Table 4 Physiological foramen shape frequency (%) of first and second maxillary and mandibular molars

From: Three-dimensional analysis of the physiological foramen geometry of maxillary and mandibular molars by means of micro-CT

1st MX

M (S)

MB (2)

MB (3)

DB (S)

DB (2)

P (S)

Oval

64.4

69.4

44.4

67.8

75.0

70.9

Round

25.7

23.9

44.4

18.1

25.0

20.1

Irregular

9.9

6.7

11.2

14.1

0.0

9.0

n

109

134

9

177

4

179

2nd MX

M (S)

MB (2)

MB (3)

DB (S)

DB (2)

P (S)

Oval

77.6

75.5

66.7

68.4

100.0

73.1

Round

11.9

13.2

22.2

23.1

0.0

20.2

Irregular

10.5

11.3

11.1

8.5

0.0

6.7

n

67

106

9

117

6

119

1st MA

M (S)

M (2)

M (3–5)

D (S)

D (2)

D (3–4)

Oval

76.9

70.5

64.9

86.8

71.1

84.3

Round

19.2

21.9

29.8

11.8

24.2

9.8

Irregular

3.9

7.6

5.3

1.4

4.7

5.9

n

26

146

114

76

128

51

2nd MA

M (S)

M (2)

M (3–5)

D (S)

D (2)

D (3–4)

Oval

82.0

82.6

85.7

81.7

63.7

100.0

Round

14.0

10.6

14.2

14.6

27.5

0.0

Irregular

4.0

6.8

0.0

3.7

8.8

0.0

n

50

132

7

82

102

3

  1. 1st, first; 2, two foramina; 2nd, second; 3, three foramina; 3–5, three, four or five foramina; 3–4, three or four foramina; D, distal; DB, distobuccal; M, mesial; MA, mandibular; MB, mesiobuccal; MX, maxillary; n, total foramina per root; P, palatal; S; single foramen.