The aim of the present study was to explore the relation between cervical spine and cranial base inclination in patients with temporomandibular joint bony ankylosis.Patients and methods
The present study included 48 participants. They were divided into two groups. Group I (ankylosis group) included 24 patients with temporomandibular joint bony ankylosis. Group II (control group) included 24 healthy individuals. Lateral cephalometric radiographs were performed for both groups. Tracing was performed using the manual method. Reference points in the craniocervical region were marked and traced for each radiograph in both groups. Several vertical and angular cephalometric measurements were selected on the tracing. These included cranial base inclination upon cervical column [nasion-sella line (NSL)/odontoid process tangent (OPT), NSL/cervical vertebrae tangent (CVT), and atlanto-occipital (AO) distance]; inclination of cervical column (CVT/horizontal); and inclination of the odontoid process (OPT/horizontal). Comparisons were performed between the ankylosis group and the control group.Results
An unpaired t-test showed a significant increase in the NSL/OPT and NSL/CVT angles along with a significant decrease in the AO distance in the ankylosis group than the normal participants. The CVT/horizontal angle also a showed significant increase in the ankylosis group.Conclusion
There was a significant increase in NSL/OPT and NSL/CVT (cranial base inclination upon the cervical column) and this was supported by a significant decrease in the AO distance in ankylosis patients. The CVT/horizontal angle was increased, indicating an increase in the inclination of the cervical column and more accentuation of lordosis curve in ankylosis patients.