A lateral cephalogram study for evaluation of pharyngeal airway space and its relation to neck circumference and body mass index to determine predictors of obstructive sleep apnea

Abstract

Introduction: The airway is assumed to play a role in dentofacial development. So, several studies tried to correlate patients with normal nasorespiratory functions with different malocclusions and airway dimensions. A narrow upper airway is associated with obstructive sleep apnea (OSA). Currently neck size and obesity are considered to be the most important physical characteristics of patients with sleep apnea. Aim: To study the interaction between craniofacial structures and pharyngeal airway space along with soft palate and tongue in patients with different anteroposterior skeletal patterns using lateral cephalogram. The correlation of upper airway and soft-tissue measurements with neck circumference (NC) and body mass index (BMI) was elucidated to evaluate the predictors on lateral cephalogram, in order to determine the etiology of OSA. Materials and Methods: Lateral cephalograms of 45 subjects were used to measure the pharyngeal airway and were divided into three groups (each group included 15 subjects) according to ANB angle: Class I (ANB angle 2°-4°), Class II (ANB angle >4°), and Class III (ANB angle <2°). Velar morphology along with its length was also analyzed and categorized into different types. The NC and BMI of all the patients were also calculated. Student′s t-test for paired samples was used to compare the mean values of the study variable vital parameters. Results: Significant reduction was found in pharyngeal airway in ANB group II. The soft palate and tongue size increased with increasing BMI and NC. Conclusion: Sagittal skeleton pattern had a close association with the dimensions of pharyngeal airway passage. The correlation of NC with increase in soft-tissue size (soft palate and tongue) suggested that obesity mediates its effects in OSA through fat deposition in the neck.

Keywords

• Airway space
• BMI
• lateral cephalogram
• malocclusion
• NC
• OSA
• soft-tissue area