[Age determination by macro- and micrometry of a proximal phalanx of the V finger]. / Diagnostika vozrasta cheloveka po makro- i mikrometrii proksimal'noi falangi V pal'tsa kisti.

The authors have analyzed the data base of L.P. Astanin (1951) by 19 macro- and microscopic signs of the proximal phalanx of the V finger of the left hand of 40 Russian women aged 18-85. With the increase of years, the external parameters of the proximal phalanx change insufficiently, the medullary cavity increases, and the compact substance area decreases due to the erosion of bone lamellas. The total number of vascular channels changes insufficiently, but their average sizes dramatically increase due to resorption. The majority of the studied age-related markers are correlation-dependent on each other. Three diagnostic models with significant indices of determination (R2=0.719-0.804) have been calculated using multiple regression analysis in a stepwise manner. By the verification results, the diagnostic models can be used in forensic medical practice.

Biomechanical Study of the Development of Long Bones: Finite Element Structure Synthesis of the Human Second Proximal Phalanx Under Growth Conditions.

Torsional loads are a possible mechanical explanation for the architecture of long bone. Finite element structure synthesis (FESS) has previously successfully been used as a deductive technique using Wolff's Law by applying expected loads to an unspecific homogeneous solid and eliminating stress free parts to verify muscle forces. The extended approach presented in this article includes further mechanobiological rules to model the development from a cartilage model to a finger bone. In contrast to former computational models, simulation of processes leading to both external growth and internal differentiation are included. Combined axial and torsional loads synthesize a complete human secondary proximal phalanx model comparable to form and internal structure to that observed in vivo. While the computational model is very sensitive to initial alterations of loads, changes after growth have a minor effect as observed in animal models. Predictions of cartilage growth and ossification during FESS showed significant similarities to ontogeny indicating the importance of mechanical factors for the morphogenesis of bone during growth. Anat Rec, 302:1389-1398, 2019. © 2018 Wiley Periodicals, Inc.

Correlation between Cervical Vertebrae Volume Parameter and the Skeletal Maturation Status.

AIM: Assessing skeletal maturity is a critical factor in orthopedic treatment and orthognathic surgery. Quantitative methods have been suggested to decide the skeletal age. This study aims to assess the correlation between the middle phalanx of the third finger (MP3) method and cervical vertebral volume parameters (CVVP) in skeletal age determination. MATERIALS AND METHODS: This cross-sectional study was conducted on 21 boys and 29 girls between the ages of 8 and 16 years, who were divided into five groups of skeletal maturation: 100 MP3 radiographs and cone beam computed tomography (CBCT) were obtained and analyzed. Middle phalanx of the third finger maturation stages were evaluated according to Perinetti method (stages F-FG-G-H-I). The CVVP was determined on CBCT using Mimics Medical software. Analysis of variance (ANOVA) and Bonferroni tests were utilized to investigate the differences in volumetric parameters between MP3 stages. Spearman correlation coefficient was employed to obtain the correlation between MP3 stages and the CVVP. RESULTS: The differences in CVVP concentrated between MP3-I stage and the previous stages, with the highest values those for the 4th vertebra. Spearman test revealed a significant highest correlation between MP3 stages and the CVVP in the 4th vertebra; the lowest was in the 2nd, which was higher in the girls group. CONCLUSION: Strong level of agreement between the two methods was significant in the 4th vertebra. CLINICAL SIGNIFICANCE: Measurement of volumes of the 4th CVVP could be used as simple quantitative analysis in clinical practice to evaluate the maturity in orthodontic patients.

A computational model for the joint onset and development.

Joints connect the skeletal components and enable movement. The appearance and development of articulations is due to different genetic, biochemical, and mechanical factors. In the embryonic stage, controlled biochemical processes are critical for organized growth. We developed a computational model, which predicts the appearance, location, and development of joints in the embryonic stage. Biochemical events are modeled with reaction diffusion equations with generic molecules representing molecules that 1) determine the site where the articulation will appear, 2) promote proliferation, and matrix synthesis, and 3) define articular cartilage. Our model accounts for cell differentiation from mesenchymal cells to pre-cartilaginous cells, then cartilaginous cells, and lastly articular cartilage. These reaction-diffusion equations were solved using the finite elements method. From a mesenchymal 'bud' of a phalanx, the model predicts growth, joint cleavage, joint morphology, and articular cartilage formation. Our prediction of the gene expression during development agrees with molecular expression profiles of joint development reported in literature. Our computational model suggests that initial rudiment dimensions affect diffusion profiles result in Turing patterns that dictate sites of cleavage thereby determining the number of joints in a rudiment.

Exploring the existence of better hands for manipulation than the human hand based on hand proportions.

Human exhibits the most dexterous manual manipulation among the anthropoids. The sophisticated dexterity of human hand has been linked to its distinctive morphology compared to the nonhuman anthropoids. The human hand is derived from the ancestral hands after longtime evolution. However, there are more possible morphologies that the hands could take during the evolutionary process. It remains unknown whether better hands for manipulation than the human hand exist among these possible hands. To answer the question, the relationship between the manipulative capability and hand morphology need to be investigated in the region of more possible hands. Here we employ a kinematic model to quantitatively assess the manipulative ability of the possible hands from the aspect of hand proportions. The segment length proportions of each possible hand are reconstructed by the major evolutionary patterns of the anthropoid hands. Our results reveal that too long and too short thumbs relative to fingers both hamper the manual dexterity, though the long thumb of human hand is traditionally thought to be beneficial to manipulation. The results promote the understanding of the link between hand morphology and function. Furthermore, we find out the optimal hand for dexterous manipulation within the region reconstructed by the major evolutionary patterns of the anthropoid hands. The optimal hand is more dexterous than the human hand. Compared to the optimal hand, the human hand has shorter metacarpals relative to phalanges, which is thought to be advantageous to the prehensility. It suggests that the human hand is not an organ exclusive for the dexterous manipulation, but a trade-off between multiple functions.

Maturation of the Middle Phalanx of the Third Finger: A Comparative Study between Right and Left Hand.

OBJECTIVES: Recently a classification of patient's skeletal age based on the phalanx maturation, The Middle Phalanx Maturation of the third finger (MPM) method, was suggested. The aim of this study is to evaluate if there is a difference in MPM between the right and left hand. STUDY DESIGN: Two hundred fifty-four patients were obtained from the Complex Operating Unit of Orthodontics of Padua University Hospital. The total sample size has been selected by appropriate statistical calculations resulting in 130 patients. It was decided to further double the sample size of a previous study to ensure a robust statistical analysis. Radiographs of the right and left were obtained using the MPM method. Stages were compared using the right hand as a reference. The statistical analysis (Fisher exact test) was performed for the entire sample and related to gender in order to compare the right and the left hand stages. RESULTS: In MPS2, 6 out 49 (12.2%) males and 7 out 27 females (25.9%) showed MPS3 in the left hand (p-value < 0.05). In all other stages, a total agreement (100%) was found. CONCLUSION: The authors confirm the use of the right hand as reference. In patients with MPS2 an additional radiograph on the left hand can be taken in order to increase the diagnostic accuracy. In all other stages other radiographs are not needed as a total agreement between the right and left hand was found.

Multiple Enchondromas of the Hand in Children: Long-Term Follow-Up of Mean 15.4 Years.

BACKGROUND: Multiple enchodromatosis of bone, termed Ollier's disease, or Maffucci syndrome when associated with hemangiomas, is a rare disease that can affect the pediatric hand. This condition often causes a finger mass, deformity, pain and possible pathologic fractures, and has been associated with malignant transformation to chondrosarcoma. The aim of our study is to describe the long-term sequela of multiple enchondromatosis of the hand in the pediatric population, specifically the rates of malignant transformation, tumor recurrence, rates of pathologic fracture, and phalangeal growth arrest. METHODS: We examined 15 pediatric patients who were treated in our institute with a total of 127 phalanges and metacarpals lesions. Only patients with follow-up of at least 4 years were included. We retrospectively reviewed patients' chart and hand radiograph for symptoms including pathologic fractures, indications for surgery, and postoperative complications including tumor recurrence, and malignant transformation. We assessed phalangeal growth arrest with radiographs and normalized phalangeal growth charts. RESULTS: Mean age of diagnosis was 5.8 years and mean follow-up time was 15.4 years. Pathologic fractures were common at 46% of pediatric patients, but ceased to occur once reaching adulthood. Outcomes of pathologic fractures were excellent, regardless of treatment. Malignant transformation occurred in 1 patient and did not occur during childhood. A total of 80% of patients and 29% of lesions underwent surgical treatment of curettage and bone graft for the lesion, yet recurrence was common and affected 33% of treated patients. Phalangeal growth arrest was the most common long-term sequela and affected 11% of phalanxes and metacarpals. This sequela was significantly more prevalent in patients who had surgical excision of the tumor. CONCLUSIONS: Our findings reassure that malignant transformation of enchodromatosis of the hand is unlikely in the pediatric population. Pathologic fracture is common, but has excellent outcomes. When considering surgery, parents should be counseled about the possibility of phalangeal growth arrest and recurrence of the lesion. TYPE OF STUDY/LEVEL OF EVIDENCE: Level IV-therapeutic.

Reliability of Growth Indicators and Efficiency of Functional Treatment for Skeletal Class II Malocclusion: Current Evidence and Controversies.

Current evidence on the reliability of growth indicators in the identification of the pubertal growth spurt and efficiency of functional treatment for skeletal Class II malocclusion, the timing of which relies on such indicators, is highly controversial. Regarding growth indicators, the hand and wrist (including the sole middle phalanx of the third finger) maturation method and the standing height recording appear to be most reliable. Other methods are subjected to controversies or were showed to be unreliable. Main sources of controversies include use of single stages instead of ossification events and diagnostic reliability conjecturally based on correlation analyses. Regarding evidence on the efficiency of functional treatment, when treated during the pubertal growth spurt, more favorable response is seen in skeletal Class II patients even though large individual responsiveness remains. Main sources of controversies include design of clinical trials, definition of Class II malocclusion, and lack of inclusion of skeletal maturity among the prognostic factors. While no growth indicator may be considered to have a full diagnostic reliability in the identification of the pubertal growth spurt, their use may still be recommended for increasing efficiency of functional treatment for skeletal Class II malocclusion.

Diagnostic reliability of the third finger middle phalanx maturation (MPM) method in the identification of the mandibular growth peak.

Background/objectives: The use of the sole third finger middle phalanx for a maturational method has been proposed but not fully investigated. Herein, the diagnostic reliability of an improved five-stage third finger middle phalanx maturation (MPM) method in the identification of mandibular growth peak has been investigated. Subjects/methods: From the files of the Burlington Growth Study, 35 subjects (20 males, 15 females) with at least 7 annual lateral cephalograms taken from 9 to 16 years were included. Mandibular growth was defined as annual increments in condylion-gnathion (Co-Gn) distance. Subsequently, individual annual increments in Co-Gn were arranged according to annual age intervals, with the first and last intervals defined as 9-10 years and 14/15-16 years, respectively. A full diagnostic reliability analysis (including positive likelihood ratio) was performed to establish the diagnostic reliability of the MPM stage 2 (MPS2) in the identification of the imminent mandibular growth peak. Results: The MPS2 had a satisfactory accuracy in the identification of imminent mandibular growth peak with an overall positive likelihood ratio of 10.3. However, reliability showed noteworthy variability being greater and lower for younger and older age intervals, respectively. Limitations: Secular trend, limited sample size, and annual recording in conjunction with the use of a discrete staging system. At the 15 years recording, 28 of 35 cases were missing. Conclusions/implications: The MPS2 and MPS3 may be considered associated with the onset and maximum mandibular growth peak, respectively, in most of the subjects, indicating their use in planning treatment timing.

Mammalian evolution. Evolutionary development in basal mammaliaforms as revealed by a docodontan.

A new Late Jurassic docodontan shows specializations for a subterranean lifestyle. It is similar to extant subterranean golden moles in having reduced digit segments as compared to the ancestral phalangeal pattern of mammaliaforms and extant mammals. The reduction of digit segments can occur in mammals by fusion of the proximal and intermediate phalangeal precursors, a developmental process for which a gene and signaling network have been characterized in mouse and human. Docodontans show a positional shift of thoracolumbar ribs, a developmental variation that is controlled by Hox9 and Myf5 genes in extant mammals. We argue that these morphogenetic mechanisms of modern mammals were operating before the rise of modern mammals, driving the morphological disparity in the earliest mammaliaform diversification.

Lateral comparisons using Fishman's skeletal maturation assessment.

OBJECTIVE: To assess lateral differences between ossification events and stages of bone development in the hands and wrists utilizing Fishman's skeletal maturation indicators (SMIs). MATERIALS AND METHODS: The skeletal ages of 125 subjects, aged 8 to 20 years, were determined with left and right hand-wrist radiographs using Fishman's SMI assessment. Each subject was also given the Edinburgh Handedness Questionnaire to assess handedness. The skeletal ages of both hand-wrist radiographs were analyzed against each other, handedness, chronologic age, and gender. RESULTS: There were no significant differences overall in right and left SMI scores (P  =  .70); 79% of all patients showed no difference in right and left SMI scores, regardless of handedness, gender, or age. However, when patients were categorized based on clinical levels of SMI score for the right hand-wrist, there was a significant difference (P  =  .01) between the SMI 1-3 group and the SMI 11 group. Subjects in the SMI 1-3 group were more likely to show a left > right SMI score, while subjects in the SMI 11 group were likely to show a right > left SMI score. CONCLUSION: Although no significant overall lateral differences in SMI scores were noted, it may be advisable to obtain a left hand-wrist radiograph and/or additional diagnostic information to estimate completion of growth in young surgical patients.

Maturation of the middle phalanx of the third finger and cervical vertebrae: a comparative and diagnostic agreement study.

OBJECTIVE: Diagnostic agreement on individual basis between the third middle phalanx maturation (MPM) method and the cervical vertebral maturation (CVM) method has conjecturally been based mainly on overall correlation analyses. Herein, the true agreement between methods according to stage and sex has been evaluated through a comprehensive diagnostic performance analysis. SUBJECTS AND METHODS: Four hundred and fifty-one Caucasian subjects were included in the study, 231 females and 220 males (mean age, 12.2 ± 2.5 years; range, 7.0-17.9 years). The X-rays of the middle phalanx of the third finger and the lateral cephalograms were examined for staging by blinded operators, blinded for MPM stages and subjects' age. The MPM and CVM methods based on six stages, two pre-pubertal (1 and 2), two pubertal (3 and 4), and two post-pubertal (5 and 6), were considered. Specifically, for each MPM stage, the diagnostic performance in the identification of the corresponding CVM stage was described by Bayesian statistics. RESULTS: For both sexes, overall agreement was 77.6%. Most of the disagreement was due to 1 stage apart. Slight disagreement was seen for the stages 5 and 6, where the third middle phalanx shows an earlier maturation. CONCLUSIONS: The two maturational methods show an overall satisfactorily diagnostic agreement. However, at post-pubertal stages, the middle phalanx of the third finger appears to mature earlier than the cervical vertebrae. Post-pubertal growth phase should thus be based on the presence of stage 6 in MPM.

Tooth mineralization stages as a diagnostic tool for assessment of skeletal maturity.

INTRODUCTION: The objective of this study was to determine whether dental calcification can be used as a first-level diagnostic tool for assessment of skeletal maturity. METHODS: A total of 150 healthy subjects (79 boys, 71 girls; mean age, 12.19 ± 2.03 years; range, 8-16 years) were enrolled in the study. Dental maturity was assessed through the calcification stages from panoramic radiographs of the mandibular canine, the first and second premolars, and the second molar. Determination of skeletal maturity was according to the modified middle phalanx of third finger (MP3) stages method on digital radiographs. RESULTS: Diagnostic ability was evaluated according to the dental maturation stages for each tooth for identification of the MP3 stages and the growth phases (prepubertal, pubertal, postpubertal) using positive likelihood ratios. Dental maturation stage E of the first premolars and the combination of canine stage F, first premolar stage E, second premolar stage E, and second molar stage D (FEED) gave the highest values for identification of the prepubertal growth phase, and stage H of the second molar had the highest value for identification of the postpubertal growth phase. CONCLUSIONS: Dental maturation assessment is only useful for diagnosis of the prepubertal and postpubertal growth phases.

Quantitative ultrasound at the hand phalanges in adolescent boys in relation to their pubertal development and physical efficiency.

INTRODUCTION: Our aim was to assess the ultrasound properties of bone measured at hand phalanges in 55 adolescent boys aged 13-15 years regarding the influence of pubertal status and level of physical efficiency including muscular strength. MATERIAL AND METHODS: They were divided into two age groups: Group I (n = 37, boys aged 159-171 months) and Group II (n = 18, aged 172-184 months). The controls were 94 boys matched for age, recruited from 1,256 subjects undergoing bone measurement for screening purposes. The skeletal status (amplitude-dependent speed of sound - Ad-SoS) was assessed by quantitative ultrasound (QUS) at proximal phalanges with the use of DBM Sonic 1200. Physical efficiency was assessed using Zuchora's test, and pubertal development by Tanner's score. RESULTS: There was no difference in mean Ad-SoS between the entire study group and controls. Ad-SoS values were greater in older than in younger boys, both in right and left hands. There were no differences between left and right hand measurements. There were positive correlations between Ad-SoS and shoulder muscle strength in boys. Negative correlations between Ad-SoS at phalanges of right and left hand and BMI were shown in younger adolescent boys only. Similarly, only in the younger group were positive correlations present between both hands Ad-SoS and overall physical efficiency and age. Ad-SoS correlated positively better with Tanner's scale scoring in the older group. CONCLUSION: QUS at hand phalanges in adolescent boys aged 13-15 years depends on pubertal development and shoulder muscle strength. The overall physical efficiency has limited influence on bone properties assessed by QUS.

Digital radiograph of the middle phalanx of the third finger (MP3) region as a tool for skeletal maturity assessment.

OBJECTIVE: To evaluate the reliability of the digital radiograph of the middle phalanx of the third finger (MP3) in skeletal maturity assessment. STUDY DESIGN: Fifty children (24 girls and 26 boys) belonging to the circumpubertal age-group were selected for the study. Two radiographs - lateral cephalogram and digital radiograph of the MP3 region - were taken in each child. Age assessment was based on the changes in shape of the cervical vertebrae and the epiphysis of the middle phalanx of the third finger of the left hand. The radiographs were assessed by three examiners. The inter- and intraexaminer variability were determined by the Wilcoxon rank sign test and the Kruskal-Wallis test and were found to be nonsignificant. Examiner 3 showed the best intraexaminer agreement and was selected to evaluate the radiographs for the entire study. RESULTS: The correlation determined between the MP3 stages and cervical vertebrae maturity index (CVMI) stages, the peak-wise distribution of the MP3 stages, and the correlation between the MP3 stages and the chronological age were found to be highly significant. CONCLUSIONS: Digital radiograph of the MP3 region is definitely a simple, reliable, cost-effective, and time-saving technique for the assessment of skeletal maturity.

Determining skeletal maturation using insulin-like growth factor I (IGF-I) test.

OBJECTIVE: To investigate the validity of Insulin like Growth Factor -1(IGF-1) as a skeletal maturity indicator by comparing serum IGF-1 levels with the stages in cervical vertebral maturation (CVM) and in the middle phalanx of the third finger (MP3). MATERIALS AND METHODS: The study population was selected by using simple random sampling technique and consisted of 30 female subjects in the age range of 8-23 years who had blood sample, cephalometric and MP3 radiographs taken on the same day. Serum IGF-I estimation was carried out on the blood samples using chemiluminescence immunoassay (CLIA) method. CVM was evaluated using method by Baccetti et al and MP3 staging was done using Rajagopal & Kansal method. Mean IGF-1 level between the stages was compared by Kruskal-Wallis and Mann Whitney test. RESULTS: Serum IGF-1 levels in females correlate well with skeletal maturity determined by CVM and MP3 stages and increase sharply during early pubertal stages followed by a decrease in late puberty. In addition we hypothesis that serum IGF-1 testing can be undertaken as a preliminary screening test in patients in whom the orthodontist predicts the possibility of using myofunctional appliance but in whom the chronologic age is not suggestive for a growth modification therapy. CONCLUSIONS: The finding of the study highlights the fact that the serum IGF-1 estimation can be a valuable tool in assessing skeletal maturation.

Quantitative skeletal evaluation based on cervical vertebral maturation: a longitudinal study of adolescents with normal occlusion.

The study aims were to investigate the correlation between vertebral shape and hand-wrist maturation and to select characteristic parameters of C2-C5 (the second to fifth cervical vertebrae) for cervical vertebral maturation determination by mixed longitudinal data. 87 adolescents (32 males, 55 females) aged 8-18 years with normal occlusion were studied. Sequential lateral cephalograms and hand-wrist radiographs were taken annually for 6 consecutive years. Lateral cephalograms were divided into 11 maturation groups according to Fishman Skeletal Maturity Indicators (SMI). 62 morphological measurements of C2-C5 at 11 different developmental stages (SMI1-11) were measured and analysed. Locally weighted scatterplot smoothing, correlation coefficient analysis and variable cluster analysis were used for statistical analysis. Of the 62 cervical vertebral parameters, 44 were positively correlated with SMI, 6 were negatively correlated and 12 were not correlated. The correlation coefficients between cervical vertebral parameters and SMI were relatively high. Characteristic parameters for quantitative analysis of cervical vertebral maturation were selected. In summary, cervical vertebral maturation could be used reliably to evaluate the skeletal stage instead of the hand-wrist radiographic method. Selected characteristic parameters offered a simple and objective reference for the assessment of skeletal maturity and timing of orthognathic surgery.

Lengths, girths, and diameters of children's fingers from 3 to 10 years of age.

We obtained data on the lengths, girths, and diameters of the fingers of children from 3 to 10 years of age. A total of 160 children (78 girls, 82 boys) were examined in a cross-sectional investigation. The length of each finger of the right hand of every child was measured, as were the girths of the proximal, middle, and distal phalanges, and of the proximal and distal interphalangeal joint. The average length of the thumb was 49 (35-65) mm. The index and ring fingers both averaged 69 (index, 50-88; ring, 42-96) mm in length, while the middle and little fingers averaged 72 (57-100) and 56 (40-74) mm, respectively. Average diameter, calculated from the girth measurement, was 16 (11-22) mm for the thumb, 15 mm for both the index (9-22) and middle (10-21) fingers, 14 (10-20) and 13 (8-19) mm for the ring and little fingers, respectively. The average length of each finger increased by 37% from 3 to 10 years of age, average girth by 24%, and diameter increased by 20%. We observed no differences in length, girth, and diameter between the sexes. The dimensions of children's fingers are relevant to injuries from automatic, power-operated window lifters of motor vehicles because risk of injury to a finger jammed between an ascending window and the seal entry depends upon the diameter of the finger. Additionally, short fingers of young children can be jammed over almost their entire length in the oblique design of a car window seal entry.

Finger bone immaturity and 2D:4D ratio measurement error in the assessment of the hyperandrogenic hypothesis for the etiology of autism spectrum disorders.

Emerging hypotheses suggest a causal role for prenatal androgen exposure in some cases of autism spectrum disorders (ASD). The ratios of the lengths of the bones of the 2nd to the 4th digit (2D:4D) are purported to be markers for prenatal androgen exposure and to be established early in gestation. Elongation of the 4th digit in response to testosterone is said to reduce 2D:4D in males versus females. We examined the ratios of bones from the left hand radiographs of 75 boys and 6 girls 4-8 years of age, diagnosed with ASD, to evaluate digit ratio as a marker for gestational androgen exposure. Contrary to our expectations, girls had reduced 2D:4D compared to boys but the difference was not significant (Cohen's D 0.51-0.66, P>0.05). The limited sample size for this study and the absence of a referent group precluded providing robust estimates for girls and identifying possible statistical differences between the sexes. Tanner-Whitehouse 3 (TW3) rating of finger bone growth suggested relative immaturity of the 4th relative to the 2nd digits. Positive correlations were detected for 2D:4D ratios, body mass index (r=0.23, P=0.039), chronologic age (r=0.35, P=0.001), and skeletal age (r=0.42, P<0.0001). The TW3 ratings and associations between 2D:4D ratios and indicators of growth suggest that digits develop at different rates. This asynchronous development may produce differences in 2D:4D over time which could lead to erroneous interpretation of androgen exposure in utero among young ASD children.

The first metacarpal is the thumb first phalange: EvoDevo implications / El primer metacarpiano es la primera falange del pulgar: implicaciones en EvoDevo

We examined the status of the first metacarpal bone whose shape, fetal and post-natal development correspond to those of the thumb proximal phalanx. Galen already described this, circa 170 CE. Our radiographic data confirm that the pre-axial (radial or anterior) side of the hand matures, later than the post-axial (ulnar or posterior) side, both, pre- and post-natally. A new perspective on thumb primate and human ontogeny is discussed and comparative observations on the Evolutionary Development (EvoDevo) of the thumb and the first toe are proposed along with a nomenclature honoring Galen's original roposition.

Se analiza el estado del primer metacarpiano cuya forma y desarrollo embrionario, fetal y postnatal corresponde a los de la primera falange del pulgar. Galeno notó que éste era la primera falange del pulgar cerca de 170 DC. Esto no es un simple cambio de nomenclatura, ya que da una nueva luz a los problemas evolutivos de ontogenia (EvoDevo). Nuestros datos radiográficos confirman que el lado radial (anterior o pre-axial) de la mano madura, pre y post-natalmente, mas tardíamente que el lado cubital (posterior o post-axial). Se discuten nuevas perspectivas sobre la ontogenia y filogenia humana y de primates, y se proponen estudios comparativos del desarrollo del pulgar y del ortejo mayor.