Table 2 Summary of the incidences of documented ethnic and population variations in the anatomy of mandibular second premolars.
Geographic Materials No. of teeth in the study (
) Root anatomy Root canal anatomy Root canal pattern (Vertucci) Apical foramina References 1 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 328 97.6% (320) 2.4% (8) 0% 86.6% (284) 13.4% (44) Geider et al. [4 ], 1989 Germany In vitro: analysis of extracted teeth 2089 99.85% (2086) 0.05% (1) 0.1% (2) Visser [41 ], 1948 Poland In vitro: extraction and RCT 56 68.2% (38) 31.8% (18) 0% 0% Rózyło et al. [6 ], 2008 U.S.A In vitro: clearing 400 100% (400) 0% 0% 97.5% (390) 2.5% (10) 0% 0% 97.5% (390) 0% 0% 0% 2.5% (10) 0% 0% 0% 0% 97.5% (390) 2.5% (10) 0% Vertucci [7 ], 1984 In vitro: sectioning 32 100% (32) 0% 0% 65.6% (21) 34.4% (11) Barrett [11 ], 1925 In vitro: extraction and radiograph 906 96.6% (902) 0% 3.4% (4) 87.5% (792) 12.5 0.4% (2) 0% Zillich and Dowson [12 ], 1973 In vitro: grinding and examination under magnification 50 92% (46) 8% 0% 0% 96% (48) 4% (2) 0% Green [9 ], 1973 Subgroup ethnic incidence 3861 98.81% 0.49% 0.7% 82.9% 17.1% 0.07% 0% 97.5% 2.5% 96.75% 3.25% African Senegalese In vivo: radiographic examination 408 86% (351) 12% (49) 2% 0% Mbaye et al. [15 ], 2008 Indian India In vitro: clearing 40 80% (32) 20% 0% 0% 80% (32) 0% 0% 2.5% (1) 17.5% (7) 0% 0% 0% 0% 80% (32) 20% (8) 0% Parekh et al. [19 ], 2011 In vitro: SCT 96 97.9% (94) 2.1% (2) 0% 87% (83) 13.5% (13) 0% 0% 80% (78) 9% 3% 2% 4% 0% 0% 0% 0% 94% (90) 6% 0%
V. K. Sikri and P. Sikri [21 ], 1994 Subgroup ethnic incidence 136 97.9% 2.1% 0% 83.5% 16.75% 0% 0% 80% 4.5% 1.5% 2.25% 10.75% 87% 13% Mongoloid China In vivo: CBCT 178 100% (178) 0% 0% 97.2% (173) 2.2% 0% 0.6% 97.2% (173) 0% 0% 0.5% (1) 1.69% (3) 0% 0% 0% 0.5% Tian et al. [25 ], 2012 Japan In vitro: radiograph 40 97.9% (39) 2.1% 0% 0% Miyoshi et al. [29 ], 1977 Korea CBCT 789 99.4% (784) 0.6% (5) 0% Park et al. [31 ], 2013 Subgroup ethnic incidence 1007 99.7% 0.3% 0% 97.5% 2.15% 0% 0.3% 97.2% 0.5% 1.69% 0.5% Middle east Kuwait In vitro: radiograph of RCT teeth 64 95.6% (61) 4.4% (3) 0% 95.3% (61) 4.7% 0% 0% 95.3% (61) 4.7% (3) 0% Zaatar et al. [32 ], 1997 Jordan In vitro: clearing 400 97.2% (389) 2.8% (11) 0% 72% (288) 27.5% (110) 0.5% (2) 0% 78% (288) 3.8% (15) 0.1% (4) 7.5% (30) 15.3% (61) 0% 0% 0% 0.5% 74.2% (337) 15.8% (63) 0% Awawdeh and Al-Qudah [33 ], 2008 Iran In vitro: clearing 103 100% (103) 0% 0% 80.5% (83) 17.5% (18) 0% 2% 76.3% (76) 7.9% (9) 9.9% (11) 5.9% (7) 0% 0% 0% 0% 0% 94.1% (97) 5.9% (6) 0% Rahimi et al. [35 ], 2007 In vitro: clearing and sectioning 80 88.8% (71) 11.2% (9) 0% 0% 91.2% (73) 0% 0% 0% 0% 0% 0% 0% 0% 97.5% (78) 2.5% (2) 0% Hasheminia and Hashemi [39 ], 2005 In vitro: clearing 137 94.2% (129) 5.8% 0% 0% 75.9% (104) 24.1% (33) 0% Rahimi et al. [40 ], 2009 Turkey In vitro: clearing 100 100% (100) 0% 0% 93.6% (94) 6.4% 0% 0% 93.6% (94) 0% 0% 0% 6.4% (6) 0% 0% 0% 0% 93.6% (94) 6.4% (6) 0% Çalişkan et al. [36 ], 1995 In vitro: clearing 200 100% (200) 0% 0% 71% (142) 29% (58) 0% 0% 71% (142) 7% (14) 3.5% (7) 9% (18) 7% 1.5% (3) 1% 0% 0% 81.5% (163) 18.5% (37) 0% Sert and Bayirli [37 ], 2004 Subgroup ethnic incidence 1084 98.56% 1.44% 0% 85.06% 14.59% 0.07% 0.29% 82.02% 3.74% 2.7% 4.48% 5.74% 0.3% 0.2% 0.1% 87.44% 11.13% Hispanic Mexico In vitro: radiographs 250 98.8% (247) 1.2% 0% 0% 98.8% (247) 1.2% (3) 0% Pineda and Kuttler [38 ], 1972 Total no of teeth 6746 5649 34 6 3364 489 12 3 1346 46 46 58 105 3 2 0 3 1741 179 0 Overall incidence 99.28% 0.61 0.01% 86.9% 12.64% 0.31% 0.08% 83.65% 2.86% 2.86% 3.6% 6.52% 0.18%
0.12% 0% 0.18% 90.68% 9.32% 0%
