Midsagittal Research Articles

Axial muscle‐fibre orientations in larval zebrafish

AbstractMost teleost fish propel themselves with lateral body waves powered by their axial muscles. These muscles also power suction feeding through rapid expansion of the mouth cavity. They consist of muscle segments (myomeres), separated by connective tissue sheets (myosepts). In adult teleosts, the fast axial muscle fibres follow pseudo‐helical trajectories, which are thought to distribute strain (relative fibre length change) approximately evenly across transverse sections during swimming, thereby optimizing power generation. To achieve strain equalization, a significant angle to the longitudinal axis on the frontal plane (azimuth) is necessary near the medial plane, increasing strain. Additionally, a deviation from longitudinal orientation on the sagittal plane (elevation) is required laterally to decrease strain. Despite several detailed morphological studies, our understanding of muscle‐fibre orientations in the entire axial musculature of fish remains incomplete. Furthermore, most research has been done in post‐larval stages, leaving a knowledge gap regarding the changing axial muscle architecture during larval development. Larval fish exhibit different body size, body shape and swimming kinematics compared to adults. They experience relatively high viscous forces, requiring higher tail‐beat amplitudes to overcome increased drag. Additionally, larval fish swim with higher tail‐beat frequencies. Histological studies have shown that in larval fish, muscle fibres in the anal region transition from an almost longitudinal orientation to a pseudo‐helical pattern by 3 dpf (days post‐fertilization). However, these studies were limited to a few sections of the body and were prone to shrinkage and tissue damage. Here, we introduce a novel methodology for quantifying muscle‐fibre orientations along the entire axial muscles. We selected 4 dpf larval zebrafish for our analyses, a stage where larvae are actively swimming but not yet free‐feeding. High‐resolution confocal 3D scans were obtained from four genetically modified zebrafish expressing green fluorescent protein in fast muscle fibres. Fluorescence variation allowed segmentation of individual muscle fibres, which were then converted to fish‐bound coordinates by correcting for the fish's position and orientation in the scan, and normalized to pool results across individuals. We show that at 4 dpf, muscle‐fibre trajectories exhibit a helical pattern tapering towards the tail. Average fibre angles decrease from anterior to posterior, with azimuth varying over the dorsoventral axis and elevation varying over the mediolateral axis. Notably, only the anteriormost 20% of the body displayed higher azimuth angles near the medial plane. Angles between neighbouring fibres were substantial, particularly at the rim of the epaxial and hypaxial muscles. The revealed muscle‐fibre architecture at this age presumably contributes to the swimming performance of these larvae, but that swimming performance is probably not the only driving factor for the fibre pattern. Our methodology offers a promising avenue for exploring muscle‐fibre orientations across ontogenetic series and provides a foundation for in‐depth functional studies on the role of muscle architecture in facilitating swimming performance of larval fish.

Three-dimensional evaluation of maxillofacial symmetry improvement following orthognathic surgery in patients with asymmetrical jaw deformities.

The aim of this study was to clarify the three-dimensional changes in maxillofacial morphology following orthognathic surgery using 3D-CT in patients with asymmetrical jaw deformities. The subjects were 30 patients with asymmetrical jaw deformities. Three-dimensional images taken preoperatively and 6months postoperatively were re-aligned using image processing software with the horizontal plane, coronal plane, and midsagittal plane as reference axes. Thirty-nine measurements including 28 distances, nine angles, and two volumes were recorded, and differences between preoperative and postoperative measurements and percentage differences between paired measurements on the deviated and unevolved sides were calculated. Translational and rotational movements of the maxillary dentition and mandibular body and the mandibular ramus internally rotating contributed to improved symmetry of the maxillofacial morphology, but the degree and proportion of these changes varied from case to case and mild asymmetry remained even after surgery. 3D-CT analysis of maxillofacial morphology is essential to accurately evaluate the asymmetry of hard and soft tissue morphology in the maxillofacial region and the degree of improvement after orthognathic surgery, and the tooth movement during preoperative orthodontic treatment should be determined taking into account the movement of the upper and lower jaws during orthognathic surgery.

Three-Dimensional Volume Ultrasound Assessment of Cesarean Scar Niche and Cervix in Pregnant Women: A Reproducibility Study.

To assess the reproducibility of standardized 3-dimensional (3D) ultrasound volume analysis of the dimensions and the position of cesarean birth (CB) scar niche relative to the cervix in pregnant women. This prospective single-center study in women with 1 previous CB ≥8 cm cervical dilatation acquired ultrasound volumes between 11 and 24 weeks' gestation in a mid-sagittal plane. Two experienced operators processed the volumes using virtual organ computer-aided analysis. A CB scar niche was defined as an indentation at the scar site of ≥2 mm in depth. Niche and cervix volumes were calculated using manual contouring. Agreement for categorical variables was expressed using intraclass correlation coefficient (ICC). The Bland-Altman method was used to assess numerical variable reproducibility. To achieve the desired statistical power, 52 participants were included. The intraobserver agreement on niche classification relative to the internal os was 100%, with an interobserver kappa coefficient of 0.98 (95% confidence interval [CI] 0.97-0.99, P < .05). The intraobserver ICC for niche volume was 0.94 (95% CI 0.90-0.96; P < .001), with a mean difference of -15.32 mm3 (±109.32). The interobserver ICC was 0.78 (95% CI 0.62-0.87; P < .001), with a mean difference of -21.57 mm3 (±202.01). The ICC for niche/cervix volume ratio were 0.94 (95% CI 0.90-0.96; P < .001) and 0.79 (95% CI 0.63-0.87; P < .001) for intra- and interobserver reproducibility, respectively. This study demonstrates that 3D CB scar sonographic features are highly reproducible in pregnant women with a history of advanced labor CB. The validated protocol can guide future research on the association with subsequent adverse pregnancy outcomes.

Nasal dermoid sinus cyst with intracranial extension and atretic sinus tract in an adult patient

Nasal dermoid sinus cyst (NDSC) is a rare congenital lesion due to cephalic neural tube defect. It may also have been seen in other parts of the body. NDSC constitutes 1–3% of all dermoid cysts and 11–12% of those in the head and neck. A NDSC is located in the median line of the nasofrontal region from the glabella to the columella. The differential diagnosis based on location includes epidermal inclusion cyst, glioma, meningomyelocele, meningoencephalocele, teratoma, teratoid cyst, thyroglossal duct cyst, branchial cleft cyst, and benign lymphadenopathy. Intracranial extension causes serious complications such as meningitis, osteomyelitis, abscess formation, hydrocephalus, seizures, and personality changes. All patients with NDSC should be considered to have a potential intracranial extension and should, therefore, undergo pre-operative radiological evaluation. Herein, the authors report an unusual adult patient with NDSC with intracranial extension.

A modified protocol merging two published techniques for computer guided zygomatic implants surgery: a technical note

ObjectivesZygomatic implant surgery can be difficult due to the limited intraoperative visibility of the surgical field and the complex anatomy of the zygomatic bone, which could lead to serious complications. This study aims to assess the accuracy of zygomatic implants placement using computer-guided surgical templates.Materials and methodsA total of 13 zygomatic implants were placed in four participants. Double-sleeve drill guides were used with the help of computer-guided surgical templates designed with a lateral window. The accuracy was evaluated by measuring the linear deviations regarding the implants’ platforms and apices’ positions in addition to the angular deviations. Moreover, deviations of both implants from three fixed planes of space were measured.ResultsThe mean linear deviation at platforms was 2.44 mm ± 1.57 and at the apices 2.32 mm ± 1 while the mean angular deviation was 3.6˚ ± 1.92. Differences at the entry points were 0.43 ± 1.79 mm, 0.39 ± 1.12 mm, and − 0.54 ± 2.00 mm from the mid-sagittal, horizontal, and coronal planes respectively. Differences at the exit points were − 0.75 ± 1.25 mm, -0.06 ± 1.09 mm, and 0.63 ± 1.24 mm from the same planes respectively. Within all planes, there was no statistically significant difference.ConclusionGiven the limitations of this study, the use of the computer-guided surgical templates augmented by the double sleeve drill guides allowed favorable control over the tip of the long surgical drill away from vital structures during the zygomatic implant osteotomy. It also allowed control over alveolar crest osteotomy and its placement in a favorable prosthetic position. Overall, this protocol should be considered for further research and improvement to allow more predictable surgical outcomes while preventing the occurrence of complications. Before conducting this study, the protocol was reviewed and approved by the Research Ethical Committee of Faculty of Dentistry, Ain Shams University in meeting no. (105), on 15th of July 2020 with the application no.: (FDASU-RecD072029).

The Implementation of Equidistance Line on Maritime Delimitation between Indonesia-Australia in Perth Treaty 1997

This article proposes some suggestions to the government in renegotiating the Perth Treaty to provide a solution for a definitive maritime boundary between Indonesia and Australia. Renegotiation of the Perth Treaty in terms of maritime delimitation between the two countries needs to be done in relation to the limitation of sovereignty of both countries. This treaty has never been ratified by both countries after the signing in 1998. The fundamental reason of Australia is associated with the independence of Timor-Leste in 1999 so that the rebus sic stantibus principle then applies. This research employed legal method to provide recommendations to the government as a basis for renegotiating the Perth Treaty according to international law. It also used a statutory and case approach. There are underlying reasons for the urgency of renegotiating the Perth Treaty using the median line with an equidistance line approach. The median line in UNCLOS 1982 has proven to provide progressive results regarding the maritime delimitation of countries. However the decisions of the International Court of Justice, resulted in various side effects with the use of the median line as a single effort to resolve maritime delimitation disputes. Therefore, a new solution is proposed, namely the median line with an equidistance line approach as the most effective method to create justice for each party. The equidistance line in international law serves as a legal resolution method, emerging from customary practices. It is recognized as new customary law for resolving maritime delimitation disputes between countries. Harmonisation of the median line concept using the equidistance line approach in resolving maritime delimitation disputes between Indonesia and Australia is a new approach that can be used based on the successful harmonisation of these two concepts in resolving delimitation disputes globally.

Gross Anatomical, Histological, Histochemical and Scanning Electron Microscopic Examination of Glandular Stomach of Chinese Goose (Anser cygnoides)

Background: The digestive system is responsible for the intake, conversion and absorption of nutrients and the elimination of wastes from the body in order to provide the necessary energy for the continuation of vitality and functions. The aim of this study was to examine the glandular stomach of the Chinese goose (Anser cygnoides) by histological, histochemical and scanning electron microscopic methods. Methods: The glandular stomachs of 12 (6 males and 6 females) healthy adult Chinese geese (Anser cygnoides) were used in the study. The tissues taken were subjected to routine histological procedures. Result: Gross anatomically, it was seen that the Proventriculus was a fusiform or spindle-shaped organ, extending along the median plane between the esophagus and the muscular stomach. Scanning electron microscopic (SEM) observations revealed that the glandular stomach surface of Chinese goose (Anser cygnoides) contained many mucosal folds. Parallel grooves and proventricular gland openings were observed between these folds. Histologically, it was observed that the glandular stomach wall of Chinese goose (Anser cygnoides) consisted of four layers: tunica mucosa, submucosa, tunica muscularis and tunica serosa. The tunica mucosa was observed to have lamina epithelialis, lamina propria and lamina muscularis sublayers. Single layer prismatic cells secreting mucus were found in the lamina epithelialis layer. These cells showed local Alcian Blue (AB) pH:2,5 positive reaction. Lamina muscularis consisted of longitudinal smooth muscle fiber bundles. Compound, branched tubular glands were observed in the submucosal layer. Again, a regional AB positive reaction was observed in the lumen-facing parts of the tubular glands. Periodic acid Schiff (PAS) positive reaction was noted in the basal parts of the tubular glands. In Gordon-Sweet (GS) staining method, reticular threads easily distinguished in all areas where connective tissue present.

The contribution of dynamic cues to externalization of virtual source in virtual auditory display

It is well known that static virtual auditory display with headphone is inclined to create the auditory perception of in-head-localization, especially for target virtual sources in the median plane. By introducing the dynamic variation of binaural pressures caused by head turning, dynamic virtual auditory display eliminates the in-head-localization effectively. The present work investigates the contributions of dynamic interaural time difference (ITD) and dynamic interaural level difference (ILD) in binaural pressures to the externalization of auditory perception. By modifying the head-related transfer functions used in a dynamic virtual auditory display, binaural signals with dynamic ITD or dynamic ILD alone are created and presented by headphone. A psychoacoustic experiment is conducted to evaluate the extent of perceived externalization. The experiment results prove that, for the target virtual source in the median plane, dynamic ITD and dynamic ILD contribute to the externalization of low and high frequency components of the stimuli respectively. For wideband stimulus with low and high frequency components, both dynamic ITD and dynamic ILD contribute externalization but dynamic ITD contributes more than that of dynamic ILD.

Dynamic and static nasolabial muscle anatomy of unilateral cleft lip adult patients based on magnetic resonance imaging data.

This study aims to obtain a three-dimensional reconstruction model based on magnetic resonance imaging (MRI) data of patients with different degrees of unilateral cleft lip and analyze the anatomy and changes in multiple groups of nasolabial muscles under dynamic and static conditions. One normal person and four adult patients with unilateral cleft lip were included, and MRI was performed under static (upper and lower lips closed naturally) and dynamic (pout and grin) conditions. 3D Slicer software was used to reconstruct the model and draw the anatomic morphology of nasolabial muscles. The distance between the junction (where the muscle merges into the orbicularis oris) of the levator muscle, zygomaticminor muscle, and zygomatic major muscle to the median sagittal plane, the starting point to the junction point, the dynamic and static junction points, and the angle between the connection of dynamic and static junctions and the horizontal plane were measured under three kinds of movements, and the ratio was calculated. In all patients, under dynamic and static conditions, the distance from the muscle junction to the median sagittal plane, their ratios of the cleft side to the non-cleft side were all greater than 1. While the ratio of the distance from the starting point of the muscle to the junction point is less than 1. At static conditions, the two ratios of the same muscle increased gradiently with the severity of the cleft, and the ratio of the zygomatic minor muscle was prominent in the same patient. The ratio of the cleft side to the non-cleft side was greater than 1, and the value for comparison was the angle of the line from the static to the dynamic junction and the horizontal plane. The symmetry of the insertion site of the orbicularis oris and the linear distance of both sides of the muscle are related to muscle and cleft types. The angle of muscle contraction on the cleft side is greater than that on the non-cleft side.

Mineralization of equine proximal sesamoid bones precedes articular cartilage and fibrocartilaginous enthesis maturation in early postgestational development.

To describe the development and maturation of equine proximal sesamoid bones (PSBs) in fetuses and young horses using radiography, microcomputed (micro)-CT, and histology. A descriptive study. Forelimb PSBs from 12 equids ranging in age from 105 days of gestation to 540 days postgestation were evaluated. Radiography was used for preliminary assessment of metacarpophalangeal joint and PSB mineralization, and micro-CT imaging was performed to assess mineralized PSBs. Tissue volume, bone volume fraction, height, width, depth, trabecular thickness, and anisotropy were quantified from midplanar micro-CT sections in 3 dimensions. Midsagittal PSB histologic sections stained with H&E and Safranin O/Fast Green were used to determine the ratio of ossification center to cartilage template size and to describe the formation and development of the cartilage template, ossification center, spherical growth plate, articular cartilage, and entheses. Mineralization of equine PSBs is associated with cartilage canals and a spherical growth plate that undergoes endochondral ossification during the late gestation to early postgestational period. The apical, flexor, basilar, and articular ossification fronts demonstrate morphologic variability. Structural organization of the articular cartilage and entheses occurs concurrently with the development of an underlying plate of compact bone. At 540 days postgestation, the fibrocartilaginous entheses of the flexor cortex of the PSB had yet to mature. Equine PSBs mineralize predominantly by endochondral ossification during the late gestation to early postgestational period. Mineralization precedes maturation of the articular cartilage and fibrocartilaginous entheses. The postgestational maturation of the PSB and its surrounding tissues may predispose young horses to developing lesions at these sites, such as apical avulsion fractures, warranting further investigation.

Developmental trends in corpus callosum thickness among preschool children

BackgroundThe corpus callosum plays a crucial role in integrated brain functions, and its development in childhood is strongly associated with subsequent cognitive, emotional, and behavioral development. However, there is still a lack of clear understanding regarding the developmental trends of the corpus callosum in preschool children. This study aims to comprehensively investigate age and sex differences in the thickness of the corpus callosum in typical developing children between 1 and 6 years old. MethodsT1-weighted structural MRI data were collected from a sample of 295 neurologically normal children aged 1–6 years. Utilizing the specialized corpus callosum segmentation software Yuki, thickness measurements of the mid-sagittal plane of the corpus callosum were obtained. ResultsThe anterior part exhibited faster growth compared to the middle and posterior sections, while growth at the extremities was not statistically significant. Furthermore, gender differences were identified, with males showing earlier development of the corpus callosum, particularly between ages 1 and 3. Conversely, females exhibited the most notable increase in thickness between ages 3 and 5. ConclusionThis study provides significant insights into the developmental trends of the mid-sagittal plane of the corpus callosum in preschool children. It reveals distinct non-linear developmental patterns in different sections of the corpus callosum and highlights the influence of sex on these developmental patterns.

Evaluating cranial landmarks for yaw orientation in natural head position: a 3D study.

To assess the symmetry of various cranial anthropometric points used as references for yaw orientation in the natural head position (NHP), relative to the mid-sagittal plane. A prospective analysis using tomography data from 55 patients was conducted. Radiopaque markers, placed on patients in NHP, facilitated head position recording in three planes, with subsequent digital transfer for orientation analysis. Symmetry of eight points (zygomaxillare, zygion, ectoconchion, frontozygomatic suture, stephanion, porion, mastoidale, condylion laterale) was measured against the mid-sagittal plane. Significant asymmetry was observed in the stephanion, frontozygomatic suture, and ectoconchion points (p < 0.05). No significant differences were found in the symmetry of other points (p > 0.05). Findings suggest that stephanion, frontozygomatic suture, and ectoconchion are unreliable for yaw orientation in NHP. Other points, combined with clinical measurements, may offer better reliability.

Assessment of pharyngeal airway space with MRI In oral submucous fibrosis: A cross-sectional observational study

IntroductionOral submucous fibrosis (OSMF) alters the pharynx, which may affect airway size. MRI will be useful for diagnosing pharyngeal abnormalities. MRI is used to evaluate pharyngeal airway and soft palate changes in OSMF patients. Materials and methodsThis study is a cross-sectional observational study that included a sample size of 42 patients. Group A consisted of 21 patients with OSMF, while Group B consisted of 21 volunteers without OSMF, who served as the control group. The patients with OSMF were classified into Stages I, II, and III according to the categorization established by Pindborg JJ in 1989, Stop-Bang questionnaire was employed to assess obstructive sleep apnoea. Magnetic Resonance Imaging (MRI) was utilized to acquire evaluations of the pharyngeal airway, encompassing measurements in the midsagittal, cross-sectional width, length planes, and cross-sectional area with volume, for all participants. The Shapiro-Wilk test determines distribution normality. We utilized one-way ANOVA to compare the means between groups. ResultsThe average age of OSMF patients was 45.9 ± 8.16, while the control group was 39.19 ± 4.21. Stage I of OSMF had the highest mean Stop Bang questionnaire score (2.75), followed by stage III (2.22), and stage II (1.75). Statistically significant differences (p < 0.001) were seen in volume, linear midsagittal planes, cross-sectional width and length planes, cross-sectional area, and soft palate breadth and length between OSMF and control groups. ConclusionMRI can effectively examine early changes in the pharyngeal airway of patients with OSMF thereby serving as a constructive diagnostic and motivational tool.

Auto-segmentation of hemi-diaphragms in free-breathing dynamic MRI of pediatric subjects with thoracic insufficiency syndrome.

In respiratory disorders such as thoracic insufficiency syndrome (TIS), the quantitative study of the regional motion of the left hemi-diaphragm (LHD) and right hemi-diaphragm (RHD) can give detailed insights into the distribution and severity of the abnormalities in individual patients. Dynamic magnetic resonance imaging (dMRI) is a preferred imaging modality for capturing dynamic images of respiration since dMRI does not involve ionizing radiation and can be obtained under free-breathing conditions. Using 4D images constructed from dMRI of sagittal locations, diaphragm segmentation is an evident step for the said quantitative analysis of LHD and RHD in these 4D images. In this paper, we segment the LHD and RHD in three steps: recognition of diaphragm, delineation of diaphragm, and separation of diaphragm along the mid-sagittal plane into LHD and RHD. The challenges involved in dMRI images are low resolution, motion blur, suboptimal contrast resolution, inconsistent meaning of gray-level intensities for the same object across multiple scans, and low signal-to-noise ratio. We have utilized deep learning (DL) concepts such as Path Aggregation Network and Dual Attention Network for the recognition step, Dense-Net and Residual-Net in an enhanced encoder-decoder architecture for the delineation step, and a combination of GoogleNet and Recurrent Neural Network for the identification of the mid-sagittal plane in the separation step. Due to the challenging images of TIS patients attributed to their highly distorted and variable anatomy of the thorax, in such images we localize the diaphragm using the auto-segmentations of the lungs and the thoraco-abdominal skin. We achieved an average±SD mean-Hausdorff distance of ∼3±3 mm for the delineation step and a positional error of ∼3±3 mm in recognizing the mid-sagittal plane in 100 3D test images of TIS patients with a different set of ∼430 3D images of TIS patients utilized for building the models for delineation, and separation. We showed that auto-segmentations of the diaphragm are indistinguishable from segmentations by experts, in images of near-normal subjects. In addition, the algorithmic identification of the mid-sagittal plane is indistinguishable from its identification by experts in images of near-normal subjects. Motivated by applications in surgical planning for disorders such as TIS, we have shown an auto-segmentation set-up for the diaphragm in dMRI images of TIS pediatric subjects. The results are promising, showing that our system can handle the aforesaid challenges. We intend to use the auto-segmentations of the diaphragm to create the initial ground truth (GT) for newly acquired data and then refining them, to expedite the process of creating GT for diaphragm motion analysis, and to test the efficacy of our proposed method to optimize pre-treatment planning and post-operative assessment of patients with TIS and other disorders.

Altered Movement Coordination during Functional Reach Tasks in Patients with Chronic Low Back Pain and Its Relationship to Numerical Pain Rating Scores.

Identifying the effects of pain catastrophizing on movement patterns in people with chronic low back pain (CLBP) has important clinical implications for treatment approaches. Prior research has shown people with CLBP have decreased lumbar-hip ratios during trunk flexion movements, indicating a decrease in the contribution of lumbar flexion relative to hip flexion during trunk flexion. In this study, we aim to explore the relationship between pain catastrophizing and movement patterns during trunk flexion in a CLBP population. Participants with CLBP (N = 98, male = 59, age = 39.1 ± 13.0) completed a virtual reality standardized reaching task that necessitated a progressively larger amount of trunk flexion. Specifically, participants reached for four virtual targets to elicit 15°, 30°, 45°, and 60° trunk flexion in the mid-sagittal plane. Lumbar flexion was derived from the motion data. Self-report measures of numerical pain ratings, kinesiophobia, and pain catastrophizing were obtained. Pain catastrophizing leads to decreased lumbar flexion angles during forward reaching. This effect is greater in females than males.

Arbor vitae cerebelli: Fractal properties and their quantitative assessment by novel “contour scaling” fractal analysis method (an anatomical study)

BackgroundArbor vitae cerebelli (tree-like branching white matter of the cerebellum) has a complex spatial configuration that is challenging to assess using conventional morphometric methods. This study proposes a fractal approach to describe and quantify the anatomy of Arbor vitae cerebelli. For this purpose, a new “contour scaling” method for fractal analysis of cerebellar white matter was developed. Material and methodsThe cerebella of 100 cadavers (50 male and 50 female) who died from causes unrelated to brain pathology, aged 20–95 years, were examined. Mid-sagittal sections of the cerebellar vermis were studied. The fractal dimension values of the cerebellar white matter were determined using both the developed fractal analysis method and the conventional “box counting” method, along with measurements of non-fractal parameters including cerebellar weight, area and perimeter of the vermis cross-section, perimeter-to-area ratio, and circularity. ResultsConsidering the cerebellar white matter as a tree-like fractal, it was found to have 7 or 8 primary branches, which subdivide into 10-18 second-iteration branches, 19–38 third-iteration branches, and 34–53 fourth-iteration branches. Females more often had 8 primary branches compared to males, while males had a greater number of branches in the second to fourth iterations. The mean fractal (Hausdorff) dimension was 1.697 (1.721 in males, 1.674 in females, P = 0.01). The fractal dimension correlated most strongly with the perimeter and area of the vermis cross-section and had no significant relationship with age. ConclusionThe fractal (Hausdorff) dimension, determined using the novel “contour scaling” method, quantitatively assesses the degree of branching of the cerebellar white matter. An increase in the absolute size of the cerebellum leads to a higher degree of branching of its white matter and an increase in the number of its constitutive components – white matter branches and folia.

Influence of Pre-Operative Estimation of Draf III Expected Diameter on Surgical Outcome.

Introduction: The DRAF III procedure is indicated for the treatment of benign and selected malignant frontal sinus pathology. Several attempts have been made to find an intra or pre-operative measurement that was predictive of the feasibility of this operation and its success. Among those, the frontal sinus outflow tract anteroposterior diameter (FOAP) appears to be the one with the highest applicability in clinical practice, since it is easy to measure on pre-operative CT scan. The objective of the study is to evaluate whether the minimum and maximum frontal sinus outflow anteroposterior diameters (FOAP min and FOAP max) are associated with the risk of failure and consequently with the need for surgical revision. Secondly, we ought to evaluate whether the angle between the glabella and the nasion on the sagittal plane could influence surgical outcome. Material and Methods: This is a retrospective study on patients who underwent DRAF III for benign pathologies at a tertiary Italian referral center from January 2000 to July 2022. FOAP min and FOAP max were measured on the mid-sagittal sections of a pre-operative CT scan. The glabella-nasion angle (G-N angle) was calculated on the same sagittal section. These measurements were compared between patients who experienced a recurrence and those who did not. If a post-operative CT scan was available, the obtained anteroposterior diameter (OD) of the frontal sinus neo-ostium was also measured on the same section. A correlation analysis was performed between the three pre-operative radiologic parameters and OD. Results: Twenty-nine patients were included in the study. Six patients experienced restenosis requiring surgical revision. The median FOAP max resulted significantly higher in patients who did not experience recurrence (median: 14.8 mm, IQR: 3.84) than in patients who experienced a recurrence (median: 11.9 mm, IQR: 1.14) (p = 0.04). The FOAP max also showed a good positive correlation with OD (p = 0.0001; r = 0.7). The correlation between FOAP min and OD was not statistically significant, nor was a correlation found between FOAP min and recurrence risk. The G-N angle was not significantly different in patients who experienced recurrence and those who did not, nor did it show a correlation with OD. Discussion: The FOAP max might be a valid pre-operative radiologic parameter to guide a surgeon's approach to a DRAF III procedure, as it is easy to measure, shows a good correlation with OD, and seems to influence the risk of recurrence.

Proposed correction to the Gamma method for estimating the bending stiffness of CLT panels

Engineered wood products, such as Cross Laminated Timber (CLT), have been widely used in civil construction. Standard calculation methods, like the Gamma method commonly used in structural design, estimate the bending stiffness of elements. However, these methods are based on one-dimensional solids (bar elements), which can be limiting. This limitation may result in inaccurate estimates, especially when the panel's dimensions, measured in the median plane, significantly differ by an order of magnitude. In this research, a parametric study was carried out using the finite element method (three-dimensional approach), varying the panel's dimensions (width and length), the layers' thickness, and the number of layers (cross-section height), and adopting elastic properties considering either the wood's orthotropy or the rolling shear estimation (108 numerical simulations in all). Based on the parameterization, multiple variable regression models were used to establish a correction coefficient to be incorporated into the Gamma method to improve its accuracy in estimating bending stiffness. Therefore, the single adjusted equation (considering the wood's orthotropy) showed values closer to the numerical ones (MAPE = 0.95 %, RMSE = 2.96 × 1011 N⋅mm2, and CV = 1.60 %) than those obtained by the Gamma method (MAPE = 2.13 %, RMSE = 7.47 × 1011 N⋅mm2, and CV = 4.04 %).

Comparison of the Vaginal and Labial Dimensions of Ethnic Chinese and Western Nullipara.

Vaginal dimensions have clinical and surgical implications. We sought to quantify the differences between vaginal and labial dimensions in healthy ethnic Chinese and Western women with normal pelvic organ support. This is a cross-sectional study of a convenience sample of ethnic Chinese nulliparas (n = 33) and Western nulliparas (n = 33) recruited for research purposes. For each subject, magnetic resonance imaging was used to quantify the vaginal and labial dimensions. Specifically, we identified the anterior and posterior vaginal wall, the outline of the cervix in the mid-sagittal and coronal planes, and the distance from the labia majora to the hymenal ring at the urethral meatus. There were significant differences in age and weight between groups. Substantial variation in vaginal and labial dimensions was found within each group. The vaginal and labial dimensions of ethnic Chinese women ranged from 9-21% smaller than those of Western women; In the ethnic Chinese group, increasing weight and BMI correlated with greater labial distance (r = 0.66 and r = 0.63 respectively); as did height and the distance from the vaginal opening to the cervical os (r = 0.5). In the Western group, only weight correlated with the labial distance (r = 0.51). Significant group differences in vaginal and labial dimensions were found, with the dimensions of Chinese nulliparas being up to 21% smaller than those of Western nulliparas.

Complete Platysma Muscle Suspension in Deep Plane Facelift Surgery.

Deep plane facelift surgery is not new, having originally been described over 30 years ago, however the technique has seen a recent surge in popularity. While proponents emphasize its ability to deliver very natural results, critics often cite the possibility of additional risk of the procedure due to its technically challenging dissection in proximity to branches of the facial nerve and other critical structures. These risks are perhaps greatest when operating in what have historically been described as the "danger zones," particularly when releasing the zygomatic retaining ligaments, when performing the medial deep plane dissection in the midface, and when extending the platysma flap over the angle of the mandible into the neck. The senior author (DBR) has performed deep plane facelift surgery for over 20 years, training many novice surgeons to perform this procedure safely and incrementally. Herein, we illustrate surgical techniques to optimize safety when performing deep plane dissections. A novel vertical midline platysmaplasty combined with extended release of the low cervical platysma provide rejuvenation of the neck that extends to the clavicles.