Objective: Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented. Methods: Studies on Google Scholar© , PubMed© , and Cochrane Library, providing quantitative information on optimal central incisor position were included. Results: Upper incisors supero-inferior position (4–5 mm to upper lip, 67–73 mm to axial plane through pupils), antero-posterior position (3–4 mm to Nasion-A, 3–6 mm to A-Pogonion, 9–12 mm to true vertical line, 5 mm to A-projection, 9–10 mm to coronal plane through pupils), bucco-lingual angulation (4–7° to occlusal plane perpendicular on models, 20–22° to Nasion-A, 57–58° to upper occlusal plane, 16–20° to coronal plane through pupils, 108–110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41–48 mm to soft-tissue mandibular plane), antero-posterior position (3–4 mm to Nasion-B, 1–3 mm to A-Pogonion, 12–15 mm to true vertical line, 6–8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87–94° to mandibular plane, 68° to Frankfurt plane, 22–25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesiodistal angulation (2° to occlusal plane perpendicular on models). Conclusions Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods.Therefore, the optimal incisal position remains debatable.

Objective: Controlling the incisal inclination is fundamental in orthodontics. However, the relationship between the inclination prescription and its clinical outcome is not obvious, and the incisal inclination changes generated by different bracket prescriptions were investigated. Methods: Twenty-eight nonextraction dental Class II patients (15 females, 13 males; mean age = 12.9) were retrospectively analyzed. Patients were treated using passive self-ligating fixed appliances with three inclination prescriptions for maxillary incisors (high, standard, low), and two for mandibular incisors (standard, low). Clinical outcomes were compared among different prescriptions, and regression analysis was used to explain the effects of bracket prescriptions and to understand the prescription selection criteria (α = 0.05). Results: For maxillary central incisors, low and high prescriptions were related to linguoversion (p = 0.046) and labioversion (p = 0.005), respectively, while standard prescription maintained the initial dental inclination. Maxillary lateral incisors did not show significant changes. For mandibular incisors, low prescription led to linguoversion (p = 0.005 for central incisors, p = 0.010 for lateral incisors), while standard prescription led to labioversion (p = 0.045 for central incisors, p = 0.005 for lateral incisors). The factors affecting inclination changes were the imposed change and selected prescription, while prescription selection was influenced by the initial dental inclination and initial intercanine distance. Conclusions The direction of correction of incisal inclination can be controlled by choosing a certain prescription, but the final inclination may show limited consistency with it. The amount of imposed inclination change was the most relevant predictor of the clinical outcome.