Abstract Background Our understanding of the functional anatomy of the face is constantly improving. To date, it is unclear whether the anatomic location of the line of ligaments has any functional importance during normal facial movements such as smiling. Objectives The authors sought to identify differences in facial movements between the medial and lateral midface by means of skin vector displacement analyses derived from 3-dimensional (3D) imaging and to further ascertain whether the line of ligaments has both a structural and functional significance in these movements. Methods The study sample consisted of 21 healthy volunteers (9 females and 12 males) of Caucasian ethnic background with a mean age of 30.6 (8.3) years and mean BMI of 22.57 (2.5) kg/m2. 3D images of the volunteers’ faces in repose and during smiling (Duchenne type) were taken. 3D imaging-based skin vector displacement analyses were conducted. Results The mean horizontal skin displacement was 0.08 (2.0) mm in the medial midface (lateral movement) and was −0.08 (1.96) mm in the lateral midface (medial movement) (P = 0.711). The mean vertical skin displacement (cranial movement of skin toward the forehead/temple) was 6.68 (2.4) mm in the medial midface, whereas it was 5.20 (2.07) mm in the lateral midface (P = 0.003). Conclusions The results of this study provide objective evidence for an antagonistic skin movement between the medial and lateral midface. The functional boundary identified by 3D imaging corresponds to the anatomic location of the line of ligaments. Level of Evidence: 4
To click or not to click – The importance of understanding the layers of the forehead when injecting neuromodulators – A clinical, prospective, interventional, split‐face study
AbstractBackgroundDifferences in the effectiveness of neuromodulator treatments for horizontal forehead lines dependent on depth of product administration have been described. However, knowledge in respect to the fascial anatomy of the forehead still remains elusive.AimsTo relate the fascial anatomy of the forehead to the effectiveness of neuromodulator treatments by conducting a clinical, prospective, interventional split‐face study in which injections for the treatment of horizontal forehead lines are performed differently between facial sides.MethodsThis study included a total of n = 14 patients with a mean age of 35.71 (7.8) years and mean body mass index of 21.9 (3.0) kg/m2. One side of the forehead was injected superficially by positioning the product in the superficial fatty layer, whereas the contralateral side was injected deep targeting the supraperiosteal plane (random selection). The treatment outcome was rated by the physician and by two independent observers according to a forehead line severity scale (0‐4) at 14 and at 30 days.ResultsAll three observers agreed in their ratings (ICC: 0.942) that the deep injection technique resulted in a superior outcome: D14 (superficial vs deep) 0.17 (0.4) vs 0.14 (0.4; P = .583) at rest and 1.26 (0.6) vs 0.43 (0.5; P < .001) for frontalis contraction; D30 0.17 (0.4) vs 0.14 (0.3) at rest (P = .583) and 1.21 (0.6) vs 0.43 (0.5; P < .001) for frontalis contraction.ConclusionThe results of this study underscore how detailed anatomic knowledge can enhance results of aesthetic interventions, in this case horizontal forehead line treatment with neuromodulators.
The Course of the Angular Artery in the Midface: Implications for Surgical and Minimally Invasive Procedures
Abstract Background Previous anatomic studies have provided valuable information on the 2-dimensional course of the angular segment of the facial artery in the midface and its arterial connections. The third dimension (ie, the depth of the artery) is less well characterized. Objectives The objective of the present study was to describe the 3-dimensional pathway of the angular segment of the facial artery and its relationship to the muscles of facial expression. Methods The bilateral location and the depth of the midfacial segment of the facial artery was measured utilizing multi-planar computed tomographic image analyses obtained from contrast agent-enhanced cranial computed tomographic scans of 156 Caucasians aged a of 45.19 ± 18.7 years and with a mean body mass index of 25.05 ± 4.9 kg/m2. Results At the nasal ala, the mean depth of the main arterial trunk was 13.7 ± 3.7 mm (range, 2.7-25.0 mm), whereas at the medial canthus it was 1.02 ± 0.62 mm (range, 1.0-3.0 mm). This was reflected by the arteries’ relationship to the midfacial muscles: at the nasal ala superficial to levator anguli oris in 62.0% but deep to the levator labii superioris alaeque nasi in 53.6%; at the medial canthus superficial to the levator labii superioris alaeque nasi in 83.1% and superficial to the orbicularis oculi in 82.7%. Conclusions The results presented herein confirm the high variability in the course of the angular segment of the facial artery. Various arterial pathways have been identified providing evidence that, in the midface, there is no guaranteed safe location for minimally invasive procedures.
Three-Dimensional Description of the Angular Artery in the Nasolabial Fold
Abstract Background Due to its arterial vasculature, the nasolabial sulcus is one of the most challenging facial regions to treat when trying to ameliorate the signs of facial aging. Objectives The aim of the present study was to provide data on the 3-dimensional course of the angular artery within the nasolabial sulcus in relation to age, gender, and body mass index to increase safety during minimally invasive treatments. Methods Thee hundred nasolabial sulci from 75 males and 75 females of Russian Caucasian ethnic background (mean [standard deviation] age, 45.7 [18.7] years; mean body mass index, 25.14 [4.9] kg/m2) were analyzed. Bilateral multiplanar measurements were based on contrast-enhanced computed tomography cranial scans. Results Up to 3 arteries could be identified within the nasolabial sulcus: ~90% contained 1 arterial trunk, ~9% had 2 trunks, and ~1% had 3 trunks; females had more arteries than men. The artery is located at mean depths of 21.6 mm at the oral commissure and 8.9 mm at the nasal ala. The angular artery was lateral to the nasolabial sulcus in 100% of cases; the smallest distance between the artery and the nasolabial sulcus was at the oral commissure (11.91 [7.9] mm) and the greatest was at the nasal ala (13.73 [3.9] mm). Conclusions In contrast to current concepts, the angular artery is not located strictly subdermal to the nasolabial sulcus but at a variable depth, and in 100% of the investigated cases lateral to the nasolabial sulcus. With increasing age, the depth and lateral distance between arteries and sulci reduces significantly, underscoring the need for special caution when injecting this site.