01 1.82 3.51 4.00

⫺1.11 ⫺1.82 ⫺0.03 ⫺0.17 ⫺0.37 ⫺0.64 ⫺0.75 ⫺1.00 ⫺0.37 ⫺0.92 ⫺4.37 ⫺6.94 ⫺1.55 ⫺2.17 ⫺1.73 ⫺3.58

1.33 1.52 0.35 0.43 0.48 0.54 0.67 0.61 2.86 1.99 4.38 5.44 1.01 0.99 2.33 2.68

.9154 .0439* .1457 .0346* .2209 .0052** .2743 .0371* .6410 .1813 .5017 .1925 .9552 .3072 .9537 .1735

Independent t test was done. SD means standard deviation; Sig., significance; *P ⬍ .05; **P ⬍ .01; positive (⫹) value, upward, forward, patient’s left side movements; negative (⫺) value, downward, backward, patient’s right side movements.

e32

OOOOE May 2010

Kim et al.

Appendix C. Comparison of the changes in the coordinate values (X, Y, and Z) of the soft tissue landmarks between nongenioplasty group and genioplasty group (mm) X Nongenioplasty Variables Upper lip 15 Upper lip point (Rt) 16 Upper lip point (Lt) 17 Labrale superius 21 Upper lip prominent 23 Upper lip border (Rt) 24 Upper lip border (Lt) 29 Ac-cheilion midpoint (Rt) 30 Ac-cheilion midpoint (Lt) 18 Cheilion (Rt) 19 Cheilion (Lt) Stomion 20 Stomion 25 Stomion (Rt) 26 Stomion (Lt) Lower lip 22 Lower lip prominent 27 Lower lip border (Rt) 28 Lower lip border (Lt) 32 B-cheilion midpoint (Rt) 33 B-cheilion midpoint (Lt) 34 Labrale inferius Chin area 31 B point 35 Pogonion 50 Menton Cheek area 36 Ac-exocanthion (Rt) 37 Ac-exocanthion (Lt) 38 Mid-Ac-endocanthion (Rt) 39 Mid-Ac-endocanthion (Lt) 40 Midpoint of upper cheek (Rt) 41 Midpoint of upper cheek (Lt) 42 Mid-Ac-Ac-exocanthion (Rt) 43 Mid-Ac-Ac-exocanthion (Lt) 44 Zygomatic point (Rt) 45 Zygomatic point (Lt) 46 Cheilion-exocanthion (Rt) 47 Cheilion-exocanthion (Lt) 48 Midpoint of lower cheek (Rt) 49 Midpoint of lower cheek (Lt) 51 Lateral point of lower cheek (Rt) 52 Lateral point of lower cheek (Lt)

Y

Genioplasty

Nongenioplasty

Z

Genioplasty

Nongenioplasty

Genioplasty

Mean

SD

Mean

SD

Sig.

Mean

SD

Mean

SD

Sig.

Mean

SD

Mean

SD

Sig.

0.10 ⫺0.01 0.20 0.24 0.01 0.07 0.12 0.08 1.89 ⫺1.46

0.65 0.65 0.72 0.61 0.30 0.52 0.51 0.23 1.12 1.82

0.44 ⫺0.42 ⫺0.14 ⫺0.17 0.03 ⫺0.20 ⫺0.01 0.31 1.70 ⫺1.47

0.67 0.90 0.41 0.45 0.29 0.38 0.35 0.47 1.25 1.77

.1640 .1335 .1393 .0483* .8599 .1268 .4478 .1324 .6620 .9851

⫺0.38 ⫺0.31 ⫺1.02 ⫺1.73 ⫺1.00 ⫺1.05 ⫺0.17 ⫺0.08 ⫺1.01 ⫺1.00

0.82 1.07 1.25 1.64 0.91 1.14 0.53 0.76 1.23 1.98

⫺1.22 ⫺1.12 ⫺1.52 ⫺2.10 ⫺1.81 ⫺1.97 ⫺0.39 ⫺0.40 ⫺1.34 ⫺1.43

1.31 1.23 1.33 1.39 1.16 0.95 0.79 1.15 1.26 1.66

.0292ⴱ .0557 .2945 .5111 .0336* .0247* .3573 .3367 .4644 .5315

⫺0.80 ⫺0.89 ⫺1.09 ⫺1.67 ⫺0.98 ⫺1.26 ⫺0.91 ⫺1.23 ⫺4.38 ⫺4.59

0.99 1.14 1.26 1.97 1.24 1.69 1.07 1.18 1.85 2.28

⫺1.01 ⫺1.13 ⫺1.50 ⫺1.86 ⫺1.32 ⫺1.55 ⫺1.04 ⫺1.03 ⫺5.07 ⫺5.06

0.75 0.97 1.00 1.17 1.00 1.16 0.66 0.92 2.04 2.36

.5207 .5492 .3413 .7710 .4296 .6021 .7141 .6199 .3340 .5785

0.16 0.03 0.28

0.60 0.33 0.38

⫺0.11 ⫺0.30 0.13

0.38 0.49 0.32

.1712 .0299* .2434

⫺1.84 ⫺1.87 ⫺1.80

1.57 1.26 1.69

⫺2.54 ⫺2.51 ⫺2.39

0.99 0.95 1.19

.1721 .1342 .2910

⫺3.70 ⫺3.03 ⫺3.58

1.89 1.52 2.22

⫺4.73 ⫺4.29 ⫺4.49

1.58 1.11 1.29

.1216 .0180* .2072

0.09 ⫺0.08 0.33 0.17 0.05 ⫺0.01

0.93 0.42 0.78 0.53 1.52 0.95

⫺0.09 ⫺0.34 0.13 0.15 ⫺0.07 ⫺0.20

0.62 0.45 0.44 0.57 1.05 0.69

.5473 .1009 .4248 .9210 .8134 .5413

⫺1.29 ⫺1.34 ⫺1.15 0.40 0.36 ⫺0.40

2.00 1.59 1.88 1.20 1.30 1.62

⫺2.32 ⫺1.65 ⫺1.64 ⫺1.61 ⫺1.34 ⫺0.60

1.39 1.22 1.42 0.96 0.79 1.85

.1240 .5674 .4346 ⬍ .0001*** .0003*** .7441

⫺6.60 ⫺7.35 ⫺7.70 ⫺7.22 ⫺7.72 ⫺7.48

2.66 2.76 3.22 2.30 3.36 2.61

⫺7.60 ⫺8.10 ⫺8.94 ⫺8.11 ⫺8.86 ⫺8.23

1.94 2.30 2.46 1.96 2.18 2.21

.2663 .4329 .2561 .2689 .3002 .4087

0.09 0.07 0.20

1.05 1.18 1.57

⫺0.53 ⫺0.46 ⫺1.72

0.69 1.21 2.06

.0770 .2271 .0051**

1.35 1.47 0.62

2.22 2.36 2.42

0.58 2.77 3.88

1.74 3.95 4.29

.3063 .3173 .0285*

⫺7.94 ⫺7.68 ⫺10.80

3.25 3.85 5.40

⫺7.27 ⫺6.80 ⫺6.32

2.16 3.20 4.76

.5250 .5036 .0232ⴱ

⫺0.22 0.29 0.17 0.11 0.04 0.09 ⫺0.07 0.08 ⫺0.59 0.08 ⫺0.54 0.13 ⫺0.13 0.26 ⫺0.26 0.53

0.44 0.48 0.19 0.22 0.31 0.25 0.25 0.31 2.43 2.05 0.76 1.73 0.24 0.29 0.49 0.58

⫺0.17 0.19 0.10 ⫺0.07 0.03 0.07 ⫺0.20 ⫺0.02 0.88 ⫺0.13 ⫺0.32 0.84 ⫺0.21 0.29 ⫺0.32 0.34

0.43 0.39 0.26 0.30 0.21 0.26 0.28 0.18 2.20 1.88 1.59 0.72 0.22 0.33 0.42 0.39

.7334 .5337 .4119 .0628 .9327 .7586 .1803 .3257 .0949 .7739 .6561 .1136 .4011 .8033 .7149 .3130

⫺0.12 0.03 ⫺0.09 ⫺0.02 ⫺0.06 ⫺0.05 0.04 ⫺0.01 ⫺0.38 ⫺0.50 ⫺0.53 ⫺0.62 ⫺0.08 ⫺0.16 ⫺0.25 ⫺0.30

0.26 0.22 0.21 0.27 0.22 0.27 0.23 0.17 0.85 0.81 0.88 0.76 0.20 0.30 0.28 0.33

0.06 0.06 0.08 0.03 0.02 0.05 ⫺0.11 0.02 0.07 ⫺0.23 ⫺0.65 ⫺0.66 ⫺0.12 ⫺0.13 ⫺0.23 ⫺0.14

0.39 0.26 0.27 0.35 0.23 0.26 0.19 0.24 0.56 0.70 0.62 0.69 0.25 0.22 0.32 0.27

.1153 .7365 .0449ⴱ .6495 .3491 .2746 .0631 .6365 .1097 .3385 .6889 .8801 .6144 .7345 .8266 .1645

⫺1.38 ⫺1.48 0.12 ⫺0.03 ⫺0.28 ⫺0.37 ⫺0.58 ⫺0.68 ⫺1.04 ⫺0.64 ⫺3.49 ⫺5.53 ⫺1.48 ⫺2.10 ⫺1.68 ⫺3.41

1.71 2.17 0.77 0.69 0.90 0.85 1.53 1.54 2.62 1.85 5.70 6.85 1.74 1.75 3.19 3.89

⫺0.74 ⫺0.32 0.20 0.30 ⫺0.01 0.08 ⫺0.33 ⫺0.21 0.17 ⫺0.11 ⫺4.05 ⫺5.11 ⫺1.63 ⫺1.51 ⫺1.92 ⫺1.33

1.43 1.39 0.46 0.64 0.62 0.84 0.60 0.80 2.13 1.77 4.39 5.20 1.42 0.87 2.74 2.35

.2865 .1051 .7525 .1855 .3532 .1557 .5125 .2606 .1839 .4281 .7685 .8541 .7993 .2913 .8275 .1033

Independent t test was done. *P ⬍ .05; **P ⬍ .01; ***P ⬍ .001.