Ultrasound studies on the time course of clavicular ossification

When preparing forensic age estimates for living subjects over 18 years of age, it is crucial to evaluate the stage of ossification of the medial clavicular epiphysis. The establishment of radiation-free imaging techniques for assessment of clavicular ossification would be desirable in order to reduce the radiation exposure associated with forensic age estimations. In the present study, 84 right clavicles of test subjects 12–30 years of age were prospectively evaluated by means of ultrasound. Ossification stage classification was possible in 80 of the 84 medial clavicular epiphyses studied. In the remaining cases, stage classification was not possible due to the presence of developmental anomalies. The earliest ages at which the respective ossification stages were observed were 17.1 years for stage 2, 16.7 years for stage 3, and 22.5 years for stage 4. The age intervals observed for the ossification stages are consistent with the known data from radiological and computed tomography assessments. The present study results should be confirmed in a larger number of cases and with analysis of observer variability. Evaluation of medial clavicular epiphyseal ossification by ultrasound could ultimately be a rapid and economic non-ionizing diagnostic imaging procedure for forensic age estimation.     

Magnetic resonance imaging of the clavicular ossification

Assessment of the degree of ossification of the medial clavicular epiphyseal cartilage is of vital importance in forensic age diagnostics of living individuals aged more than 18 years. To date, reference studies on the assessment of clavicular ossification using imaging procedures only relate to conventional radiography and computed tomography (CT). In this study, magnetic resonance (MR) scans of 54 sternoclavicular joints of bodies aged between 6 and 40 years were evaluated prospectively. All of the examined medial clavicular epiphyseal cartilages permitted an assessment of the degree of ossification. Stage 2 was first observed at the age of 15.0 years, the earliest age at which stage 3 was observed was 16.9 years, and stage 4 was first observed at the age of 23.8 years. The observed age intervals of the respective degrees of ossification correspond to the known data from X-ray and CT scan examinations. The achieved results should be examined with a larger number of cases. A modified examination protocol is required for the MR examination of the medial clavicular epiphyseal cartilage for the purpose of forensic age diagnostics of living individuals.     

Age estimation from sternebral fusion in an Indian population – A computed tomographic evaluation

Forensic age estimation is a crucial aspect of the human identification process. Sternebral fusion is one of the skeletal indicators of age that has not been thoroughly researched for the purpose of age estimation. The present study was conducted with the aim of assessing the utility of each of the sternebral fusion in age estimation, and to ascertain if these fusion stages can help in identifying whether an individual has attained the medicolegally significant ages of 16 and 18 years. Thoracic CT images of 148 study participants (74 females, 74 males) were analysed to evaluate the fusion of sternebrae 1–2, sternebrae 2–3, and sternebrae 3–4. The fusion scores for these were found to be statistically significant (P < 0.001) with sternebrae 1–2 fusion showing the highest coefficient of correlation at R = 0.900. Linear regression models were generated using each of the sternebral fusions separately and together for estimation of age. The standard error of estimate for the regression models ranged from 1.51 to 2.86 years. Box and Whisker plots were constructed to see the fusion score wise age distribution of the study population, and it was observed that sternebral fusion has the ability to indicate whether an individual has attained the age of 16 and 18 years. Our study concludes that sternebral fusion can act as an accurate method of forensic age estimation of juveniles and young adults.     

Studies on the time frame for ossification of the medial clavicular epiphyseal cartilage in conventional radiography

Radiological assessment of the degree of ossification of the medial clavicular epiphyseal cartilage plays a vital part in forensic age diagnosis of living adolescents and young adults. A total of 873 plain chest radiographs requested by the staff medical officer for members of staff aged 16–30 at the University Hospital Charité were evaluated retrospectively. Of these X-rays 699 permitted an assessment of ossification of at least 1 side of the clavicle. In addition to the customary stages (1: non-ossified epiphysis, 2: discernible ossification centre, 3: partial fusion, 4: total fusion) a stage 5 was also defined, characterised by the disappearance of the epiphyseal scar following total fusion. The earliest age at which stage 3 was detected in either gender was 16 years. Stage 4 was first observed in women at 20 years and in men at 21 years. In both genders, the earliest observation of stage 5 was at 26 years. It was concluded that plain chest radiographs can essentially be used to assess clavicular ossification. In practice, if overlap in posterior-anterior views impedes evaluation, a lateral view should also be taken to facilitate age estimation. In forensic practice the reference values of the present paper should be applied.     

Age estimation from clavicular epiphyseal union sequencing in a Northwest Indian population of the Chandigarh region

Medial clavicular epiphysis is the long bone epiphysis to fuse last and therefore, is useful for estimating age in the post-pubertal period. Age estimation was done from clavicles obtained from 343 cadavers (252 males and 91 females) of known age. The data was subjected to statistical analysis to see whether the difference obtained in the various ages was significant or not. Commencement of fusion was seen as early as 18 years of age in both male and female clavicles. No clavicle showed complete fusion until the age of 22 years. Complete fusion of the medial end of the clavicle was seen latest at 32 years in the male clavicles while the same was observed at 31 years in the female bones, i.e., the medial epiphysis of female clavicles fused one year earlier than their male counterparts. Advanced stages of clavicular epiphyseal union were seen in most of the clavicles after 24 years of age in females and 23 years of age in males. No significant difference was noticed in both sexes for the right and left clavicles as regards to the occurrence of various stages of epiphyseal union.     

Age estimation using third molar maturation based on Demirjian’s criteria

Dental age estimation is routinely used in human identification, in both the living and the dead. Teeth follow a predictable pattern of eruption and maturation that can be assessed radiographically in the living, allowing experts to estimate an individual’s age. Third molars develop much later than the other permanent teeth, and can be used to estimate age of individuals nearing the age of maturity. Ability of third molar maturation when graded using Demirjian’s method in ascertaining whether an individual has attained the medicolegal ages of 16 and 18 years has not yet been verified. The present study involved assessing the third molar maturation of 220 individuals of a training set using Demirjian’s scoring system, generating regression models to estimate age using the third molar maturity scores, applying these models on a test set of 40 individuals, and calculating the mean difference (MD) and the mean absolute error (MAE) between the chronological and estimated ages of the test set participants. It was observed that the lowest mean difference and mean absolute error was observed for the maturation of the left mandibular third molar (MD = 1.05 years, MAE = 2.09 years). Boxplots generated in the study report that the third molar maturation stages given by Demirjian can identify whether an individual has attained the medicolegally significant ages of 16 and 18 years of age.     

Applicability of 3.0 T MRI images in the estimation of full age based on shoulder joint ossification: Single-centre study

Skeletal maturity is evaluated by many radiological methods for forensic age estimation. Direct radiography and computed tomography lead to a rise in ethical concerns due to radiation exposure. Therefore, magnetic resonance imaging (MRI) has currently been used in recent studies. In this study, the ossification stage of the shoulder joint was determined retrospectively in 178 male and 109 female individuals in the age group 12 to 30 years using 3.0 T MRI. All the images were evaluated with T1-weighted turbo spin echo (T1 TSE) sequence and T1 fast low angle shot two-dimensional sequence (T1 FL2D). The combined staging method, which was defined by Kellinghaus et al. and Schmeling et al., was used. The intra- and inter-observer agreement levels were very good (κ and κ_w). There were no significant age differences between males and females in all stages. In most of the stages, the ossification of the proximal humeral epiphyses occurred earlier in females than in males. Stage 4 did not occur in either of the sexes before the 18th birthday as the youngest patients in this stage was at 19 and 18 years of age in males and females, respectively. We concluded that evaluating the ossification of the proximal humeral epiphysis with MRI imaging for forensic age estimation may be beneficial. Evaluating the same anatomical structure with different MRI sequences may be useful for accurate staging diagnosis.     

Forensic age estimation in living subjects based on the ossification status of the medial clavicular epiphysis as revealed by thin-slice multidetector computed tomography

Determination of the stage of ossification of the medial clavicular epiphysis is a crucial part of age estimation in criminal proceedings when evaluating individuals with completed hand ossification. In order to ensure a maximum of accuracy in forensic age estimation practise, it is recommended to perform thin-slice CT scans; but to date there exist no reference data on the bone development of the region in question based on thin-slice computed tomography. In this retrospective study, the authors evaluated thin-slice multidetector CT images of 592 individuals aged between 10 and 35 years produced in the University Hospital of Münster. The ossification status of the medial epiphysis of the clavicle could be reliably determined in 502 cases using the classification of stages by Schmeling et al. In male individuals, stage 2 was first noted at age 14, in female individuals at age 13. Stage 3 was first achieved by male individuals at age 17, by female individuals at age 16. The occurrence of stage 4 was first found in both sexes at the age of 21. In either sex, the earliest observation of stage 5 was at age 26. The findings are basically in line with those from the only CT-based study on the subject in question using the same classification of five stages, except from the fact that in the present study, stage 5 first occurs at age 26, which is 4 or 5 years later than what was found in the CT study using 7 mm slices in the majority of cases. This vast difference may be explained through the partial volume effect occurring with thick-slice CT images by a visual deception of the epiphyseal scar occurring with stage 4.     

Bone age determination based on the study of the medial extremity of the clavicle

The development of the medial clavicular epiphysis and its fusion with the clavicular shaft have been a subject of medical research since the second decade of this century. Computed tomography provides the imaging modality of choice in analyzing the maturation process of the sternal end of the clavicle. In a retrospective study, we analyzed normal development in 380 individuals under the age of 30 years. The appearance of an epiphyseal ossification center occurred between ages 11 and 22 years. Partial union was found from age 16 until age 26 years. Complete union was first noted at age 22 years and in 100 % of the sample at age 27 years. Based on these data, age-related standardized age distributions and 95 % reference intervals were calculated. Compared to the experience recorded in the relevant literature, there are several landmarks that show no significant change between different ethnic groups and different periods of publication; these are the onset of ossification, the time span of partial union, and the appearance of complete union. Despite the relatively long time spans of the maturation stages, bone age estimation based on the study of the development of the medial clavicular epiphysis may be a useful tool in forensic age identification in living individuals, especially if the age of the subject is about the end of the second or the beginning of the third decade of life (e. g. in determining the applicability of adult or juvenile penal systems). Another possible use is in identifying human remains whose age is estimated at under 30 years. Received 31 December 1997; Revision received 11 February 1998; Accepted 23 February 1998     

A new analytical cut-off point for determining 18 years of age using MRI on medial clavicular epiphysis

Evaluation of the ossification of the medial clavicular epiphysis plays a key role in forensic age estimation. The purpose of the present study was to assess a new numerical cut-off at the age of 18 years, taking into consideration Magnetic Resonance (MR) images of the medial clavicular epiphysis. We analyzed 163 MR scans of Italian subjects aged between 14 and 25 years. Using the data obtained we calculated two ratios: REM-1 (ratio between the length of the whole epiphysis and the length of the metaphysis) and REM-2 (ratio between the length of epiphyseal-metaphyseal fusion and the length of the metaphysis). In 68 out of 163 cases it was not possible to measure REM-2. The reproducibility was demonstrated using the Intraclass Correlation Coefficient (ICC) (Cronbach’s alpha > 0.80). REM-1 and REM-2 were compared in each category of age (adult and minor) by the Wilcoxon signed-rank test. The cut-off points for measurements of REM-1 and REM-2 were determined by logistic regression. For REM-1, the cut-off scores were 0.83 for all individuals (accuracy = 94.77%) and males (accuracy = 96.05%), and 0.86 for females (accuracy = 92.30%). For REM-2, the cut-off values were 0.40 for all individuals and males (accuracy = 100.00%), and 0.41 for females (accuracy = 100.00%). Finally, receiver operating characteristic (ROC) curves for age classification based on REM-1 and REM-2 were constructed, showing that REM-2 had the highest discriminative power. Thus, a new cut-off model for predicting the age of majority has been introduced, conducting a quantitative analysis thanks to the use of a high-resolution imaging tool.     

Study of age dependence of epiphyseal ossification of the hand skeleton

Radiological analysis of the hand skeleton is a key pillar of forensic age diagnostics in living subjects undergoing criminal proceedings. The present study investigated whether ossification stage classification of selected epiphyses of the hand could provide added value to hand radiograph analysis. Hand radiographs from 265 male and 164 female subjects aged 10–18years old who had been X-rayed due to traumatological indications were therefore assessed. Epiphyseal ossification of selected elements of the hand skeleton (ulna, radius and third metacarpal, basal phalanx, mesophalanx and telephalanx) was graded based on the criteria of the five-stage classification system of Schmeling et al. (Int J Legal Med, 118:5–8, 2004) for clavicular epiphyseal cartilage. Stage 5 (absence of the epiphyseal scar) does not occur in the radius of men before the age of 18. Stage 5 can therefore be regarded as a potential parameter for valid determination of a minimum age of 18 years for forensic age estimation in criminal proceedings.     

Sonographic assessment of the ossification of the medial clavicular epiphysis in 616 individuals

Establishing radiation-free imaging methods for the assessment of clavicular ossification in forensic age determination is desirable as it reduces radiation exposure in living individuals. For this purpose the stage of ossification of the right medial clavicular epiphysis was determined prospectively using sonography in 309 male and 307 female healthy volunteers. The classification of stages according to Schulz et al. was used for this purpose. Stage 2 was first noticed at the age of 14.4 years in males, and at the age of 14.1 years in females. Stage 3 was first achieved by males at the age of 17.6 years and by females at the age of 17.4 years. Stage 4 first occurred in males at the age of 19.3 years and at the age of 18.9 years in females. The mean age for stage 1 was 13.6 years. The mean age of stage 2 ranged between 17.3 and 17.6 years. For stage 3 the mean age varied from 20.7 to 21.2 years, and for stage 4 from 23.3 to 23.5 years. It was concluded that sonographically determined stage 4 clavicular ossification provides evidence for the completion of the nineteenth year of life in males and the eighteenth year of life in females. In order to increase the reliability of age determination using this method it is recommended that findings be recorded by at least two experienced independent examiners who then reach a consensus.     

Sonographic evaluation of apophyseal ossification of the iliac crest in forensic age diagnostics in living individuals

Due to the requirement to minimise exposure to radiation, it is desirable to develop non-ionising imaging procedures for the analysis of skeletal maturation for forensic age diagnostics in living individuals. The present pilot study analyses the applicability of ultrasound examinations for the evaluation of apophyseal ossification of the iliac crest. With reference to the sonographic staging of clavicular ossification, the maturation stages of the iliac crest apophysis of 23 male and 16 female subjects, aged 11–20 years, were determined. Ossification stage I occurred in the male subjects at a minimum age of 15.7 years. Ossification stage II was diagnosed in boys at a minimum age of 14.1 years and in girls at a minimum age of 11.7 years. The earliest observation of ossification stage III was at a chronological age of 16.2 years in males and 15.2 years in females. The earliest age of occurrence of ossification stage IV was at least 18.0 years in male test persons and at least 17.1 years in female test persons. The results obtained should be reassessed in a larger number of cases. It is to be expected that sonographic examination of the iliac crest apophysis will become established as a valid and efficient method for forensic age diagnostics in living individuals.     

Age estimation by an analysis of spheno-occipital synchondrosis using cone-beam computed tomography

The spheno-occipital synchondrosis has a relatively late ossification in comparison with other cranial base synchondroses, which makes it a point of interest for forensic age determination studies. The purpose of the present study was to evaluate the reliability of spheno-occipital synchondrosis development in age determination in a Turkish population and to evaluate the reproducibility and reliability of cone beam computed tomography (CBCT) in an evaluation of the fusion stages of spheno-occipital synchondrosis. CBCT mid-sagittal images of 238 (90 males and 148 females) patients between the ages of 7 and 25, with a mean age of 15.45 ± 0.26 and 16.43 ± 0.37, respectively, were examined by three Oral and Maxillofacial Radiologists who evaluated the degree of synchondrosis fusion using a four-stage system. A reevaluation of 50 cases was conducted for intraobserver assessment. Multiple statistical analyses were used to assess the correlation between age and the fusion stage, to compare gender and age according to stages, and to evaluate the inter- and intraobserver agreement. The mean ages for complete fusion (Stage 3) were 18 and 20 for females and males, respectively. The interobserver agreement ranged between substantial and perfect, while the intraobserver agreement was substantial for all three observers. Based on these results, CBCT, when available, might be the method of choice for age estimation using the spheno-occipital synchondrosis fusion stages. Evaluating spheno-occipital synchondrosis has a value for age estimation around the age of 18 years, which affects the legal decisions in Turkey.     

Enhanced possibilities to make statements on the ossification status of the medial clavicular epiphysis using an amplified staging scheme in evaluating thin-slice CT scans

Thin-slice computed tomography provides the imaging modality of choice in analysing the ossification process of the medial clavicular epiphysis for the purpose of forensic age diagnostics in the living in the course of criminal proceedings. The classification of the ossification stages by Schmeling et al. compass the emergence of an epiphyseal ossification centre (stage 2), the partial fusion of the epiphysis with the metaphysis (stage 3), the complete fusion of these osseous elements including a visible epiphyseal scar (stage 4), and the complete fusion without a visible epiphyseal scar (stage 5). In the present study, each of the ossification stages 2 and 3 was divided into an early, intermediate and late phase. The authors evaluated the thin-slice CT scans of 185 patients aged between 13 and 26 years. In all these cases, a stage 2 or 3 had been determined in a previous study. The late stage 3, which is characterized by a fusion between metaphysis and epiphysis completing more than two thirds of the former epiphyseal gap, first appeared at age 19 in both sexes. If a late stage 3 is found, it is therefore possible to substantiate that an individual has already reached the legally important age threshold of 18 years.     

Magnetic resonance imaging of the proximal tibial epiphysis: could it be helpful in forensic age estimation?

There is an increasing demand for age estimations of living persons who are involved in civil and criminal procedures but lack a valid birth certificate indicating their date of birth. Several studies have recommended the application of magnetic resonance imaging (MRI) and assessment of the stage of epiphyseal fusion in age estimation. This study involved retrospective MRI analysis of 335 cases (217 males and 118 females) whose ages ranged from 8 to 28 years (yrs). We assessed the degree of ossification of the proximal tibial epiphysis depending on the classifications of Schmeling and Kellinghaus used for the main stages (I, II, III, IV & V) and substages (IIa, b, c & IIIa, b, c). Significant differences between males and females at stages IIIc, IV and V (p < 0.001) were observed. Additionally, the ossification of the proximal tibial epiphyses occurred earlier in females than in males (2–4 yrs). The mean of ages in stage IV was approximately 18.6 yrs. in females and 22.5 yrs. in males, meaning that stage IV can be used as a valuable forensic marker to determine whether the person in question has reached the age of 18 yrs. We concluded that the application of MRI in the assessment of the ossification status of the proximal tibial epiphysis could be helpful in age estimation for various forensic purposes.     

Evaluation of the ossification of the medial clavicular epiphysis with a digital ultrasonic system to determine the age threshold of 21 years

In this study, both medial clavicular epiphyses of 77 men were evaluated by two researchers with a digital ultrasound system. The degree of ossification was classified in four stages according to Schulz et al. (Int J Legal Med 122:55–58, 17). Of the test persons over 21 years of age, stage 4 was found bilaterally in 25 (60%), while for five (12%) stage 4 was found on only one side; 12 (28%) further subjects did not show stage 4 on either side, although nine were exactly 21 years old. For the subjects under 21 years of age, stage 4 was found bilaterally in three cases (8.5%), and in three additional cases stage 4 was found on one side. Particularly, the three cases in which stage 4 was diagnosed bilaterally before completion of the 21st year of age limit the value of the used examinatory technique. For these cases it would be interesting to know if parts of the epiphyseal plate that might have been obstructed from the view of the ultrasound transducer would have been visible with CT.     

Bone age estimation based on multislice computed tomography study of the scapula

Progress in medical imaging has opened new areas of research in forensic anthropology, especially in the context of the study of bone age assessment. The study of bone age has become a useful tool for age estimation at death or age of young adult migrants in an anthropological context. We retrospectively evaluated multislice computed tomography (MSCT) explorations focused on scapulae of 232 individuals (123 males; 109 females) aged between 8 and 30 years old. Computed tomography (CT) scans were viewed in axial and multiplanar reconstructed images using OsiriX 5.9 (64 bit)®. The ossification centers of the scapula studied were as follows: acromial, sub-coracoid, glenoid, coracoid, coracoid apex, and inferior angle epiphyses. Fusion status was scored based on a five-stage system (stage 1: no ossification, stage 2: visualization of an ossification center, stage 3: partial ossification, stage 4: full ossification associated to an epiphyseal scar, and stage 5: full ossification without epiphyseal scar). Intra-observer variability was excellent, and inter-observer variability was good, demonstrating the reliability of this MSCT staging system. The fusion of scapular ossification centers was statistically associated with age (p < 0.001) but not with sex (p > 0.05). In conclusion, MSCT of the scapula is an efficient method for age assessment, which is complementary to preexisting methods particularly for specifying the 18-year threshold. Further studies with larger groups are needed to support our results.

     

Radiographic staging of ossification of the medial clavicular epiphysis

Determination of the stage of ossification of the medial clavicular epiphysis is a crucial part of forensic age estimation when evaluating living subjects over 18 years of age. In the present study, we comparatively assessed conventional radiographs and computed tomography (CT) scans of sternoclavicular joints used to perform forensic age assessments in 57 individuals undergoing criminal proceedings. With CT, it was possible to determine the ossification stage of all clavicles studied. In the case of conventional radiography, reliable assessment of ossification stage was not possible in 15 out of 114 clavicles studied due to the superimposition of other structures. Regarding agreement between the methods, both radiography and CT produced identical staging results in 97 out of 99 clavicular epiphyses. In two cases, however, ossification was classified as stage 2 by CT and as stage 3 by conventional radiography. Regarding stages 4 and 5, both methods produced identical staging results in all cases. In forensic age estimation practice, it is necessary that conventional radiographic reference studies be used for ossification stage classification by conventional radiography and that CT reference studies be used for ossification stage classification by CT. Further studies in dead bodies of known age are required to issue a recommendation as to whether conventional radiography using obtained in three planes or CT is the method of choice for the assessment of clavicular ossification.     

The persistence of epiphyseal scars in the adult tibia

Estimation of chronological age from skeletal material is dependent upon estimation of maturational stage observed. Following completion of epiphyseal fusion, a transverse radio-opaque line, termed “epiphyseal scar”, may be observed in the region of the former growth plate. According to the literature, this line is likely to become obliterated shortly after completion of epiphyseal fusion. Consequently, presence of an epiphyseal scar has been interpreted as an indication of recent epiphyseal fusion; however, this has not been validated by quantitative research. A study was undertaken to determine persistence of the epiphyseal scars in a cross-sectional population of adults between 20 and 50 years of age. This study examined 1,216 radiographs of proximal and distal tibiae from both sexes and sides of the body. This study suggested that 98.05 % of females and 97.74 % of males retained some remnant of the epiphyseal scar at the proximal tibia whilst 92.72 % of females and 92.95 % of males retained some remnant of the epiphyseal scar at the distal tibia. General linear model (GLM) analysis determined that chronological age accounted for 2.7 % and 7.6 % of variation in persistence of the epiphyseal scar at the proximal and distal tibiae, respectively. This study suggests that obliteration of the epiphyseal scar is not as dependent on chronological age as previously thought. It is, therefore, recommended that this feature not be used as an indicator of chronological age during forensic age assessment.