The effects of nasoalveolar molding on maxillary central icisor position and inclination in unilateral cleft lip/palate patients: a retrospective cephalometric study

Abstract

AbstractAim: The aim of this study was to investigate the impact of nasoalveolar molding (NAM) on the position and inclination of the maxillary central incisor in patients with unilateral cleft lip and palate. Methods: This retrospective cohort study involved cephalometric analysis of fifty-six children with unilateral cleft lip and palate who met the inclusion criteria. Of these, thirty children were treated with NAM, while the remaining twenty-six did not receive NAM therapy. Lateral cephalometric radiographs were analyzed using Dolphin Imaging software to obtain cephalometric measurements related to the position of the maxilla and mandible and the position and inclination of central incisors. Key cephalometric variables included SNA, SNB, ANB, and angular and linear measurements assessing the inclination and position of the maxillary central incisor on the cleft-affected side. Additionally, for the NAM subgroup, data was available on the initial and final cleft widths, allowing assessment of the relationship between the amount of alveolar segment approximation and the resulting position and inclination of the central incisor. Comparisons were made between the NAM and non-NAM groups, as well as against standardized cephalometric normative values, to evaluate skeletal and dental differences relative to non-cleft populations, as well as to explore potential associations between cleft severity, closure, and incisor angulation. Results: Children who did not receive NAM therapy exhibited greater variability and more frequent outliers across all cephalometric measurements, particularly in variables related to incisor position and inclination, including U1-FH°, U1-NA°, U1-NA (mm), and U1-SN°. Statistical analysis using the non-parametric Kruskal-Wallis test revealed several significant differences between the NAM and non-NAM groups (p < 0.05). On average, children treated without NAM were older at the time of radiograph acquisition, with a mean age of 9.22 years compared to 7.95 years in the NAM group. The non-NAM group also demonstrated a smaller mean SNA of 77.12°, compared to 80.45°, and a reduced ANB angle of 1.6° versus 4.7°, indicating a more retrusive maxillary position relative to the cranial base and mandible. Notably, children treated with NAM showed a more retruded maxillary central incisor, with a mean U1-NA (mm) measurement of -8.34 mm compared to -3.75 mm. Conclusions: The findings of this study suggest that NAM does not significantly impact the inclination of the permanent maxillary central incisor in children with UCLP. While there may be a tendency toward a more retruded tooth position, NAM appears to be a safe and effective pre-surgical intervention with minimal long-term effects on dental and skeletal outcomes.