The research, published in The Science of Nature by a team from the Department of Anthropology at Comenius University in Bratislava, was led by Zuzana Kozáková together with Petra Švábová, Michal Soták, Mária Matláková and Radoslav Beňuš. Their pilot cross-sectional study enrolled 246 adult participants, 176 women and 70 men, and measured facial soft tissue thickness, or FSTT, using B-mode ultrasonography. The technique is a relatively recent addition to the forensic toolkit: instead of measuring tissue depths on cadavers or through expensive imaging such as MRI and computed tomography, ultrasound allows researchers to capture living, breathing faces quickly, safely and with a standardized protocol that has been gaining traction in craniofacial identification since around 2020.

The team measured tissue depth at sixteen anatomical landmarks: eight located along the midline of the face, running from the forehead down to the chin, and eight paired landmarks positioned on both left and right sides of the face, including sites such as the fossa canina, the small depression above the canine tooth where tissue thickness is notoriously variable. This bilateral approach matters because previous work by some of the same authors had shown that head position can subtly alter ultrasound readings, and because asymmetry itself carries forensic information. Each measurement was then fed into a statistical battery that included non-parametric tests, Spearman rank correlations and general linear models, with body mass index and age entered as covariates so that the independent contribution of each factor could be untangled.

The headline finding is that the three variables the researchers probed, body mass index, age and smoking status, do not act uniformly. Instead, their influence depends strongly on both sex and the specific anatomical site. In women, BMI emerged as the dominant predictor of facial tissue thickness, producing effects the authors classified as medium to large across most of the measured landmarks. That is perhaps intuitive: subcutaneous fat is distributed across the face in ways that scale with overall adiposity, and a heavier face is simply a fuller face. Age, by contrast, contributed only modestly to variation in the female sample, with its effects concentrated in the lower face, where soft tissue tends to sag and redistribute over the decades.

In men, the pattern flipped. Age, not BMI, showed the stronger and more consistent association with facial soft tissue thickness, with age-related variation most evident in the midfacial and mandibular regions. This sexual dimorphism in how the face ages and accumulates tissue is not merely an academic curiosity. Forensic facial reconstruction depends on choosing the right tissue depth standards for the unknown individual, and if a male skull is estimated to belong to a middle-aged man, the tissue depths an artist should apply at the midface and jaw may differ systematically from those used for a young man, independently of his weight. Population-specific databases, like the Slovak dataset this team has been building since their earlier 2012 midface study, are what make those calibrated choices possible.

And what about smoking? Given the well-documented effects of tobacco on skin, including premature wrinkling, altered biophysical skin properties, and tobacco-smoke-induced degradation of the extracellular matrix, the researchers had good reason to suspect that chronic smoking might thin or remodel the facial soft tissues in measurable ways. The results, however, were strikingly localized rather than global. In women, conventional smokers did show significantly lower FSTT values than non-smokers, but only at one landmark: the left fossa canina, where the difference reached statistical significance at p = 0.046. Everywhere else, the smoking signal dissolved into the noise. In men, direct comparison between smokers and non-smokers revealed no significant differences in tissue thickness at any of the sixteen landmarks.

The authors are careful about what this means. Overall smoking status was not consistently associated with FSTT in their sample, and they explicitly frame the female fossa canina result as a preliminary association that requires confirmation. The study is a pilot, and its design carries real limitations: the sample is heavily skewed toward women, who outnumbered men 176 to 70, and the researchers themselves state that larger and more balanced samples are needed before any firm conclusions can be drawn. Smoking behavior also correlates with body mass index in population studies, which makes it statistically difficult to isolate a pure smoking effect from the confounding influence of weight, a problem the covariate-based modeling was designed to address but which no observational design can fully eliminate.

Why does a single significant landmark among sixteen matter at all? For forensic facial reconstruction, even localized differences could matter if they are real. The fossa canina is one of the classic tissue-depth points used when clay or digital layers are added over a skull, and it sits in a region of the cheek where tissue thickness helps define the shape of the nasolabial area, one of the most recognizable features of a reconstructed face. If smoking genuinely thins tissue at this site in women, then a reconstruction of a female skull that assumed average tissue depths could subtly misrepresent the cheek contour of a woman who was a lifelong smoker. Conversely, the study’s broader message may be reassuring for forensic practitioners: smoking status, unlike sex, age and BMI, does not appear to demand its own correction factors in tissue depth tables, at least not on current evidence.

The work also fits into a larger methodological shift in forensic anthropology. Traditional FSTT databases, such as the large-scale Caucasian dataset assembled in 2006, were built largely from cadaver needle measurements and later from radiographic imaging. Ultrasound offers a way to build population-specific databases from living volunteers at low cost, and recent studies have applied it to populations ranging from northern Chinese Han to Australians, Brazilians, Iranians and sub-adults in Türkiye, each documenting how sex, age and BMI shape the facial soft tissue envelope differently across populations. The Slovak team’s earlier work measured midface tissue depths and tested the effect of head position on ultrasound readings; the new study extends that program into behavioral variables, a relatively unexplored frontier.

For now, the practical takeaways are measured. Facial reconstruction should continue to prioritize sex, age and BMI as the primary drivers of tissue depth variation, with sex-specific standards applied carefully: BMI dominates in women, age dominates in men. Smoking, despite its visible effects on skin texture and wrinkling, does not currently justify a systematic adjustment in tissue depth standards, though the localized female finding at the left fossa canina is worth watching as larger datasets accumulate. The study also underscores a broader lesson about the human face: it is not a static mask over bone but a living, changing structure that records biology and behavior in unequal measure across its contours. As ultrasound technology spreads through forensic laboratories, the maps of that structure will only grow more detailed, and the faces reconstructed from unidentified remains will, ideally, grow more faithful to the people they once belonged to.

Subject of Research: Effects of BMI, age and smoking on facial soft tissue thickness measured by ultrasound for forensic facial reconstruction

Article Title: Smoking-related variation in facial soft tissue thickness assessed by ultrasound: forensic implications for facial analysis

Article References: Kozáková, Z., Švábová, P., Soták, M., Matláková, M., & Beňuš, R. (2026). Smoking-related variation in facial soft tissue thickness assessed by ultrasound: forensic implications for facial analysis. The Science of Nature, 113(6), Article 126. https://doi.org/10.1007/s00114-026-02173-5

Image Credits: AI Generated

DOI: 10.1007/s00114-026-02173-5

Keywords: facial soft tissue thickness, ultrasonography, forensic facial reconstruction, smoking, body mass index, aging, sexual dimorphism, forensic anthropology, craniofacial identification, Slovak population, pilot study, Comenius University Bratislava

The study’s central focus on sub-adults — individuals in developmental stages distinct from fully mature adults — provides crucial data at a critical juncture in human growth. Soft tissue thickness varies not only with age but also with genetic, environmental, and nutritional factors. By capturing these nuances through MRI scans, the study surpasses traditional methods, which often relied on less precise caliper measurements or two-dimensional radiographs. MRI technology offers a three-dimensional, volumetric view of facial tissues without exposing subjects to ionizing radiation, thus making it ethically and technically superior for studying children and adolescents.

Researchers meticulously gathered data from a representative sample of Türkiye’s sub-adult demographic, ensuring that the findings could be generalized within this population. This careful sampling enhances the credibility and applicability of the dataset in both forensic reconstruction and clinical diagnoses. The focus on Türkiye is particularly notable given the country’s unique genetic heterogeneity and geographic bridge between Europe and Asia, factors that may influence soft tissue characteristics significantly. Such region-specific data are vital because existing FSTT databases are predominantly derived from Western populations, which may not accurately reflect anatomical variability elsewhere.

A standout feature of the study is the exploration of correlations between facial tissue thickness and body mass index (BMI). BMI is a globally recognized marker for nutritional status and overall health, reflecting an individual’s body fat composition. Sub-adult facial soft tissues are subject to developmental changes influenced by nutritional and metabolic status, so understanding this relationship can elucidate how BMI contributes to facial morphology. The findings indicate that BMI has a quantifiable impact on soft tissue thickness at various anatomical landmarks, emphasizing the need to incorporate such physiological parameters into forensic reconstructions and anthropometric modeling.

The MRI-based methodology enabled researchers to capture high-resolution images of multiple standard facial landmarks, which are crucial for detailed anthropometric analysis. By examining these landmarks across individuals with diverse BMI values, the study not only provides mean thickness values but also reveals patterns of variability that hold significance for practical applications. This level of detail offers forensic artists and anthropologists a refined toolkit to reconstruct faces with greater accuracy, especially in scenarios involving decomposed or incomplete remains where tissue depth estimates are paramount.

Beyond forensic implications, the research has potential clinical significance. Understanding sub-adult facial tissue thickness is relevant for pediatric reconstructive surgery, orthodontics, and craniofacial anomaly interventions. Surgeons planning interventions can benefit from precise normative data tailored to the age and physiological status of their young patients, enhancing surgical outcomes and aesthetic results. This cross-disciplinary utility underlines the importance of the study’s findings and encourages integration between forensic scientists and healthcare professionals.

The study also addresses the limitations inherent in previous facial soft tissue thickness research. Historically, many datasets suffered from limited sample sizes, reliance on two-dimensional measurements, and a lack of focus on sub-adult populations. By overcoming these obstacles through a robust MRI protocol and a sizable, demographically representative cohort, the researchers set a new standard for FSTT research methodology. This advancement could foster more standardized practices internationally, facilitating data comparison and collaborative research.

Moreover, the comprehensive dataset established in this study offers future researchers a valuable reference point. It paves the way for expanded investigations into ethnic and genetic variability in soft tissue thickness and encourages longitudinal studies monitoring facial changes throughout childhood and adolescence. Understanding how facial tissues evolve with growth and external factors will enhance not only forensic reconstructions but also biometric technologies and facial recognition systems, with implications for security and identity verification.

In addition to technological prowess, the study underscores the importance of interdisciplinary collaboration. Radiologists, forensic experts, anthropologists, and statisticians worked in concert to ensure the collection, interpretation, and application of the data were scientifically rigorous and socially responsible. This collaborative model may inspire similar research initiatives worldwide, emphasizing the integration of advanced imaging with forensic science to achieve breakthroughs in human identification.

The nutritional and environmental context of the sub-adult participants is another aspect considered by the research team. Türkiye presents diverse socioeconomic conditions which can influence BMI and, consequentially, soft tissue properties. The analysis acknowledges these factors by incorporating BMI as a covariate and discussing how disparities in nutrition and health status could affect soft tissue measurements. This nuanced approach enriches the relevance of the findings for forensic casework in varying circumstances, where body composition may deviate from population averages due to malnutrition or obesity.

An intriguing aspect of the study is its potential to enhance facial approximation protocols used in forensic investigations. Typically, these protocols rely heavily on adult data, often extrapolated for younger individuals without validation. The precise MRI data now available allows for age-appropriate correction factors to be developed, improving the fidelity of reconstructive techniques applied to juvenile remains. This not only aids identification but also serves justice by providing families and investigators with more reliable visualizations.

Technological advances in MRI scanning, coupled with the analytical algorithms employed by the researchers, illustrate how modern imaging can push boundaries in forensic anthropology. The development of reproducible, quantifiable measurements from high-resolution scans ensures that soft tissue depth data is no longer an estimate but a verifiable metric. This transition from estimation to quantification is pivotal for forensic experts who often operate under high-stakes conditions where accuracy can determine case outcomes.

The psychological and social implications of the study should not be overlooked. Improving facial reconstructions for sub-adults can have profound effects on missing persons investigations and disaster victim identification. Families seeking closure benefit emotionally when reconstructions are more lifelike and accurate, which enhances recognition and identification rates. This humane aspect adds an ethical dimension to the scientific advances presented, underscoring why such research is critically important.

Furthermore, the study prompts a reevaluation of existing forensic databases and encourages a paradigm shift towards region-specific, age-appropriate data collection. Global databases may benefit from incorporating findings like these, ensuring that facial reconstruction software and protocols adapt to diverse populations rather than relying on generalized or outdated data. This shift could initiate a wave of regionally tailored forensic solutions, more sensitive to population diversity in our increasingly interconnected world.

Lastly, the research sets a trajectory for future technological integrations, such as combining MRI data with 3D printing and artificial intelligence (AI) driven facial reconstruction tools. Such innovations may expedite forensic identification processes, reduce human error, and enable the rapid generation of three-dimensional facial models for investigative and judicial use. The foundational data this study provides will be integral to these forthcoming technological synergies.

In summary, this MRI-based investigation into facial soft tissue thickness in Türkiye’s sub-adult population provides a landmark contribution to forensic anthropology, medical sciences, and biometric research. By linking tissue thickness to BMI and mapping detailed anatomical landmarks in a scientifically rigorous manner, the study equips practitioners with robust, population-specific data that can revolutionize facial approximations, pediatric interventions, and biometric applications. This multidisciplinary breakthrough promises enhanced accuracy, ethical integrity, and practical utility in diverse fields centered on understanding and reconstructing the human face.

Subject of Research: Facial soft tissue thickness in the sub-adult population of Türkiye and its correlation with body-mass index (BMI).

Article Title: Facial soft tissue thickness in the sub-adult population of Türkiye: MRI-based assessment and its correlation with body-mass index (BMI).

Article References:
Arslan, Z., Bol, E.A., Kaynak Şahap, S. et al. Facial soft tissue thickness in the sub-adult population of Türkiye: MRI-based assessment and its correlation with body-mass index (BMI). Int J Legal Med (2025). https://doi.org/10.1007/s00414-025-03588-x

Image Credits: AI Generated