"Radiological morphometric analysis of the zygomatic arch: Application of osteosynthesis on the upper arch border for rigid fixation".

Background: This study was designed to introduce a novel method of applying osteosynthetic materials to the upper zygomatic arch border for fracture fixation through a temporal incision, and analyze the radiologic morphometric dimensions of the arch to verify its validity.

Methods: Radiological morphometry was analyzed in 51 adult patients with unilateral isolated zygomatic arch fractures. Frequent fracture sites, sites of minimal thickness and height, and their correlation were evaluated, as were the locations and dimensions of fixation vantage points. The novel surgical method based on the results was implemented in 17 clinical cases.

Results: Frequent fracture sites, occurring 4.40, 16.47 and 30.48 mm posterior to the arch origin, did not correlate to sites of minimal height and thickness. Arch minimal thickness and height locations were 12.23 and 27.09 mm behind its origin, respectively. Fixation vantage point dimensions varied from point to point, with upper thickness ranging from 1.67 to 4.86 mm and mid-portion thickness ranging from 2.06 to 7.36 mm, and height ranging from 8.99 to 22.53 mm. Arch vertical axis inclination ranged from 6.51° to 16.47°, which increased as the arch stretches posteriorly. These results suggested the use of 1.5 mm-wide plates and 1 mm-diameter screws with 6-8 mm length. Patients received surgery based on these morphometry results for satisfactory stabilization.

Conclusions: This study introduces a new method for open reduction and internal fixation of arch fractures, with morphometric analysis of the arch verifying the validity of tangential plate application to the upper border.