Table 4 Number (n) and percentage (%) of the isthmus (Type1–7) in different locations and its length (mm)
Type1 | Type2 | Type3 | Type4 | Type5 | Type6 | Type7 | Total | |
|---|---|---|---|---|---|---|---|---|
Cervical third | + | + | + | + | – | – | – | |
Middle third | + | + | – | – | + | – | + | |
Apical third | + | – | + | – | + | + | – | |
Number | 28 | 24 | 11 | 108 | 10 | 13 | 4 | 198 |
Percentage of isthmus | 7.9% | 6.7% | 3.1% | 30.3% | 2.8% | 3.6% | 1.1% | 55.5% |
Length | 9.9 ± 3.3 | 5.9 ± 1.2 | 5.7 ± 1.7 | 2.4 ± 0.9 | 6.2 ± 1.9 | 2.5 ± 1.4 | 2.1 ± 1.5 | 4.3 ± 3.1 |