CBCT-Based Analysis of the Anatomic Characteristics of the Articular Eminence in a Sample of Iraqi Patients

Background: The articular eminence (AE) of the temporal bone plays a pivotal role in the biomechanics of the temporomandibular joint (TMJ), guiding the trajectory and dynamics of the condyle-disc complex during mandibular motion. Represented by the anterior root of the zygomatic process, the AE varies in morphology and orientation, which may influence joint function and susceptibility to degenerative changes. This study evaluated the normal anatomic characteristics of the articular eminence (AE)—including shape, height, and inclination—using cone-beam computed tomography (CBCT) in healthy Iraqi adults to establish normative reference data for temporomandibular joint (TMJ) assessment. Materials and Methods: This retrospective study included 50 CBCT scans, totaling 100 TMJs, from 27 male and 23 female subjects aged 19 to 43years. CBCT data were acquired using a Kavo 3D unit (3D On Demand software) with the following parameters: field of view 8 × 16 cm, 90 kV, 10 mA, and voxel size 0.38 mm. Statistical analyses included Pearson correlation, χ 2 tests, 1-way and 2-way ANOVA, and Tukey post hoc comparisons. Results: Box-shaped Articular eminences were most frequent on the left side (60.0%), whereas sigmoid forms predominated on the right (52.0%). A significant bilateral association was found (χ²=16.783, P <0.001, r =0.577). AE shape significantly influenced inclination and height [left: F(1,48)=26.40, P <0.001, partial η²=0.355; right: F(2,47)=14.49, P <0.001, partial η²=0.381]. Inclination correlated strongly with height bilaterally (left: r =0.802; right: r =0.744; P <0.001). Males exhibited slightly higher AE dimensions, with left inclination reaching significance [ t (47.2)=–2.079, P =0.043, Cohen d=0.576]. Age was unrelated to most AE parameters except for a moderate effect on left inclination ( P =0.027, partial η²=0.230). Conclusions: Articular eminence morphology shows significant shape-dependent variations in inclination and height, with box-shaped eminences displaying the steepest and tallest profiles. These dimensions exhibit strong bilateral symmetry and are more influenced by AE form than age or sex. These normative data provide valuable benchmarks for TMJ evaluation, prosthetic rehabilitation, and surgical planning.