The Difference in Facial Movement Between the Medial and the Lateral Midface: A 3-Dimensional Skin Surface Vector Analysis.

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.

Performing Distance Measurements in Curved Facial Regions: A Comparison between Three-Dimensional Surface Scanning and Ultrasound Imaging.

Facial flap surgery depends strongly on thorough preoperative planning and precise surgical performance. To increase the dimensional accuracy of transferred facial flaps, the methods of ultrasound and three-dimensional (3D) surface scanning offer great possibilities. This study aimed to compare different methods of measuring distances in the facial region and where they can be used reliably. The study population consisted of 20 volunteers (10 males and 10 females) with a mean age of 26.7 ± 7.2 years and a mean body mass index of 22.6 ± 2.2 kg/m2. Adhesives with a standardized length of 20 mm were measured in various facial regions through ultrasound and 3D surface scans, and the results were compared. Regardless of the facial region, the mean length measured through ultrasound was 18.83 mm, whereas it was 19.89 mm for 3D surface scans, with both p < 0.0001. Thus, the mean difference was 1.17 mm for ultrasound measurements and 0.11 mm for 3D surface scans. Curved facial regions show a great complexity when it comes to measuring distances due to the concavity and convexity of the face. Distance measurements through 3D surface scanning showed more accurate distances than the ultrasound measurement. Especially in "complex" facial regions (e.g., glabella region and labiomental sulcus), the 3D surface scanning showed clear advantages.

Three-Dimensional Description of the Angular Artery in the Nasolabial Fold.

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.

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.

BACKGROUND: Differences 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. AIMS: To 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. METHODS: This 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. RESULTS: All 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. CONCLUSION: The 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.

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.