Table 2 Characteristics of the number of accentuated lines, of the width of the neonatal line (NNL) and of the periodicity of the striae of Retzius depending on the tooth type.

Total

56

0.79

1.16

56

14.13

3.77

21

10.23

1.26

incisors

42

0.71

1.17

42

14.49

3.95

16

10.27

1.37

i¹

30

0.83

1.26

30

13.55

3.21

16

10.27

1.37

i²

7

0.00

0.00

7

16.48

5.67

–

–

–

i₂

5

1.00

1.22

5

17.34

3.69

–

–

–

molars

14

1.00

1.11

14

13.06

3.01

5

10.09

1.00

m¹

5

0.80

1.30

5

13.22

2.72

2

9.76

0.54

m²

1

2.00

–

1

12.00

–

–

–

–

m₁

3

1.33

1.15

3

11.71

1.86

3

10.31

1.30

m₂

5

0.80

1.10

5

13.91

4.21

–

–

–

Autistic boys

22

1.41

1.33

22

13.98

3.33

9

9.75

1.13

incisors

17

1.65

1.37

17

14.17

3.54

6

9.89

1.34

i¹

15

1.67

1.35

15

13.94

3.59

6

9.89

1.34

i²

–

–

–

–

–

–

–

–

–

i₂

2

1.50

2.12

2

15.95

3.61

–

–

–

molars

5

0.60

0.89

5

13.30

2.71

3

m¹

3

0.33

0.58

3

14.43

2.71

2

9.77

0.54

m²

–

–

–

–

–

–

–

–

–

m₁

1

2.00

–

1

10.00

–

1

8.87

–

m₂

1

0.00

–

1

13.20

–

–

–

–

Healthy boys

34

0.38

0.82

34

14.24

4.07

12

10.59

1.29

incisors

25

0.08

0.28

25

14.71

4.27

10

10.50

1.39

i¹

15

0.00

0.00

15

13.17

2.85

10

10.50

1.39

i²

7

0.00

0.00

7

16.48

5.67

–

–

–

i₂

3

0.67

0.58

3

18.27

4.19

–

–

–

molars

9

1.22

1.20

9

12.92

3.31

2

11.03

0.54

m¹

2

1.50

2.12

2

11.41

1.97

–

–

–

m²

1

2.00

–

1

12.00

–

–

–

–

m₁

2

1.00

1.41

2

12.56

1.60

2

11.03

0.54

m₂

4

1.00

1.15

4

14.09

4.84

–

–

–