Best Fit Analysis—Suture Displacement

Suture-specific displacement is obtained similarly to rotation except that the five ZMC sutures on the nontrauma, mirrored zygoma are selected for instead of the zygomatic body (Fig. ​(Fig.2A,2A, B). The displacement is then calculated at the predefined suture points to yield an average displacement score (Fig. ​(Fig.22C).

Calculation of suture displacement. A, Right-sided ZMC fracture. B, Mirrored, nontrauma zygoma with the five suture points outlined. C, Heatmap indicating displacement distances between the fractured and mirrored zygoma.

In summary, if the nontrauma mirrored ZMC travels farther or rotates more to align with the fractured ZMC, then the values returned will be greater. As a result, the data generated represents the quantitative displacement at each of the five sutures and the rotational pattern and rotational distance, in degrees, of the ZMC body along the anterior-posterior axis, lateral-medial axis, and superior-inferior axis (Fig. ​(Fig.3).3). A total displacement score was calculated by summation of the displacement values at each suture.

Example of rotation patterns on a left-sided ZMC fracture. A, Anterior rotation; B, Posterior rotation; C, Superior rotation; D, Inferior rotation; E, Lateral rotation; and F, Medial rotation.