Demographic characteristics of the subjects
Table 1 presents the basic demographic characteristics of the study population. The patients had an average age of 10.7 ± 2.4 years, and 46.0% (433/942) of them were boys. The average BMI was 18.1 ± 1.6 kg·m− 2. Isolated adenoid hypertrophy was observed in 26.1% (246/942) of the subjects, 14.2% (134/942) of the subjects had isolated tonsillar hypertrophy, and adenotonsillar hypertrophy was observed in 27.0% (254/942) of the subjects.
Of all the subjects, 189 participants (20.0%) were aged between 6 and 9 years, 383 (40.7%) were aged between 9 and 12 years, and 370 (39.3%) were aged between 13 and 15 years. There was no significant difference in gender distribution among the three age groups. The younger age groups had a significantly higher proportion of adenoid hypertrophy and adenotonsillar hypertrophy (p < 0.001).
Table 1
Basic characteristics of study patients
Variable
|
Total
(N = 942)
|
6–9 years
(n = 189)
|
9–12 years
(n = 383)
|
12–15 years
(n = 370)
|
p-value
|
Age (yr)
|
10.7 ± 2.4
|
7.3 ± 0.7
|
10.1 ± 0.8 a
|
13.1 ± 1.0 ab
|
< 0.001***
|
Gender, boy (%)
|
433 (46.0)
|
90 (47.6)
|
169 (44.1)
|
174 (47.0)
|
0.638
|
BMI (kg/m2)
|
18.1 ± 1.6
|
16.6 ± 0.9
|
17.7 ± 0.8 a
|
19.3 ± 1.5 ab
|
< 0.001***
|
Adenoid&Tonsillar group
|
|
|
|
|
< 0.001***
|
CG, n (%)
|
308 (32.7)
|
25(13.2)
|
116 (30.3) a
|
167(45.1) ab
|
|
AG, n (%)
|
246 (26.1)
|
68 (36.0)
|
99 (25.8) a
|
79 (21.4) a
|
|
TG, n (%)
|
134 (14.2)
|
20 (10.6)
|
54 (14.1)
|
60 (16.2)
|
|
ATG, n (%)
|
254 (27.0)
|
76(40.2)
|
114 (29.8) a
|
64 (17.3) ab
|
|
Note: “a,” “b,” and “c” indicate significant difference versus the “6–9 years,” “9–12 years,” and “12–15 years” groups in the Bonferroni multiple comparison, respectively. |
* p < 0.05, ** p < 0.01, *** p < 0.001 |
Abbreviations: CG, control group; AG, adenoid hypertrophy group; TG, tonsillar hypertrophy group; ATG, adenotonsillar hypertrophy group.
|
Differences among CG, AG, TG and ATG by comparison of cephalometric variables in various age groups
The multi-group comparison of cephalometric variables among CG, AG, TG and ATG in various age groups is shown in Table 2 and Fig. 2.
Table 2 Cephalometric measurements among Adenoid & Tonsillar group in different age groups.
Variable
|
CG
|
AG
|
TG
|
ATG
|
p-value
|
6-9 years
|
n=25
|
n=68
|
n=20
|
n=76
|
|
SNA (°)
|
79.7±3.3
|
79.5±3.1
|
80.3±2.0
|
80.1±3.7
|
0.710
|
SNB (°)
|
76.9±3.2
|
76.8±4.4
|
77.5±3.5
|
78.5±3.8
|
0.051
|
ANB (°)
|
2.8±3.4
|
2.6±3.2
|
2.7±3.5
|
1.5±3.6
|
0.130
|
Sagittal skeletal pattern
|
|
|
|
|
0.169
|
Class I (%)
|
7 (28.0)
|
16 (23.5)
|
9 (45.0)
|
12 (15.8)
|
|
Class II (%)
|
4 (16.0)
|
11 (16.2)
|
2 (10.0)
|
9 (11.8)
|
|
Class III (%)
|
14 (56.0)
|
41 (60.3)
|
9 (45.0)
|
55 (72.4)
|
|
MP/SN (°)
|
36.0±4.7
|
35.6±5.6
|
35.6±3.5
|
35.1±5.1
|
0.900
|
SGn/FH (°)
|
63.5±3.5
|
64.4±4.0
|
65.0±4.1
|
62.7±3.3 b
|
0.015*
|
ANS-PNS (mm)
|
37.7±3.4
|
37.4±3.1
|
38.3±3.1
|
37.6±3.5
|
0.812
|
Go-Me (mm)
|
58.7±4.9
|
59.2±4.0
|
61.3±4.5
|
60.9±4.6
|
0.031
|
SN-PP (°)
|
8.5±2.6
|
8.9±3.1
|
8.4±3.0
|
7.8±3.3
|
0.231
|
|
|
|
|
|
|
9-12 years
|
n=116
|
n=99
|
n=54
|
n=114
|
|
SNA (°)
|
81.0±3.4
|
80.2±3.6
|
80.3±3.4
|
80.8±3.4
|
0.355
|
SNB (°)
|
77.3±3.7
|
76.5±4.1
|
78.6±3.8 b
|
77.6±4.2
|
0.017*
|
ANB (°)
|
3.6±2.8
|
3.7±3.7
|
1.7±3.7 abd
|
3.2±3.6
|
0.003***
|
Sagittal skeletal pattern
|
|
|
|
|
0.004**
|
Class I (%)
|
54 (46.6)
|
39 (39.4)
|
14 (25.9)
|
33 (28.9) a
|
|
Class II (%)
|
36 (31.0)
|
30 (30.3)
|
12 (22.2)
|
37 (32.5)
|
|
Class III (%)
|
26 (22.4)
|
30 (30.3)
|
28 (51.9) a
|
44 (38.6) a
|
|
MP/SN (°)
|
34.3±5.3
|
34.9±5.9
|
33.3±5.0
|
35.0±5.0
|
0.175
|
SGn/FH (°)
|
63.4±3.3
|
64.8±3.6 a
|
62.5±3.3 b
|
63.5±3.5
|
0.001**
|
ANS-PNS (mm)
|
40.2±3.3
|
40.4±3.5
|
40.1±3.1
|
40.2±3.6
|
0.957
|
Go-Me (mm)
|
63.2±4.5
|
62.1±4.0
|
64.9±4.8 b
|
63.6±4.8
|
0.003**
|
SN-PP (°)
|
8.4±3.6
|
8.9±3.7
|
8.3±3.0
|
8.2±3.2
|
0.474
|
|
|
|
|
|
|
12-15 years
|
n=167
|
n=79
|
n=60
|
n=64
|
|
SNA (°)
|
81.5±3.1
|
81.0±3.7
|
82.0±3.7
|
80.7±3.1
|
0.151
|
SNB (°)
|
78.1±3.6
|
77.4±3.8
|
78.3±3.6
|
77.1±3.7
|
0.123
|
ANB (°)
|
3.3±2.6
|
3.7±2.7
|
3.6±2.8
|
3.5±2.8
|
0.760
|
Sagittal skeletal pattern
|
|
|
|
|
0.791
|
Class I (%)
|
97 (58.1)
|
41 (51.9)
|
28 (46.7)
|
35 (54.7)
|
|
Class II (%)
|
51 (30.5)
|
30 (38.0)
|
24 (40.0)
|
21 (32.8)
|
|
Class III (%)
|
19 (11.4)
|
8 (10.1)
|
8 (13.3)
|
8 (12.5)
|
|
MP/SN (°)
|
33.6±5.3
|
34.9±6.1
|
33.8±6.6
|
35.1±5.0
|
0.135
|
SGn/FH (°)
|
63.6±3.5
|
64.0±3.3
|
63.8±3.7
|
64.4±2.9
|
0.448
|
ANS-PNS (mm)
|
41.8±3.6
|
42.0±3.5
|
41.8±3.7
|
41.3±3.7
|
0.618
|
Go-Me (mm)
|
67.3±4.7
|
66.6±4.4
|
67.9±3.7
|
67.5±4.5
|
0.384
|
SN-PP (°)
|
8.3±3.4
|
8.7±3.7
|
7.7±3.6
|
8.0±3.9
|
0.364
|
Note: “a,” “b,” “c” and “d” indicate significant difference versus the “CG,” “AG,” “TG” and “ATG” groups in the Bonferroni multiple comparison, respectively.
* p < 0.05, ** p < 0.01, *** p < 0.001
Abbreviations: CG, control group; AG, adenoid hypertrophy group; TG, tonsillar hypertrophy group; ATG, adenotonsillar hypertrophy group.
In children aged 6-9 years old, those with adenotonsillar hypertrophy showed a tendency towards a horizontal growth direction (smaller SGn/FH) compared to those with isolated obstructive adenoids. Among children aged 9-12 years old, those in the AG group exhibited a steep growth direction (larger SGn/FH), while those in the TG group showed higher probability of Class III skeletal pattern (smaller SNB, ANB and SGn/FH, and larger Go-Me). Additionally, children in the ATG group also manifested a higher proportion of Class III skeletal pattern. In children aged 12-15 years old, no significant differences were observed among the CG, AG, TG and ATG groups.
Multivariable linear regression for age, cephalometric variables, and different obstructive sites of upper airway
After controlling for the age, gender, and BMI, multiple linear regression (Table 3) revealed a different association between obstructive lymphoid tissues and craniofacial variables. In children aged 6-9 years old, TG was positively correlated with Go-Me (unstandardized regression coefficient B=2.6, 95%CI 0.1-5.2, p=0.042) when compared with CG. Similarly, ATG was positively correlated with Go-Me (unstandardized regression coefficient B=2.2, 95%CI 0.2-4.1, p=0.029) when compared with CG. In other words, children with obstructive adenoids and tonsils or isolated tonsillar hypertrophy correlated with increased mandible body length. No significant association was found between adenoid hypertrophy and craniofacial variables. Among children aged 9-12 years old, AG was found to be related to a larger SGn/FH angle (unstandardized regression coefficient B=1.5, 95%CI 0.5-2.4, p=0.002) when compared with CG. Children with isolated tonsillar hypertrophy correlated with protruded mandible, increasing mandible length and skeletal Class III pattern. Multiple linear regression analysis showed no significant association between cephalometric measurements and pharyngeal lymphoid tissue enlargement in children aged 12-15 years old.
Table 3 Multiple linear regression analysis of cephalometric variables in adenoid hypertrophy group, tonsillar hypertrophy group, adenotonsillar hypertrophy group and control group
Predictor
|
AG a
|
TG a
|
ATG a
|
B(95%CI)
|
p-value
|
B(95%CI)
|
p-value
|
B(95%CI)
|
p-value
|
6-9 years
|
|
|
|
|
|
|
Sagittal
|
|
|
|
|
|
|
|
SNA (°)
|
-0.3(-1.8-1.2)
|
0.701
|
0.5(-1.5-2.5)
|
0.628
|
0.3(-1.2-1.8)
|
0.706
|
SNB (°)
|
-0.1(-1.9-1.7)
|
0.932
|
0.6(-1.7-3.0)
|
0.591
|
1.7(-0.1-3.5)
|
0.067
|
ANB (°)
|
-0.2(-1.8-1.4)
|
0.788
|
-0.2(-2.2-1.9)
|
0.887
|
-1.4(-3.0-0.2)
|
0.089
|
ANS-PNS (mm)
|
-0.2(-1.7-1.3)
|
0.799
|
0.4(-1.5-2.3)
|
0.699
|
-0.3(-1.8-1.2)
|
0.658
|
Go-Me (mm)
|
0.8(-1.2-2.8)
|
0.438
|
2.6(0.1-5.2)
|
0.042*
|
2.2(0.2-4.1)
|
0.029*
|
Vertical
|
|
|
|
|
|
|
|
MP/SN (°)
|
-0.5(-2.9-1.8)
|
0.668
|
-0.8(-3.8-2.2)
|
0.610
|
-1.1(-3.4-1.2)
|
0.353
|
SN-PP (°)
|
0.3(-1.1-1.7)
|
0.692
|
-0.3(-2.1-1.5)
|
0.747
|
-0.9(-2.3-0.5)
|
0.220
|
Growth direction
|
|
|
|
|
|
|
SGn/FH (°)
|
0.8(-0.9-2.5)
|
0.365
|
1.3(-0.9-3.4)
|
0.250
|
-0.9(-2.6-0.7)
|
0.265
|
|
|
|
|
|
|
|
|
9-12 years
|
|
|
|
|
|
|
Sagittal
|
|
|
|
|
|
|
|
SNA (°)
|
-0.5(-1.4-0.5)
|
0.307
|
-0.6(-1.7-0.5)
|
0.295
|
0.0(-1.0-0.9)
|
0.925
|
SNB (°)
|
-0.6(-1.7-0.4)
|
0.246
|
1.3(0.0-2.6)
|
0.042*
|
0.3(-0.7-1.4)
|
0.514
|
ANB (°)
|
0.1(-0.8-1.1)
|
0.757
|
-1.9(-3.0--0.8)
|
0.001**
|
-0.4(-1.3-0.5)
|
0.395
|
ANS-PNS (mm)
|
0.4(-0.5-1.3)
|
0.364
|
-0.2(-1.3-0.9)
|
0.709
|
-0.1(-0.9-0.8)
|
0.895
|
Go-Me (mm)
|
0.3(-1.5-0.8)
|
0.552
|
1.7(0.3-3.0)
|
0.015*
|
0.4(-0.7-1.5)
|
0.449
|
Vertical
|
|
|
|
|
|
|
|
MP/SN (°)
|
0.6(-0.8-2.1)
|
0.389
|
-1.1(-2.8-0.7)
|
0.222
|
0.7(-0.7-2.1)
|
0.300
|
SN-PP (°)
|
0.5(-0.4-1.5)
|
0.278
|
-0.1(-1.2-1.0)
|
0.873
|
-0.2(-1.1-0.7)
|
0.725
|
Growth direction
|
|
|
|
|
|
|
SGn/FH (°)
|
1.5(0.5-2.4)
|
0.002**
|
-0.9(-2.0-0.2)
|
0.115
|
0.2(-0.7-1.1)
|
0.689
|
|
|
|
|
|
|
|
|
12-15 years
|
|
|
|
|
|
|
Sagittal
|
|
|
|
|
|
|
|
SNA (°)
|
-0.1(-1.1-0.8)
|
0.760
|
0.6(-0.4-1.6)
|
0.236
|
-0.5(-1.5-0.5)
|
0.357
|
SNB (°)
|
-0.5(-1.5-0.5)
|
0.293
|
0.3(-0.8-1.4)
|
0.588
|
-0.8(-1.8-0.3)
|
0.171
|
ANB (°)
|
0.4(-0.4-1.1)
|
0.299
|
0.3(-0.5-1.1)
|
0.455
|
0.3(-0.5-1.1)
|
0.483
|
ANS-PNS (mm)
|
0.2(-0.7-1.2)
|
0.624
|
-0.1(-1.1-0.9)
|
0.903
|
-0.4(-1.4-0.7)
|
0.494
|
Go-Me (mm)
|
-0.4(-1.6-0.8)
|
0.505
|
0.7(-0.6-1.9)
|
0.298
|
0.7(-0.6-2.0)
|
0.293
|
Vertical
|
|
|
|
|
|
|
|
MP/SN (°)
|
1.3(-0.3-2.9)
|
0.101
|
0.2(-1.5-1.9)
|
0.800
|
1.5(-0.2-3.2)
|
0.079
|
SN-PP (°)
|
0.4(-0.6-1.4)
|
0.467
|
-0.7(-1.7-0.4)
|
0.215
|
-0.3(-1.4-0.8)
|
0.604
|
Growth direction
|
|
|
|
|
|
|
SGn/FH (°)
|
0.2(0.07-1.2)
|
0.616
|
0.2(-0.9-1.2)
|
0.768
|
0.7(-0.4-1.7)
|
0.212
|
AG, adenoid hypertrophy group, TG, tonsillar hypertrophy group, ATG, adenotonsillar hypertrophy
group
B value: unstandardized regression coefficients representing age-, BMI- and sex-adjusted differences between groups
a Reference group: control group
* p < 0.05, ** p < 0.01, *** p < 0.001