Diagnosis of upper airway obstruction in panoramic radiographs

One of the diagnostic aids used in dentistry is the panoramic radiograph. It's used by general practitioners and pedodontists who examine the children prior to the appropriate age for orthodontic treatment and the use of the cephalometric radiograph. In previous reontgenographic studies, the evaluation of the airway was done on cephalometric radiographs. Objectives: The objectives of this study were to identify the airway on a panoramic radiograph and to compare its' measurement to that on the cephalometric radiograph of the same patient. Materials and methods: Cephalometric and panoramic radiographs were taken of a skull with metal markers in the soft palate and pharynx area. A soft palate enlargement of 1.45 was found on the panoramic radiograph in comparison to that measured on the cephalometric radiograph. Next, radiographs of 50 patients with clinically diagnosed airway obstruction by an E.N.T specialist were chosen, as well as a control group of 30 patients with no signs or symptoms of airway obstruction. Measurements of the airway and the soft palate were done on both radiographs. Results: This study found a radiographic airway enlargement of about 1.5 on the panoramic in comparison with the cephalometric, and a soft palate enlargement of about 1.4. The correlation between both methods (panoramic and cephalometric radiographs) was high with a Kappa of 0.93. Conclusion: the panoramic radiograph represents as reliable a diagnostic tool as the cephalometric radiograph in measuring the upper airway. As in the cephalometric radiograph, an obstruction is defined as an airway width narrower than the width of the soft palate. A panoramic radiograph which is often taken at a younger age by the general practitioner and pedodontist, may render important information for the early diagnosis and referral for treatment of upper airway obstruction, and the possible prevention of difficult and costly future orthodontic or orthognathic treatment.