Open Access

Class II division 1 malocclusion treatment with extraction of maxillary first permanent molars: cephalometric evaluation of treatment and post-treatment changes

Johan Willem Booij
Johan Willem Booij
, 
Anne Marie Kuijpers-Jagtman
Anne Marie Kuijpers-Jagtman
, 
Ewald M. Bronkhorst
Ewald M. Bronkhorst
, 
Frits A. Rangel
Frits A. Rangel
, 
Christos Livas
Christos Livas
, 
Yijin Ren
Yijin Ren
, 
Christos Katsaros
Christos Katsaros
 and 
Edwin M. Ongkosuwito
Edwin M. Ongkosuwito
   | Oct 06, 2021
Australasian Orthodontic Journal's Cover Image
About this article
Previous Article
Next Article
Cite
Article Category: research-article
Published Online: Oct 06, 2021
Page range: 294 - 310
DOI: https://doi.org/10.21307/aoj-2021.032
© 2021 Johan Willem Booij et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.

Figure 1.

Reference lines and cephalometric points used in this study: A = A-point; ANS = Anterior nasal spine; B = B – point; L1 = Lower incisor edge tip; Li = Lower lip; Ls = Upper lip: Me = Menton; N = Nasion; n = Soft tissue nasion; No = Pronasale; PNS = Posterior nasal spine; Pog = Pogonion; S = Sella; Sn = Subnasale; U1 = Upper incisor edge tip (figure adapted from Stalpers et al.8).
Reference lines and cephalometric points used in this study: A = A-point; ANS = Anterior nasal spine; B = B – point; L1 = Lower incisor edge tip; Li = Lower lip; Ls = Upper lip: Me = Menton; N = Nasion; n = Soft tissue nasion; No = Pronasale; PNS = Posterior nasal spine; Pog = Pogonion; S = Sella; Sn = Subnasale; U1 = Upper incisor edge tip (figure adapted from Stalpers et al.8).

Supplementary Figure 1.

Bland Altman plots for the cephalometric variables.
Bland Altman plots for the cephalometric variables.

Linear regression analysis to analyze the effects of sex, age, hypodivergent facial type, and hyperdivergent facial type (reference is normodivergent) on cephalometric outcome variables.

Analysis T1 to T2 (during treatment) Analysis T2 to T3 (after treatment)
Intercept Gender Age Hypo Hyper Intercept Gender Age Hypo Hyper
(M = 0; F = 1) (M = 0; F = 1)
Skeletal sagittal Outcome (degrees): SNA (R 2 = 0.032) Outcome (degrees): SNA (R 2 = 0.13)
Effect ‒3.66 0.47 0.13 ‒0.52 ‒0.55 7.35 0.89 ‒0.43 2.12 0.37
95%CI [‒8.11...0.8] [‒0.46...1.4] [‒0.19...0.44] [‒1.88...0.84] [‒1.68...0.59] [1.19...13.52] [‒0.4...2.17] [‒0.86...0.01] [0.23...4.01] [‒1.19...1.94]
p 0.106 0.316 0.431 0.449 0.34 0.02 0.172 0.056 0.028 0.635
Outcome (degrees): SNB (R 2 = 0.07) Outcome (degrees): SNB (R 2 = 0.085)
Effect ‒0.28 ‒0.14 0 0.64 ‒0.17 5.24 0.13 ‒0.29 1.34 0.73
95%CI [‒3.16...2.61] [‒0.74...0.46] [‒0.21...0.2] [‒0.24...1.53] [‒0.9...0.56] [0.66...9.81] [‒0.82...1.09] [‒0.61...0.04] [‒0.06...2.74] [‒0.43...1.89]
p 0.85 0.637 0.967 0.151 0.648 0.026 0.787 0.081 0.061 0.216
Outcome (degrees): ANB (R 2 = 0.123) Outcome (degrees): ANB (R 2 = 0.084)
Effect ‒3.4 0.61 0.13 ‒1.15 ‒0.39 2.14 0.75 ‒0.14 0.77 ‒0.36
95%CI [‒6.7... ‒0.1] [‒0.08...1.3] [‒0.1...0.37] [‒2.16... ‒0.14] [‒1.23...0.45] [‒2.15...6.43] [‒0.14...1.65] [‒0.44...0.17] [‒0.55...2.08] [‒1.45...0.73]
p 0.044 0.081 0.265 0.026 0.355 0.323 0.097 0.368 0.248 0.516
Skeletal vertical Outcome (degrees): SN/ANS-PNS (R 2 = 0.153) Outcome (degrees): SN/ANS-PNS (R 2 = 0.079)
Effect 1.49 0.29 ‒0.13 ‒0.68 0.46 ‒0.91 ‒1.26 ‒0.02 ‒0.29 ‒0.3
95%CI [‒1.64...4.63] [‒0.36...0.95] [‒0.35...0.09] [‒1.64...0.28] [‒0.33...1.26] [‒5.81...3.99] [‒2.28... ‒0.23] [‒0.37...0.33] [‒1.79...1.21] [‒1.54...0.94]
p 0.345 0.372 0.25 0.162 0.25 0.713 0.017 0.901 0.7 0.633
Outcome (degrees): SN/ML (R 2 = 0.029) Outcome (degrees): SN/ML (R 2 = 0.105)
Effect 2.33 ‒0.1 ‒0.12 ‒0.73 ‒0.37 ‒6.02 0.74 0.38 ‒1.41 ‒0.97
95%CI [‒1.47...6.13] [‒0.89...0.69] [‒0.39...0.15] [‒1.89...0.44] [‒1.33...0.6] [‒11.31... ‒0.73] [‒0.36...1.84] [0.01...0.76] [‒3.03...0.21] [‒2.31...0.37]
p 0.226 0.799 0.374 0.217 0.449 0.026 0.185 0.045 0.087 0.154
Outcome (degrees): ANS-PNS/ML (R 2 = 0.079) Outcome (degrees): ANS-PNS/ML (R 2=0.211)
Effect 0.94 ‒0.41 0 ‒0.05 ‒0.85 ‒5.34 1.85 0.43 ‒0.87 ‒0.57
95%CI [‒2.84...4.72] [‒1.2...0.38] [‒0.27...0.27] [‒1.21...1.11] [‒1.81...0.11] [‒10.01... ‒0.67] [0.88...2.82] [0.1...0.76] [‒2.3...0.56] [‒1.75...0.62]
p 0.623 0.307 0.989 0.932 0.083 0.026 <0.001 0.012 0.227 0.345
Outcome (ratio): ANS-Me by N-Me (R 2 = 0.096) Outcome (ratio): ANS-Me by N-Me (R 2 = 0.104)
Effect ‒0.52 ‒0.03 0.09 0.25 ‒0.56 3.21 0.29 ‒0.18 0.98 ‒0.11
95%CI [‒3.32...2.28] [‒0.62...0.55] [‒0.11...0.29] [‒0.61...1.11] [‒1.28...0.15] [‒0.12...6.53] [‒0.4...0.99] [‒0.41...0.06] [‒0.04...2] [‒0.95...0.74]
p 0.713 0.916 0.381 0.56 0.118 0.058 0.402 0.136 0.059 0.801
Dento-alveolar Outcome (degrees): U1L/ANS-PNS (R 2 = 0.137) Outcome (degrees): U1L/ANS-PNS (R 2 = 0.087)
Effect ‒3.42 ‒1.15 0.05 5.25 ‒0.04 3.23 ‒1.89 ‒0.27 0.46 1.74
95%CI [‒17.19...10.36] [‒4.02...1.72] [‒0.92...1.03] [1.03...9.47] [‒3.54...3.46] [‒5.41...11.87] [‒3.69... ‒0.09] [‒0.89...0.34] [‒2.18...3.11] [‒0.45...3.93]
p 0.623 0.427 0.913 0.015 0.981 0.459 0.04 0.375 0.729 0.118
Outcome (mm): U1 to A-Pog (R 2 = 0.13) Outcome (mm): UI to A-Pog (R 2 = 0.055)
Effect ‒2.19 ‒0.18 ‒0.02 1.11 ‒0.56 ‒1.54 ‒0.01 0.08 ‒0.53 0.14
95%CI [‒6.27...1.9] [‒1.03...0.67] [‒0.31...0.27] [‒0.14...2.36] [‒1.6...0.48] [‒4.18...1.09] [‒0.56...0.54] [‒0.1...0.27] [‒1.34...0.27] [‒0.53...0.8]
p 0.29 0.672 0.881 0.081 0.285 0.247 0.961 0.373 0.191 0.688
Outcome (degrees): L1L to ML (R 2 = 0.05) Outcome (degrees): L1L to ML (R 2 = 0.013)
Effect 15.47 ‒1.35 ‒0.67 ‒0.01 ‒1.19 0.01 0.21 0.03 ‒0.52 0.42
95%CI [3.87...27.07] [‒3.77...1.07] [‒1.49...0.15] [‒3.56...3.54] [‒4.13...1.76] [‒8.13...8.16] [‒1.48...1.91] [‒0.54...0.61] [‒3.01...1.97] [‒1.64...2.49]
p 0.01 0.271 0.11 0.994 0.425 0.997 0.802 0.91 0.679 0.684
Outcome (mm): L1 to A-Pog (R 2 = 0.127) Outcome (mm): L1 to A-Pog (R 2 = 0.034)
Effect 6.62 ‒0.62 ‒0.31 0.7 ‒0.09 ‒2.01 0 0.07 ‒0.34 0.2
95%CI [3.11...10.13] [‒1.35...0.11] [‒0.56... ‒0.07] [‒0.38...1.77] [‒0.98...0.8] [‒4.77...0.75] [‒0.57...0.58] [‒0.12...0.27] [‒1.19...0.5] [‒0.5...0.9]
p <0.001 0.097 0.014 0.2 0.847 0.152 0.994 0.474 0.42 0.569
Soft tissue Outcome (degrees): Nasolabial angle (R 2 = 0.066) Outcome (degrees): Nasolabial angle (R 2 = 0.02)
Effect 12.83 ‒3.2 ‒0.68 ‒2 ‒0.14 ‒5.68 ‒0.29 0.42 1.68 ‒0.05
95%CI [‒1.94...27.6] [‒6.28... ‒0.12] [‒1.73...0.36] [‒6.52...2.52] [‒3.89...3.61] [‒22.3...10.93] [‒3.75...3.18] [‒0.76...1.59] [‒3.41...6.76] [‒4.27...4.17]
p 0.088 0.042 0.198 0.381 0.942 0.498 0.87 0.48 0.514 0.981
Outcome (mm): Ls to E-line (R 2 = 0.104) Outcome (mm): Ls to E-line (R 2 = 0.068)
Effect ‒6.44 0.65 0.3 ‒0.43 ‒0.53 ‒3.04 0.74 0.14 0.24 0.18
95%CI [‒10.07... ‒2.81] [‒0.1...1.41] [0.05...0.56] [‒1.55...0.68] [‒1.45...0.39] [‒6.21...0.13] [0.08...1.4] [‒0.08...0.37] [‒0.73...1.21] [‒0.63...0.98]
p <0.001 0.089 0.021 0.439 0.254 0.06 0.029 0.205 0.624 0.658
Outcome (mm): Li to E-line (R 2 = 0.02) Outcome (mm): Li to E-line (R 2 = 0.048)
Effect ‒2.73 0.32 0.07 0.32 ‒0.14 ‒2.27 0.33 0.13 0.6 0.41
95%CI [‒6.44...0.98] [‒0.45...1.09] [‒0.19...0.33] [‒0.82...1.45] [‒1.08...0.8] [‒5.07...0.53] [‒0.26...0.91] [‒0.07...0.32] [‒0.26...1.45] [‒0.3...1.12]
p 0.147 0.412 0.59 0.581 0.77 0.111 0.269 0.205 0.169 0.254
Outcome (mm): n-No (R 2 = 0.419) Outcome (mm): n-No (R 2 = 0.121)
Effect 13.45 ‒2.58 ‒0.71 ‒0.31 0.18 6.67 ‒1.2 ‒0.37 ‒0.81 ‒0.15
95%CI [9.59...17.3] [‒3.38... ‒1.78] [‒0.99... ‒0.44] [‒1.49...0.87] [‒0.8...1.16] [2.19...11.14] [‒2.13... ‒0.27] [‒0.69... ‒0.06] [‒2.18...0.56] [‒1.29...0.98]
p <0.001 <0.001 <0.001 0.602 0.721 0.004 0.012 0.021 0.243 0.787
Outcome (mm): Ls-U1 (R 2 = 0.023) Outcome (mm): Ls-U1 (R 2 = 0.099)
Effect 1.68 ‒0.07 0.06 ‒0.35 0.22 2.16 0.5 ‒0.2 0.24 0.59
95%CI [‒1.78...5.13] [‒0.8...0.65] [‒0.19...0.3] [‒1.41...0.71] [‒0.65...1.1] [‒1.48...5.79] [‒0.26...1.26] [‒0.46...0.06] [‒0.87...1.35] [‒0.33...1.52]
p 0.337 0.837 0.646 0.513 0.613 0.241 0.195 0.125 0.669 0.204
Outcome (mm): Li-L1 (R 2 = 0.042) Outcome (mm): Li-L1 (R 2 = 0.031)
Effect ‒2.84 ‒0.44 0.11 0.21 0.05 1.37 0.06 ‒0.11 0.31 0.34
95%CI [‒6.33...0.65] [‒1.17...0.29] [‒0.14...0.35] [‒0.86...1.28] [‒0.83...0.94] [‒1.57...4.31] [‒0.55...0.67] [‒0.32...0.1] [‒0.59...1.21] [‒0.41...1.08]
p 0.11 0.236 0.398 0.698 0.905 0.357 0.846 0.285 0.494 0.373

Descriptive statistics for cephalometric variables (mean and SD) at the start of treatment (T1), posttreatment (T2) and 2 years posttreatment (T3).

Variable T1 T2 T3
Skeletal sagittal
 SNA (0) 79.48 (3.66) 77.25 (3.71) 80.07 (3.79)
 SNB (0) 74.00 (3.51) 73.65 (3.54) 75.86 (3.74)
 ANB (0) 5.48 (1.77) 3.60 (2.19) 4.22 (2.20)
Skeletal vertical
 SN/ANS-PNS (0) 7.58 (3.21) 7.63 (3.18) 5.65 (3.18)
 SN/ML (0) 35.35 (5.48) 35.68 (6.04) 34.15 (6.59)
 ANS-PNS/ML (0) 27.77 (5.22) 28.05 (5.64) 28.61 (6.23)
 ANS-Me by N-Me (ratio) 57.98 (2.39) 58.33 (2.38) 59.47 (2.15)
Dentoalveolar
 U1L/ANS-PNS (0) 110.23 (5.63) 108.13 (5.52) 108.04 (6.16)
 U1 to A-Pog (mm) 9.00 (2.42) 6.36 (1.89) 5.88 (1.96)
 L1L to ML (0) 97.77 (6.28) 103.20 (6.44) 103.87 (6.99)
 L1 to A-Pog (mm) 1.61 (2.02) 3.94 (1.86) 2.90 (2.04)
Soft tissue
 Nasolabial angle (0) 115.10 (9.12) 117.05 (9.78) 117.09 (8.71)
 Ls to E-line (mm) ‒0.73 (2.57) ‒3.30 (2.25) ‒3.97 (2.52)
 Li to E-line (mm) 0.08 (2.44) ‒1.58 (2.37) ‒1.67 (2.76)
 n-No (mm) 48.82 (3.79) 51.8 (3.96) 52.77 (4.15)
 Ls-U1 (mm) 11.08 (2.18) 13.52 (1.98) 13.66 (2.00)
 Li-L1 (mm) 14.61 (1.53) 13.05 (1.42) 13.22 (1.55)

Mean increments of the cephalometric variables and 95% confidence intervals (95% CI) for the two different time periods (T2–T1 and T3–T2).

T2–T1 T3–T2
Mean diff 95% CI p value Mean diff 95% CI p value
Skeletal sagittal
 SNA (0) ‒2.23 ‒2.66... ‒1.80 <0.001 2.82 2.19...3.45 <0.001
 SNB (0) ‒0.35 ‒0.64... ‒0.07 0.016 2.21 1.75...2.67 <0.001
 ANB (0) ‒1.88 ‒2.22... ‒1.54 <0.001 0.61 0.18...1.04 0.006
Skeletal vertical
 SN/ANS-PNS (0) 0.04 ‒0.28...0.37 0.797 ‒1.98 ‒2.46... ‒1.49 <0.001
 SN/ML (0) 0.33 ‒0.04...0.70 0.08 ‒1.53 ‒2.06... ‒0.99 <0.001
 ANS-PNS/ML (0) 0.28 ‒0.09...0.66 0.137 0.56 0.06... 1.06 0.029
 ANS-Me by N-Me (ratio) 0.35 0.07…0.63 0.015 1.14 0.81… 1.48 <0.001
Dentoalveolar
 U1L/ANS-PNS (0) ‒2.10 ‒3.51... ‒0.68 0.004 ‒0.09 ‒0.96... 0.77 0.828
 U1 to A-Pog (mm) ‒2.64 ‒3.05... ‒2.22 <0.001 ‒0.48 ‒0.74... ‒0.22 <0.001
 L1L/ML (0) 5.43 4.29... 6.56 <0.001 0.67 ‒0.11... 1.45 0.092
 L1 to A-Pog (mm) 2.33 1.97... 2.68 <0.001 ‒1.03 ‒1.30... ‒0.77 <0.001
Soft tissue
 Nasolabial angle (0) 1.95 0.49... 3.41 0.009 0.04 ‒1.56... 1.64 0.961
 Ls to E-line (mm) ‒2.57 ‒2.93... ‒2.20 <0.001 ‒0.67 ‒0.99... ‒0.36 <0.001
 Li to E-line (mm) ‒1.67 ‒2.02... ‒1.31 <0.001 ‒0.09 ‒0.36... 0.18 0.519
 n-No (mm) 2.98 2.50... 3.46 <0.001 0.97 0.51... 1.42 <0.001
 Ls-U1 (mm) 2.44 2.11... 2.78 <0.001 0.13 ‒0.23... 0.50 0.469
 Li-L1 (mm) ‒1.56 ‒1.90... ‒1.22 <0.001 0.18 ‒0.11... 0.46 0.223

ANOVA followed by Tukey’s post hoc test for the differences in the increments of the cephalometric variables for the three facial types.

95% CI for Mean Tukey
Cephalometric variable Facial type N Mean SD Lower bound Upper bound ANOVA p value Normo vs hypo Normo vs hyper Hypo vs hyper
T2–T1
 ANB (0) Hypo 18 ‒2.64 1.24 ‒3.26 ‒2.03 0.034 x
Normo 17 ‒1.35 1.27 ‒2.00 ‒0.70
Hyper 48 ‒1.78 1.64 ‒2.26 ‒1.30
 SN/ANS-PNS (0) Hypo 18 ‒0.86 1.43 ‒1.57 ‒0.15 0.005 x
Normo 17 ‒0.10 1.15 ‒0.69 0.49
Hyper 48 0.43 1.48 0.00 0.86
 ANS-Me by N-Me (ratio) Hypo 18 0.91 1.19 0.31 1.50 0.027
Normo 17 0.64 0.91 0.17 1.11
Hyper 48 0.04 1.36 ‒0.36 0.43
 U1L/ANS-PNS (0) Hypo 18 2.30 6.34 ‒0.85 5.45 0.004 x x
Normo 17 ‒3.24 6.87 ‒6.77 0.29
Hyper 48 ‒3.34 5.77 ‒5.02 ‒1.67
 U1 to A-pog (mm) Hypo 18 ‒1.41 2.01 ‒2.41 ‒0.41 0.004 x
Normo 17 ‒2.56 1.94 ‒3.56 ‒1.57
Hyper 48 ‒3.12 1.69 ‒3.61 ‒2.63

Intra-observer reliability and measurement error for the cephalometric values.

Variable Reliability DME Mean diff 95% CI for diff. p value
SNA (0) 0.981 0.42 ‒0.07 ‒0.27... 0.14 0.502
SNB (0) 0.994 0.25 ‒0.15 ‒0.27... ‒0.03 0.018
ANB (0) 0.971 0.38 0.07 ‒0.11... 0.26 0.421
SN/ANS-PNS (0) 0.979 0.46 0.36 0.14... 0.59 0.002
SN/ML (0) 0.998 0.30 ‒0.14 ‒0.28... 0.01 0.065
ANS-PNS/ML (0) 0.992 0.51 ‒0.49 ‒0.74... ‒0.24 <0.001
ANS-Me by N-Me (ratio) 0.961 0.53 ‒0.01 ‒0.26... 0.25 0.968
U1L/ANS-PNS (0) 0.989 0.64 0.16 ‒0.15... 0.47 0.295
U1 to A-Pog (mm) 0.892 0.72 0.03 ‒0.33... 0.38 0.883
L1L/ML (0) 0.975 1.17 0.75 0.18... 1.32 0.012
L1 to A-Pog (mm) 0.979 0.26 0.27 0.14... 0.39 <0.001
Nasolabial angle (0) 0.849 3.60 0.70 ‒1.05... 2.45 0.423
Ls to E-line (mm) 0.941 0.56 ‒0.19 ‒0.46... 0.08 0.164
Li to E-line (mm) 0.953 0.45 ‒0.15 ‒0.37... 0.06 0.159
n-No (mm) 0.972 0.75 ‒0.14 ‒0.50... 0.23 0.451
Ls-U1 (mm) 0.912 0.67 0.40 0.08... 0.73 0.017
Li-L1 (mm) 0.840 0.64 ‒0.67 ‒0.98... ‒0.36 <0.001

Sample distribution.

Treatment stage and facial type N Male Female Mean age (SD) Min Max
T1 Start of treatment 83 47 36 13.2 (1.5) 10.5 17.1
Hypodivergent 18 14 4
Normodivergent 17 9 8
Hyperdivergent 48 24 24
T2 End of treatment 83 47 36 15.6 (1.6) 12.4 19.3
T3 Two years posttreatment 83 47 36 18.2 (1.9) 14.4 23.9
eISSN:
2207-7480
Language:
English
Publication timeframe:
Volume Open
Journal Subjects:
Medicine, Basic Medical Science, other
Journal RSS Feed