Effects of rapid palatal expansion (RPE) and twin block mandibular advancement device (MAD) on pharyngeal structures in Class II pediatric patients from Cluj-Napoca, Romania.

Objective: To compare cephalometric changes of pharyngeal structures after rapid palatal expansion (RPE) with those induced by a twin block mandibular advancement device (MAD) with palatal expansion capability. Methods: This retrospective study investigated 55 Class II pediatric patients, divided into two groups: 29 patients treated with RPE and 26 patients treated with MAD. Lateral cephalometric measurements were compared before and after treatment. Results: Changes in pharyngeal airway space were statistically significant in both groups ( p  < 0.001) from a pre-treatment mean distance measured between the lower posterior pharyngeal wall and the hyoid bone (LPF-H) of 25.42 mm in the MAD group and 28.62 mm in the RPE group, to a post-treatment mean LPF-H of 27.96 mm in the MAD group and 31.52 mm in the RPE group. Conclusion: Significant changes in pharyngeal space may be obtained in Class II patients through both rapid palatal expansion and mandibular advancement devices with palatal expansion capability.