Pharyngeal dimensions in skeletal class I, II, and III orthodontic patients in a Nigerian population

Abstract

Background: Routine lateral cephalometric radiographs can determine upper and lower pharyngeal airway constriction or patency depending on the dentofacial skeletal discrepancy. Appropriate orthodontic treatment that would maintain or improve the airway patency can be considered if the width of the airway in the various skeletal classes is determined. Aim: The aim of this study was to evaluate the upper and lower pharyngeal widths in skeletal Class I, II, and III untreated orthodontic patients in Benin City, Nigeria. Materials and Methods: In this study, 188 lateral cephalometric radiographs comprising three groups based on the ANB angle: Class I (ANB 2-4°), Class II (ANB >4), and Class III (ANB < 2) were analyzed using the method described by McNamara. The vertical facial pattern (the Sella-Nasion-GoGn angle) and palatal length were also determined. The differences between groups and correlations between variables were determined with the Students t-test and the Spearman correlation coefficient, respectively. Results: The mean upper and lower pharyngeal width for skeletal Classes I were 10.56 ± 3.67 mm and 11.14 ± 3.79 mm, respectively. Skeletal Class II had the narrowest upper airway width, whereas skeletal Class III had the narrowest lower airway widths, respectively. The palatal length was 9.04 mm in males and 8.6 mm in females, and there was a highly statistically significant difference P < 0.05 between hyperdivergent facial pattern and the upper pharyngeal width. There was a significant difference between skeletal pattern II and the upper pharyngeal width. Conclusion: Pharyngeal dimensions should be taken into consideration when managing patients with skeletal patterns II and III and the hyperdivergent facial patterns.