Abstract:

Objective To construct a three-dimensional finite element model of the cranio-maxillary complex combined with a palatal obturator in neonates with unilateral complete cleft lip and palate(UCCLP), and to evaluate the effects of different combinations of alveolar cleft closure distance and palatal obturator thickness on mucosal stress distribution and cleft closure efficiency. Methods Based on MDCT data, a three-dimensional finite element model incorporating the cranio-maxillary complex, cranial sutures, alveolar mucosa, and palatal obturator was established using Mimics 18.2, Geomagic Wrap 2021, and ANSYS 19.0. The geometries of key anatomical structures, including cranial sutures and dental germs, were reconstructed with reference to previous studies. Under consistent model geometry, material properties, boundary conditions, and contact settings, different combinations of alveolar cleft closure distance and palatal obturator thickness were simulated. The maximum von Mises stress in the alveolar mucosa and the cleft closure efficiency were calculated to analyze the regulatory relationship between thickness displacement parameters and stress efficiency outcomes. Results A patient-specific finite element model of the UCCLP neonatal cranio-maxillary complex with a palatal obturator was successfully established, demonstrating satisfactory mesh quality and good anatomical agreement with clinical morphology. The cleft closure efficiency increased with increasing palatal obturator thickness. However, the effect of palatal obturator thickness on the maximum von Mises stress in the alveolar mucosa was modulated by the magnitude of closure distance. Within a small range of movement distance, the stress in the 0.5 mm and 1.5 mm groups exhibited an overall trend of first decreasing and then increasing with increasing palatal obturator thickness, whereas the stress in the 1.0 mm group showed a fluctuating pattern of first increasing, then decreasing, and then increasing again. In contrast, under large displacement conditions, mucosal stress decreased continuously with increasing thickness, indicating a trade-off between thickness and displacement. Conclusion A three-dimensional finite element model of the UCCLP neonatal cranio-maxillary complex combined with a palatal obturator was successfully developed, providing a reliable computational framework for subsequent biomechanical investigations. The results suggest a coupled effect between palatal obturator thickness and alveolar cleft closure distance on the maximum von Mises stress in the alveolar mucosa and closure efficiency.

Key words: UCCLP, MDCT modeling, finite element analysis, cranio-maxillary complex, palatal obturator