Evaluation of mallear ligaments in different voxel resolutions using cone beam computed tomography

The aim of this study was to assess the visibility of discomallear ligament and anterior mallear ligament together with anatomical morphometric measurements of petrotympanic fissure, and to determine whether the mallear ligaments correlate with the bone compartment changes of temporomandibular joint.

Cone beam CT images of 275 patients were evaluated retrospectively. The visibility of discomallear and anterior mallear ligaments were evaluated by two observers. The petrotympanic fissure was classified into four groups. Morphologic features of petrotympanic fissure and mandibular fossa were also measured in sagittal, axial and three-dimensional cone beam CT reconstructed images. Pearson's χ2 test and Student's t-test were performed for statistical analysis of differences voxel sizes, age, gender, localization, temporomandibular joint and measurements (p < 0.05). Intra- and interobserver reliability was also performed.

Type 3 petrotympanic fissure was more frequent in male, whereas females showed Type 1 and Type 2 petrotympanic fissure structures (p < 0.05). Anterior mallear ligament visibility on cone beam CT images was statistically higher in bone compartment changes of temporomandibular joint. In cone beam CT images, petrotympanic fissure tunnel types 1, 2, 3 and 4 were seen in 11.5, 35.63, 51.34 and 1.53% of patients, respectively.

Knowledge of the anatomy may help in identifying temporomandibular joint pain and auditory symptoms due to temporomandibular disorder. Further cross-sectional studies with larger populations are needed to investigate the physiopathological relation of both disorders.