Do long-faced subjects really have a long anterior face? A longitudinal study

Introduction

The aims of this study were to investigate and compare the anterior facial heights of children with long, normal, and short faces during growth and to discover whether long-faced subjects have long dimensions in both the upper and lower anterior facial heights compared with the others.

Methods

Longitudinal lateral cephalometric data of 167 children (83 girls, 84 boys) from 6 to 14 years of age were used. Total anterior face height, upper anterior face height, lower anterior face height, and the closest distance from the Frankfort horizontal plane to nasion were measured. The samples were classified as long-faced, normal-faced, and short-faced according to the ratio of lower to total face heights at 14 years old. All data were analyzed statistically and compared between the groups according to age.

Results

The mean lower anterior face height in the long-faced group was larger than in the normal-faced and short-faced groups for all ages in both sexes. In contrast, subjects in the normal-faced group had a longer mean upper anterior face height than did subjects in the long-faced and short-faced groups. In addition, the mean upper anterior face height of the short-faced group was larger than the long-faced group for girls at all ages and for boys at 12 to 14 years.

Conclusions

The long-faced children did not have longer upper facial heights compared with normal-faced and short-faced children, and their long faces were mainly determined by the length of the lower face.

The improvement of facial appearance is an objective common to a variety of clinicians including orthodontists, and facial balance is a cardinal concern. In the formulation of the orthodontic treatment plan and the prognosis of treatment, the patient’s facial type is important. There have been numerous facial type classifications based on the view perspective, and the vertical relationship is particularly important, since vertical skeletal discrepancies have been considered a particularly difficult challenge to orthodontists.

Under the vertical facial type classification, the face is identified as either long or short compared with normal, although some use the terms dolichofacial (leptoprosopic) or brachyfacial (euryprosopic). Severe cases of these vertical dysplasias have been characterized as skeletal open bite or hyperdivergent, and skeletal deepbite or hypodivergent. Some authors have also used the terms “long face syndrome” and “short face syndrome.”

Patients with long faces have characteristic facial appearances, including a long lower anterior facial height (LAFH) with or without a dental anterior open bite, with several accompanying manifestations, such as lip incompetence, posterior rotation of the palatal plane, excessive eruption of the posterior maxillary teeth, and clockwise rotation of the mandible. The upper third of the face of a patient with a long face syndrome is usually within normal limits according to Bell and McBride. Schendel et al originally described the most important feature of the long face syndrome as vertical maxillary excess, although a later report stated that there is variation in this syndrome.

Our questions arose in response to these reports, in particular regarding whether long-faced patients have a morphology that is evenly long throughout the entire face or whether they have only a long lower anterior face. If the latter is true, it may be more pertinent to denote them as patients with a long lower third of the face.

Until now, little attention has been paid to the upper anterior facial height (UAFH) and its growth in long-faced persons. In our investigation, we followed the growth change of anterior facial heights of long-faced adolescents and compared them with those of normal-faced and short-faced adolescents using 9 years of longitudinal cephalometric data. Our aims were to compare the changes in the UAFH between long-faced and normal-faced and short-faced adolescents and to discuss the appropriateness of the term “long face.”

Material and methods

The study subjects were selected from participants in the Korean Dental Growth Study, which took place from 1995 to 2003. A total of 410 subjects from northern Gyeonggi-do, Korea, participated in this study, and they were all healthy without systemic diseases or developmental anomalies. No one had received any treatment interfering with growth or had any orthodontic treatment before or during the observation period. The parents or guardians of all subjects provided written informed consent. Among the subjects, we chose to examine the lateral cephalometric radiographs of 167 children (83 boys, 84 girls) with full sets of 9-year data sufficient to clearly trace all measurements for this study. The subjects were followed annually from 6 to 14 years of age, with the exception of their tenth year in which the study was temporarily suspended for financial reasons. The institutional review board for the protection of human subjects of Seoul National University reviewed and approved the research protocol (S-D2010013).

All radiographs were traced by 1 observer (Y.-S.P.) to eliminate interexaminer variability and analyzed using Vceph (version 6.0; Osstem, Seoul, Korea). Landmarks, reference planes, and measurements are shown in Figure 1 . The following linear measurements were taken from the cephalometric radiographs of all children at all ages: (1) total anterior face height (TAFH), from nasion to menton; (2) UAFH, from nasion to anterior nasal spine; (3) LAFH, from anterior nasal spine to menton; and (4) the closest distance from the Frankfort horizontal to nasion (NFH).

Fig 1
Cephalometric landmarks: N , Nasion; S , sella; Me , menton; Po , porion; Or , orbitale; ANS , anterior nasal spine. Cephalometric measurements: N-Me, TAFH , Total anterior facial height; N-ANS, UAFH , upper anterior facial height; ANS-Me, LAFH , lower anterior facial height; NFH , distance from nasion to the Frankfort horizontal plane.

In selecting long-faced and short-faced subjects, the protocol from a previous study was followed. One radiograph obtained at 14 years of age was used for the final measurements because it represented each subject’s most mature state. On the basis of the LAFH/TAFH ratio, the subjects with the most extreme values at both ends of the distribution (ie, >1 SD from the mean) were selected as long-faced or short-faced subjects from the cohort of 167 subjects. The subjects with in-between values were designated as normal-faced. This resulted in 12 long-faced, 57 normal-faced, and 14 short-faced girls, and 15 long-faced, 56 normal-faced, and 13 short-faced boys ( Table I ). Then the records of all measurements were reviewed back to 6 years of age according to group and sex to trace the changes of anterior facial heights longitudinally.

Table I
Comparison of the ratio of LAFH to TAFH for the long-, normal-, and short-faced groups at 14 years of age
Girls Boys
n Mean (SD) Max Min n Mean (SD) Max Min
Long-faced 13 0.591 (0.010) 0.603 0.58 15 0.589 (0.007) 0.601 0.581
Normal-faced 56 0.561 (0.010) 0.579 0.544 56 0.562 (0.010) 0.581 0.547
Short-faced 14 0.535 (0.008) 0.544 0.527 13 0.536 (0.013) 0.546 0.523
Total 83 0.562 (0.015) 0.603 0.527 84 0.560 (0.016) 0.601 0.523

Max , Maximum; Min , minimum.

Statistical analysis

SPSS software (SPSS for Windows, version 12.0; Chicago, Ill) was used for statistical analysis. All data showed normal distributions according to the Shapiro-Wilks normality test. Analysis of variance (ANOVA) with the post-hoc test was used to determine significant differences between groups according to age. Significance was set at the 0.05 level of confidence but was also assessed at the 0.01 level.

Results

Intraexaminer reliability coefficients ranged from 0.927 to 0.976. In terms of root mean square values, the random errors of estimation were less than 0.67 mm for linear measurements and 1.02° for angular measurements. No variable was significantly different between the test and retest measurements.

Descriptive statistics and the results of the comparisons between the sexes are shown in Tables II and III . Graphic representations are shown in Figures 2 and 3 . The mean TAFH had statistically significant differences among the groups at 6 and 14 years of age for girls and at 6, 7, 8, 9, 11, and 12 years for boys. Generally, the long-faced subjects had the greatest TAFH, the normal-faced subjects had a shorter TAFH, and the short-faced had smallest TAFH, but the normal-faced group had a greater TAFH than did the long-faced group at ages 6, 7, and 8 years for girls.

Table II
Comparisons with ANOVA between groups of anterior facial height dimensions (mm) according to age in girls
Age (y) Long faced Normal faced Short faced
Mean (SD) Max Min Mean (SD) Max Min Mean (SD) Max Min
TAFH
6 108.29 (3.83) a,b 115.29 101.62 109.30 (3.95) a 116.52 97.42 105.48 (2.61) b 110.15 100.26
7 110.12 (4.23) 118.03 104.26 111.33 (4.67) 120.46 98.46 108.51 (3.58) 115.08 101.34
8 113.00 (4.29) 121.43 106.93 113.54 (4.98) 124.46 102.59 110.88 (3.35) 115.95 104.85
9 115.18 (4.38) 123.34 109.68 115.56 (5.20) 126.01 103.18 113.27 (3.43) 119.00 107.08
11 122.51 (5.11) 128.49 113.45 121.45 (5.36) 131.57 107.55 119.03 (4.67) 124.42 108.85
12 124.62 (4.73) 132.63 116.44 123.68 (5.19) 133.08 110.56 121.18 (3.69) 125.68 113.34
13 126.78 (5.73) 138.26 116.44 125.59 (5.44) 134.9 113.61 122.73 (3.82) 129.94 115.73
14 128.12 (5.12) a 138.26 120.87 127.45 (5.15) a,b 134.9 113.61 123.64 (3.61) b 129.95 116.45
UAFH
6 †,‡ 46.63 (1.53) a 48.95 43.24 52.21 (3.40) b 60.28 44.87 49.18 (2.12) c 54.02 46.11
7 47.79 (2.29) a 51.37 43.88 52.98 (3.88) b 65.58 44.77 50.27 (2.53) a,b 54.88 45.99
8 †,‡ 49.23 (2.52) a 54.06 45.13 54.40 (3.74) b 64.64 45.98 52.33 (1.82) b 55.77 49.57
9 50.61 (2.31) a 54.16 45.47 55.30 (3.43) b 64.8 47.63 53.51 (2.10) b 56.39 50.34
11 52.79 (2.83) a 57.69 46.41 56.54 (3.19) b 66.54 49.20 56.13 (1.79) b 58 52.13
12 53.58 (3.22) a 57.09 47.28 57.79 (3.36) b 68.39 50.59 57.12 (1.79) b 59.67 53.19
13 †,‡ 54.50 (3.29) a 59.55 47.2 59.02 (3.79) b 67.57 49.22 58.67 (1.42) b 60.92 56.62
14 54.76 (2.83) a 59.6 51.09 59.97 (3.63) b 71.26 51.65 59.66 (1.25) b 61.2 57.34
LAFH
6 63.43 (2.87) a 68.2 57.73 62.32 (2.40) a 67.70 57.06 57.98 (1.94) b 60.31 52.99
7 64.03 (3.18) a 68.59 59.61 63.18 (2.97) a 71.60 56.79 59.23 (2.15) b 61.9 53.74
8 †,‡ 65.41 (2.75) a 68.94 60.65 63.86 (3.58) a 71.85 56.54 59.48 (2.45) b 63.07 53.92
9 66.67 (3.42) a 72.3 61.42 64.87 (3.25) a 70.59 57.26 61.45 (2.28) b 64.17 56.73
11 71.17 (3.33) a 76.53 65.48 67.81 (3.68) b 74.37 59.80 63.58 (2.93) c 67.86 55.74
12 72.64 (3.45) a 79.57 66.98 69.39 (3.49) b 75.02 61.84 64.51 (2.87) c 69.21 58.41
13 74.15 (3.55) a 82.43 68.45 70.16 (3.62) b 77.38 62.24 65.66 (3.63) c 70.38 57.43
14 75.42 (3.51) a 82.17 70.18 71.49 (3.36) b 79.31 64.45 66.79 (2.57) c 70.48 61.36
NFH
6 27.59 (1.56) 31.12 25.34 27.18 (2.07) 35.25 22.50 26.35 (1.55) 28.49 22.25
7 28.29 (1.77) 31.66 25.73 27.96 (2.03) 33.60 23.27 27.18 (1.58) 29.78 23.94
8 29.19 (1.47) 31.47 26.10 28.53 (2.02) 33.34 23.46 27.77 (1.50) 30.66 25.08
9 29.58 (1.44) 31.32 26.53 29.13 (1.97) 33.61 24.12 28.47 (1.48) 30.81 25.76
11 30.16 (1.06) 32.14 28.11 29.79 (1.89) 34.31 25.26 29.33 (1.63) 31.60 26.59
12 30.88 (1.43) a 33.25 28.38 30.43 (1.91) a,b 35.96 25.63 29.63 (1.55) b 32.09 26.94
13 31.99 (1.92) a 37.24 30.02 30.79 (2.04) a 36.10 25.55 30.15 (1.51) b 32.38 27.49
14 32.34 (1.74) 36.90 30.44 31.22 (1.92) 37.44 25.50 30.60 (1.62) 33.85 27.67
The letters a , b , or c denote homogeneous subsets according to the post-hoc test.
Max , Maximum; Min , minimum.

Statistically significant difference between groups ( P <0.05).

Statistically significant difference between groups ( P <0.01).

Dunnett T3 post-hoc test was used instead of Tukey test because the sample did not meet the hypothesis of homoscedasticity.

Table III
Comparisons with ANOVA between groups of anterior facial height dimensions (mm) according to age in boys
Age (y) Long faced Normal faced Short faced
Mean (SD) Max Min Mean (SD) Max Min Mean (SD) Max Min
TAFH
6 113.77 (5.37) a 123.34 105.68 110.96 (4.18) a,b 118.78 100.81 108.28 (3.41) b 114.6 102.69
7 116.27 (5.46) a 124.85 108.21 113.11 (3.94) a,b 120.29 103.69 110.21 (4.37) b 117.13 102.71
8 118.26 (6.39) a 130.64 109.44 115.88 (3.91) a,b 121.82 107.24 112.84 (4.71) b 121.44 106.30
9 120.99 (6.22) a 132.34 110.60 118.31 (3.88) b 125.97 111.02 114.78 (4.57) b 121.03 108.43
11 127.01 (6.97) a 138.30 117.79 123.53 (4.79) a,b 133.8 114.89 119.98 (5.35) b 128.45 112.72
12 130.23 (7.17) a 143.37 121.08 126.85 (5.76) a,b 137.97 112.41 123.45 (5.33) b 132.31 115.98
13 133.37 (8.71) 148.37 121.78 130.38 (5.95) 142.34 113.91 127.76 (5.43) 137.14 118.83
14 137.63 (8.88) 154.68 124.70 134.41 (4.85) 145.35 124.76 131.57 (5.51) 154.68 124.70
UAFH
6 48.93 (3.77) a 56.55 43.87 52.68 (3.10) b 61.03 45.80 48.85 (1.69) a 51.68 45.27
7 50.52 (2.56) a 54.65 45.67 53.24 (2.67) b 58.50 47.21 50.27 (2.66) a 53.67 45.37
8 52.29 (2.74) a 56.22 46.65 54.78 (2.85) b 61.13 48.56 51.64 (2.37) a 54.84 48.12
9 53.57 (2.83) a 57.16 49.09 56.27 (2.75) b 63.40 49.33 52.62 (2.01) a 54.85 49.91
11 ∗, 55.87 (3.28) a 61.47 52.57 57.47 (2.62) a 64.72 53.78 55.28 (1.89) b 57.39 51.79
12 57.37 (2.53) a 62.45 54.76 58.67 (2.89) b 67.10 50.84 57.45 (2.93) a 63.36 53.1
13 58.33 (2.90) a 63.55 54.73 61.00 (3.61) b 69.74 52.91 60.10 (2.65) a,b 65.13 54.45
14 59.47 (3.18) 65.03 a 54.79 62.16 (2.84) b 68.87 56.18 62.11 (3.33) b 67.92 54.09
LAFH
6 66.73 (2.78) a 71.44 62.8 63.13 (3.08) b 68.46 57.14 61.08 (2.83) b 65.78 56.99
7 67.91 (3.77) a 73.54 61.88 64.36 (3.10) b 69.99 56.12 61.57 (3.33) c 70.14 57.66
8 68.97 (4.25) a 76.65 62.69 65.33 (2.86) b 71.10 58.67 62.98 (3.52) c 69.62 57.59
9 70.33 (4.21) a 78.39 63.94 66.39 (3.16) b 72.85 59.39 64.07 (4.01) c 74.19 58.92
11 73.07 (4.52) a 80.77 66.4 69.00 (3.34) a 77.06 63.08 65.58 (4.17) b 74.63 60.82
12 75.86 (4.93) a 85.91 69.14 71.20 (3.83) b 81.97 64.35 67.83 (4.17) c 77.84 62.6
13 77.61 (6.11) a 88.19 68.34 72.72 (4.43) b 81.21 56.16 69.01 (4.31) c 78.14 64.4
14 80.89 (5.68) a 92.86 72.58 75.49 (3.37) b 81.96 69.29 70.69 (3.77) c 78.55 65.75
NFH
6 27.15 (1.74) 29.56 24.32 27.80 (2.06) 32.81 21.03 28.04 (2.71) 33.27 24.43
7 27.79 (1.62) 30.27 24.64 28.38 (1.98) 33.43 21.19 29.02 (2.17) 33.46 25.77
8 28.18 (1.66) 31.41 25.97 28.92 (1.92) 34.74 22.78 29.31 (2.23) 33.89 26.07
9 29.00 (1.57) 31.49 26.62 29.69 (1.79) 35.05 26.27 29.84 (2.16) 34.32 26.53
11 30.00 (1.23) 31.74 27.94 30.47 (1.72) 35.22 26.42 30.43 (2.08) 35.08 27.79
12 30.60 (1.40) 32.94 28.47 31.12 (1.67) 35.38 27.23 30.80 (1.98) 35.03 28.25
13 31.17 (1.38) 33.92 29.29 31.61 (1.68) 35.63 27.45 31.05 (1.96) 35.01 28.77
14 32.34 (1.38) 35.57 29.05 32.20 (1.81) 37.91 27.67 31.70 (1.78) 35.58 28.97
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Apr 6, 2017 | Posted by in Orthodontics | Comments Off on Do long-faced subjects really have a long anterior face? A longitudinal study
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