COVID-19-induced Scalp Alopecia Treated Effectively with Stem Cell Serum.

Up to 36.7% of symptomatic COVID-19 patients will have telogen effluvium (TE), which refers to diffuse scalp alopecia. With the continuing global pandemic, a review of literature reports unpredictable and incomplete recovery with conventional treatment like minoxidil. The pathogenesis of COVID-19-induced TE may be more severe than that of conventional TE as the hair follicles are proposed to be directly damaged by cytokines and thromboembolism. There is no current standardized treatment for COVID-19-induced TE. We present a patient with severe chronic TE, with no spontaneous recovery after 6 months of hair loss and minimal response to minoxidil. We commenced monthly applications of stem cell serum (Calecim). We present the results of five treatments spaced monthly, after which he experienced effective regrowth of scalp hair. We propose stem cell serum for patients who have failed conventional treatment or as an adjunct to conventional therapy in COVID-19-induced TE.

Feasibility of using computer simulation to predict the postoperative outcome of the minimally invasive Nuss procedure: Simulation prediction vs. postoperative clinical observation.

The Nuss procedure is the most minimally invasive and commonly used surgical correction for pectus excavatum (PE) by using a prebent pectus bar to elevate the deformed chest wall. However, there are some complications associated with this procedure such as postoperative pain as well as surgical uncertainties because of human judgment. It is therefore important to understand the biomechanical effect of the pectus bar on PE thoraces undergoing an operation to alleviate the postoperative pain as well as to improve surgical outcome. The current study incorporated the finite element method (FEM) to simulate the entire Nuss procedure including the flipping process of the pectus bar on a preoperative PE patient-specific thorax model, in conjunction with comparison against the postoperative CT scans. The mid-sagittal sternovertebral elevation was found to be within 5.32 mm, whereas the transverse sternal deviations ranged from 1.59 to 3.02 mm. The average discrepancy between the predicted contour and postoperative CT contour was approximately 3%. On a different note, the stress and strain distributions largely concurred with reported findings. High bilateral stress was seen to occur at the back of ribs near the vertebral column, and particularly over the second to fifth ribs, whereas the greatest strain was found to be confined to the regions of costal cartilages. It is evident that the FEM is a feasible and robust approach in predicting the outcome of the mechanical surgical procedure. This contributes to the future development of a predictive tool incorporated in surgical planning to enhance surgical management of PE.

Similar Fracture Patterns in Human Nose and Gothic Cathedral.

This study proposes that the bony anatomy of the human nose and masonry structure of the Gothic cathedral are geometrically similar, and have common fracture patterns. We also aim to correlate the fracture patterns observed in patients' midface structures with those seen in the Gothic cathedral using computational approach. CT scans of 33 patients with facial fractures were examined and compared with computer simulations of both the Gothic cathedral and human nose. Three similar patterns were found: (1) Cracks of the nasal arch with crumpling of the vertical buttresses akin to the damage seen during minor earthquakes; (2) lateral deviation of the central nasal arch and collapse of the vertical buttresses akin to those due to lateral forces from wind and in major earthquakes; and (3) Central arch collapse seen as a result of collapse under excessive dead weight. Interestingly, the finding of occult nasal and septal fractures in the mandible fractures with absence of direct nasal trauma highlights the possibility of transmission of forces from the foundation to the arch leading to structural failure. It was also found that the structural buttresses of the Gothic cathedral delineate the vertical buttresses in the human midface structure. These morphologic similarities between the human nose and Gothic cathedral will serve as a basis to study the biomechanics of nasal fractures. Identification of structural buttresses in a skeletal structure has important implications for reconstruction as reestablishment of structural continuity restores normal anatomy and architectural stability of the human midface structure.

Investigation of the relationship between facial injuries and traumatic brain injuries using a realistic subject-specific finite element head model.

In spite of anatomic proximity of the facial skeleton and cranium, there is lack of information in the literature regarding the relationship between facial and brain injuries. This study aims to correlate brain injuries with facial injuries using finite element method (FEM). Nine common impact scenarios of facial injuries are simulated with their individual stress wave propagation paths in the facial skeleton and the intracranial brain. Fractures of cranio-facial bones and intracranial injuries are evaluated based on the tolerance limits of the biomechanical parameters. General trend of maximum intracranial biomechanical parameters found in nasal bone and zygomaticomaxillary impacts indicates that severity of brain injury is highly associated with the proximity of location of impact to the brain. It is hypothesized that the midface is capable of absorbing considerable energy and protecting the brain from impact. The nasal cartilages dissipate the impact energy in the form of large scale deformation and fracture, with the vomer-ethmoid diverging stress to the "crumpling zone" of air-filled sphenoid and ethmoidal sinuses; in its most natural manner, the face protects the brain. This numerical study hopes to provide surgeons some insight in what possible brain injuries to be expected in various scenarios of facial trauma and to help in better diagnosis of unsuspected brain injury, thereby resulting in decreasing the morbidity and mortality associated with facial trauma.

Computer-Aided Analysis of the "Beautiful" Umbilicus.

BACKGROUND: The position, shape, size, and depth of the umbilicus influence the overall aesthetics of the abdomen. Hence, umbilicoplasty is a common adjunct to aesthetic and reconstructive surgery of the abdominal wall. Delineation of the position and shape of the "beautiful" umbilicus can aid in the planning of abdominoplasty and lipoabdominoplasty. OBJECTIVES: The authors aimed to identify key parameters of the beautiful umbilicus. METHODS: Previously, the authors developed software (the Aesthetic Analyzer) for marking and analyzing parameters from images of the nose, breast, and umbilicus. In the present study, the Aesthetic Analyzer was utilized to determine parameters of the beautiful umbilicus from images of 37 Playboy playmates. The vertical position, horizontal position, length, and shape of the umbilicus were assessed. RESULTS: Based on these images, the beautiful umbilicus possesses the following properties: a vertical ratio of 46:54 (with respect to the xiphoid process and lower limit of the vulvar cleft), a midline horizontal position, a length that is 5% of the length from the xiphoid process to the lower limit of the vulvar cleft, and an oval shape with no hooding (29.8%) or superior hooding (21.6%). CONCLUSIONS: Awareness of the ideal position, shape, and size of the umbilicus can be useful for achieving successful reconstruction of the umbilicus during abdominoplasty and lipoabdominoplasty.

Reconstructing a large helical rim defect: synergy of a postauricular perforator flap, diced cartilage, and otoplasty technique.

Large full thickness helical ear defects are a challenge to reconstruct. A 25-year-old woman presented to us with loss of a large portion of the helical rim after an assault. A successful 2-stage reconstruction was performed, incorporating the principles of perforator flaps, otoplasty techniques, and use of diced cartilage more commonly used for rhinoplasty. There was a 5 × 0.5-cm central helical defect of the right ear. In the first stage, the original defect was recreated and a 7 × 1.5-cm inferiorly based postauricular artery perforator flap was raised from the right postauricular sulcus. Diced cartilage was harvested from the adjacent conchal bowl and conchomastoid sutures were used to set the relatively prominent ear back so as to facilitate tension-free donor-site closure. Diced cartilage was wrapped in the deep fascia of the perforator flap and the edges of the deep fascia were sutured to the perichondrium of the exposed cartilage. The pedicle was divided at a second stage. At 1-year postoperation, the reconstructed ear maintained good form and symmetry, and the patient was satisfied with the outcome. This is a novel efficient technique of reconstructing large ear helical defects combining a postauricular artery perforator flap with wrapped diced cartilage augmentation, and incorporating classical otoplasty technique for virtually scarless donor-site closure.

Development and validation of two subject-specific finite element models of human head against three cadaveric experiments.

Head injury, being one of the main causes of death or permanent disability, continues to remain a major health problem with significant socioeconomic costs. Numerical simulations using the FEM offer a cost-effective method and alternative to experimental methods in the biomechanical studies of head injury. The present study aimed to develop two realistic subject-specific FEMs of the human head with detailed anatomical features from medical images (Model 1: without soft tissue and Model 2: with soft tissue and differentiation of white and gray matters) and to validate them against the intracranial pressure (ICP) and relative intracranial motion data of the three cadaver experimental tests. In general, both the simulated results were in reasonably good agreement with the experimental measured ICP and relative displacements, despite slight discrepancy in a few neutral density targets markers. Sensitivity analysis showed some variations in the brain's relative motion to the material properties or marker's location. The addition of soft tissue in Model 2 helped to damp out the oscillations of the model response. It was also found that, despite the fundamental anatomical differences between the two models, there existed little evident differences in the predicted ICP and relative displacements of the two models. This indicated that the advancements on the details of the extracranial features would not improve the model's predicting capabilities of brain injury.

Simulators of squamous cell carcinoma of the skin: diagnostic challenges on small biopsies and clinicopathological correlation.

Squamous cell carcinoma (SCC) is a common and important primary cutaneous malignancy. On skin biopsies, SCC is characterized by significant squamous cell atypia, abnormal keratinization, and invasive features. Diagnostic challenges may occasionally arise, especially in the setting of small punch biopsies or superficial shave biopsies, where only part of the lesion may be assessable by the pathologist. Benign mimics of SCC include pseudoepitheliomatous hyperplasia, eccrine squamous syringometaplasia, inverted follicular keratosis, and keratoacanthoma, while malignant mimics of SCC include basal cell carcinoma, melanoma, and metastatic carcinoma. The careful application of time-honored diagnostic criteria, close clinicopathological correlation and a selective request for a further, deeper, or wider biopsy remain the most useful strategies to clinch the correct diagnosis. This review aims to present the key differential diagnoses of SCC, to discuss common diagnostic pitfalls, and to recommend ways to deal with diagnostically challenging cases.

Lamin B1 fluctuations have differential effects on cellular proliferation and senescence.

The nuclear lamina consists of A- and B-type lamins. Mutations in LMNA cause many human diseases, including progeria, a premature aging syndrome, whereas LMNB1 duplication causes adult-onset autosomal dominant leukodystrophy (ADLD). LMNB1 is reduced in cells from progeria patients, but the significance of this reduction is unclear. In this paper, we show that LMNB1 protein levels decline in senescent human dermal fibroblasts and keratinocytes, mediated by reduced transcription and inhibition of LMNB1 messenger ribonucleic acid (RNA) translation by miRNA-23a. This reduction is also observed in chronologically aged human skin tissue. To determine whether altered LMNB1 levels cause senescence, we either increased or reduced LMNB1. Both LMNB1 depletion and overexpression inhibited proliferation, but only LMNB1 overexpression induced senescence, which was prevented by telomerase expression or inactivation of p53. This phenotype was exacerbated by a simultaneous reduction of LMNA/C. Our results demonstrate that altering LMNB1 levels inhibits proliferation and are relevant to understanding the molecular pathology of ADLD.

Inspirational airflow patterns in deviated noses: a numerical study.

This study attempts to evaluate the effects of deviation of external nose to nasal airflow patterns. Four typical subjects were chosen for model reconstruction based on computed tomography images of undeviated, S-shaped deviated, C-shaped deviated and slanted deviated noses. To study the hypothetical influence of deviation of external nasal wall on nasal airflow (without internal blockage), the collapsed region along the turbinate was artificially reopened in all the three cases with deviated noses. Computational fluid dynamics simulations were carried out in models of undeviated, original deviated and reopened nasal cavities at both flow rates of 167 and 500 ml/s. The shape of the anterior nasal roof was found to be collapsed on one side of the nasal airways in all the deviated noses. High wall shear stress region was found around the collapsed anterior nasal roof. The nasal resistances in cavities with deviated noses were considerably larger than healthy nasal cavity. Patterns of path-line distribution and wall shear stress distribution were similar between original deviated and reopened models. In conclusion, the deviation of an external nose is associated with the collapse of one anterior nasal roof. The crooked external nose induced a larger nasal resistance compared to the undeviated case, while the internal blockage of the airway along the turbinates further increased it.

Infraorbital nerve schwannoma presenting as an upper lip mass in an adolescent boy.

BACKGROUND: Schwannomas of the head and neck are uncommon tumors that arise from the nerve sheath and may afflict peripheral, autonomic, or cranial nerves. It is important to consider the possible differential diagnoses of a nasolabial lump in a child because its appropriate treatment varies widely. METHODS: The authors describe a case of a 12-year-old boy who presented with a 2.5-cm right nasolabial subcutaneous lump of 3 months in duration. Computed tomographic scan showed a homogeneously attenuated lesion. RESULTS: An intraoral incision was used for complete extirpation of this tumor while preserving the infraorbital nerve and facial aesthetics in this adolescent boy. Histopathologic examination showed palisades of spindle cells and Verocay bodies characteristic of schwannomas. The patient has been followed up for 2 years with no clinical evidence of recurrence. CONCLUSIONS: Only 9 cases of infraorbital nerve schwannoma have been described in literature, and the sublabial intraoral incision was attempted in only 1 case. The authors describe a rare case of an extraosseous schwannoma arising from the infraorbital nerve that presented as a cheek lump, its workup, its differentials, its treatment, and a review of literature. The use of a preoperative computed tomographic scan permitted the use of a sublabial intraoral incision with good visual access to the lesion and facilitated its complete extirpation without incurring external scars.

Preliminary Deformational Studies on a Finite Element Model of the Nasal Septum Reveals Key Areas for Septal Realignment and Reconstruction.

Background. With the current lack of clinically relevant classification methods of septal deviation, computer-generated models are important, as septal cartilage is indistinguishable on current imaging methods, making preoperative planning difficult. Methods. Three-dimensional models of the septum were created from a CT scan, and incremental forces were applied. Results. Regardless of the force direction, with increasing force, the septum first tilts (type I) and then crumples into a C shape (type II) and finally into an S shape (type III). In type I, it is important to address the dislocation in the vomer-ethmoid cartilage junction and vomerine groove, where stress is concentrated. In types II and III, there is intrinsic fracture and shortening of the nasal septum, which may be dislocated off the anterior nasal spine. Surgery aims to relieve the posterior buckling and dislocation, with realignment of the septum to the ANS and possible spreader grafts to buttress the fracture sites. Conclusion. By identifying clinically observable septal deviations and the areas of stress concentration and dislocation, a straighter, more stable septum may be achieved.

Passive movement of human soft palate during respiration: A simulation of 3D fluid/structure interaction.

This study reconstructed a three dimensional fluid/structure interaction (FSI) model to investigate the compliance of human soft palate during calm respiration. Magnetic resonance imaging scans of a healthy male subject were obtained for model reconstruction of the upper airway and the soft palate. The fluid domain consists of nasal cavity, nasopharynx and oropharynx. The airflow in upper airway was assumed as laminar and incompressible. The soft palate was assumed as linear elastic. The interface between airway and soft palate was the FSI interface. Sinusoidal variation of velocity magnitude was applied at the oropharynx corresponding to ventilation rate of 7.5L/min. Simulations of fluid model in upper airway, FSI models with palatal Young's modulus of 7539Pa and 3000Pa were carried out for two cycles of respiration. The results showed that the integrated shear forces over the FSI interface were much smaller than integrated pressure forces in all the three directions (axial, coronal and sagittal). The total integrated force in sagittal direction was much smaller than that of coronal and axial directions. The soft palate was almost static during inspiration but moved towards the posterior pharyngeal wall during expiration. In conclusion, the displacement of human soft palate during respiration was mainly driven by air pressure around the surface of the soft palate with minimal contribution of shear stress of the upper airway flow. Despite inspirational negative pressure, expiratory posterior movement of soft palate could be another factor for the induction of airway collapse.

Supraorbital nerve conduction study in normal subjects.

There is currently no examination technique that allows direct measurement of supraorbital nerve conduction velocity and amplitude. Therefore, in this study we describe a novel nerve conduction technique that allows measurement of the supraorbital sensory nerve action potential (SNAP) distal to the supraorbital foramen. Supraorbital SNAPs were recorded bilaterally from 17 healthy volunteers using an antidromic technique. The SNAPs were consistently recordable over the site 6 cm lateral to the midline point that was marked 10 cm above the nasion. Measured parameters included peak latency (mean 2.3 ms, SD 0.3), amplitude (mean 14.6 µV; SD 10.5), and velocity (mean 51.3 m/s, SD 6.8). The mean percentage of interside difference in amplitude was 25.6% (SD 17.3). Cut-off values (97th percentile) were 2.7 ms (peak latency), 3.3 µV (amplitude), 41.9 m/s (conduction velocity), and 54.9% (interside difference in amplitude). Supraorbital SNAPs can be recorded in all normal subjects and used as a quantitative measure of the functioning large fibers in the nerve.

Computer-aided design and rapid prototyping-assisted contouring of costal cartilage graft for facial reconstructive surgery.

Complex 3-D defects of the facial skeleton are difficult to reconstruct with freehand carving of autogenous bone grafts. Onlay bone grafts are hard to carve and are associated with imprecise graft-bone interface contact and bony resorption. Autologous cartilage is well established in ear reconstruction as it is easy to carve and is associated with minimal resorption. In the present study, we aimed to reconstruct the hypoplastic orbitozygomatic region in a patient with left hemifacial microsomia using computer-aided design and rapid prototyping to facilitate costal cartilage carving and grafting. A three-step process of (1) 3-D reconstruction of the computed tomographic image, (2) mirroring the facial skeleton, and (3) modeling and rapid prototyping of the left orbitozygomaticomalar region and reconstruction template was performed. The template aided in donor site selection and extracorporeal contouring of the rib cartilage graft to allow for an accurate fit of the graft to the bony model prior to final fixation in the patient. We are able to refine the existing computer-aided design and rapid prototyping methods to allow for extracorporeal contouring of grafts and present rib cartilage as a good alternative to bone for autologous reconstruction.

Evaluation and comparison of nasal airway flow patterns among three subjects from Caucasian, Chinese and Indian ethnic groups using computational fluid dynamics simulation.

Nasal airflow is one of the most important determinants for nasal physiology. During the long evolution of human beings, different races have developed their own attributes of nasal morphologies which result in variations of nasal airflow patterns and nasal functions. This study evaluated and compared the effects of differences of nasal morphology among three healthy male subjects from Caucasian, Chinese and Indian ethnic groups on nasal airflow patterns using computational fluid dynamics simulation. By examining the anterior nasal airway, the nasal indices and the nostril shapes of the three subjects were found to be similar to nasal cavities of respective ethnic groups. Computed tomography images of these three subjects were obtained to reconstruct 3-dimensional models of nasal cavities. To retain the flow characteristics around the nasal vestibules, a 40 mm-radius semi sphere was assembled around the human face for the prescription of zero ambient gauge pressure. The results show that more airflow tends to pass through the middle passage of the nasal airway in the Caucasian model, and through the inferior portion in the Indian model. The Indian model was found with extremely low flow flux flowing through the olfactory region. The sizes of vortexes near the anterior cavity were found to be correlated with the angles between the upper nasal valve wall and the anterior head of the nasal cavity.

Deformation of nasal septum during nasal trauma.

BACKGROUND: Injury to the nasal septum is commonly found in most nasal fractures. The nasal septum deforms and crumples, leading to nasal deviation and internal nasal obstruction. AIM: This study aims to identify the main areas of high stress concentration when a dynamic anteroposterior load is applied to the nasal tip, simulating nasal trauma. We wish to determine if the nasal septum acts as a crumpled zone, and deforms significantly during nasal trauma. MATERIALS AND METHODS: An idealized and a patient-specified finite element model have been generated for the present study. Several models with various combinations of narrower angle at the Vomer Ethmoidal Junction (VEJ) are also constructed from this septum model. Finite element analyses are carried out to determine the deformation and stress distribution in the nasal septum when a dynamic anteroposterior load is applied to the nasal tip. CONCLUSIONS: The maximum stress areas in the nasal septum are in the vicinity of the bony-cartilaginous (BC) junction and the anterior nasal spine (ANS), which are consistent with clinical experience. A larger anteroposterior load, a longer loading duration, and a more acute VEJ angle would result in higher maximum stresses. The observations were identical in both idealized and patient-specific models. The findings of this analysis also suggest that the septum does function as a crumpled zone, absorbing a significant amount of stress before it is transmitted to the skull.

Biomechanics of the deformity of septal L-Struts.

OBJECTIVES/HYPOTHESIS: A septal L-strut is often preserved or created during septoplasty. The main intention is to provide structural stability and to straighten the nasal septum. Deformity or excessive deformation of the L-strut might cause functional or aesthetic complications. The objectives were to examine the effects of material properties, the boundary conditions, the nasal tip support, and the geometry of the L-struts on the deformity of septal L-struts. STUDY DESIGN: Computer-aided modeling was used to create a spring-supported nasal tip and free nasal tip L strut septal cartilage models upon which simulation was performed to analyse the deformation patterns. METHODS: A five-sided septum model was first created from the computed tomography scan of a human subject. Several models with various combinations of wider or narrower dorsal struts as well as arc of cartilage were then constructed from this septum model. The edges connected to bony supports were assumed to be fixed, and the nasal tip was assumed to be spring supported. Finite element analyses were carried out to determine the deformation and stress distribution in the septal strut for different combinations of material properties and nasal tip spring support. RESULTS: The spring-supported nasal tip model provides a more accurate representation of the boundary conditions in the nose. In both the free and spring-supported nasal tips-the BC junction and the nasal spine are found to be the consistent points of maximum stress regardless of material properties. The preservation of an arc of cartilage and a wider dorsal strut increase the stability of the structure. CONCLUSIONS: The introduction of a spring-supported nasal tip model provided a more accurate representation of the boundary conditions in the nose. The bony-cartilaginous junction and the nasal spine were found to be the consistent points of maximum stress, regardless of material properties. The preservation of an arc of cartilage and a wider dorsal strut increased the stability of the structure.