Cephalometric Evaluation of Changes in Tongue Position, Posture and Pharyngeal Airway Dimensions Following Treatment of Angle’s Class 1 Bimaxillary Proclination

Abstract

Objectives:The aim of the study is to determine and correlate the effects of anterior teeth retraction on tongue position, posture and pharyngeal airway dimensions, in Angle’s Class 1 bimaxillary dentoalveolar proclination cases treated with all first premolar extraction. Materials and Methods:Pre and post treatment lateral cephalogram of fifteen Class I bimaxillary dentoalveolar proclination patients in the age group of 15-25years treated orthodontically as maximum anchorage cases with Preadjusted Edgewise Appliances (MBT prescription) and extraction of all first premolars were compared. Results:Tongue position analysis showed significant decrease in tg1: 2.2 +/- 1.52 mm (p = 0.001) and TGL: 4.2 +/- 3.877 mm (p = 0.001). Tongue posture analysis showed a significant decrease in Point 1: 1.48 +/- 1.92 mm (p=0.028), Point 2: 1.44 +/- 1.46 mm (p=0.008) and Point 5: 1.92 +/- 2.45 mm (p=0.026).Pharyngeal airway analysis showed significant increase in PNS-Ad1: 1.2 +/- 1.69 mm (p=0.016) while V-LPW: 2.0 +/- 3.047 mm (p=0.023) was decreased. No significant correlation was found between changes in total tongue length and velopharyngeal and glossopharyngeal airway. Conclusions:A significant reduction in the total tongue length particularly in the posterior region was observed after retraction. Also there was a reduction in the distance between root of the tongue and uvula, dorsum of the tongue and the roof of mouth in the posterior and anterior part of palate respectively. There was an increase in the lower nasopharyngeal airway and a decrease in the hypopharyngeal airway.