A Cephalometric Study of Pharyngeal Dimensions Following Twin Block Treatment

Abstract

Objective: To assess and compare changes in pharyngeal airway widths (PAW) using lateral cephalograms before and after treatment with a removable twin block appliance.

Methodology: Lateral cephalogram records were taken before (T0) and after (T1) the treatment of 50 Class II subjects (ANB>40; 28 males, 22 females; mean age 12.6 years) using the removable twin block appliance. The study period spanned 12 months. Airway volumes, including upper airway width (UAW), middle airway width (MAW), and lower airway width (LAW), were compared between T0 and T1. The data were analyzed using SPSS statistical software via paired t-test. A p-value of ?0.05 was considered statistically significant.

Results: A total of 50 patients were included in the study, and airway changes were analyzed at two different times prospectively (T0 and T1). The male-to-female ratio was 1:0.8 (44% females, 56% males). The mean upper airway width (UAW) at T0 and T1 was 14.04 mm and 15.3 mm, respectively. The mean middle airway width (MAW) at T0 and T1 was 8.8 mm and 11.8 mm, respectively, while the mean lower airway width (LAW) at T0 and T1 was 7.5 mm and 10.2 mm, respectively. The mean age was 12.6 years, and the mean BMI was 21. The mean SN-Md angle was 31.8 degrees. At T1, a significant increase in airway volume was observed in upper airway width (UAW), middle airway width (MAW), and lower airway width (LAW) (P=0.000).

Conclusion: Treatment with the Twin Block Appliance in growing subjects resulted in an increase in the overall posterior pharyngeal airway volumes.