Three-Dimensional Morphological Study on the Effectiveness of Expanded Polytetrafluoroethylene Prosthesis in the Paranasal Augmentation.

ABSTRACT

BACKGROUND: The paranasal depression is a common facial feature of Oriental populations. One of the most wildly used method to improve it was paranasal augmentation using expanded polytetrafluoroethylene (ePTFE). The effectiveness of it should be tested by three-dimensional morphological measurements. METHODS: Patients who underwent paranasal augmentation using ePTFE between January 2017 and December 2022 were recruited in the study. The preoperative and postoperative clinical variables and three-dimensional measurement of patients were also collected. The satisfaction outcome were assessed. RESULTS: By establishing a coordinate system based on the Frankfurt plane, 16 landmarks including nasal alar crest, subnasal point, upper lip, pogonion, glabella, sub-cheek, orbitale, tragion in left and right side of faces were marked. Five segments, 4 ratios, and 3 angles were measured based on it. The significant increase of segments, ratios, and angles indicated that paranasal augmentation could increase the protrusion of paranasal area, both in absolute value and relative proportion. The significant decrease of other data indicated that the protrusion difference between paranasal base and upper lip, forehead, and chin, respectively, were shortened after surgery. The average size of implant was 6.54 ± 1.02 mm, and the average increase of paranasal height was 4.38 ± 1.04 mm postoperatively. This indicates that two-thirds of its height will ultimately be reflected effectively in the sagittal elevation of the paranasal base. CONCLUSIONS: Paranasal augmentation using ePTFE could effectively increase paranasal height and improve subunits relationships, and the ePTFE prosthesis should be designed and carve considering the 1/3 loss of height after implantation. LEVEL OF EVIDENCE III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .