measurements between Mx ext and Mx & Mn ext group
SD indicates standard deviation; Sig, significance; NS, not significant; Mx ext, extraction of upper premolars only;
Mx & Mn ext, extraction of upper and lower premolars;
Δ, change of each measurements between before and after treatment;
SN, sella-nasion plane; MP, mandibular plane; U1, upper central incisal edge; VRP, vertical reference plane; HRP, horizontal reference plane; UIP, point of intersection of the hard tissue with the line drawn from Labrale superious perpendicular to VRP; L1, lower central incisal edge; IMPA, incisal mandibular plane angle;* p < 0.05(significant difference between before and after treatment measurements); + p < 0.05(significant difference between Mx ext and Mx & Mn ext group); See Table 3 for measurement parameters
Mean SD Mean SD Sig Mean SD Mean SD Sig
∆SNA, degrees -0.53 2.37 -0.50 1.18 NS -0.65 2.26 -0.48 1.36 NS
∆SNB, degrees -0.23 1.55 -0.32 0.94 NS -0.51 1.40 -0.23 1.03 NS
∆ANB, degrees -0.29 1.70 -0.18 1.14 NS -0.14 1.73 -0.25 1.37 NS
∆SN-MP, degrees 0.03 1.97 0.54 1.59 NS 0.54 1.33 0.43 1.56 NS
∆U1 to SN, degrees -10.52 * 9.55 -20.07 * 8.01 + -15.75 * 7.32 -18.87 * 6.51 NS
∆VRP-U1 apex, mm 0.14 2.59 -0.18 2.35 NS 0.70 2.03 -0.24 2.54 NS
∆VRP-L1, mm -0.83 2.64 -6.69 * 2.44 + -1.40 * 2.06 -6.38 * 2.35 +
나. 연조직 변화
Li와 B’는 양악발치군에서 유의하게 더 많이 후방이동 되었으며 B’에서의 하순 두께(LLT)가 양악발치군에서 유의성 있게 더 감소하였다(p <0.05)(Table 5).
Table 5. Comparison of post treatment soft tissue changes of cephalometric measurements between Mx ext and Mx & Mn ext group
SD indicates standard deviation; Sig, significance; NS, not significant; Mx ext, extraction of upper premolars only; Mx & Mn ext, extraction of upper and lower premolars;
Δ, change of each measurements between before and after treatment;
Sn, subnasale; Ls, Labrale superious; Li, Labrale inferious; M, point of intersection of the soft tissue profile with the bisector of the line joining Sn and Ls; VRP, vertical reference plane; HRP, horizontal reference plane; Stms, stomion superious; Stmi, stomion inferious; UIP, point of intersection of the hard tissue with the line drawn from Labrale superious perpendicular to VRP; L1, lower central incisal edge; IMPA, incisal mandibular plane angle; * p < 0.05(significant difference between before and after treatment measurements); + p < 0.05 (significant difference between Mx ext and Mx & Mn ext group); See Mean SD Mean SD Sig Mean SD Mean SD Sig∆Nasolabial angle, degrees 6.33 * 6.08 8.37 * 6.98 NS 4.82 * 6.86 9.06 * 6.77 +
∆Mentolabial angle, degrees 6.72 * 10.21 5.68 * 11.15 NS 9.59 * 12.56 4.64 * 12.96 NS
∆VRP-Sn, mm -0.66 1.91 -0.95 * 1.29 NS -0.43 1.41 -0.71 * 1.58 NS
∆Upper lip area, mm² 4.95 25.52 16.46 * 30.96 NS 7.93 29.25 3.98 29.27 NS
∆Lower lip area, mm² 1.35 26.25 -12.21 33.22 NS -2.92 30.52 -18.19 * 26.75 +
Male Female
Mx ext Mx & Mn ext Mx ext Mx & Mn ext
2. 치아 이동량과 입술 이동량 간 비율
상악 전치와 상순 이동량 간의 비율(U1:Ls)은 남성에서 편악발치군 1.89:1, 양악 발치군 2.39:1 이었으며, 여성에서는 편악발치군 2.20:1, 양악발치군 2.25:1 이었다.
상악전치 이동량 계측기준을 UIP로 한 경우의 비율(UIP:Ls)은 남,녀 편악발치군이 각각 1.06:1, 1.21:1, 남,녀 양악발치군이 각각 1.24:1, 1.28:1 이었다.
하악전치와 하순 이동량 간의 비율(L1:Li)은 남성에서 편악발치군 0.53:1, 양악발치군 1.37:1, 여성에서 편악발치군 0.61:1, 양악발치군 1.26:1을 각각 나타냈다.
상악 전치와 하순 이동량 간의 비율(U1:Li)은 남성에서 편악발치군 3.13:1, 양악발치군 1.71:1 이었으며 여성에서 편악발치군 2.53:1, 양악발치군 1.62:1 이었다(Table 6).
Table 6. Ratios of the amount of incisor retraction to lip retraction
Mx ext indicates extraction of upper premolars only; Mx & Mn ext, extraction of upper and lower premolars; U1, upper central incisal edge; Ls, Labrale superious; UIP, point of intersection of the hard tissue with the line drawn from Labrale superious perpendicular to vertical reference plane; L1, lower central incisal edge; Li, Labrale inferious; See Table 3 for measurement parameters
Mx ext Mx & Mn ext Mx ext Mx & Mn ext Mx ext Mx & Mn ext
U1 : Ls 1.89:1 2.39:1 2.20:1 2.25:1 2.09:1 2.31:1
UIP : Ls 1.06:1 1.24:1 1.21:1 1.28:1 1.16:1 1.26:1
L1 : Li 0.53:1 1.37:1 0.61:1 1.26:1 0.59:1 1.31:1
U1 : Li 3.13:1 1.71:1 2.53:1 1.62:1 2.70:1 1.66:1
Male
FemaleTotal
3. 전치와 입술 이동량 간의 상관관계
상악 전치 절단의 이동량과 Ls의 이동량, 하악 전치 절단의 이동량과 Li 이동량 간의 Pearson 상관계수를 구하였다(Table 7). 편악발치군에서 상악 0.704, 하악 0.770의 상관계수를 보였으며 양악발치군에서는 상악 0.648, 하악 0.826 이었다(p <
0.05). UIP 의 이동량과 Ls 이동량 간의 상관계수는 편악발치군 0.681, 양악발치군은 0.679 이었다(p < 0.05). 상악절치 절단과 Li 간의 상관계수는 편악발치군 0.625, 양악발치군 0.675 였다(p < 0.05).
Table 7. Pearson correlation coefficients between the amount of incisor retraction and lip retraction
Male Female Total
Mx ext Mx & Mn ext Mx ext Mx & Mn ext Mx ext Mx & Mn ext U1 : Ls 0.758* 0.510* 0.642* 0.754* 0.704* 0.648*
UIP : Ls 0.776* 0.596* 0.562* 0.741* 0.681* 0.679*
L1 : Li 0.834* 0.801* 0.702* 0.852* 0.770* 0.826*
U1 : Li 0.696* 0.665* 0.527* 0.691* 0.625* 0.675*
Mx ext indicates extraction of upper premolars only; Mx & Mn ext, extraction of upper and lower premolars; U1, upper central incisal edge; Ls, Labrale superious; UIP, point of intersection of the hard tissue with the line drawn from Labrale superious perpendicular to vertical reference plane; L1, lower central incisal edge; Li, Labrale inferious; * p < 0.05; See Table 3 for measurement parameters
4. 다중회귀분석
Table 8. Regression model fit test by ANOVA
F value Sig R Square Adjusted R Square
Mx Ext 6.248 * 0.319 0.268
Mx & Mn Ext 10.2 * 0.264 0.238
Sig indicates Significance; Mx ext, extraction of upper premolars only; Mx & Mn ext, extraction of upper and lower premolars; * p < 0.05
Table 9. Regression parameter estimates and significance test
B Std. Error Beta t Sig
Sig indicates significance; B, unstandardized coefficients; Beta, standardized coefficients; Mx ext, extraction of upper premolars only; Mx & Mn ext, extraction of upper and lower premolars; * p <0.05; See Table 3 for measurement parameters