The research team conducted a secondary analysis of the OpenNeuro ds005713 dataset, combining two dataset versions and removing duplicate records identified by participant identifier. The baseline comparison included 86 people with trigeminal neuralgia and 40 healthy controls. Participants were excluded when essential demographic data or usable baseline MRI were unavailable, when they had conditions that could compromise segmentation, or when the scans showed structural, vascular or space-occupying abnormalities that might affect cerebellar measurements. People with trigeminal autonomic cephalalgias, previous surgery for trigeminal neuralgia or Fazekas grade 3 white-matter lesions were also excluded. The longitudinal component was limited to the 49 patients for whom usable paired preoperative and postoperative MRI could be found.

All scans were acquired with a 3.0-T Philips Ingenia scanner and a 16-channel head coil. The investigators used high-resolution sagittal three-dimensional T1-weighted images, acquired with a fast field echo sequence at approximately 1.0-mm isotropic resolution and reconstructed at approximately 0.5-mm resolution. DeepCERES version 1.1, running on the volBrain platform, processed the images through denoising, registration to the Montreal Neurological Institute 152 standard space, bias-field correction, intensity normalization and intracranial-cavity segmentation. The pipeline generated synthetic T2-weighted images and subject-specific multi-atlas priors before an ensemble model delineated cerebellar gray matter, white matter and bilateral lobules. The preoperative and postoperative scans were processed independently rather than through a joint longitudinal segmentation pipeline.

For each participant, the researchers extracted absolute volume and MRI-derived mean cortical thickness from 12 bilateral cerebellar regions: Lobules I–II, III, IV, V, VI, Crus I, Crus II, VIIb, VIIIa, VIIIb, IX and X. Bilateral volume was the sum of the left and right absolute volumes in cubic centimetres, while bilateral thickness was the arithmetic mean of the two sides in millimetres. The measurements also included intracranial volume and the absolute volumes of the whole cerebellum, cerebellar gray matter and cerebellar white matter. DeepCERES thickness is a macroscopic estimate based on MRI contrast and segmentation boundaries; it is not a histological measurement and cannot establish changes in cells or tissue layers.

The main cross-sectional models included diagnostic group, linear and quadratic age terms and sex, while volume models also included intracranial volume. The investigators treated regional volume and regional thickness as separate families of 12 tests and applied the Benjamini–Hochberg procedure to control the false discovery rate within each family. The adjusted thickness difference was 0.104 millimetres for Lobule IV, with a 95% confidence interval of 0.040 to 0.168 and a corrected q value of 0.020. Lobule VI was 0.071 millimetres thicker, with a 95% confidence interval of 0.021 to 0.121 and q equal to 0.036. Neither the remaining lobules nor the regional, whole-cerebellum, cerebellar gray-matter or cerebellar white-matter volume measures showed a significant group difference after correction. The confidence intervals were not themselves adjusted for multiple comparisons.

Sensitivity analysis indicated that the Lobule IV result was the more dependable of the two cross-sectional findings. It remained significant across three approaches to age, with adjusted differences of 0.104 to 0.105 millimetres, and it also remained significant when intracranial volume or automated image-quality scores were added to the model. Lobule VI was more sensitive to analytical choices: its adjusted difference was 0.057 millimetres under a linear age model and did not meet the corrected significance threshold, although a restricted cubic spline model produced a similar estimate of 0.073 millimetres that did pass the threshold. Neither result reversed direction in leave-one-out analyses, and bootstrap confidence intervals excluded zero. Within the trigeminal neuralgia group, however, Lobule VI thickness was positively correlated with automated quality scores, indicating that image quality and the measured structure were not entirely independent.

Disease duration, pain side and imaging-based Sindou grade were not significantly associated with regional volume or thickness after correction for multiple testing. Exploratory analyses also found no pain-related cerebellar asymmetry that passed the corrected threshold. The longitudinal group contained 33 patients who underwent microvascular decompression and 16 who underwent a percutaneous intervention. Clinical follow-up information was incomplete: among 26 patients with available immediate postoperative pain records, 21 had a recorded 100% reduction in pain. The first follow-up was reported for those 26 patients, and second telephone follow-up pain scores were available for 24. The study did not test whether changes in cerebellar morphology were associated with pain improvement, limiting interpretation of the imaging changes as clinically meaningful.

Within the 49 paired scans, postoperative volume increased significantly in Lobules IV, V, VI, VIIb, VIIIa and VIIIb. Mean absolute increases ranged from 0.044 to 0.103 cubic centimetres, while the mean of individual percentage changes ranged from 0.86% to 1.69%. Thickness increased in Lobules IV, V and VI: Lobule IV rose by 0.039 millimetres, Lobule V by 0.066 millimetres and Lobule VI by 0.037 millimetres, with corrected q values of 0.003, 0.002 and 0.003. The corresponding mean individual percentage changes were 1.82%, 3.00% and 1.38%. Supportive analyses also showed increases of 0.594 cubic centimetres in whole-cerebellum volume and 0.538 cubic centimetres in cerebellar gray-matter volume, although white-matter volume did not change significantly after correction.

These small postoperative signals were generally supported by alternative statistical tests, but their stability varied among regions. Nonparametric paired tests and bootstrap resampling supported all nine primary volume and thickness increases, and none reversed direction when individual patients were omitted. Models that simultaneously accounted for changes in intracranial volume and automated quality scores retained significant estimates for volume in Lobules IV, V and VIIIb and thickness in Lobules IV–VI. The volume increases in Lobules VI, VIIb and VIIIa did not pass the corrected threshold in those models, and the leave-one-out results for VIIb and VIIIa were less stable. The direction of the findings also matters: Lobules IV and VI were already thicker between groups, so their postoperative increases cannot be interpreted as normalization toward healthy-control levels.

Several limitations constrain what can be concluded. The cross-sectional design cannot establish whether cerebellar differences preceded or resulted from trigeminal neuralgia, and the longitudinal cohort lacked repeated scans in controls or matched test–retest measurements from the same software version and scanning conditions. Earlier repeat-scan work cited by the authors reported coefficients of variation ranging from 0.70% to 2.95% for unilateral lobular volume and from 0.57% to 1.60% for unilateral thickness in regions corresponding to some findings here, but coefficients of variation and mean changes measure different aspects and cannot show whether the postoperative shifts exceeded measurement error. Most patients also took medication, usually including carbamazepine, with insufficient information on dose, treatment duration and postoperative changes to separate medication effects from disease effects. Visual quality review was not blinded to diagnosis or scan time, and the two procedures were combined despite their potential differences. The results therefore identify MRI-derived morphometric patterns for further study, not a cellular mechanism, causal treatment effect or demonstrated link between postoperative brain change and pain relief.

Subject of Research: MRI-based cerebellar lobular morphometry in patients with trigeminal neuralgia

Article Title: Cerebellar lobular morphometry in trigeminal neuralgia: cross-sectional and exploratory postoperative analyses

Article References: Li, H., Chen, J., Wang, X., She, J., Gao, W., & Wu, T. (2026). Cerebellar lobular morphometry in trigeminal neuralgia: cross-sectional and exploratory postoperative analyses. Frontiers in Neurology, 17, Article 1964745. https://doi.org/10.3389/fneur.2026.1964745

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1964745

Keywords: trigeminal neuralgia, cerebellar morphology, cortical thickness, MRI, DeepCERES, postoperative imaging, morphometry, cerebellar lobules, longitudinal analysis, neuroimaging, Cerebellar, lobular

Leucism is one of several color-altering conditions that can appear in vertebrates, and it is often confused with albinism. In albinistic animals, pigment production fails in both the skin and the eyes, which typically appear red or pink. Leucistic animals, by contrast, lack pigmentation in epithelial tissue while the eyes retain their normal color. Other related conditions include melanism, an excess of dark pigment, and xanthochromism, an unusual abundance of yellow to red pigments. For a nocturnal, bottom-dwelling catfish whose normal earth-brown coloring helps it blend into streambeds and avoid the gaze of fish-eating birds and mammals, the near-white appearance of a leucistic individual would seem to be a serious liability. Yet the new study suggests that in the right circumstances, this mutation may not be a death sentence at all.

The researchers sampled the site using pulsed electric fishing during field campaigns in August 2015 and April 2016. At Vista Alegre Waterfall they captured a total of 39 Heptapterus mustelinus, of which 35 showed the species’ normal coloration and four displayed leucism. The leucistic group included one adult measuring 112.8 millimeters in standard length and three juveniles averaging 62.5 millimeters. The presence of both adults and juveniles, and the fact that leucistic individuals were collected again in a second sampling year after earlier specimens had been removed, convinced the team that the trait was recurring in the population rather than being a one-off curiosity. That recurrence points toward a heritable genetic basis maintained within an isolated subpopulation.

To determine whether leucistic individuals differed from their normally colored relatives in any other way, the team carried out an extensive morphometric analysis. Each fish was measured using 32 characters, including standard length, head length, and dozens of proportional measurements of the body and fins. The leucistic specimens from the Mampituba basin were compared with normally colored fish from the same river and with museum specimens from six additional river basins: the Araranguá River on the coastal drainage, and the dos Sinos, Caí, Gravataí, Jacuí, and Piratini Rivers, all part of the Laguna dos Patos system. These drainages belong to two biogeographic regions recognized for southern Brazil and are known to harbor high levels of endemism among freshwater fishes.

The statistical treatment relied on principal component analysis, or PCA, after log transformation of the data. The results were unambiguous: the morphometric measurements of the leucistic individuals overlapped almost completely with those of normally colored fish from the Mampituba River. In other words, leucistic catfish are not structurally different from their pigmented counterparts; they retain the species’ typical body plan. The components explaining the greatest variation were associated with interdorsal length and preadipose distance, but these accounted for well under one percent of total variation and did not separate leucistic individuals as a distinct group. Among the broader population comparisons, only fish from the Araranguá River showed slight differences from the other basins, and even that did not affect the conclusion about the leucistic specimens.

Why, then, does leucism persist at Vista Alegre? The authors argue that the answer lies in a combination of environmental isolation and relaxed predation pressure. The sampling site is a small stream segmented by rapids and waterfalls, geological features that act as barriers to gene flow among subpopulations. Such isolation can allow unusual traits to become established where they would otherwise be diluted. The stream also runs through dense gallery forest, creating deeply shaded conditions with small caves between the rocks where the catfish can shelter during daylight hours. Under reduced light, the visual advantage that normal brown coloration confers against predators largely disappears, and the conspicuousness of a pale fish matters far less.

The community of fish sharing the stream reinforces this interpretation. Alongside the leucistic catfish, the researchers found only small species: Characidium pterostictum, the armored catfish Pareiorhaphis hypselurus, and a couple of loricariid specimens, all of which are insectivorous or feed on invertebrates and periphyton. Crucially, no piscivorous fish were present at the site. The remaining potential predators, such as the South American raccoon and kingfishers, hunt by sight, and their success in the dim, shaded water is likely to be low. Without strong visual predation, there is little selective pressure against pale individuals, and the mutation can be passed on.

The study also weighs, and largely dismisses, alternative explanations. Exposure to heavy metals is known to induce pigment abnormalities in fish embryos, but the sampling site lies downstream of an environmentally preserved area near a national park, making contamination an implausible cause. Dietary deficiencies, such as a lack of tyrosine needed for melanin synthesis, cannot be ruled out entirely, but the recurrence of the trait across two size classes and two sampling years fits better with a Mendelian pattern of inheritance. The authors point to a comparable case in Japan, where a leucistic catfish crossed with a normal specimen produced offspring in which roughly one quarter lacked skin color, exactly the ratio expected for a recessive trait.

Pigmentation mutations are especially well documented in the order Siluriformes, the catfishes, which account for the majority of the handful of albinism and leucism records in Neotropical freshwater fishes. The broader evolutionary context is provided by the blind cavefish Astyanax mexicanus, which lost its color and eyes after colonizing subterranean environments repeatedly throughout its history. The Brazilian case is different in an important respect: it involves a surface-dwelling species in an open stream, where a color mutation is usually assumed to be deleterious. The authors argue that their findings show such mutations cannot automatically be classified as harmful. In populations restricted to geographically isolated streams with few sympatric species and weak visual predation, leucistic individuals may not only survive but be maintained across generations, and in some circumstances could even increase in abundance.

The team calls for further research into how such traits persist, noting that reports of pigment abnormalities are appearing with growing frequency across the Neotropical region and may reflect environmental influences specific to small, stream-restricted habitats. For now, the pale catfish of Vista Alegre stand as a reminder that a trait which looks like a handicap in a textbook can be a perfectly viable strategy in a dark forest stream, where waterfalls wall off a population and the sun rarely reaches the water.

Subject of Research: Leucism and its possible adaptive value in isolated populations of the catfish Heptapterus mustelinus in southern Brazilian streams

Article Title: A case of leucosis in Heptapterus mustelinus ( Siluriformes , Heptapteridae ) among populations of streams in southern Brazil. Has leucosis in Heptapterus mustelinus an adaptive value in shaded streams?

Article References: Ferraz, M., Schulz, U. H., Santos de Lucena, C. A., & Lehmann A., P. (2023). A case of leucosis in Heptapterus mustelinus (Siluriformes, Heptapteridae) among populations of streams in southern Brazil. Has leucosis in Heptapterus mustelinus an adaptive value in shaded streams?. Neotropical Biology and Conservation, 18(3), 177-189. https://doi.org/10.3897/neotropical.18.e103523

Image Credits: AI Generated

DOI: 10.3897/neotropical.18.e103523

Keywords: leucism, Heptapterus mustelinus, catfish, Brazil, morphometry, PCA, predation, geographic isolation, pigmentation, Neotropical fishes, stream ecology, genetics

The core idea behind the pipeline is elegantly pragmatic. Rather than training a deep neural network to recognize every fine-grained subregion from scratch—an approach that would require enormous amounts of expert-labeled training data—the researchers built their system on top of an existing whole-bone segmentation tool called TotalSegmentator. That tool first identifies the parent bone structures in a scan. The pipeline then applies a set of fixed, anatomy-driven rules to carve those parent masks into 81 distinct segments, including the iliac columns, the acetabular regions that form the hip socket, and the proximal femoral regions. Because the division follows deterministic anatomical rules rather than learned approximations, the output is reproducible and transparent, and the entire process runs as a one-click operation within 3D Slicer, a widely used open-source platform for medical image analysis.

To test the system, the team retrospectively collected anonymized pelvic CT scans of normal adults and screened 1,316 cases against predefined quality criteria. A total of 757 scans passed the filter and were processed through the pipeline. The primary endpoint of the study was deliberately conservative: instead of simply measuring how well the automated segments matched some ideal, the researchers asked how much manual correction a human expert would actually need to make the outputs anatomically acceptable. In 100 randomly selected cases, every one of the 81 segments was expert-reviewed and corrected wherever necessary, with the frequency of correction serving as the study’s key metric.

The results were striking. Across 8,100 individual segment observations, 93.8 percent were accepted by the expert reviewers without any correction at all. Even more telling, 51 of the 81 segments required no correction in any of the hundred cases examined. When corrections were needed, they clustered tightly in a small number of boundary regions, chiefly the ischium and the femoral neck, where the transition between bones is anatomically subtle. On average, the median correction burden amounted to just 4.5 segments per case—a modest workload compared with the dozens of contours that would otherwise have to be drawn by hand.

Accuracy, computed only on the segments that required correction, told a similarly encouraging story. The median Dice similarity coefficient—a standard overlap metric where 1.0 indicates perfect agreement—reached 0.94 for these corrected segments, indicating that even where the pipeline deviated from expert judgment, the errors were spatially modest rather than gross. A secondary symmetry analysis, which compared corresponding structures on the left and right sides of the pelvis, showed median surface agreement of 90 percent within 2 millimeters and 99.9 percent within 5 millimeters. This bilateral symmetry check matters because the human pelvis is nominally symmetric, and deviations can flag either genuine anatomical variation or segmentation error.

Normal anatomy, of course, is the easy case. The true test of any automated segmentation tool is whether it survives contact with the fractured, deformed, and diseased anatomy that fills real clinical caseloads. To probe this, the researchers assembled a separate 60-case cohort featuring pathological anatomy and compared the pipeline’s output on affected segments against manually segmented ground truth. The pooled median Dice coefficient across affected components was 0.970, a figure that suggests the rule-based approach retains much of its reliability even when fractures or deformities disrupt the expected geometry. Pooled landmark error came in at a median of 5.37 millimeters, and 91.9 percent of manually placed landmark clicks fell inside the automated landmark regions.

The implications for clinical practice and research extend well beyond the numbers. Precise subregional segmentation of the pelvis underpins a remarkable range of interventions: planning total hip arthroplasty, where cup positioning depends on accurate acetabular morphology; managing acetabular fractures, where classification systems depend on identifying which columns and walls are involved; and morphometric studies that map population-level variation in pelvic shape. By converting a raw CT scan into a structured, labeled map in a single click, the pipeline could compress hours of manual contouring into minutes of light review, while preserving exactly the anatomical detail that morphometric analyses and dataset generation require.

The study also highlights a broader trend in medical imaging: the rise of hybrid pipelines that combine learned and rule-based components. Deep learning models excel at the perceptual task of finding organs and bones in noisy images, but they can be brittle at boundaries, inconsistent across cases, and expensive to retrain for new label sets. Deterministic anatomical rules, by contrast, are transparent, cheap, and easy to audit, but they need a reliable starting point. By chaining TotalSegmentator’s learned whole-bone masks into a rule-based subdivision stage, the Aachen team gets the best of both worlds—and, crucially, they quantify the residual human workload rather than hiding it behind a single accuracy score. That honest accounting of the correction burden is what makes the results actionable for clinics deciding whether such a tool is ready for their workflow.

The authors are careful to draw the line between what has been validated and what remains unproven. The pipeline is validated for normal adult anatomy, and its performance held up in an initial pathological-anatomy sample, but the researchers explicitly state that extension to fracture management, deformity correction, or clinical decision-making requires dedicated validation in abnormal anatomy. Fractured pelvises can shatter the geometric assumptions on which any rule-based subdivision depends, and a tool that works beautifully on intact bones cannot simply be assumed to work on a shattered acetabulum. That caveat is not a weakness of the study but a roadmap: the 0.970 pooled Dice in the pathological cohort provides a credible foundation for the larger, fracture-specific validation studies that would need to follow.

For a field where the pelvis has long been described as among the most demanding regions in musculoskeletal imaging, the arrival of a one-click, anatomy-driven subsegmentation tool marks a genuine shift. The work, published open access under a Creative Commons license, emerged from a collaboration between the departments of Orthopaedic Surgery and Diagnostic and Interventional Radiology at University Hospital Aachen, with the team reporting no funding sources or conflicts of interest. If subsequent validation in fractured and deformed anatomy confirms the early promise, the tedious manual contouring that has long been the hidden cost of pelvic surgery planning and morphometric research may finally give way to a workflow in which the computer does the drawing and the surgeon does the deciding.

Subject of Research: Automated anatomy-driven subsegmentation of pelvic and proximal femoral CT into surgical subregions and landmarks

Article Title: Anatomy-driven automated subsegmentation of pelvic and proximal femoral CT into clinically relevant subregions and landmarks

Article References: Rashed, M., Alabdulrahman, H., Westfechtel, S. D., Hildebrand, F., & Truhn, D. (2026). Anatomy-driven automated subsegmentation of pelvic and proximal femoral CT into clinically relevant subregions and landmarks. BMC Medical Imaging, 26(1), Article 454. https://doi.org/10.1186/s12880-026-02753-x

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02753-x

Keywords: pelvic CT, automated segmentation, subsegmentation, proximal femur, acetabulum, anatomical landmarks, 3D Slicer, TotalSegmentator, Dice coefficient, orthopedic surgery, medical imaging, morphometry

The zygomatic bone, commonly known as the cheekbone, connects to four neighbouring bones through four sutures: the zygomaticomaxillary suture where it meets the upper jaw, the sphenozygomatic suture where it meets the sphenoid bone deep within the skull, the temporozygomatic suture where it meets the temporal bone, and the frontozygomatic suture where it meets the frontal bone of the forehead. Together, these junctions form the architectural framework of the zygomaticomaxillary complex, a structure that is frequently fractured in facial trauma from road accidents, sports injuries and assaults. When surgeons repair such fractures, they rely on anatomical landmarks to restore the original position of the bone, but until now there has been limited comparative data on the projected geometry of all four sutures measured within a single, consistent imaging protocol.

The research team took a retrospective cross-sectional approach, analysing cranial CT examinations that yielded 762 measurable sides across 381 adult patients. Rather than measuring the sutures directly on individual axial slices, which can distort their true course, the researchers used a technique called maximum intensity projection reformats with standardised thick slabs. This method projects the brightest bone signals along a viewing axis onto a single plane, allowing the entire winding course of each suture to be visualised and measured as a continuous line. On these projected images, the team recorded four parameters for each suture on both sides of every patient: the projected length along the suture’s full course, the end-to-end straight-line distance between its endpoints, the sinuosity, which is the ratio of the full course length to the straight-line distance and captures how winding the suture is, and the angle the suture makes with the Frankfort horizontal plane, a standard cranial reference plane that runs from the lower edge of the eye socket to the upper edge of the ear canal.

The statistical analysis was designed with care for the fact that measurements from the two sides of the same patient are not independent observations. The researchers used generalised estimating equations, a method that accounts for this within-patient correlation, and applied false discovery rate adjustment to control for the many comparisons being made simultaneously. They also calculated patient-level Spearman correlations to explore whether the dimensions of one suture predict those of another within the same individual, and intraclass correlation coefficients to quantify how closely the left and right sides of each suture matched within a single person. This combination of approaches allowed the team to distinguish genuine group-level patterns from individual variability, a distinction that proved central to their findings.

The results revealed that each of the four sutures possesses its own characteristic geometric signature. Among the defined projected measurement courses, the zygomaticomaxillary suture showed the greatest mean length and the greatest end-to-end distance, reflecting its role as the long horizontal junction between the cheekbone and the upper jaw. The orientation measurements were particularly striking: the mean angles to the Frankfort horizontal plane ranged from 15.3 degrees for the frontozygomatic suture, which runs nearly parallel to that reference plane, to 67.1 degrees for the sphenozygomatic suture, which plunges steeply into the depth of the skull. In other words, the four sutures are not variations on a theme but genuinely different structures in terms of size, winding pattern and three-dimensional orientation, each demanding its own reference values in any clinical or anatomical application.

The correlations between sutures added another layer of nuance. For dimensional parameters such as length and distance, and for sinuosity, the intersuture correlations were weak to moderate, with the largest Spearman coefficient reaching only 0.40. This suggests that a person with a long zygomaticomaxillary suture cannot be assumed to have correspondingly long other zygomatic sutures; each suture appears to develop largely on its own geometric trajectory. The angular correlations were even smaller, with the largest absolute coefficient at just 0.12, and none of the angular correlations remained statistically significant after false discovery rate adjustment. The orientation of one suture, in short, tells you essentially nothing about the orientation of its neighbours, reinforcing the picture of four independently patterned anatomical features.

Sex and side differences emerged in a pattern that clinicians will find informative. Length and end-to-end distance were greater in males for all four sutures, consistent with the overall sexual dimorphism of the craniofacial skeleton. Side differences, however, were remarkably limited at the group level: the only directional left-right difference detected was in the sphenozygomatic straight-line distance. This near-symmetry at the population level might suggest that the two sides of any individual’s face are mirror images, but the bilateral intraclass correlation coefficients told a more complicated story. These coefficients, which measure how strongly the left and right measurements correspond within the same person, ranged from 0.37 to 0.80 across the different sutures and parameters. Small average side differences, in other words, coexist with considerable individual variation in symmetry, meaning that some people have closely matched pairs of sutures while others show substantial left-right divergence even though the group averages look balanced.

This distinction between group-level symmetry and individual-level agreement has practical implications for the concept of using the uninjured side as a template for reconstructing the injured side, a common strategy in maxillofacial surgery. If bilateral agreement varies substantially from person to person, then the healthy side of a patient with a zygomaticomaxillary complex fracture may be a more or less reliable guide depending on which suture is involved and which parameter is being compared. The authors are careful to stress, however, that their data come from a single centre and a single scanner, and that the measurements were descriptive projected morphometric values obtained from a general adult population rather than from fracture patients. Before these reference values can be used in fracture reduction assessment or surgical planning, they require external validation in independent cohorts and direct evaluation in patients with actual zygomatic fractures.

The study also stands as an example of methodological transparency in modern anatomical research. The protocol was approved by the İstanbul Medipol University Non-Interventional Clinical Research Ethics Committee, and the requirement for individual informed consent was waived because of the retrospective design and the use of fully anonymised archival imaging data. The authors disclosed that a generative artificial intelligence tool was used for English-language editing, assistance with statistical coding and document formatting, but not for autonomous data analysis or interpretation, with all statistical analyses executed, reviewed and interpreted by the researchers themselves. The work received no specific external funding, and the authors declared no competing interests.

For a field in which surgical decisions can hinge on millimetre-scale judgments of bone position, the value of a large, standardised morphometric dataset is difficult to overstate. By demonstrating that the four zygomatic sutures have distinct projected profiles, that their orientations span a remarkable range from nearly horizontal to steeply inclined, and that individual bilateral symmetry is variable even when population averages appear balanced, the study gives anatomists, radiologists and surgeons a firmer quantitative foundation for understanding the midface. The next step, as the authors make clear, is to test whether these normal values can discriminate between restored and malpositioned bones in real fracture cohorts, transforming a descriptive anatomical atlas into a practical instrument for reconstructive care.

Subject of Research: Computed tomography-based morphometry of the four zygomatic sutures in adults

Article Title: Computed tomography-derived projected morphometry of four zygomatic sutures: distinct geometric profiles and bilateral agreement

Article References: Altıntaş, H. M., Köksal, A., Cingöz, G., Eberliköse, H., & Demir, B. T. (2026). Computed tomography-derived projected morphometry of four zygomatic sutures: distinct geometric profiles and bilateral agreement. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02896-x

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02896-x

Keywords: computed tomography, zygomatic sutures, morphometry, craniofacial anatomy, zygomaticomaxillary complex, facial asymmetry, maxillofacial surgery, maximum intensity projection, bilateral agreement, Frankfort horizontal plane, facial trauma, BMC Medical Imaging

The mitral valve sits between the left atrium and the left ventricle, and its two leaflets—anterior and posterior—must open and close tens of thousands of times a day without leaking. When the valve fails, surgeons may reconstruct the leaflets using a patch of pericardium harvested from the patient. The success of such reconstruction depends on getting the geometry right: the height, width, and free-edge length of each scallop of the leaflets determine how well the repaired valve coapts and seals during systole. Conventional proportional formulas, which estimate leaflet dimensions from a few reference measurements, provide only simplified approximations that ignore the considerable anatomical variability between individuals.

To address this gap, a team of researchers from I.M. Sechenov First Moscow State Medical University (Sechenov University) in Moscow and Universiti Malaysia Sarawak analyzed clinical and morphometric data from 72 adult autopsy cases in which the mitral valve was free of structural disease. From each case, they recorded a set of patient-level characteristics and valve-level measurements, then defined eight anatomical targets that would be required for building a leaflet template: heights and free-edge lengths of the individual anterior and posterior leaflet scallops. The posterior leaflet is typically divided into three scallops—P1, P2, and P3—while the anterior leaflet is similarly segmented into A1, A2, and A3 regions, and each of these segments has its own measurable geometry.

The researchers compared eight different regression approaches in separate target-specific modeling workflows rather than forcing a single algorithm onto all eight anatomical outputs. This design reflected an important practical insight: different anatomical dimensions may depend on different combinations of inputs and may exhibit different statistical relationships with the available predictors. After systematic comparison, the final model set consisted of four ElasticNet regressors and four random forest regressors, a split that balances the interpretability and regularization of penalized linear models against the flexibility of ensemble tree-based methods.

The clinically oriented configuration used 17 patient- and valve-level inputs to estimate the eight anatomical dimensions. Predictive performance varied considerably across targets. The most accurate predictions were achieved for the heights of the P1 and P3 scallops of the posterior leaflet, where the mean absolute error was between 1.68 and 1.70 millimeters and the coefficient of determination, R-squared, reached 0.54 to 0.55. In practical terms, the models could estimate these posterior scallop heights to within roughly a millimeter and a half to two millimeters of the true anatomical value, and they explained a moderate share of the variance across individuals. Among the anterior-leaflet parameters, the A3 height showed the best performance, with a mean absolute error of 2.33 millimeters and an R-squared of 0.21, indicating that while the average error remained clinically modest, the models captured much less of the individual-to-individual variability in this region.

The least predictable target was the free-edge length of the posterior leaflet, where the mean absolute error rose to 13.32 millimeters and the R-squared dropped to just 0.02—essentially no better than predicting the population mean. This result is anatomically meaningful rather than merely a modeling failure. The free edge of the posterior leaflet is a long, scalloped, highly variable structure, and its total length appears to depend on factors not well represented among the 17 inputs available in this dataset. The finding highlights a key limitation of the proof-of-concept stage: the models are only as informative as the morphometric and clinical variables they are given, and some dimensions of the valve may require additional predictors, such as imaging-derived measurements of the annulus, chordae, or ventricular geometry.

A central strength of the study lies in its clinical orientation. Rather than stopping at statistical performance metrics, the authors incorporated the model outputs into an interactive tool for generating individualized computer-aided leaflet templates. In the envisioned workflow, a surgeon would enter a small set of patient- and valve-level measurements, the trained models would predict the eight required anatomical dimensions, and the tool would translate those predictions into digital templates sized for the individual patient. Such templates could then be used to cut and shape an autologous pericardial patch with a precision that proportional rules cannot deliver, potentially reducing intraoperative guesswork and improving the geometric fidelity of the repair.

The authors are careful to frame the work as a proof of concept rather than a clinical tool ready for the operating room. The dataset of 72 anatomical cases, while sufficient to train and compare regression models, is modest by machine-learning standards, and the models were developed on autopsy-derived measurements rather than on living patients. Before any clinical implementation, the researchers emphasize that a prospective comparison of imaging-derived and anatomical measurements is required to confirm that predictions based on clinical imaging data align with true anatomical geometry, followed by validation in independent cohorts. These steps are essential to ensure that the millimeter-level accuracies observed in the anatomical dataset translate into real-world surgical reliability.

The study also carries implications for how patient-specific modeling may evolve in structural heart surgery more broadly. Individualized prediction of valve geometry fits into a larger trend toward computational planning in cardiac surgery and interventional cardiology, where three-dimensional echocardiography, computed tomography, and cardiac magnetic resonance imaging increasingly feed patient-specific models that simulate device behavior and repair outcomes. A machine-learning layer that estimates otherwise unmeasurable anatomical parameters could complement these imaging pipelines, particularly in settings where advanced imaging is incomplete or where the relevant dimensions are not directly accessible. The Sechenov and UNIMAS team’s target-specific approach—fitting and selecting a different model for each anatomical output—offers a pragmatic template for other groups attempting to map clinical predictors onto complex three-dimensional anatomy.

For now, the message of the study is one of careful, incremental progress. The models perform well for some dimensions, notably the heights of the P1 and P3 posterior scallops, but struggle with others, especially the posterior free-edge length, and the authors do not overstate their case. What they have demonstrated is that the full chain—from anatomical measurement, through machine-learning estimation, to digital template construction—is technically feasible, ethically approved, and open to refinement. If subsequent prospective and independent validation confirms the approach, the humble autopsy dataset could become the foundation for a new generation of personalized mitral valve reconstructions, in which the leaflet a surgeon implants is not an approximation drawn from population averages but a prediction tailored to the anatomy of a single patient.

Subject of Research: Machine-learning prediction of patient-specific mitral valve anatomical parameters for reconstructive planning

Article Title: Machine-learning prediction of patient-specific mitral valve anatomical parameters for reconstructive planning

Article References: Komarov, R. N., Dydykin, S. S., Vasalatiy, I. M., Kapitonova, M., & Drakina, O. V. (2026). Machine-learning prediction of patient-specific mitral valve anatomical parameters for reconstructive planning. BioMedical Engineering OnLine. https://doi.org/10.1186/s12938-026-01624-4

Image Credits: AI Generated

DOI: 10.1186/s12938-026-01624-4

Keywords: mitral valve, machine learning, morphometry, patient-specific prediction, autologous pericardium, reconstructive planning, ElasticNet, random forest, cardiovascular models, echocardiography, predictive medicine, biomedical engineering

The study, led by Yadigar Kastamoni and Kenan Öztürk of the Department of Anatomy at Süleyman Demirel University, together with Ahmet Dursun, Onur Can Şanlı and radiologist Veysel Atilla Ayyıldız, set out to reveal sex-related characteristics through morphometric measurements taken on the mandible, and to predict sex in individuals from different age groups using those variables. The work addresses one of the enduring challenges of forensic anthropology: identifying reliable, population-appropriate skeletal markers of sexual dimorphism that remain robust across the adult lifespan.

The research team analysed head and neck computed tomography images from 152 individuals, 77 males and 75 females, aged between 20 and 98 years. From these scans, the researchers generated three-dimensional reconstructions of each mandible using the RadiAnt DICOM viewer, a software platform that converts the two-dimensional slice data produced by CT scanners into volumetric models that can be measured in three dimensions. This approach reflects a broader shift in forensic science away from measurements taken with calipers on dry skulls and toward virtual anthropology, in which clinical imaging archives become rich sources of skeletal data.

The specific landmarks chosen for measurement were carefully selected regions of the mandible with well-established anatomical identities. The team measured dimensions relating to the foramen mentale, the mental foramen through which the mental nerve and vessels emerge on the front of the jaw; the condylus mandibulae, the rounded condyles that articulate with the skull at the temporomandibular joints; the incisura mandibulae, the notch between the condyle and the coronoid process on the upper margin of the ramus; and the angulus mandibulae, the angle of the jaw at the back and lower corner of the bone. In addition, the researchers measured the bigonial distance, the straight-line breadth of the jaw between the two gonion points at the angles on either side. All measurements, except those involving the mandibular angle, were carried out in RadiAnt DICOM Viewer 2020.1.1, and the resulting data were analysed statistically using SPSS 20.0 for Windows.

The results were strikingly consistent with the known biology of the human mandible. When the parameters were compared between the sexes, the mean values of all measurements, with the single exception of the left mandibular angle, were larger in males than in females. This pattern mirrors the influence of testosterone-driven bone growth during puberty, which produces a generally larger, squarer and more robust jaw in men, while hormonal and muscular factors in women tend to produce a jaw with a more obtuse gonial angle and finer proportions. The only measurement that failed to show a statistically significant sex difference was the gonial angle itself on the left side, a finding that reinforces a long-standing caution in the literature: angular measures of the jaw are notoriously variable and are influenced by age-related remodelling, tooth loss and chewing forces.

The degree of sexual dimorphism varied considerably across the measured parameters. The highest dimorphism rate was observed in the incisura mandibulae, the mandibular notch, which differed between the sexes by 14.39 percent on the right side and 14.29 percent on the left. At the opposite extreme, the angulus mandibulae showed almost no dimorphism, with differences of just 0.12 percent on the right and 0.57 percent on the left. This gradient is informative for forensic practice: it suggests that linear distances spanning the ramus, particularly between the mandibular condyle and the gonion, carry far more sex-diagnostic information than the angle of the jaw, which should be treated with caution when sexing fragmentary remains.

Indeed, the statistically significant differences between the sexes were found specifically in the distances from the condylus mandibulae to the gonion on both sides of the jaw, alongside the bigonial distance. These findings give forensic anthropologists a small set of hardy landmarks, robust bony points that survive decomposition and trauma relatively well, from which reliable linear measurements can be taken. Because the condyle and gonion are prominent structures on the ramus, they remain measurable even when the delicate alveolar portion of the jaw bearing the teeth has been damaged or lost, a common scenario in archaeological and forensic contexts.

What elevates the study beyond a simple descriptive anatomy exercise is its predictive modelling. The researchers built a logistic regression model from their measured variables, which correctly classified 91.4 percent of individuals in the development sample. A parallel discriminant function analysis achieved 90.1 percent classification accuracy on the original sample, and, crucially, retained 85.5 percent accuracy under leave-one-out cross-validation, a stringent test in which each individual is classified by a model trained on everyone else. The modest drop between original and cross-validated performance indicates that the model generalises reasonably well rather than simply memorising the training data, an important consideration for any method intended for real casework.

The authors conclude that sex estimation can be successfully performed using external measurements of the mandible, and they highlight the bigonial distance and the gonion-to-condyle measurements as particularly valuable parameters for sex differentiation. They suggest the method may prove useful in anatomy, forensic medicine and anthropology, especially in studies requiring sex estimation. This positions the mandible alongside the pelvis and skull as a first-rank bone for sex estimation, with particular value in contexts where those more classically dimorphic elements are missing. The mandible is also among the densest and most durable bones in the human skeleton, frequently surviving fire, fragmentation and long burial, which makes any validated method for reading sex from it disproportionately useful.

The study also carries broader implications for how forensic science will develop in the coming years. Computed tomography is now routinely performed in hospitals worldwide, and archives of clinical scans represent vast, untapped populations of reference data. Virtual osteometry of this kind does not require a physical skeleton at all: it can be applied ante-mortem to living patients in identification contexts, and post-mortem using clinical or forensic CT, avoiding destructive sampling of evidence. Earlier work cited by the team, including validation studies of three-dimensional CT measurements and postmortem CT morphometry of the mandible in Japanese populations, had already established the technical reliability of imaging-based measurement; the new study extends that framework with a large, wide-ranging adult sample spanning nearly eight decades of age, from 20 to 98 years.

As with all skeletal sex-estimation methods, population specificity remains the central caveat. The dimensions of the mandible vary across ancestral and geographic groups, and the classification functions derived here were developed on a Turkish sample; forensic practitioners applying them elsewhere would need to validate or recalibrate the model against local reference data before relying on it in identification casework. The retrospective design, approved by the Human Research Ethics Committee of Süleyman Demirel University with informed consent waived for anonymised data, also means the findings describe a clinical imaging population rather than a random demographic one. Nevertheless, with cross-validated accuracy approaching ninety percent from a handful of simple linear measurements, the message of the study is clear and, for a field where even a single additional clue can resolve an identification, quietly revolutionary: the jawbone remembers who you were, and it is willing to tell.

Subject of Research: Sex estimation from morphometric measurements of the human mandible in three-dimensional computed tomography images

Article Title: Sex estimation from the mandible in 3D computed tomography images

Article References: Kastamoni, Y., Dursun, A., Şanlı, O. C., Ayyıldız, V. A., & Öztürk, K. (2026). Sex estimation from the mandible in 3D computed tomography images. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04001-x

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04001-x

Keywords: sexual dimorphism, mandible, computed tomography, forensic anthropology, 3D imaging, morphometry, sex estimation, bigonial distance, logistic regression, discriminant analysis, human identification, osteometric analysis