Table 1.
Prevalence of root canal isthmus
| Teeth | Root | Prevalence of teeth with RCI (%) | Region-wise occurrence | Total number of RCI present | |||||
|---|---|---|---|---|---|---|---|---|---|
| CT-CT | CT-MT | CT-AT | MT-MT | MT-AT | AT-AT | ||||
| First mandibular molar (n=272) | Mesial | 224 (82.3) | 157 | 37 | 16 | 71 | 10 | 16 | 307 |
| Distal | 53 (19.5) | 16 | 26 | 5 | 18 | 4 | 1 | 70 | |
| Second mandibular molar (n=246) | Mesial | 209 (85) | 100 | 66 | 16 | 68 | 18 | 6 | 209 |
| Distal | 5 (2) | 1 | 3 | 0 | 2 | 0 | 0 | 5 | |
| First mandibular premolar (n=406) | Single/double root | 47 (11.5) | 4 | 9 | 0 | 25 | 9 | 4 | 51 |
| Second mandibular premolar (n=396) | Single root | 13 (3) | 7 | 3 | 0 | 3 | 0 | 0 | 13 |
| First maxillary molar (n=379) | Mesiobuccal | 290 (76.5) | 94 | 123 | 28 | 60 | 0 | 40 | 345 |
| Distobuccal | 2 (0.5) | 0 | 1 | 0 | 1 | 0 | 0 | 2 | |
| Second maxillary molar (n=335) | Mesiobuccal | 145 (43.2) | 27 | 36 | 12 | 28 | 4 | 3 | 110 |
| First maxillary premolar (n=439) | Single/double root | 413 (94) | 306 | 41 | 18 | 79 | 3 | 15 | 462 |
| Second maxillary premolar (n=436) | Single/double root | 275 (63) | 131 | 44 | 20 | 96 | 5 | 24 | 320 |
| Mandibular lateral incisor (n=486) | Single root | 153 (31) | 7 | -/- | -/- | 143 | 3 | -/- | 153 |
| Mandibular central incisor (n=472) | Single root | 107 (23) | 8 | -/- | -/- | 98 | 1 | -/- | 107 |
| Mandibular canine (n=521) | Single root | 60 (11) | 4 | -/- | -/- | 54 | 1 | 1 | 60 |
| Maxillary canine (n=507) | Single root | 15 (3) | -/- | -/- | -/- | 15 | -/- | -/- | 15 |
RCI: Root canal isthmus, CT: Cervical third, MT: Middle third, AT: Apical third