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

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 .

Morphological Measurement of Asian Osteal Nasal Base for Paranasal Augmentation.

BACKGROUND: Paranasal augmentation has been a popular approach in restoring Asian patients' lateral profile. Irregular surface in the surgical area emphasizes the importance of morphological evidence for the preoperative evaluation and the design of paranasal implants. METHODS: We retrospectively collected craniofacial computer tomography scans of patients in the department of plastic surgery from 2020 to 2022. The imaging data were imported to Mimics (version 20.0; Materialize, Leuven, Belgium) for three-dimensional reconstruction. Measurements of osteal nasal base were performed in 3-matics (version 12.0; Materialize). The severity of paranasal concavity was graded by a senior doctor to study the correlation with measured variables. RESULTS: Fifty-seven patients with a median age of 27 years (IQR: 22-33) were included in the study. For design of paranasal implants, the lengths of both lower and lateral edge were measured for reference. In the regression analysis, the alar base-alveolar process angle was significantly associated with the degrees of paranasal concavity (OR = 1.222, p = 0.00001). CONCLUSIONS: Morphological data of osteal nasal base were measured and presented in the current study. The analysis supported that alar base-alveolar process angle be used for preoperative grading and evaluation to help guiding treatment decisions. LEVEL OF EVIDENCE IV: 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 .

Expanded forehead flap in Asian nasal reconstruction.

This article reviewed our experience of Chinese nasal reconstruction over 12 years and evaluated the effect of expanded forehead flap both aesthetically and functionally. The special skin type and other anatomic features of Chinese patients was understood thoroughly during the treatment. This article thus catered for the need of multiracial nasal reconstruction. We analyzed existing clinical data and demonstrated a typical case in detail. The postoperative result supported our strategy which advocated the extensive application of expanded forehead flap, together with flip scar flap as the internal lining. The features of Chinese patients also prompted the use of costal and auricular cartilage. Emerging technology like 3D-printing would benefit nasal reconstruction from more aspects.