Preoperative Three-Dimensional Assessment of Secondary Naso-Palato-Alveolar Clefts Using Computed Tomography: A Retrospective Observational Study

Introduction: Secondary naso-palato-alveolar clefts exhibit considerable three-dimensional anatomical variations, which may complicate preoperative assessment and surgical planning.This study evaluated the morphological characteristics of these clefts using three-dimensional computed tomography (3DCT).Materials and methods: This retrospective observational study included patients with secondary nasopalato-alveolar clefts who underwent preoperative 3DCT between January 2019 and December 2024.Demographic and clinical records were reviewed, and cleft volume, anteroposterior length, transverse width, and vertical height were assessed.Adjacent tooth/root involvement and nasal floor discontinuity were recorded.Comparisons between unilateral and bilateral clefts accounted for within-patient clustering by using mixed-effects models.Measurement reproducibility was assessed using intraclass correlation coefficients (ICCs) and Cohen's kappa.Results: Ninety-five patients (mean age, 11.8 ± 3.4 years) contributed 112 cleft observations, comprising 78 unilateral and 34 bilateral clefts.The overall mean cleft volume was 1.82 ± 0.71 cm³.Bilateral clefts demonstrated a greater mean volume than unilateral clefts (2.30 ± 0.82 vs. 1.61 ± 0.56 cm³; mean difference, 0.69 cm³; p < 0.001; Cohen's d = 0.91).Bilateral clefts also exhibited greater anteroposterior length (18.90 ± 5.40 vs. 15.30± 4.10 mm; mean difference, 3.60 mm; p = 0.001; d = 0.76), transverse width (8.50 ± 2.60 vs. 6.50 ± 1.90 mm; mean difference, 2.00 mm; p < 0.001; d = 0.86), and vertical height (15.00 ± 4.30 vs. 13.00 ± 3.60 mm; mean difference, 2.00 mm; p = 0.023; d = 0.51).Adjacent tooth/root involvement and nasal-floor discontinuity were more frequent in bilateral clefts, with odds ratios of 3.46 (95% CI, 1.40-8.55;p = 0.007) and 6.42 (95% CI, 2.52-16.36;p < 0.001), respectively.Cleft volume was positively associated with anteroposterior length (ρ = 0.72), transverse width (ρ = 0.65), and vertical height (ρ = 0.56; all p < 0.001).Measurement reproducibility was excellent, with an ICC of 0.94 (95% CI, 0.88-0.97)for cleft volume.Conclusion: 3DCT demonstrated substantial variation in secondary naso-palato-alveolar cleft morphology.Bilateral clefts showed greater anatomical involvement, whereas cleft volume was consistently related to the linear dimensions.Standardized three-dimensional assessment may provide useful anatomical information for individualized preoperative evaluation and surgical planning.