Objective. To develop a method for assessing the midface soft tissue changes after thread-lifting by comparing 3D models obtained by combining photogrammetric scans before and at various periods after procedure with CT data.

Material and methods. Implantation of PLCL threads with notches for aesthetic correction of the midface was performed in 5 patients aged 28, 32, 45, 55 and 70 years. Photogrammetry scans were performed before, early after thread-lifting, a week, two weeks, one month, two months and three months later. Patients underwent CT of facial soft tissues at baseline and 3 months after surgery. CT and photogrammetric scans were superimposed by the benchmarks, and subsequent analysis of volumetric changes at the follow-up stages was performed. Clinical examination was performed before, one week, two weeks, one month, two months and three months after procedure.

Results. Volume redistribution shows significant edema early after procedure with regression a month later. Volume changes within 1-3 months after procedure reveal residual soft tissue redistribution along the vector of thread implantation (minimum positive height 0.7 mm, maximum positive height 1.92 mm). Area of changes decreases over time with minimum of 374 mm and maximum of 3496.32 mm. Thread-lifting has a more effect in older patients as evidenced by maximum positive and negative changes in these ones.

Conclusion. Thread lifting has the effect of soft tissue volume redistribution after regression of edema. Photogrammetry is the optimal method for assessing changes after implantation of threads in the midface.

Keywords. thread lifting, photogrammetry, facial rejuvenation, minimally invasive aesthetic procedure