Vertical Skeletal Patterns as Predictors of Functional Need in Orthognathic Patients: A Retrospective Study Based on IOFTN Scores

Abstract Objectives To assess the relationship between the Index of Orthognathic Functional Treatment Need (IOFTN) and vertical skeletal patterns in two samples of orthognathic patients. Methodology Two retrospective samples of orthognathic patients were included: Iranian ( n = 103; 58 females, 45 males; mean age = 23.47 ± 6.44 years) and Turkish ( n = 200; 120 females, 80 males; mean age = 23.4 ± 5.4 years). IOFTN scores and two measures of vertical skeletal pattern were recorded: GoGnSN° in the Turkish sample and lower anterior face height% (LAFH%) in the Iranian sample. The chi-square test assessed the association between vertical skeletal pattern categories (GoGnSN° and LAFH%) and IOFTN treatment need categories (Venugoplan et al. in J Oral Maxillofac Surg 70:e77–86, 2012;Khechoyan in Semin Plast Surg 27:133–136, 2013;Achal et al. Dent Update 45:1048–1056, 2018;Perkovic et al. Orthod Craniofac Res 25:112–118, 2022;Kerr et al. Br J Orthod 19:21–24, 1992). Spearman’s correlation coefficient (r) was used to examine the relationship between functional need (IOFTN score) and vertical skeletal pattern (GoGnSN° or LAFH%). Results Overall, 68% of the Iranian sample and 64% of the Turkish sample were categorized as having increased vertical proportions. In the Iranian sample, a significant association was found between vertical skeletal pattern categories (LAFH%) and IOFTN treatment need categories (χ² = 23.110, p < 0.001). However, no significant association was observed between vertical skeletal pattern categories (GoGnSN°) and IOFTN treatment need categories in the Turkish sample (χ² = 2.891, p = 0.576). In the Iranian sample, a weak positive correlation was found between LAFH% and IOFTN score ( r = 0.299, p = 0.002). No significant correlation was found between GoGnSN° and IOFTN in the Turkish sample ( r = 0.062, p = 0.381). Conclusion LAFH% may be more closely related to the functional aspects of dentofacial deformity, as assessed by IOFTN, than GoGnSN°. Future research should evaluate the relationship between IOFTN and vertical skeletal measurements by assessing both vertical parameters within the same cohort.