Abstract Background Uncontrolled product spread is an important issue to consider in facial filler injections. Lack of precision can result in reduced effectiveness and surface projection, as well as irregularities and product visibility. Objectives The authors sought to assess the precision of soft-tissue filler injections in the face by employing a cannula. Methods This single-center observational study investigated soft-tissue filler distribution utilizing real-time non-invasive ultrasound imaging. Outcome parameters included (1) the tissue plane of product distribution, (2) the extent of horizontal as well as vertical product spread at the injection site, and (3) the product surface area taking into account the multifactorial influence of several independent variables. Participants were followed up to 30 days post-injection. Results A total 100 facial injections were performed in 8 patients (2 males, 6 females) with a mean age of 37.20 (±6.34) years and a mean BMI of 22.21 (±1.39) kg/m.2. The plane of product distribution remained constant in approximately 90% of cases at day 0 (d0), d14, and d30. Mean horizontal product spread was higher compared with vertical spread, and both significantly decreased over all time points (P < .001). Mean product surface area was 22.51 ± 16.34 mm2 at d0, 15.97 ± 11.28 mm2 at d14, and 12.9 ± 9.15 mm2 at d30. Analysis employing generalized linear models revealed that injection volume and injection depth significantly influenced product surface area. Conclusions Injection of soft-tissue filler employing a cannula allows precise application of the product within the intended tissue plane. Precision can be improved by injecting less product into deeper tissue layers. Level of Evidence: 5
Applied anatomy of the layers and soft tissues of the forehead during minimally‐invasive aesthetic procedures
AbstractBackgroundAn increasing demand of minimally‐invasive aesthetic procedures of the forehead concomitantly leads to higher numbers of adverse events. Adequate application of anatomical knowledge is required to increase safety and efficacy of different minimally‐invasive aesthetic procedures in this anatomical region.ObjectiveTo describe the layered anatomy of the forehead soft tissues with respect to their thicknesses and how they relate to different minimally‐invasive aesthetic treatments.MethodsA total of n = 85 healthy study participants (69 females and 16 males) with a mean age of 40.84 ± 10.9 years and a mean body mass index of 22.65 ± 2.6 kg/m2 were investigated with ultrasound‐based imaging to measure the thickness of different forehead soft tissues.ResultsThe mean overall soft tissue thickness of the forehead was measured to be 4.18 ± 0.7 mm for the entire study population. Increasing BMI values correlated statistically significantly with increasing thickness of all measured forehead soft tissues with exception of the frontalis muscle. On a statistically significant level, males showed thicker forehead soft tissues than females, with exception of the retrofrontalis fat and the frontalis muscle.ConclusionOn basis of the findings obtained in this study, basic treatment principles can be derived and improved for the injection of neuromodulators, hyaluronic acid as well as the application of polydiaxonane (PDO) threads and micro‐focused ultrasound. Precise knowledge and thorough understanding of the layers and soft tissues of the forehead is required to guarantee safe and effective procedures in this aesthetically important facial region.
Real-Time Ultrasound Imaging of the Tear Trough: Lessons Learned From Functional Anatomy
AbstractBackgroundThe tear trough is one of the most challenging facial regions for soft-tissue filler injections. A thorough understanding of the underlying facial, muscular, and vascular anatomy is crucial to perform safe and effective tear trough injectable treatments.ObjectivesThe authors sought to evaluate the location and function of the angular vein in the tear trough in 3 different facial expressions: repose, smiling, and max. orbicularis oculi contraction.MethodsTwenty study participants with a mean age of 48.3 years and mean BMI of 24.5 kg/m2 were investigated via functional ultrasound imaging. The diameter of the angular vein and the velocity and direction of venous blood flow were analyzed in repose, smiling, and during max. orbicularis oculi contraction.ResultsThe angular vein was identified in 100% of the cases to travel inside the orbicularis oculi muscle (intra-muscular course) within the tear trough, whereas the angular artery was not identified in this location. The distance between the angular vein and the inferior orbital rim was (lateral to medial): 4.6 mm, 4.5 mm, 3.9 mm, and 3.8 mm. The caudally directed blood flow was in repose 10.2 cm/s and was 7.3 cm/s at max. orbicularis oculi muscle contraction; however, no blood flow was detectable during smiling.ConclusionsThe diameter and the venous blood flow of the angular vein varied between the 3 tested facial expressions. Based on these anatomical findings, the deep injection approach to the tear trough is recommended due to the intramuscular course of the angular vein.