Comparative Evaluation of Five Alternative Methods for Estimation of Point A with Different Maxillary Incisor Inclinations: A Cephalometric Study

Abstract Objective: This study aimed to evaluate the reliability of five alternative cephalometric landmarks (A1–A5) as substitutes for Point A across varying maxillary incisor inclinations—normally inclined, proclined, and retroclined—using angular and linear cephalometric parameters. Materials and Methods: A total of 120 pretreatment lateral cephalograms were analyzed and divided into three groups (40 each) based on U1-PP angulation. Point A (Downs) and five alternatives—A1 (Jacobson), A2 (Tindlund), A3 (Prosthion projection), A4 (Labial lamella), and A5 (2 mm anterior to apex)—were identified on each radiograph. Angular (SNA, U1–NA, N–A–Pog) and linear (NA–P, U1–NA) measurements were recorded. Intra- and intergroup comparisons were made using ANOVA, post hoc Bonferroni tests, and Pearson correlation analysis. Results: Points A1 and A2 showed minimal variation from Point A across all groups and had the highest correlation coefficients, indicating strong reliability. Point A3 demonstrated the greatest variability, particularly in proclined incisors, while A4 and A5 were moderately reliable in retroclined cases but inconsistent elsewhere. Conclusion: Point A1 emerged as the most consistent and reliable alternative to Point A, regardless of incisor inclination. Point A2 serves as a viable secondary landmark. A3, A4, and A5 should be used with caution due to positional variability influenced by incisor angulation.