Table 1.
Summary of the incidence of documented ethnic and population variations in the anatomy of mandibular first premolars.
| Geographic and ethnic distribution |
Materials and methods |
No. of teeth in the study (n) |
Root anatomy | Root canal anatomy | Root canal configuration (Vertucci) | Apical foramina |
References | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 root | 2 roots | >2 roots | 1 canal | 2 canals | >2 canals | C-shaped | Type I | Type II | Type III | Type IV | Type V | Type VI | Type VII | Type VIII | Others types | 1 | 2 | 3 | ||||
| Caucasian | ||||||||||||||||||||||
| France | In vitro: radiograph and sectioning | 341 | 90.6% (309) | 6.4% (22) | 3% (10) | 68.9% (235) | 31.1% (106) | 0% (0) |
0% (0) |
Geider et al. [4], 1989 | ||||||||||||
| Germany | In vitro: examination | 2369 | 99.3% (2352) | 0.7% (17) | 0% (0) |
Schulze. [5], 1970 | ||||||||||||||||
| Poland | In vitro: extraction and RCT | 83 | 89.3% (74) | 10.7% (9) | 0% (0) |
0% (0) |
Rózyło et al. [6], 2008 | |||||||||||||||
| USA | In vitro: clearing | 400 | 100% (400) | 0% (0) |
0% (0) |
70% (280) | 25% (100) | 5% (20) | 0% (0) |
70% (280) | 0% (0) |
4% (16) | 1.5% (6) | 24% (96) | 0% (0) |
0% (0) |
0% (0) |
0% (0) |
74% (296) | 26% (104) | 0% (0) |
Vertucci [7], 1894 |
| In vivo: radiographic examination | 1002 | 81.8% (820) | 18.2% (182) | 0% (0) |
0% (0) |
Sabala et al. [8], 1994 | ||||||||||||||||
| In vitro: grinding and examination under magnification | 50 | 86% (43) | 14% (7) |
0% (0) |
0% (0) |
90% (45) | 10% (5) | 0% (0) |
Green [9], 1973 | |||||||||||||
| In vitro: sectioning | 106 | 74% (78) | 26% (28) | 0% (0) |
14% (15) |
76% (80) | 0% (0) |
0% (0) |
24% (26) | 0% (0) |
0% (0) |
0% (0) |
0% (0) |
0% (0) |
76% (80) | 24% (26) | 0% (0) |
Baisden et al. [10], 1992 | ||||
| In vitro: sectioning | 32 | 100% (32) | 0% (0) |
0% (0) |
35.5% (12) | 62.5% (20) | 0% (0) |
0% (0) |
Barrett. [11], 1925 | |||||||||||||
| Extraction and radiograph | 1287 | 66.9% (861) |
32.7% (421) |
0.4% (5) | 0% (0) |
80.7% (1039) | 19.3% (248) | 0% (0) |
Zillich and Dowson [12], 1973 | |||||||||||||
| In vitro: radiographs | 156 | 95.5% (149) | 4.5% (7) |
0% (0) |
0% (0) |
Mueller et al. [13], 1933 | ||||||||||||||||
| In vivo: radiographic examination | 400 | 94.5% (378) | 5.5% (22) | 0% (0) |
86.3% (345) | 13.7% (55) | 0% (0) |
0% (0) |
Trope et al. [14], 1986 | |||||||||||||
| Subgroup Ethnic Incidence | 6226 |
96.88%
(3471) |
2.52%
(61) |
0.6%
(10) |
75.42%
(2586) |
23.84%
(935) |
0.54%
(25) |
1.4%
(15) |
73%
(360) |
2%
(16) |
12.75
(32) |
12%
(96) |
80%
(1490) |
20%
(383) |
||||||||
|
| ||||||||||||||||||||||
| African | ||||||||||||||||||||||
| African American | In vivo: radiographic examination |
400 | 83.8% (335) | 16.2% (65) | 0% (0) |
67.2% (269) | 32.8% (131) | 0% (0) |
0% (0) |
Zillich and Dowson [12], 1973 | ||||||||||||
| Senegalese | In vivo: radiographic examination |
412 | 81.3% (335) | 15.1% (62) | 3.6% (15) | 0% (0) |
Mbaye et al. [15], 2008 | |||||||||||||||
| Subgroup Ethnic Incidence | 812 |
83.8%
(335) |
16.2%
(65) |
74%
(604) |
23.95%
(193) |
1.8%
(15) |
||||||||||||||||
| Indian | ||||||||||||||||||||||
| India | In vitro: SCT | 100 | 80% (80) | 11% (11) |
0% (0) |
2% (2) |
80% (80) | 9% (9) |
3% (3) |
2% (2) |
4% (4) |
0% (0) |
0% (0) |
0% (0) |
2% (2) |
94% (94) | 6% (6) |
0% (0) |
Sandhya et al. [16], 2010 | |||
| In vivo: radiographic examination | 1000 | 95.9% (959) | 3.9% (39) | 0.2% (2) | 75.4% (754) | 1% (10) | 0% (0) |
20.8% (208) | 2.4% (24) | 0% (0) |
0% (0) |
0.4% (4) |
0% (0) |
76.4% (764) | 23.2% (232) | 0.4% (4) | Iyer et al. [17], 2006 | |||||
| In vitro: clearing | 100 | 72% (72) | 27% (27) | 0% (0) |
1% (1) |
72% (72) | 6% (6) |
3% (3) |
10% (10) | 8% (8) |
0% (0) |
0% (0) |
0% (0) |
0% (0) |
82% (82) | 18% (18) | 0% (0) |
Velmurugan and Sandhya [18], 2009 | ||||
| In vitro: clearing | 40 | 50% (20) | 50% (20) | 0% (0) |
0% (0) |
50% (20) | 5% (2) |
5% (2) |
25% (10) | 12.5% (5) | 2.5% (1) | 0% (0) |
0% (0) |
0% (0) |
82% (82) | 18% (18) | 0% (0) |
Parekh et al. [19], 2011 | ||||
| In vitro: clearing | 138 | 97.1% (134) | 2.89% (4) | 0% (0) |
67% (92) | 33% (46) | 0% (0) |
0% (0) |
67.4% (92) | 8% (11) |
3.7% (5) | 3.9% (5) | 17.4% (24) | 0.7% (1) | 0% (0) |
0% (0) |
0% (0) |
77.8% (107) | 22.2% (31) | 0% (0) |
Jain and Bahuguna [20], 2011 | |
| In vitro: SCT | 112 | 96.4% (108) | 3.4% (4) | 0% (0) |
70.5% (79) |
29.5% (33) |
0% (0) |
10.7% (12) |
80% (90) |
9% (10) |
3% (3) |
2% (2) |
4% (4) |
0% (0) |
0% (0) |
0% (0) |
0% (0) |
98% (110) | 2% (2) |
0% (0) |
V. K. Sikri and P. Sikri [21], 1994 | |
| Subgroup Ethnic Incidence | 1490 |
96.47%
(1201) |
3.4%
(47) |
0.07%
(2) |
68%
(343) |
30%
(137) |
0% |
3%
(15) |
71%
(1108) |
6%
(48) |
3%
(16) |
11%
(237) |
8%
(69) |
0.53%
(2) |
0.06%
(4) |
0.33
(2) |
85%
(1239) |
15%
(307) |
0.07%
(4) |
|||
|
| ||||||||||||||||||||||
| Mongoloid | ||||||||||||||||||||||
| China | In vitro: radiographs | 100 | 64% (64) | 34% (34) | 2% (2) |
0% (0) |
78% (78) | 6%` (6) |
6% (6) |
10% (10) | 0% (0) |
0% (0) |
0% (0) |
0% (0) |
0% (0) |
90% (90) | 10% (10) | 0% (0) |
Walker [22], 1988 | |||
| In vitro: radiograph and sectioning | 82 | 54% (44) | 46% (38) | 0% (0) |
0% (0) |
Lu et al. [23], 2006 | ||||||||||||||||
| In vitro: Micro-CT | 115 | 65.2% (75) | 26.1% (40) | 0% (0) |
0% (0) |
65.2% (75) | 0% (0) |
2.6% (3) | 0% (0) |
22.6% (26) | 0% (0) |
0.9% (1) | 0% (0) |
0% (0) |
76.5% (88) | 23.5% (27) | 0% (0) |
Liu et al. [24], 2013 | ||||
| In vivo: CBCT | 178 | 98% (174) | 2% (4) |
0% (0) |
87.1% (155) | 11.2% (20) | 0.6% (1) | 1.1% (2) |
86.8% (151) | 0% (0) |
1.7% (3) | 0% (0) |
9.8% (17) | 0% (0) |
0% (0) |
0.6% (1) |
0% (0) |
89.6% (160) | 9.8% (17) | 0.6% (1) |
Tian et al. [25], 2012 | |
| In vivo: CBCT | 97 | 83.5% (81) | 12.4% (12) | 0% (0) |
4.1% (4) |
83.5% (81) | 0% (0) |
3.6% (3) | 0% (0) |
8.8% (8) | 0% (0) |
0% (0) |
0% (0) |
0% (0) |
91.2% (88) | 8.8% (9) | 0% (0) |
Liao et al. [26], 2011 | ||||
| In vivo: CBCT | 440 | 99.5% (439) | 0.5% (1) | 0% (0) |
75.2% (340) | 21% (92) | 0.7% (3) | 1.1% (5) |
76% (335) | 3.4% (15) | 2.7% (12) | 6.6% (21) | 9.3% (41) | 0% (0) |
0% (0) |
0.7% (3) |
0% (0) |
83.4% (367) | 15.9% (70) | 0.7% (3) |
Tian et al. [27], 2013 | |
| In vitro: Micro-CT | 358 | 24% (86) |
Fan et al. [28], 2008 | |||||||||||||||||||
| Japan | In vitro: radiographs | 516 | 86.2% (445) | 13.8% (71) | 0% (0) |
0% (0) |
Miyoshi et al. [29], 1977 | |||||||||||||||
| In vitro: Staining | 139 | 80.6% (112) | 15.1% (21) | 4.3% (6) | 0% (0) |
80.6% (112) | 19.4% (27) | 0% (0) |
Yoshioka et al. [30], 2004 | |||||||||||||
| Korea | In vivo: CBCT | 797 | 99.9% (796) | 0.1% (1) | 0% (0) |
Park et al. [31], 2013 | ||||||||||||||||
| Subgroup Ethnic Incidence | 2822 |
99%
(1409) |
1%
(6) |
74.5%
(1311) |
22.5%
(328) |
.95%
(12) |
3.7%
(97) |
78%
(720) |
0.85%
(21) |
3%
(27) |
3.32%
(31) |
10.1%
(92) |
0.18%
(1) |
0.74%
(4) |
85%
(905) |
15%
(160) |
0.65%
(4) |
|||||
|
| ||||||||||||||||||||||
| Middle East | ||||||||||||||||||||||
| Kuwait | In vivo: radiograph of RCT teeth | 20 | 85.0% (17) | 15% (3) | 0% (0) |
60% (12) |
40% (8) |
0% (0) |
0% (0) |
60% (12) | 40% (8) | 0% (0) |
Zaatar et al. [32], 1997 | |||||||||
| Jordan | In vitro: clearing | 500 | 97% (485) | 3% (15) | 0% (0) |
58.2% (291) | 39.8% (195) | 2.6% (13) | 0% (0) |
58.2% (251) | 4.8% (24) |
1.4% (7) |
14.4% (72) | 16.8% (84) | 0.8% (4) |
1% (5) |
0% (0) |
2.6% (5) |
Awawdeh and Al-Qudah [33], 2008 | |||
| Iran | In vitro: sectioning | 217 | 100% (217) | 0% (0) |
0% (0) |
88.47% (192) | 11.53% (25) |
0% (0) |
1.4% (3) |
90% (195) |
1.8% (4) | 3.2% (7) |
0.9% (2) | 4.1% (9) | 0% (0) |
0% (0) |
0% (0) |
0% (0) |
93.8% (203) |
5% (11) |
1.2% (3) |
Khedmat et al. [34], 2010 |
| In vitro: clearing | 163 | 98% (160) | 2% (3) | 0% (0) |
70.6% (115) | 27.8% (45) | 1.2% (2) |
2.4% (4) |
70.6% (113) | 1.9% (3) |
3.8% (6) |
3.8% (6) |
16.9% (27) | 1.2% (2) |
0.6% (1) |
0% (0) |
1.2% (2) |
77.5% (126) |
22.5% (37) |
0% (0) |
Rahimi et al. [35], 2007 | |
| Turkey | In vitro: clearing | 100 | 100% (100) | 0% (0) |
0% (0) |
64% (64) | 30% (30) | 5% (6) |
0% (0) |
75% (75) | 25% (25) | 0% (0) |
Çalişkan et al. [36], 1995 | |||||||||
| In vitro: clearing | 200 | 60.5% (121) | 39.5% (69) | 0% (0) |
0% (0) |
60.6% (121) | 18.5% (37) | 10.5% (21) | 7% (14) | 2.5% (5) | 0% (0) |
0% (0) |
1% (2) |
0% (0) |
89.5% (179) | 9.5% (19) | 1% (2) |
Sert and Bayirli [37], 2004 | ||||
| Subgroup Ethnic Incidence | 1200 |
96%
(979) |
6.67%
(21) |
67%
(795) |
31%
(372) |
1.46%
(21) |
0.63%
(7) |
69.85%
(680) |
6.75%
(68) |
4.73%
(41) |
6.53%
(94) |
9.85%
(125) |
0.5%
(6) |
0.4%
(6) |
0.25%
(2) |
0.95%
(7) |
79%
(595) |
20%
(100) |
0.44%
(5) |
|||
|
| ||||||||||||||||||||||
| Hispanic | ||||||||||||||||||||||
| Mexico | In vitro: radiograph | 202 | 79.3% (140) | 25.8% (62) | 0% (0) |
0% (0) |
74.2% (150) | 25.8 (52) | 0% (0) |
Pineda and Kuttler [38], 1972 | ||||||||||||
|
| ||||||||||||||||||||||
| Total no of teeth | 12752 | 7395 | 200 | 12 | 6070 | 2027 | 73 | 181 | 2868 | 137 | 100 | 394 | 382 | 8 | 7 | 10 | 9 | 4349 | 1002 | 13 | ||
| Overall Incidence (%] |
97.21
(%) |
2.63
(%) |
0.16
(%) |
73.55
(%) |
23.55
(%) |
0.91
(%) |
2
(%) |
72.6
(%) |
3.73
(%) |
2.72
(%) |
10.72
(%) |
10.4
(%) |
0.22
(%) |
0.19
(%) |
0.27
(%) |
0.24
(%) |
81.08
(%) |
18.68
(%) |
0.24
(%) |
|||