Evaluation of Alt-RAMEC With Facemask in Patients With Unilateral Cleft lip and Palate (UCLP) Using Cone Beam Computed Tomography (CBCT) and Finite Element Modeling-A Clinical Prospective Study

Objective: Evaluate the effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol on patients with unilateral cleft lip and palate (UCLP) along with maxillary protraction using cone beam computed tomography (CBCT) records and a finite element modeling (FEM) model. Materials and Methods: Twenty-five patients (aged 9-13 years) with UCLP having a GOSLON score 3 were selected for this prospective single-arm cohort study after obtaining necessary informed consent. A 9-week Alt-RAMEC protocol using a custom-made fan-shaped expansion screw was initiated, which was followed by 6-month facemask wear. Pre (T1) and posttreatment (T2) records including CBCT were taken and were evaluated for treatment changes in all 3 dimensions using paired t test. Additionally, a FEM model (ANSYS 15.0) using the Alt-RAMEC protocol was also analyzed for the displacement and stress on various craniofacial structures. Results: Significant forward movement of the maxilla along with clockwise rotation of mandible along with statistically significant increase in lower molar height and upper incisor proclination (P < .05) was observed. CBCT evaluation showed a statistical significant decrease in buccal alveolar bone thickness and increase in molar inclination (P < .05). Finite element modeling analysis highlighted that the maximum displacement occurred at the anterior region with stresses radiating till the anterior nasal spine, zygomatic arch, and sphenoid bone. Conclusion: Alt- RAMEC protocol combined with facemask protraction can lead to significant maxillary advancement, with some transient decrease in buccal bone thickness noted thereby warranting long-term studies to further assess its effect on the dentofacial apparatus.