Assessment of temporomandibular joint related arteries by 3-dimensional rotational angiography

The vascularization of the temporomandibular joint (TMJ) and arterial variations in this region lack consensus in the literature. Understanding the vascular anatomy surrounding the TMJ is crucial for preventing complications during joint surgery, both intra-operatively and post-operatively. Most studies on anatomical vascular variations in the TMJ rely on cadaver studies, some radiological investigations, and limited angiography studies. 3-dimensional rotational angiography (3D-RA) is an advanced technique that merges features of traditional angiography with cone beam computed tomography (CBCT), offering high-resolution imaging of the vascular anatomy and bone tissue in the TMJ region. It is also recognized as the best method for evaluating the vascular anatomy of the external carotid artery (ECA) and its branches. We examined variations of the ECA, superficial temporal artery (STA), maxillary artery (MA), middle meningeal artery (MMA), and transverse facial artery (TFA) in 67 cases (31 males, 36 females) using 3D-RA. We evaluated these variations according to age, gender, and side, including 33 bilateral cases, totaling 100 hemicraniums. In our study, the average diameter of the ECA was 3.28 ± 0.62 mm (min-max: 1.70-5.61 mm), STA was 2.10 ± 0.46 mm (min-max: 1.14-3.79 mm), MA was 2.31 ± 0.43 mm (min-max: 1.28-3.86 mm), MMA was 1.71 ± 0.41 mm (min-max: 0.93-2.69 mm) measured in 3D-RA. 51% of TSAs were located laterocondylarly, 49% were retrocondylarly, and 99% had bifurcation. 58.4% of the bifurcations are in the latero position and 41.6% are in the retro position relative to the condyle; while 11.1% were observed in the supra position, 28.3% were observed in the level and 60.6% were observed in the infra position relative to the zygomatic arch. In the course of STA before bifurcation, while 71% of them was straight, curve was observed in 23% and loop was observed in 6%. Of the 23 branches with curves; 56.5% were in the infra position relative to the zygomatic arch, 34.8% were in the same level with arch, 4.3% were in the supra position relative to the zygomatic arch, and the remaining 4.3% were two, one of the curves was in the arch level and the other was in the infra position. Of the 6 branches with loops; 16.7% were observed at the level of the zygomatic arch and 83.3% were observed in the infra position. The distance of the STA to the anterior point of the external auditory canal was measured as 4.79 ± 1.36 mm (min-max: 2.72-8.23 mm). The origin of 87% of TFAs was STA, 3% was ECA, and 10% had more than one branch and their origin was TSA and ECA together. 63% of the branches had a single branch, 31% had two, and 6% had three branches. The distance of TFA to the deepest point of the glenoid fossa was measured as 24.74 ± 3.28 mm (min-max: 15.55-32.68 mm). It was observed that 63% of the MA was superficial and 37% was deeply located compared to the lateral pterygoid muscle. The distance of deep MAs from the sigmoid notch was measured as 17.33 ± 3.14 mm, and the distance of superficial MAs was measured as 3.34 ± 2.93 mm. The origin of MMA was determined to be MA in all cases. The distance between the MMA and the most lateral aspect of the articular eminence was measured as 27.10 ± 2.38 (min-max: 21.45-34.93). Utilizing radiological image-guided surgeries, especially with support from interventional radiology methods like 3D-RA in complex cases, and employing ultrasound (USG) to assess STA, TFA, and superficial MA in cases where angiography is unavailable, can help predict and prevent potential complications associated with TMJ surgeries. It is anticipated that our study's findings, when further analyzed and integrated into larger, comprehensive studies, will contribute significantly to reducing complication rates in TMJ surgeries.