Short term effects produced by Cervical headgear and Hilgers’ pendulum on head posture and on airway space

The study investigates the effects of cervical headgear (CHG) in the treatment of Class II malocclusion, focusing on changes in head and cervical posture, as well as upper airway and hyoid bone positioning. Maxillary molar distalization is a critical part of Class II treatment, and although the traditional approach using extraoral appliances like CHG offers stability, its aesthetic drawbacks and the need for patient compliance have led to the exploration of non-compliant alternatives. The primary objective of the study was to assess how CHG affects the head and cervical posture, airway dimensions, and the position of the tongue and hyoid bone, in comparison with a control group treated with a Hilger’s Pendulum appliance. The study involved 40 subjects aged 11–14, divided into two groups: one treated with CHG and the other with the Pendulum appliance. Pre-treatment and post-treatment cephalometric radiographs were analyzed to assess these variables. Results showed that CHG treatment caused a significant reduction in craniocervical angles, indicating a flexion of the head. Additionally, the cervical vertebrae moved forward, with a marked increase in the distance between C1 and C2. Furthermore, there was a reduction in upper airway space, a lengthening of the tongue by 9 mm, and an anterior and downward movement of the hyoid bone. These changes were statistically significant when compared to the control group. The Pendulum appliance, however, did not show similar significant changes. The findings suggest that the use of CHG influences both craniofacial posture and airway dimensions, potentially contributing to mandibular advancement and improved airway space. Future studies could explore whether these changes persist after treatment.