Search

Background: Choke anastomosis is commonly recognized as a resistance factor that detrimentally affects the hemodynamics of the skin flap; however, its additional potential physiological roles in normal skin function are currently not fully understood., Methods: Ten cadaveric forehead flap specimens pedicled with unilateral STAs were perfused with lead oxide-gelatin mixture, and then dissected into 3 layers, including the super temporal fascia-frontalis-galea aponeurotica layer, the subcutaneous adipose tissue layer, and the "super-thin flap" layer. The forehead flap and stratified specimens underwent molybdenum target x-ray and subsequent transparent processing to effectively visualize the microscopic spatial architecture of arterial vessels across all levels., Results: Based on the different anastomoses near the midline area of the flap, 2 types of arterial perfusion were identified: choke anastomosis type (8/10) and true anastomosis type (2/10). The former formed multiple choke anastomoses near the midline. In the "super-thin flap" layer, arterial perfusion density on the ipsilateral side was significantly higher compared to that on the contralateral side. The arterioles on the ipsilateral side exhibited a dense and uninterrupted distribution, whereas those on the contralateral side appeared sparse and dispersed. The latter exhibited an alternative perfusion pattern; the bilateral arterial vessels were connected with 3 to 5 true anastomoses near the midline. Furthermore, the microscopic architecture confirmed a uniform distribution of arterioles that remained continuous from ipsilateral to contralateral sides in the "super-thin flap" layer., Conclusion: This study demonstrated that choke anastomosis not only impairs blood perfusion in the adjacent angiosomes but also acts as a shunt converter to impact the blood supply of distal skin flaps at different levels through the "trans-territory diversion phenomenon." This results in necrosis of the superficial dermis while preserving survival of the deep subcutaneous adipose tissue., Competing Interests: Conflicts of interest and sources of funding: All the authors declare that they had no financial interests or commercial associations during the course of this study., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Deep learning algorithms based on automatic 3D cephalometric marking points about people without craniomaxillofacial deformities have achieved good results. However, there has been no previous report about hemifacial microsomia (HFM). The purpose of this study is to apply a new deep learning method based on a 3D point cloud graph convolutional neural network to predict and locate landmarks in patients with HFM based on the relationships between points. The authors used a PointNet++ model to investigate the automatic 3D cephalometry. And the mean distance error (MDE) of the center coordinate position and the success detection rate (SDR) were used to evaluate the accuracy of systematic labeling. A total of 135 patients were enrolled. The MDE for all 32 landmarks was 1.46 ± 1.308 mm, and 10 landmarks showed SDRs at 2 mm over 90%, and only 4 landmarks showed SDRs at 2 mm under 60%. Compared with the manual reproducibility, the standard distance deviation and coefficient of variation values for the MDE of the artificial intelligence system was 0.67 and 0.43, respectively. In summary, our training sets were derived from HFM computed tomography to achieve accurate results. The 3D cephalometry system based on the graph convolutional network algorithm may be suitable for the 3D cephalometry system in HFM cases. More accurate results may be obtained if the HFM training set is expanded in the future., Competing Interests: Conflicts of interest and sources of funding: All authors declare no competing interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The repair of nasal deformities secondary to cleft lip and palate is complex and requires reliable preoperative nasal 3-dimensional assessment. This study explored nasal end (defined as the lower third of the external nasal and vestibular parts of the nasal cavity) deformities secondary to unilateral complete cleft lip and palate., Methods: Three-dimensional nasal end morphometric measurements were obtained from 48 patients who had undergone Millard cleft lip repair and reached skeletal maturity (cleft group) and from 36 age- and ethnicity-matched normal subjects (control group). For the cleft group, paired t tests and 1-way analysis of covariance were used to evaluate the internal and external morphological characteristics of the cleft and noncleft sides of the nasal end, and correlation analysis was done to evaluate the relationship between cleft-side measurements., Results: In the cleft group, the cleft side showed significantly smaller nasal vestibular volume and skin area, nostril area, nasal column length, and nostril height and greater nostril base length and nasal alar length than the noncleft side (all P < 0.05). Controlling for sex, there were significant differences in the nasal vestibular volume and skin area, internal nasal valve area, long nostril diameter, nostril base length, columella length, nostril height, and nasal alar length between the cleft and control groups (all P < 0.05). On the cleft side, the area of the skin lining of the nasal vestibule positively correlated with the alar length (r = 0.67, P < 0.05)., Conclusions: Three-dimensional nasal end reconstruction provides a more detailed preoperative nasal end morphological evaluation than previously available techniques., Level of Evidence: Level III, case-control study., Competing Interests: Conflicts of interest and sources of funding: The authors have no conflicts of interest. This study is supported by the Capital Medical Development Research Project (2020-2-4043)., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: This study aimed to introduce a novel approach to study the facial mimetic muscles (FMMs) related to the nasolabial fold (NLF) and realize the visualization of complex 3-dimensional (3D) structures of the FMM., Methods: Micro-computed tomography (micro-CT) and iodine staining technique were used to obtain the 2-dimensional radiographs of the FMM. Materialise Mimics software was then used to reconstruct the 3D model of the FMM., Results: The zygomaticus major muscle was not directly connected to the orbicularis oris muscle (OOM). The terminal fibers of the zygomaticus major muscle were located in the levator anguli oris. The surface of the FMM was covered with some unknown muscle fibers in the NLF. The terminal fibers of the zygolabialis ended in the middle of the ipsilateral OOM rather than the edge of the OOM. At the same anatomical level, the FMM fibers were so closely connected to each other that they were not separated by adipose tissue. A detailed 3D sequence of the muscle fibers in the modiolus at the corner of the mouth was determined. The muscle fibers in the modiolus were organized rather than disorganized. The terminal fibers of the levator anguli oris were located at the terminal fibers of the musculus depressor anguli oris at the corner of mouth., Conclusions: Although the micro-CT had many disadvantages, the micro-CT combined with iodine staining technique enabled the 3D anatomical study of the FMM related to NLF. We imported the 2-dimensional images obtained by micro-CT scanning into Mimics software, successfully reconstructed the FMM related to the NLF, and finally obtained images of complex 3D structures of the FMM related to the NLF. The shapes, positions, and 3D spatial relationships between the FMM related to the NLF were clearly visualized. The novel insights into the 3D anatomy of the FMM related to NLF may help understand the formation of the NLF. Finally, the results of this study may help improve rejuvenation surgery of the NLF in the near future.

Purpose: This study aims to investigate the 3-dimensional (3D) anatomical structure of the orbicularis oris and nasalis, which are closely associated with the appearance of the upper lip and lower part of the nose. The relationship of the complicated 3D anatomical structure with the outline shape was also determined., Methods: Microcomputed tomography combined with iodine staining was used to scan the nasolabial tissues of 3 aborted fetuses. The strictly aligned, corrected, full-capacity, 2-dimensional (2D) grayscale images obtained were then used to reconstruct 3D structures using a 3D reconstruction software., Results: 2D grayscale slices and a 3D anatomical model of the orbicularis oris and nasalis of the specimens were obtained. The 2D images and the 3D model confirmed the orbicularis oris anatomical structure reported in previous studies and also provided new insights (such as the close association of the formation of the philtral dimple, lip peak, philtral ridge, and nasal sill with the orbicularis oris). In addition, the results show that the nasolabial muscle consists of muscle fibers from different sources and is divided into four distinct parts: pars marginalis, pars peripheralis, muscle fibers of the levator labii superioris, and nasalis muscle fibers., Conclusion: The 3D anatomical structures indicate that the orbicularis oris and nasalis are closely associated with the appearances of the upper lip and lower part of the nose. The results may aid plastic surgeons in performing cleft-lip correction surgery.

Background: The upper lip can be divided into aesthetic subunits. Accordingly, we classified the upper lip defect into 3 categories: medial subunit defect, lateral subunit defect, and cross-subunit defect. The defect should be repaired aesthetically. We developed an innovative partial-thickness myocutaneous flap based on the vascular network of the submucosal and subcutaneous layers. The flap was more flexible for aesthetic reconstruction of the upper lip, even the fine anatomic structures., Methods: For three and a half years, a total of 59 patients were used with this new technique, including those with secondary deformities from bilateral cleft lip, postinjury upper lip defects, and posthemangioma treatment defects. The inclusion criteria were that the defects of the upper lip were within 2.0 cm in adults and 1.5 cm in children generally. The split flap was elevated from the posterior portion of the orbicularis oris muscle after the inferior labial artery was divided. The flap was supplied by the vascular network derived mainly from the horizontal labiomental artery and/or the vertical labiomental artery., Results: All 59 cases of musculomucosal-pedicle flaps were viable. The upper lip was reconstructed according to the aesthetic subunits. In some cases, the fine anatomic structures were reconstructed, including the philtral column, the philtral dimple, curve of the Cupid's bow, and vermilion tubercle. The patients were all satisfied with their appearance., Conclusions: This myocutaneous cross-lip flap with musculomucosal-pedicle is an effective method for aesthetic reconstruction of the upper lip. It can provide larger tissue with better flexibility and plasticity in clinical application.