Table 1.
Clinical and cephalometric variables included in this study
| Variable | Description |
|---|---|
| Sex | Female or male |
| Model variable | |
| Overjet (mm) | The distance between the incisal tips of the upper and lower incisors measured in the horizontal plane |
| Overbite (mm) | The distance between the incisal tips of the upper and lower incisors measured in the vertical plane |
| Maxillary arch discrepancy (mm) | Maxillary difference between the space available and the sum of the mesiodistal tooth width from second premolar to second premolar |
| Mandibular arch discrepancy (mm) | Mandibular difference between the space available and the sum of the mesiodistal tooth width from second premolar to second premolar |
| Anterior bolton discrepancy (mm) | Measure of the difference between the sum of the mesiodistal width of the front six mandibular teeth and the sum of the mesodistal width of the front six maxillary teeth multiplied by 0.772 |
| Molar class, modified | Numerical quantification in terms of cusps of difference, that is, with Class I being the value zero, a Class II of 1 cusp being a +1 and a Class III of 1 cusp being –1, and there are intermediate values such as, for example, a quarter cusp (0.25), a half cusp (0.5) and three quarters cusp (0.75) |
| Canine class, modified | Numerical quantification in terms of cusps of difference, that is, with Class I being the value zero, a Class II of 1 cusp being a +1 and a Class III of 1 cusp being –1, and there are intermediate values such as, for example, a quarter cusp (0.25), a half cusp (0.5) and three quarters cusp (0.75) |
| Sagittal cephalometric variable | |
| ANB (°) | The angle formed by the Nasion-Point A plane and Nasion-Point B plane |
| SNA (°) | The angle formed by the Sella-Nasion plane and the Nasion-Point A plane |
| SNB (°) | The angle formed by the Sella-Nasion plane and the Nasion-Point B plane |
| Ricketts’ facial convexity (mm) | The distance between Point A and the facial plane |
| Ricketts’ maxillary depth (°) | The angle formed by the Frankfort plane and the plane from Nasion to Point A |
| Ricketts’ facial depth (°) | The angle between the facial plane and Frankfort plane |
| Articular angle (S-Ar-Go) (°) | The angle formed by the Sella-Articulare plane and the Articulare-Gonion plane |
| Upper gonial angle (Ar-Go-N) (°) | The angle formed by the Articulare-Gonion plane and the Gonion-Nasion plane |
| Wits analysis (mm) | Distance between the AO and BO Points, along the occlusal plane |
| Maxillomandibular difference (mm) | Difference between the Condylion-Anterior Nasal Spine distance and the Condylion-Pogonion distance |
| Cephalometric overjet (mm) | The distance between the incisal tips of the upper and lower incisors measured along the occlusal plane |
| Molar relationship (mm) | The distance between the distal surfaces of the lower and upper molars measured along the occlusal plane |
| Vertical cephalometric variable | |
| Face height ratio (N-ANS/ANS-Me) (%) | Proportion between the Nasion-Anterior Nasal Spine distance and the Anterior Nasal Spine-Menton distance |
| Gonial angle (Ar-Go-Me) (°) | The angle formed by the Articulare-Gonion plane and the Gonion-Menton plane |
| Sum of the angles (°) | Sum of the Articulare-Sella-Nasion angle, the Articular angle and the Gonial angle |
| Lower gonial angle (N-Go-Me) (°) | The angle formed by the Nasion-Gonion plane and the Gonion-Menton plane |
| Jarabak Index (%) | The ratio of posterior facial height (Sella-Gonion) to anterior facial height (Nasion-Gnathion) |
| SN-GoGn (°) | The angle formed by the Sella-Nasion plane and the Gonion-Gnathion plane |
| PP-MP (°) | The angle formed by the palatal plane and the mandibular plane |
| FMA (°) | The angle formed by the Frankfort plane and the mandibular plane |
| Ricketts’ facial axis (°) | The angle formed by the Pt Point-Gnathion plane and the Nasion-Basion plane |
| Cephalometric overbite (mm) | The distance between the tips of the lower and upper incisors measured perpendicular to the occlusal plane |
| Dental cephalometric variable | |
| U1-APo (mm) | The distance from the tip of the upper incisor to the “A-Po” plane |
| U1-PP (°) | The angle between the long axis of the upper incisor and the palatal plane |
| L1-APo (mm) | The distance from the tip of the lower incisor to the “A-Po” plane |
| IMPA (°) | The angle between the long axis of the lower incisor and the mandibular plane |
| Interincisal angle (°) | The angle formed by the long axes of the central incisors |
| Soft tissue cephalometric variable | |
| Labial gap (mm) | The distance between the upper and lower Stomions, measured in the vertical plane |
| Upper lip to SnPg’ (mm) | The distance between the upper Labrale and the Subnasal-Soft Tissue Pogonion plane, along the horizontal plane |
| Lower lip to SnPg’ (mm) | The distance between the lower Labrale and the Subnasal-Soft Tissue Pogonion plane, along the horizontal plane |
| Upper lip to subnasal vertical (mm) | The distance between the upper Labrale and a vertical plane proyected over Subnasal Point |
| Lower lip to subnasal vertical (mm) | The distance between the lower Labrale and a vertical plane proyected over Subnasal Point |
| Upper incisor exposure (mm) | The distance between the tips of the upper incisor and the upper Stomion, along the vertical plane |
| Outcome variable | |
| Extractions NO/YES | Extractions done or not in the patient due to orthodontic reasons |