Table 1 Mean and standard deviation of the 14 factors of sleep apnea cephalometry and the respective p values of the comparison among the groups

 Anterior base of the cranium (N-S)

69.82

5.49

67.86

4.27

66.45

5.34

0.203

 Maxillary length (ANS-PNS)

53.93

3.88

54.12

3.39

53.44

3.87

0.877

 Mandibular length (Me-Goc)

70.74

6.27

72.01

6.50

70.96

3.38

0.803

 Atlas-maxilla distance (At-PNS)

38.59

4.08

37.74

4.91

35.22

3.25

0.080

 Superior pharyngeal space (PPFS-PP1)

15.8

2.27

13.68

2.53

14.09

6.42

0.352

 Middle pharyngeal space (PPFM-PAFM)

11.42

2.97

13.68

2.53

12.03

4.03

0.474

 TGL (tongue length) (Tt-P)

71.51

4.59

69.41

6.58

67.95

5.43

0.186

 TGH (tongue height) (Tt-DI/P)

23.85

5.27

22.3

3.45

20.70

3.43

0.129

 Median posterior palatal space (Pp2-Pp2’)

12.91^a

2.74

12.64^ab

2.30

10.64^b

1.83

0.020*

 Soft palate length (PNS-P)

34.39

8.42

31.07

4.16

33.12

3.96

0.307

 Inferior pharyngeal space (C3’-H’)

16.83

5.33

14.00

4.79

12.79

4.72

0.063

 Posterior airway space (BGo-Tt)

14.11

2.69

13.36

4.11

12.31

2.86

0.328

 Hyoid-third vertebra distance (H-C3)

76.29

7.62

79.24

6.62

76.57

6.39

0.442

 Hyoid-mandibular plane distance (MP (Me-Goc)/H)

18.95

4.37

15.97

4.97

18.74

5.53

0.201