搜索结果：Bulletin de l'Association des anatomistes

Throughout the world, there has been much emphasis on humanizing the cadaver with due respect as they are considered the first teachers for a medical student and, of late, have gained momentum. In this context, this research aimed to study the knowledge, attitude and perception of the cadaver among the Phase 1 medical students of our institution. This was a cross-sectional institution-based study of 416 medical students of Phase 1, which included 21 validated questions about the 'attitude, ethics and communication' module 1.5 of the competency-based medical education curriculum. In this study, 235 (56.5%) of our students strongly agreed that the dissection hall is the only place where the dead teach the living. A total of four hundred and five students (97.4%) approved of "cadaver as their first teacher' and 411 (98.8%) of them agreed that the cadaveric oath would inculcate responsibility, respect, and empathy in young medical undergraduates. In this study, 177 (70.8%) students expressed desire to perform cadaveric dissection on a routine basis, and the remaining 64 (25.6%) opined to perform it occasionally. Four hundred and ten (98.6%) students were aware of photographic prohibition without the permission of authoritative personnel inside the dissection hall or of specimens displayed there, and 405 (97.4%) also expressed that it is unethical to share those pictures on social media. Four hundred and thirteen (99.3%) of students were aware of the disposal protocol of the cadaveric tissues. The study observed that the Phase 1 medical students were aware of the guidelines of attitude, ethics, communication, and hygiene protocols to be followed while dissection. They acknowledged that cadavers were their first teacher, who would assist them in both teaching and research. It is believed that this study is enlightening to the students and professors at the medical schools concerning the United Nations Sustainable Development Goal-4 in offering quality education.

In the forensic field, having accurate understanding of the macroscopic and microscopic alterations that occur in teeth when exposed to temperatures has remarkable significance. The preservation of delicate incinerated teeth is crucial in fire investigations that pertain to the temperature exposed, as well as the identification of victims. This preservation is necessary in order to conduct macroscopic and microscopic ultra-structural examinations, which provide valuable insights into the structural alterations that dental tissues undergo when exposed to low to high temperatures. To analyze the macroscopic changes and the microscopic ultra-structural changes of dental hard tissue in permanent and deciduous dentition using stereomicroscope and scanning electron microscope (SEM). The study was conducted on 40 healthy freshly extracted teeth (20 permanent and 20 deciduous) which were subjected to predetermined temperatures i.e., 200̊C, 400̊C, 600̊C and 800̊C respectively for fifteen minutes using muffle furnace. Teeth were examined under stereomicroscope, later which they were processed for SEM examination at a magnification of 1000×. The parameter for macroscopic observation is colour, translucency and surface texture of enamel and cementum. The parameters used in microscopic observation of enamel such as pit and fissure morphology, prism pattern, crack/fracture lines, microporosity, debris, erosion, while for cementum, the parameters considered were crack presence, fissure morphology, collagen bundle arrangement, pattern, and debris. Both macroscopic and microscopic observations of dentition at different specific temperatures were calculated using percentage. The difference in macroscopic and microscopic changes between permanent and deciduous teeth were analyzed using chi-square test. There was no significant correlation in macroscopic and microscopic changes between permanent and deciduous teeth. Observations of dentition at various specific temperatures, both at the macroscopic and microscopic levels, revealed a noticeable reduction in the presence of each of the selected parameters in enamel and cementum. The study revealed significant macroscopic morphological alterations and consistent microscopic ultra-structural patterns alterations that were readily observable at specified temperatures. The use of scanning electron microscopy (SEM) in the examination of burnt dental remains has a special potential for enhancing victim identification and advancing the field of forensic odontology.

Gross human anatomy is essential in undergraduate programs across biological and health sciences. While extensive literature explores medical students' knowledge in this area, studies on non-medical students, particularly those in physical education, are scarce. This study assessed the anatomy knowledge among Brazilian physical education students and explored differences based on employment status, type of class instruction (face-to-face vs. online), and involvement in academic activities. Additionally, we investigated students' perceptions of the assessment instrument and the gross human anatomy course itself. We conducted a cross-sectional study involving physical education students of both sexes, aged 18 and older, from four public Brazilian universities. Participants completed a 15-question multiple-choice survey on human anatomy systems. Correct answers received one point, with a total potential score of 15 points (100%). We categorized scores as excellent (&#x2265;&#xa0;90%), good (71-89%), sufficient (50-70%), and insufficient (<&#xa0;50%). Participants had 90minutes to complete the survey. We presented data as median and interquartile range [IQR], median difference (&#x394;), and 95% confidence intervals. Scores were compared against the median absolute (7.5&#xa0;points) and relative (50%) values. We used rank-biserial correlation for effect size and set a significance level 0.05. The study included 216&#xa0;students (143&#xa0;males) with a median age of 22.4 years [IQR: 4.0]. The final scores were significantly above the cut-offs, with a median absolute score of 9.0 [IQR: 3.0] and a relative score of 60% [IQR: 20%], showing large effects (&#x394;: +2.0 [1.5-2.0], P<0.001; &#x394;: +13.33% [10.0-13.34%], P<0.001). There were no significant differences in either the absolute or relative final scores (P&#x2265;0.05) between students who participated in academic activities and those who did not, nor between students who attended face-to-face versus online gross human anatomy classes. However, we found a significant difference between non-working students and their employed counterparts, with non-workers scoring higher both absolutely (P=0.002) and relatively (P=0.002) on the gross human anatomy questionnaire. Most of the participants described the difficulty of the gross human anatomy questionnaire as "average" (51.39%, n=111) and rated the gross human anatomy course difficulty as "difficult" (52.8%, n=114). Brazilian physical education students demonstrated only sufficient knowledge in gross human anatomy (60%). Therefore, strategies to enhance or maintain their knowledge throughout the educational program are vital.

Understanding dental development within populations is essential for clinical and forensic applications, particularly for age estimation in children and adolescents. This study aimed: I) to evaluate the chronology of dental development, eruption, and exfoliation by means of radiographic analysis and II) to propose dental age estimation models based on the development of permanent teeth and third molars. The sample consisted of panoramic radiographs of individuals between 6 and 22.9years. Radiographs were analyzed for deciduous and permanent teeth, including third molars, using established staging systems for development, eruption, and exfoliation. Dental age estimation models were developed for permanent teeth and third molars, separately, using staging techniques. The models demonstrated high accuracy, with coefficients of determination (r2) of 0.94 for maxillary teeth, 0.95 for mandibular teeth, and 0.93 for third molars. The mean absolute errors (MAE) were approximately 0.6years for permanent teeth and 0.93years for third molars. This study contributes to the field of dental age estimation providing frameworks for evaluating subadults in contexts requiring legal or anthropological assessments. Future research should aim to test and validate these models in independent populations.

The intercostobrachial nerve (ICBN) typically originates from the lateral cutaneous branch of the second intercostal nerve (T2). The ICBN may sometimes arise from the lateral cutaneous branch of T3. Many authors have undertaken ICBN studies as it is a highly variable structure with numerous morphological patterns reported. Variations include double-, triple-, and multiple ICBNs and their potential interconnections (ICs). The current cadaveric study aims to explore the ICBN morphological variants, examining their origins, branching patterns, and relationships with adjacent vessels. Identifying neural variants closely correlates with arterial alterations and may reveal deviations in the ICBN typical course. Dissections were conducted on 30 (15 male and 15 female) formalin-embalmed Greek donated cadavers (60 sides in total) with an average age of 74. Forty-three out of sixty sides had typical ICBN anatomy (71.7%). ICBN variants were identified on 17/60 sides (11 unilateral [9 right and two left] and three bilateral cases) with an incidence of 28.3%. Concerning the ICBN morphology, a single ICBN existed on 9/60 sides (15%), two ICBNs (T2 and T3) on 3/60 sides (5%), three, four, and five, and multiple ICBNs on 1/60 sides (1.7%) per each. An ICBN division into two or three branches was identified on 3/60 sides (5%). ICBN interconnections (ICs) were identified with the medial brachial cutaneous nerve (MBCN) and the medial antebrachial cutaneous nerve (MACN) in 3 cases (5%) and 1 case (1.7%). ICs with the radial nerve (RN) were identified in 3 cases (5%) and ICs with both the MBCN and MACN in a unique case (1.7%). Arterial covariants were identified in 4 out of 60 cases (6.7%). The current gross anatomy study emphasizes the clinical significance of preserving the ICBN during surgical procedures to prevent sensory loss or dysesthesia in the upper arm.

The duodeno-pancreatic region is a highly vascularized area. The superior and posterior pancreaticoduodenal artery is a vessel primarily originating from the gastroduodenal artery. It exhibits rare anatomical variations, such as its emergence from the right branch of the hepatic artery, which we fortuitously identified during a cadaver dissection. The body studied in this dissection was from cadavers donated to science at the Anatomy Laboratory of the Faculty of Medicine in Amiens. This dissection was part of a Master's project aimed at studying the branches of the celiac trunk. We identified a superior and posterior pancreaticoduodenal artery arising from the right branch of the hepatic artery, coursing to the right of the gastroduodenal artery and sharing a very proximal anastomotic branch that gave rise to seven short retro-duodenal arteries. This artery provided branches to the bile duct and then ran along the duodenum and the pancreas while giving off about ten small branches to these two adjacent organs. It anastomosed with the posterior and inferior pancreaticoduodenal artery, which originated from the superior mesenteric artery. Knowledge of this anatomical variation is fundamental for the visceral surgeon performing a cephalic duodenopancreatectomy, a resection of the pancreatic head with preservation of the duodenal framework, a resection of the pancreatic head with pancreatic-jejunostomy, or even in managing a hemorrhagic duodenal ulcer. This aberrant origin of the superior and posterior pancreaticoduodenal artery should also be known by the interventional radiologist during arterial embolizations related to the rupture of pseudoaneurysms of the pancreatic arcades.

Intentional dental modifications are valuable tools in human identification and profiling, helping to determine the cultural, ethnic, or regional origins of human remains. In the Hindu-Balinese tradition, a tooth-filing ceremony called Metatah, involving the six maxillary anterior teeth, is known. This study aimed to explore its prevalence and discuss the potential use in the analysis of dentition for human identification and profiling. An anonymous eleven-question e-survey (Google Forms, 2025) was conducted among Balinese individuals, and responses were quantitatively analysed using Microsoft Excel (2025, version 16.97.2, USA). Of the 55 participants, 49 (89.1%) reported having undergone the ritual. Among them, 28 (50.9%) stated that filing was performed until the incisal edges were smooth and the canines were reshaped to reduce sharpness. The reported reasons for the ritual included the elimination of Sad Ripu, the six enemies of the mind (60%), and as a rite of passage marking the transition from childhood to adulthood (25%). In 30 cases (54.5%), the ritual was performed by a sangging, a traditional Balinese ritual specialist. Most participants described the experience as not painful, while 26.5% reported moderate pain. This study confirms that Metatah in Bali yields characteristic dental modifications relevant to human identification and profiling. Incorporating knowledge of such practices alongside physiological and pathological tooth wear of anterior teeth enhances the accuracy of dental and anthropological assessments.

The human ear is a complex organ, crucial for hearing and balance, divided into three main parts&#xa0;-&#xa0;the external, middle, and inner ear. Traditional teaching methods for ear anatomy, involving textbooks and lectures, often tend to be inadequate in conveying the three-dimensional relationships and intricate structures, leading to lower retention rates and limited understanding in students. To evaluate the impact of low-cost innovative teaching methods on students' perceptions of learning the intricate details of the inner and middle ear, comparing their perspectives before and after the instructional sessions. This study explores an innovative approach to teaching ear anatomy by incorporating temporal bone sections, ear ossicles, handmade 3D models of the middle and inner ear, and the use of an otoscope. The study involved first-year MBBS students from Diphu Medical College, Assam, India for the session 2023-2024 (n=100). Students were divided into small groups and engaged in hands-on sessions using these tools. The effectiveness of this approach was assessed through a Likert scale questionnaire. A Wilcoxon rank-sum test was employed to study the difference in responses of the cohort pre- and post-interactive classes. The response data were also correlated using Spearman's rank correlation coefficient. The results indicated significant (P<0.05) improvements in students' understanding and retention of ear anatomy and its mechanism, with enhanced spatial comprehension and practical skills. This method demonstrated higher student satisfaction and confidence in explaining the structures compared to traditional teaching methods. The findings suggest that incorporating interactive tools in anatomical education can significantly enhance learning outcomes, offering a more effective and engaging way to study complex anatomical structures.

This study analyses the efficacy of introducing digital teaching/learning resources in blended learning mode regarding students' success rate and grading on the final examination in the Human Histology & Embryology course of the Florence University Medical School (Italy). Two student cohorts were compared: early (E, years 2013-2014 and 2014-2015), where the course had only basic digital resources, and recent (R, years 2022-2023 and 2023-2024), where the course could take advantage of a broader panel of digital resources. Analysis of the results of the final exam shows a significant decrease in the number of students failing the exam and an increase in those gaining the highest score (A and A+) in the R cohort. In this cohort, the percentage of students who reached an excellent performance to deserve honours raised to 10,8% vs. 3,9% in the E cohort. The time needed for the students to prepare for the exam was also reduced in the R cohort, as shown by the significant increase in the percentage of the students who took and passed the exam in the first available session after the end of the course (1 month) and decrease in that of the students who postponed their exam till the last sessions (9 months). Our study objectively evaluates the educational value of innovative blended learning, including multiple individualized and interactive digital resources, to improve traditional face-to-face teaching, especially for morphological disciplines.

Stature, a determinant that aids in personal identification, can be estimated using measurements of various body parts. Forensic scientists often find dismembered body parts in trenches, rubbish and elsewhere that are brought for examination, leading to challenges in identification. This study measured the length and breadth of both right and left hands and the stature of the participants, aiming to develop more accurate linear regression equations for stature estimation. Regression equations may be affected by differences in measurements of right and left sides and study done in Nepalese population previously, lack to address this issue. This is a cross-sectional descriptive study in which 195 medical students aged 18 to 24 were enrolled, and measurement of stature was done by stadiometer and hand length and breadth by vernier calliper, after an informed written consent was obtained. Mean stature was higher in males (170.2&#xb1;5.8cm) as compared to females (159&#xb1;7.2cm). Mean length and breadth of both right and left hands were also found to be higher in males when compared with females. The model summary of the multiple linear regression analysis deduced that R is 0.805, which indicates that there is a strong positive correlation between stature and hand dimensions with a Standard Error of Estimates of 5.083cm. Hand length and hand breadth together, may be powerful predictor of stature, as indicated by the greater R value and higher explained variance. Estimation of stature can be done using regression equation derived from hand length and hand breadth. Stature is a changing entity and is influenced by genetics and nutritional status. Future studies can be done taking these factors into consideration and also including a larger population size.

Several radiographic methods have been proposed for dental age estimation, among which the Willems model and its Brazilian adaptation by Franco et al. (2024) have shown promising results. However, the Brazilian model has not yet been tested in Northeastern populations. This study aimed to validate Franco's model in a sample of children and adolescents from Alagoas, Northeastern Brazil. A retrospective, cross-sectional study was performed on 500 panoramic radiographs (250males, 250females) aged 6-15.99years, distributed evenly across one-year intervals. Chronological age was calculated from documentary records and compared with dental age estimated using Demirjian's staging system and Franco's Brazilian model. Mean error (ME), mean absolute error (MAE), and root mean squared error (RMSE) were calculated and complemented by Bland&#xa0;-&#xa0;Altman analysis. The mean chronological age was 11.0&#xb1;2.9years, while the mean estimated age was 10.8&#xb1;2.5years. The overall ME was 0.18years (0.06males, 0.29females). The MAE was 0.70years (0.67males, 0.73females), with the best performance between 7 and 10.99years (<0.5years). RMSE values increased in older groups, reaching>1.0year after age 13.99. Bland-Altman plots showed a transition from overestimation in younger ages to underestimation in older ages, earlier in females. The Brazilian model was adequate for the studied population, particularly for individuals aged 7-10.99years, with overall differences below one year.

To establish normative three-dimensional airway measurements in patients without dentofacial deformities (DDFs) or obstructive sleep apnea (OSA), and to identify anatomical and epidemiological factors associated with airway volume. This retrospective cross-sectional study analyzed 200 CT scans from patients aged 18-80 years, with no diagnosis of DDF, OSA, or craniofacial syndromes. Scans were processed using artificial intelligence software (NEMOFAB) for automatic segmentation and volumetric analysis. Variables assessed included age, sex, neck circumference, and craniofacial linear distances (Menton-Hyoid, Menton-3rd Vertebrae, PNS-Hyoid, Soft Palate-Hyoid). Airway volume and Minimum Axial Area (MAA) were measured and compared using ANOVA. The mean airway volume was 24,724.8mm3. Younger individuals exhibited greater airway volumes, especially among males. Patients with a neck circumference <40cm had a 28.04% reduction in airway volume. Longer PNS-Hyoid, SPH, and M3V distances were positively associated with increased airway volume, while Menton-Hyoid showed minimal impact. A low MAA (<110mm2) correlated with a significant volume decrease. Key predictors identified were age, neck circumference, PNS-Hyoid, SPH, and M3V distances. In patients without DDF or OSA, airway volume is significantly influenced by demographic and anatomical variables. These normative data provide a baseline for comparison in orthognathic surgical planning and respiratory risk assessment. Understanding normal airway morphology and its anatomical determinants enhances screening for patients at risk of airway compromise and may guide individualized treatment strategies in oral and maxillofacial surgery.

Dental morphological traits provide valuable insights into global human variation and population structure. The Arizona State University Dental Anthropology System (ASUDAS) has long been a cornerstone for documenting crown and root morphology, yet recent discussions have questioned its reliability for characterising population differences. This study aimed to (i) identify the ASUDAS traits most commonly analysed in recent research, and (ii) compare their reported frequencies with those documented in the foundational work of Turner and Scott. A systematic review identified 43 eligible studies comprising 36,919 individuals representing all major subdivisions of humankind. Thirty variants across 27 distinct traits were recorded most frequently, and 29 of these were subjected to meta-analysis using random-effects models. Nearly all traits showed significant between-group and within-group heterogeneity, indicating strong discriminatory potential but also substantial population-level variability. While broad patterns remain consistent with classic ASUDAS expectations, several traits exhibited expanded regional ranges, reflecting both greater sample diversity and admixture effects. These findings reaffirm the value of ASUDAS traits for describing broad-scale morphological patterns while underscoring the need for multi-trait, population-specific, and context-specific approaches when interpreting dental morphology in anthropological research.

As a foundational discipline of medicine, human anatomy has historically been built around dissection. In many cultural contexts, particularly in sub-Saharan Africa, representations of the body and death may limit post-mortem body donation and restrict access to dissection for educational purposes. To analyze perceptions of body donation after death and human dissection in a Bantu context, to assess their stability over time, to situate them within an international comparative perspective, and to explore appropriate pedagogical alternatives. Two successive cross-sectional surveys were conducted in Gabon among participants from the Universit&#xe9; des Sciences de la Sant&#xe9; (USS, Libreville) and three regional hospitals: the first in 2013 (n=187) and the second between 2020 and 2025 (n=218). The same questionnaire, comprising 16 items grouped into five domains (motivations, perceptions of medical systems, representations of the body, attitudes toward body donation, and pedagogical resources), was used. A descriptive comparison of anatomy teaching modalities was performed with Cheikh Anta Diop University of Dakar (Senegal) and the University of Burgundy&#xa0;-&#xa0;Europe in Dijon (France). In both surveys, donation of one's own body after death was overwhelmingly rejected (more than 95% of participants), while a majority acknowledged the educational value of human dissection. In the absence of available bodies, the most frequently cited alternative resources were medical imaging, digital tools, and observation of surgical procedures. International comparison revealed marked differences: supervised and systematic dissection in France, occasional practices in Senegal, and the absence of dissection in Gabon. The study highlights the stability of representations related to body donation in Gabon, characterized by a persistent rejection of post-mortem donation despite recognition of the pedagogical value of dissection. This dissociation reflects a coexistence of cultural and biomedical rationalities observed in various international contexts. Organizational differences between Gabon, Senegal, and France underscore the need to adapt teaching practices to local constraints by integrating complementary alternatives to dissection. In contexts where access to human dissection remains limited, the progressive development of alternative pedagogical solutions combining digital tools, medical imaging, and anatomical simulation appears to be a pragmatic approach to strengthening anatomy education. In the longer term, the structuring of teaching and simulation facilities adapted to local cultural and institutional specificities could contribute to sustainable improvement in medical training. The findings demonstrate the lasting coexistence of cultural representations of the body and a shared recognition of the pedagogical value of dissection. In contexts where body donation remains limited, anatomy teaching should rely on a pluralistic and contextualized approach, combining descriptive rigor, functional reasoning, clinical grounding, and a reasoned use of pedagogical innovations.

Third molar radiographic assessment can help determine the probability of an individual reaching the legal age of majority, typically 18&#xa0;years old. This study aims to assess this probability using third molar development through the Demirjian staging system. The sample consisted of 429&#xa0;panoramic radiographs (210&#xa0;females, 219&#xa0;males) from individuals aged 15-23.99&#xa0;years. Upper right (FDI 18) and lower right (FDI 48) third molars were assessed following Mincer's adaptation of the Demirjian staging system. Logistic regression analysis was used to evaluate the probability of being over 18&#xa0;years old, analysing both single and combined third molar stages. FDI 18 and 48 showed similar developmental stages, with FDI 18 generally developing at a faster rate. The probability of being 18&#xa0;years or older (P&#x2265;0.5) was reached at stage F for males (P=0.58) and females (P=0.54) in FDI 18, and for females in FDI 48 (P=0.61). By stage H, it was almost certain that the individual was over 18&#xa0;years old. When combining both upper and lower third molars, individuals were almost certainly over 18 if FDI 18 had reached stage H, regardless of FDI 48 stage. Third molar development assessment in Indonesian juveniles can serve as an effective tool for determining whether an individual is over or under 18&#xa0;years old using Demirjian staging. Future research should aim to refine age estimation models within specific populations to enhance accuracy and reliability in legal age assessments.

The Romero Dental Modification System offers a standardised framework for classifying intentional dental modifications, with its theoretical and classificatory structure derived largely from Mesoamerican archaeological contexts. This study evaluated visual representations of the Romero dental modification system (1970) and proposed an updated contemporary illustration approach in the form of 3D digital models. Twenty-three studies applying the Romero classification system were reviewed. Modification types, frequency distributions, affected teeth, and visual documentation practices were extracted and synthesised. A total of 80 modification occurrences representing 35 distinct types (59.3% of the 59-type system) were identified. The class I contour modifications were most frequent (67.5%), followed by class II inlays (20.0%) and class III combined modifications (12.5%). Anatomically, modifications were strongly concentrated in anterior teeth, particularly upper incisors, with no molar modifications documented. Visual documentation practices were inconsistent: 26.1% of studies provided no imagery, and many relied on low-resolution or schematic representations, although recent studies increasingly used colour photography and combined imaging methods. This study provides the first comprehensive three-dimensional (3D) digital documentation of the Romero system (1970), with 67.8% coverage across all types and a complete representation of types A and E.

Vertical integration in medical education, which means integration of basic sciences teaching in clinical practice, has gained increased scientific interest in modern curricula. We aimed to conduct a review of the literature concerning the outcomes of vertical integration of anatomy teaching in the clinical phase of undergraduate medical education. We searched in the databases PubMed, Scopus, ERIC and Cochrane library for articles with the purpose of investigating the outcomes of vertical integration of anatomy teaching in the clinical phase of undergraduate medical education. From each included article we extracted the following data: authors, number of participants, methods of vertical integration of anatomy teaching, outcomes of the educational intervention and their level according to Kirkpatrick hierarchy. Nine studies were included in the review. Of them, six explored students' examinations performance, while three studies investigated only participants' perceptions. The most common strategy of implementation of this integration is the use of a blended anatomy learning approach, mainly involving cadaveric dissection. Overall, the vertical integration of anatomical courses in medical students' clinical teaching has been accompanied by strongly positive perceptions, while both their anatomical and clinical knowledge was significantly improved. Vertical integration of anatomy teaching in the medical students' clinical phase seems to be a highly acceptable and effective educational strategy. Anatomy teachers should be encouraged to deliver courses in conjunction with medical students' clinical clerkships.

Dental age assessment may have important clinical and forensic applications. Testing the existing methods is fundamental to promoting best clinical and forensic practices. The present study aimed to test a Brazilian country-specific model for dental age assessment in a population of Bahia State, Brazil. A total of 1009 panoramic radiographs of Brazilian individuals (n=556, 55.1% females and 453, 44.9% males) aged between 6 and 15.99 years were collected. The seven permanent left mandibular teeth from central incisor to second molar were analyzed in each radiograph. Demirjian's dental staging technique was applied followed by age estimation through Franco's dental age assessment model. Differences between chronological and estimated ages were quantified as mean error (ME), mean absolute error (MAE), and root means squared error (RMSE). The overall (sex combined) ME, MAE, RMSE were -0.51, 1.11, 1.63, respectively. For females and males separately, the error metrics were: -0.55, 1.16, 1.65 and -0.45, 1.05, 1.59, respectively. Bland-Altman plots showed narrower age limits among males, while higher discrepancies were observed for females. The analysis based on age categories showed the worst predictions between the ages of 6 and 6.99 years. The tested country-specific model was applicable to individuals aged above 7 years in the target population, being an alternative for dental age assessment.

The superficial musculoaponeurotic system (SMAS) is an acronym describing a facial subcutaneous anchored three-dimensional (3D) fibro-adipose-muscular tissue network connected to mimic muscles. SMAS transfers, distributes and reinforces mimic facial muscles contractions to the skin determining mimic expression and facial fold formation. The aim of this study was the histomorphological analysis of prenatal SMAS (pre-SMAS) development in analogy to the adult SMAS typology. Histological serial sections (n=7300 of 31 embryos and fetuses) of different staining obtained from the historic Carnegie Collection, Washington D.C. and from the Historical Histological Collection, University Witten/Herdecke were analyzed. All specimens head and neck area were investigated microscopically regarding facial mimic muscles genesis, pre-SMAS development and chronological changes. Three pre-SMAS Types were described. Pre-SMAS Type I consisting of mesenchymal SMAS with low vascularity and minimal structural changes covered Regio Frontalis and Regio Occipitalis. Pre-SMAS Type II consisting of mesenchymal SMAS with low vascularity and minimal structural changes covered Regio Periocularis, Regio Preparotidea and Regio Nasalis. Pre-SMAS Type III consisting of SMAS with muscular integration and connective tissue remodeling covered Regio Parotidea, Regio Perioralis, and Regio Cervicalis. There were no morphological similarities between adult SMAS architecture compared to pre-SMAS anlage in Regio Preparotidea, Regio Frontalis, Regio Occipitalis, Regio Periocularis, Regio Cervical and Regio Nasalis. Regio parotidea pre-SMAS showed analogies in connective tissue architecture to adult type I SMAS. Regio Perioralis pre-SMAS showed isolated muscle fibers, which were aligned perpendicular to the skin level. Subcutaneous facial adipose tissue was undetectable up to the 22nd week of gestation. Pre-SMAS anlage metamorphosis seems not to emerge synchronously with mimic muscle development, but its changes and tissue differentiation are closely related to mimic muscle activity. Therefore following ontogenetic hypothesis was proposed: the development of pre-SMAS anlage follows the law "form follows functional activity".