Publications by authors named "Cheng-En Luo"

Background: Temple filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon.

Objectives: This study aimed to investigate the anatomy of the temporal vessels and provide a more accurate protocol for temple filler injection.

Methods: Computed tomography (CT) scans of 56 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3-dimensional (3D) images of the temporal vessels described by a coordinate system based on the bilateral tragus and right lateral canthus.

Results: In the XOY plane, the superficial temporal artery (STA), middle temporal artery (MTA), zygomatico-orbital artery (ZOA), posterior branch of the deep temporal artery (PDTA), and lateral margin of the orbital rim divide the temple into 4 parts (A, B, C, and D). The probabilities of the STA, MTA, ZOA, and PDTA appearing in parts A, B, C, and D were 30.73%, 37.06%, 39.48%, and 77.18%, respectively. In 3D images, these vessels together compose an arterial network that is anastomosed with other vessels, such as the external carotid, facial, and ocular arteries.

Conclusions: 3D CT images can digitally elucidate the exact positions of temporal vessels in a coordinate system, improving the safety of temple filler injections in a clinical setting.

Background: Nasal filler placement is associated with a high risk of blindness. The arterial supply to the upper nose overlaying the nasal bones is poorly understood.

Objectives: This study attempts to visualize and analyze the deployment of the ophthalmic and facial angiosomes in the upper nose and help prevent blindness in nasal filler injections.

Methods: The arterial systems of 62 cadaveric heads were filled with lead oxide contrast, and computed tomography (CT) images were acquired and reconstructed in three-dimensions.

Results: Twenty-six of the cadaveric noses examined demonstrated clear CT images for the facial and ophthalmic angiosomes in the upper nose. The Type 1 upper nose (15.4 percent) is supplied by two independent ophthalmic angiosomes that communicate indirectly through choke anastomosis. The Type 2 upper nose (38.5 percent) is supplied by two ophthalmic angiosomes with true anastomosis between them. The Type 3 upper nose (46.1 percent) is supplied by both ophthalmic and facial angiosomes with true anastomoses across the dorsal midline. These true anastomoses are mediated by the radix arcade in 46 percent of the noses and involve the dorsal nasal artery in 65 percent of the cases. The anastomoses all cross the upper dorsal midline and are directly linked to the ophthalmic angiosome.

Conclusions: The deployment and anastomosis of the facial and ophthalmic angiosomes in the upper nose fall into three major patterns. About 85 percent of the noses have true anastomotic arteries that cross the upper dorsal midline and are directly linked to the ophthalmic circulation. Dorsum filler injection poses a significant risk of blindness.

Background: Strengthening weakened ligament tissues with injectable fillers to improve their supportive effect may achieve the aesthetic goal of face lifting.

Objectives: The aim of our study was to design an injectable technique for enhancing the true facial ligaments and dissect the ligaments to provide anatomical guidance for effective injection.

Methods: Six true facial ligaments were chosen as target anatomical sites for injection. Specimens were dissected, and three-dimensional images were reconstructed to confirm the exact location of each injection site and to confirm that the proposed injection routes will not cause dangerous vascular damage. A total of five patients received the injections; three-dimensional images were taken before and after the injections for comparison and clinical outcome assessments.

Results: The injection technique was designed to target six true facial ligaments, as follows. Site 1 targeted the temporal ligamentous adhesion region to lift the lateral ends of the eyebrows. Site 2 targeted the region of the lateral orbital thickening to lift the lateral canthus. Site 3 and site 4 targeted the zygomatic retaining ligaments and zygomatic cutaneous ligaments, respectively, to augment the soft tissues of the midface. Site 5 targeted the region of the maxillary ligament to lessen the nasolabial folds, and site 6 targeted the mandibular ligament to reduce the marionette line.

Conclusions: This site-specific injection technique targeting the true ligaments may lead to increased efficiency and accuracy of face rejuvenation and exert a lifting effect.

Background: Injection-based techniques for "cheek augmentation" have gained popularity in recent years. The aim of this study was to perform a topographic analysis of the depth and distribution of the vessels in the zygomatic region to facilitate clinical procedures.

Methods: The external carotid arteries of seven cadaveric heads were infused with lead oxide contrast medium. The facial and superficial temporal arteries of another 12 cadaveric heads were injected sequentially with the same medium. Computed tomographic scanning was then performed, and three-dimensional computed tomographic scans were reconstructed using validated algorithms.

Results: The vessels on the zygomatic arch received a double blood supply from across the upper and lower borders of the arch, and the number of the vessels varied from one to four. Ninety percent of the vessels on the zygomatic arch were at a depth of 1 to 2.5 mm, and 75 percent were at a depth of 10 to 30 percent of the soft-tissue thickness. The vessels were concentrated on the midline of the zygomatic arch and the lateral margin of the frontal process. All samples showed a vessel travel along the lateral margin of the frontal process that eventually merged into the superior marginal arcades.

Conclusions: This study reported a topographic analysis of the depth and distribution of the vessels in the zygomatic region based on three-dimensional scanning. The results indicated that injection on the zygomatic arch should be performed deep to the bone, and the vascular zones anterior or posterior to the midline of the zygomatic arch were relatively safe injection areas.

Background: The forehead is a challenging area for filler injection because of the risk of serious complications. Anatomy-based filler injection techniques help to avoid severe vascular complications.

Materials And Methods: Sixty-six cadaver heads were infused with adequate lead oxide contrast through the external carotid arteries, internal carotid arteries, facial artery, and superficial temporal artery. Three-dimensional computed tomography scans were reconstructed using validated algorithms. We measured the length and arc length of "beautiful" foreheads evaluated by 3 skilled surgeons.

Results: The frontal branch of the superficial temporal artery (FBSTA) was classified based on the main trunk as follows: Type I FBSTA (89.72%) took a sudden turn (89.56° ± 11.76°) once passing through the temporal crest, whereas Type II FBSTA (10.28%) barely turned (52.26° ± 6.81°) at the temporal crest. A total of 319 arteries passed through the midline in 48 cadaver heads. There were more superficial arteries (292 of 319) than deep arteries (27 of 319). The difference in the length and arc length of the forehead was 19.66 ± 4.35 mm.

Conclusion: This study introduces an effective technique for forehead filler injection that minimizes the risk of filler injection and improves patient satisfaction.

Background: Vascular complications from periorbital intravascular filler injection are major safety concerns.

Objective: To thoroughly describe the superior orbital vessels near the orbital rim and propose considerations for upper eyelid and forehead injections.

Methods: Fifty-one cadaver heads were infused with lead oxide contrast media through the external carotid artery, internal carotid artery, and facial and superficial temporal arteries. Computed tomography (CT) images were obtained after contrast agent injection, and 3-dimensional CT scans were reconstructed by using a validated algorithm.

Results: Eighty-six qualified hemifaces clearly showed the origin, depth, and anastomoses of the superior orbital vessels, which consistently deployed 2 distinctive layers: deep and superficial. Of all hemifaces, 59.3% had deep superior orbital vessels near the orbital rim, including 44.2% with deep superior orbital arcades and 15.1% with deep superior orbital arteries, which originated from the ophthalmic artery. Additionally, 97.7% of the hemifaces had superficial superior orbital arcades, for which 4 origins were identified: ophthalmic artery, superior medial palpebral artery, angular artery, and anastomosis between the angular and ophthalmic arteries.

Limitations: The arterial depth estimated from 3-dimensional CT needs to be confirmed by standard cadaver dissection.

Conclusion: This study elucidated novel arterial systems and proposed considerations for upper eyelid and forehead injections.

Background: Filler injection is a popular cosmetic procedure, but it can entail vascular complications. Periorbital injections have the highest risk within the entire injection area.

Objectives: The authors sought to systematically screen for periorbital arterial variations prior to treatment.

Methods: The external carotid arteries of 10 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 11 cadaveric heads were injected with the contrast in sequential order. Computed tomography (CT) scanning was performed after injection of contrast, and 3-dimensional (3D) CT scans were reconstructed using validated algorithms.

Results: Three types of periorbital blood vessels were found to derive from the ophthalmic artery, including 30% directly originating from the ophthalmic artery, 65% originating from its trochlear branch, and 5% originating from its supraorbital branch. In the forehead, the ophthalmic artery, originating from the internal carotid arteries, formed anastomoses between the frontal branch of the superficial temporal artery, originating from the external carotid artery, with the deep and superficial branches of the supratrochlear and supraorbital arteries, respectively. The lateral orbit and malar plexus can be classified into 4 types based on the trunk artery: the zygomatic orbital artery (27%), the transverse facial artery (23%), the premasseteric branch of the facial artery (19%), and all 3 contributing equally (31%).

Conclusions: Postmortem 3D CT can map periorbital arterial variations. The branching pattern of the ophthalmic artery, the ophthalmic angiosome in the forehead, and the distribution of the lateral orbit and malar plexus were identified at high resolution to guide clinical practice.

Background: Vascular complications resulting from intravascular filler injection and embolism are major safety concerns for facial filler injection. It is essential to systematically screen full-face arterial variations and help design evidence-based safe filler injection protocols.

Methods: The carotid arteries of 22 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 12 cadaveric heads were injected with the contrast in a sequential order. A computed tomographic scan was acquired after each contrast injection, and each three-dimensional computed tomographic scan was reconstructed using validated algorithms.

Results: Three-dimensional computed tomography clearly demonstrated the course, relative depth, and anastomosis of all major arteries in 63 qualified hemifaces. The ophthalmic angiosome consistently deploys two distinctive layers of branch arteries to the forehead. The superficial temporal and superior palpebral arteries run along the preauricular and superior palpebral creases, respectively. The study found that 74.6 percent of the hemifaces had nasolabial trunks coursing along the nasolabial crease, and that 50.8 percent of the hemifaces had infraorbital trunks that ran through the infraorbital region. Fifty percent of the angular arteries were the direct anastomotic channels between the facial and ophthalmic angiosomes, and 29.2 percent of the angular arteries were members of the ophthalmic angiosomes.

Conclusions: Full-face arterial variations were mapped using postmortem three-dimensional computed tomography. Facial creases were in general correlated with underlying deep arteries. Facial and angular artery variations were identified at high resolution, and reclassified into clinically relevant types to guide medical practice.