Table 2.
Study cast measurements
| Number | Measurements | Definition |
|---|---|---|
| 1 | Spee's curve depth (mm) | Perpendicular distance from the line joining the mesial contact points of the lower first molars to the contact point of the lower central incisors |
| 2 | Overbite (mm) | Distance from the upper central incisor tip to the lower central incisor tip and perpendicular to the occlusal plane |
| 3 | Overjet (mm) | Distance from the upper central incisor tip to a plane tangential to the lower incisor labial surface and parallel to the occlusal plane |
| 4 | Molar relationship (mm) | Distance between the mesiobuccal cusp tip of the upper first molar and the buccal groove of the lower first molar |
| 5 | Lower anterior crowding (mm) | Discrepancy between arch length and tooth size and calculated by subtracting the arch length between distal contact points of the lower canines from the total width of lower anterior teeth |
| 6 | Bolton index 3-3 (%) | The percentage ratio of total lower anterior teeth width to total upper anterior teeth width |
| 7 | Bolton index 6-6 (%) | The percentage ratio of total lower teeth width of 6-6 to total upper teeth width of 6-6 |