POSITION OF HEADS OF THE TEMPOROMANDABULARY JOINT AND LINEAR DIMENSIONS OF UPPER RESPIRATORY TRACT IN PATIENTS WITH SKELETAL SAGITAL BITE ANOMALIES

Abstract

Maxillofacial anomalies not only affect aesthetics but also contribute to temporomandibular joint disease. The position of the temporomandibular joint and occlusal factors can influence the airway patency therefore medical interventions should aim at restoring normal breathing, treating TMJ and muscles, and then correcting the occlusion. The aim of this study is to investigate the relationship between the position of the lower jaw, position of TMJ heads, and changes in upper respiratory tract in patients with Class I and II skeletal sagittal bite anomalies according to Angle's classification.
 Cone-beam computer tomograms of 64 patients were analyzed. The patients were divided into two groups based on the ANB angle. The position of the temporomandibular joint heads was determined using N. Gelb's method in the mid-sagittal plane, while the linear parameters of the upper respiratory tract were assessed using the McNamara method. Regardless of the bite pathology, only 12.5% of patients (n=8) exhibited the correct symmetrical position of the TMJ heads on both sides according to the Gelb grid. In the 1st group, the average width of the upper and lower parts of the pharynx measured by the McNamara method was 17.41±0.44mm and 10.1±0.73mm, respectively. In the 2nd group, the average width of the upper part was 15.82±0.61mm, and the lower part measured 10.25±0.51mm. Among orthodontic patients with Class I and II bite anomalies, only a small percentage (12.5%) was found to have the correct and symmetrical position of the temporomandibular joint. The reduction in the width of the lower respiratory tract in these patients may be associated with posterior displacement of the temporomandibular joint heads.