Computed tomographic analysis of medial clavicular epiphyseal fusion for age estimation in Indian population

Forensic age estimation is a crucial aspect of the identification process. While epiphyseal fusion of long bones has been studied for age estimation since a long time, over the past few years, the role of medial clavicular epiphyseal fusion in age estimation is being explored. The medial clavicular epiphyseal fusion can be used to estimate age in young adults, and can also determine whether medicolegally significant ages of 16 and 18 years have been attained by an individual. The present study aimed at generating regression models to estimate age by evaluating the medial clavicular epiphyseal fusion in Indian population using Schmeling et al. and Kellinghaus et al. method, and to assess whether an individual’s age is over medicolegally significant thresholds of 16 and 18 years. Degree of ossification of the medial clavicular epiphysis was studied in CT images of 350 individuals aged 10.01–35.47 years. Significant statistical correlation (P < 0.001) was observed between the degree of fusion and the chronological age of the participants, with Spearman’s correlation (ρ) = 0.918 in females, and ρ = 0.905 in males. Regression models were generated using degree of ossification of medial end of clavicle of 350 individuals (147 females and 203 males) and these models were applied on a test set of 50 individuals (25 females and 25 males). Mean absolute error of 1.50 for females, 1.14 for males, and 1.32 for the total test set was observed when the variance between the chronological ages and estimated ages was calculated.     

Radiographic analysis of epiphyseal fusion at knee joint to assess likelihood of having attained 18 years of age

Radiological analysis of the epiphyses of the knee joint provides new valuable information, which may be used in combination with these well-established techniques in order to maximise the accuracy in the assessment of age of 18?years. A total of 215 antero-posterior radiographs of the knee was reviewed retrospectively in patients aged between 14 and 24?years old (99 boys, 116 girls). Fusion was scored as stage 1, epiphysis not fused; stage 2, epiphysis is fully ossified and epiphyseal scar is visible; and stage 3, epiphysis is fully ossified and epiphyseal scar is not visible. Scores of 0, 1 and 2 were assigned to stages 1, 2 and 3, respectively. Lastly, the score related to epiphyseal fusion at the knee joint was obtained by adding the three scores of the distal femur, proximal tibia and proximal fibula. Age distribution gradually increased with each score, for both genders. The mean age (±standard error) in each score category varied between genders, but the differences were not significant (p?>?0.11). Five tests were performed to discriminate between individuals who were or were not at age 18?years or more, according to the receiver operating curve. For boys, the highest value of accuracy was obtained with score 3, with high sensitivity (Se?=?93.33?%) and specificity (Sp?=?89.29?%). For girls, it was obtained with score 4, with high accuracy (Acc?=?85.86?%). These results indicate that radiographic analysis of the knee is a valuable alternative as a non-invasive method of estimation of 18?years of age.     

Forensic age prediction and age classification for critical age thresholds via 3.0T magnetic resonance imaging of the knee in the Chinese Han population

Objectives

To assess the performance of knee MRI for forensic age prediction and classification for 12-, 14-, 16-, and 18-year thresholds.

Methods

The ossification stages of distal femoral epiphyses and proximal tibial epiphyses were assessed using an integrated staging system by Schmeling et al. and Kellinghaus et al. for knee 3.0T MRI with T1-weighted turbo spin-echo (T1-TSE) in sagittal orientation among 852 Chinese Han individuals (483 males and 369 females) aged 7–30 years. Regression models for age prediction were constructed and their performances were evaluated based on mean absolute deviation (MAD) values. In addition, the performances of age classification were assessed using receiver operating characteristic (ROC) analyses.

Results

The intra- and inter-observer agreement levels were very good (κ > 0.80). The complete fusion of those two types of epiphyses took place before 18.0 years in our study participants. The minimum MAD values were 2.51 years (distal femur) and 2.69 years (proximal tibia) in males, and 2.75 years (distal femur) and 2.87 years (proximal tibia) in females. The specificity values of constructed prediction models were all above 90% for the 12-, 14-, and 16-year thresholds, compared to the 74.8–84.6% for the 18-year threshold. Better performances of age prediction and classification were observed in males by distal femoral epiphyses.

Conclusions

Ossification stages via 3.0T MRI of the knee with T1-TSE sequence using an integrated staging system could be a reliable noninvasive method for age prediction or for age classification for 12-, 14-, and 16-year thresholds, especially in males by distal femoral epiphyses. However, assessments based on the full bony fusion of the distal femoral epiphysis and proximal tibial epiphysis seemed not reliable for age classification for the 18-year threshold in the Chinese Han population.

     

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.     

The anterior tilt angle of the proximal tibia epiphyseal plate: A significant radiological finding in young children with trampoline fractures

Objective

Evaluation of the anterior tilt angle of the proximal tibia epiphyseal plate in young children, which suffered a trampoline fracture in comparison with a normal population.

Materials and methods

62 children (31 females, 31 males) between 2 and 5 years of age (average 2 years 11 months, standard deviation 11 months) with radiographs in two views of the tibia were included in this retrospective study. 25 children with proximal tibia fractures were injured with a history of jumping on a trampoline. All other causes for tibia fractures were excluded. A normal age-mapped control cohort of 37 children was compared. These children had neither evidence of a trampoline related injury nor a fracture of the tibia. The anterior tilt angle of the epiphyseal plate of the tibia was defined as an angle between the proximal tibia physis and the distal tibia physis on a lateral view. Two radiologists evaluated all radiographs for fractures and measured the anterior tilt angle in consensus. An unpaired Student's t-test was used for statistical analysis (SPSS). Original reports were reviewed and compared with the radiological findings and follow-up radiographs.

Results

In the normal control group, the average anterior tilt angle measured −3.2°, SD ± 2.8°. The children with trampoline fractures showed an anterior tilt of +4.4°, SD ± 2.9°. The difference was statistically significant, P < 0.0001. In 6 patients (24% of all patients with confirmed fractures) the original report missed to diagnose the proximal tibial fracture.

Conclusion

Young children between 2 and 5 years of age are at risk for proximal tibia fractures while jumping on a trampoline. These fractures may be very subtle and difficult to detect on initial radiographs. Measurement of the anterior tilt angle of the proximal tibia epiphyseal plate on lateral radiographs is supportive for interpreting correctly trampoline fractures.     

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.     

Evaluation of an automatic method for forensic age estimation by magnetic resonance imaging of the distal tibial epiphysis—a preliminary study focusing on the 18-year threshold

The contribution of magnetic resonance imaging to forensic age estimation of living individuals is a subject of ongoing research. Several studies have focused on the wrist, clavicle, knee, and foot, and shown interesting results regarding the 18-year threshold. Authors have developed various staging systems for epiphyseal growth plate maturation. However, the procedure is observer-dependent and requires experience and a certain time-learning process. To reduce these pitfalls, we have developed an automatic method based on the analysis of variations of gray levels within the epiphyseal–metaphyseal junction. This method was tested on 160 MRI scans of the distal tibial epiphysis in a sample of individuals aged from 8 to 25 years old, after intensity non-uniformity correction of all images. Results showed that in our sample, 97.4 % of males and 93.9 % of females aged 18 years or more would be correctly classified using this method. To our knowledge, automatic methods for MRI analysis have not been used in the field of age estimation yet. Further studies should be performed to assess the validity of this procedure.     

空心螺钉固定治疗儿童胫骨远端骨骺骨折

目的探讨空心螺钉固定治疗儿童胫骨远端骨骺骨折的疗效。方法回顾性分析2014年1月—2016年2月32例闭合或切开复位治疗的有移位的儿童胫骨远端骨骺骨折,采用空心螺钉内固定治疗。其中男性21例,女性11例;年龄3~14岁,平均9.4岁。摔伤26例,高处坠落伤3例,道路交通伤3例。术后按照Teeny功能评定标准、踝关节功能评分评价疗效。结果所有患儿均获得4~15个月的随访,平均7.6个月。32例骨折均愈合,时间为8~12周,平均11周,无一例出现骨不连或骨延迟愈合。X线片示所有病例达骨性愈合,未出现骨骺早闭及骨骺停止生长,无胫骨短缩、成角畸形。踝关节功能Teeny评分显示:优29例,良3例,优良率100%。结论空心螺钉内固定治疗儿童胫骨远端骨骺骨折疗效满意,是一种有效的治疗方法。     

Biometric sex assessment from the femur and tibia in a modern Greek population

Forensic anthropologists assess sex by analysing quantitative and qualitative characters of the human skeleton. In general, the pelvis and skull are the skeletal regions used most often, but in many cases, they are missing or fragmentary. In such circumstances, where only limb bones are present, it is necessary to use techniques based on other skeletal elements. Metric traits of the long bones of the lower extremities have been reported as reliable indicators of sex. This study was designed to determine whether the two main long bones of the leg, the femur and tibia, can be used for the assessment of sex on a Greek skeletal population. The skeletal sample used in this study comes from the modern human skeletal collection that is currently housed at the National and Kapodistrian University of Athens and is known as The Athens Collection. It consists of 371 femora and 372 tibiae corresponding to 200 adult individuals (111 males and 89 females). The age range is 19–96 years for males and 20–99 years for females. The maximum lengths and epiphyseal widths were measured for the present study, and it was found that the discriminant analysis of the metrical data of each long bone provided high sex discrimination accuracies. The rate of correct sex discrimination based on different long bones ranged from 91.50 % (left femur) to 93.40 % (left tibia). Our results suggest that lower limb bones can be used effectively for sexing in forensic contexts, in addition to other sex assessment techniques.     

Sports-related epiphyseal injuries of the lower extremity. An epidemiologic study.

Sports-related epiphyseal injuries in children and adolescents have been becoming more prevalent during recent years. We report 85 patients with epiphyseal fractures of the lower extremity treated in our hospital during the last twenty years, of which 60 were males and 25 females with an average age of 12.6 years (range 4 to 17 years of age). The injuries were sustained during soccer in 28% and during alpine skiing in 26% of the cases, of which the former was responsible for most of the injuries reported in males and the latter for those in females. The most frequently seen localizations were in the distal tibial epiphysis (31 cases), followed by the distal fibula (17) and the proximal tibial epiphysis (15). Of the reported 85 epiphyseal fractures 30 were Salter-Harris type I injuries, 25 type II, 8 type III and 11 were type IV fractures, while 11 were avulsion fractures. Of these patients, 56% were treated surgically, while conservative treatment was chosen for 44% of the patients. Of the 49 patients available for follow-up, complications were documented in 9 instances, including 3 leg length discrepancies, 4 axis deviations, one avascular necrosis of the femoral head and one case of osteomyelitis, of which 6 required corrective surgery.     

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.

     

Is the contralateral tibia a reliable template for reconstruction: a three-dimensional anatomy cadaveric study

Purpose

The contralateral anatomy is regularly used as a reconstruction template for corrective osteotomies of several deformities and pathological conditions. However, there is lack of evidence that the intra-individual differences between both tibiae are sufficiently small to use the contralateral tibia as a 3D reconstruction template for complex osteotomies. The aim of this study was to evaluate the intra-individual side differences of the tibia in length, torsion, angulation, and translation using 3D measurement techniques.

Methods

3D surface models of both tibiae were created from computed tomography data of 51 cadavers. The (mirrored) models of the right tibiae were divided into two halves at the centre of the shaft. Thereafter, the proximal and distal segments were aligned to the left (contralateral) tibia in an automated fashion. The relative 3D transformation between both aligned segments was measured to quantify the side difference in 6° of freedom (3D translation vector, 3 angles of rotation).

Results

The mean side difference in tibia length was 2.1 mm (SD 1.3 mm; range 0.2–5.9 mm). The mean side difference in torsion was 4.9° (SD 4.1°; range 0.2°–17.6°). The mean side difference in the coronal and sagittal planes was 1.1° (SD 0.9°; range 0.0°–4.6°) and 1.0° (SD 0.8°; range 0.1°–2.9°), respectively.

Conclusion

The present study confirms small side differences in torsion between the left and right tibia, while the side differences in the coronal and sagittal plane are probably negligible. The contralateral tibia seems to be a reliable reconstruction template for the 3D preoperative planning of complex corrective osteotomies of the tibia. However, torsional differences should be interpreted with caution, as a single cut-off value of a clinically relevant torsional side difference cannot be defined. The presented results are relevant to surgeons considering the contralateral tibia as a 3D reconstruction template for corrective osteotomies of the tibia.

Level of evidence

Basic science.

     

A preliminary anthropometric study of height and sex determination using percutaneous humeral and tibial lengths

Height, age and sex determination from different bones of the body are helpful for establishing the identity of an individual. In developed countries, established osteometric data exist for height and sex determination. However, very little information is available on the use of osteometric indices for forensic and biometric purposes in Ghana. Therefore, the aim of this study was to determine height and sex of participants using percutaneous humeral and tibial lengths. One hundred undergraduate students were recruited from the Kwame Nkrumah University of Science and Technology with 55% males and 45% females aged between 18 and 43 years for the study. Male participants had longer humeri and tibiae than females (p < 0.05). In both male and female participants, right humeri were slightly longer than the left, and left tibiae were slightly longer than the right, but these differences were not statistically significant. Mean humeral and tibial lengths of the study population differed significantly from those reported for Indians, Nigerians, Turks and Iranians. Tibial length was a better estimator of osteometric index for height and left humeral length was the only sexually dimorphic parameter, making these indices useful tools for preliminary height and sex determination.     

Activation of the growth plates on three-phase bone scintigraphy: the explanation for the overgrowth of fractured femurs

Children with an uncomplicated femoral fracture, treated with superimposition of fragments and intentional shortening, usually develop overgrowth of the fractured femur and the ipsilateral tibia which may compensate for the initial shortening and enable the limb in question to reach a length similar to that on the normal side. The overgrowth is evaluated clinically and by scanography. The increased metabolic activity of the growth plates that support this overgrowth has not been documented by any laboratory method. In order to evaluate the metabolic activity of the growth plates, 18 patients (11 males, seven females; mean age 6.1 years) with fractures of the femur were studied at three different time intervals (2-5 months, 6-12 months and 18-24 months). Three-phase bone scintigraphy was performed in all patients. Ten children (five males, five females; mean age 7.5 years) who had had bone imaging for other reasons were used as the control group. Visual analysis of the flow and equilibrium phases was performed for the distal femoral and proximal tibial growth plates. Visual and semi-quantitative analyses of the delayed images were performed for the distal femoral and proximal and distal tibial growth plates. Semi-quantitative analyses yielded the following activity ratios: (a) the distal femoral growth plate of the fractured femur to the contralateral one (FR); (b) the proximal growth plate of the tibia on the side of the fractured femur to the contralateral one (TpR); (c) the distal growth plate of the tibia on the side of the fractured femur to the contralateral one (TdR); and (d) in the control group, the distal growth plates of both femora (FCG) and the proximal (TCGp) and distal (TCGd) growth plates of the tibiae. Visual analysis of the blood flow, equilibrium and delayed images showed increased activity in the distal femoral growth plates during the first and second time intervals, but not during the third. No significant activity changes were found in the proximal and distal tibial growth plates during any of the phases analysed. The mean and standard deviation for FR in the three time intervals were: FRI=1.22+/-0.27, FRII=1.17+/-0.16 and FRIII=1.09+/-0.20. FR values were significantly higher than in the control group (FCG=0.99+/-0.03) (P=0.033). The mean and standard deviation for TpR in the three time intervals were: TpRI=1.08+/-0.18, TpRII=0.94+/-0.09 and TpRIII=0.96+/-0.20. TpR values were not significantly different from those in the control group (TCGp=1.00+/-0.05). However, TpRI was significantly higher than TpRII (P=0.043). The mean and standard deviation for TdR in the three time intervals were: TdRI=1.10+/-0.41, TdRII=1.05+/-0.15 and TdRIII=1.13+/-0.36. TdR values were not significantly higher than in the control group (TCGd=1.00+/-0.04) (P=0.777). These results support the concept that three-phase bone imaging is able to quantify and determine that activation occurs in the distal femoral and proximal tibial growth plates of fractured femora. This phenomenon may explain the overgrowth observed in this injured bone structure.     

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.     

Age estimation by magnetic resonance imaging of the distal tibial epiphysis and the calcaneum

Age estimation of living individuals is of critical importance in forensic practice, especially because of the increased migration in developed countries. Recently, the contribution of magnetic resonance imaging (MRI) to age evaluation has been studied, as it seems to be an efficient technique to analyze growth plate maturation and epiphyseal fusion. We developed an MRI staging system for the distal tibial epiphysis and the calcaneal epiphysis and evaluated its reliability on 180 MRI scans of the ankle and foot in a sample of individuals aged from 8 to 25 years old. For both bones, the degree of union between the metaphysis and epiphysis was classified in three stages. Intra- and inter-observer variabilities were good, showing the validity and reproducibility of the method. Our results were consistent with data in the literature indicating that both epiphyses mature earlier in females than in males. Bayesian predictive probabilities were used to assess the validity of our method in estimating the age of an individual in relation to the 18-year threshold. MRI of the ankle and foot can be used in association with other methods to estimate age in living individuals.     

Estimation of stature using fragmentary femur and tibia lengths in a Thai population

Stature estimation is one of the most important parameters for human identification. The current study aimed to investigate the relationship between stature and femur and tibia measurements other than length in modern Thai skeletons, and to derive regression equations that can be used for living stature estimation when complete bones are unavailable. The sample consisted of 159 males and 96 females. We used two analytical methods, i.e. direct 1-step and indirect 2-step. Results showed that the upper breadth of the femur from males and the maximum anteroposterior diameter of the lateral condyle from females were the best estimators of stature. Maximum proximal breadth of the tibia showed the lowest standard error values in males and females. The derived equations were tested on a holdout sample in which the distal breadth of the tibia exhibited the lowest mean absolute error in both males and females, while in the femur measurements, the maximum anteroposterior diameter of the lateral condyle produced the lowest mean absolute error in males, and an absolute mean value from vertical head diameter in females. The present study suggests that measurements taken from damaged bones can be used for stature estimation.     

Age estimation of immature human skeletal remains using the post-natal development of the occipital bone

Whenever age cannot be estimated from dental formation in immature human skeletal remains, other methods are required. In the post-natal period, development of the skeleton provides alternative age indicators, namely, those associated with skeletal maturity of the cranium. This study wishes to document the age at which the various ossification centres in the occipital bone fuse and provide readily available developmental probabilistic information for use in age estimation. A sample of 64 identified immature skeletons between birth and 8 years of age from the Lisbon collection was used (females?=?29, males?=?35). Results show that fusion occurs first in the posterior intra-occipital synchondrosis and between the jugular and condylar limbs of the lateral occipital to form the hypoglossal canal (1–4 years), followed by the anterior intra-occipital (3–7 years). Fusion of the post-natal occipital does not show differences in timing between males and females. Relative to other published sources, this study documents first and last ages of fusion of several ossification centres and the posterior probabilities of age given a certain stage of fusion. Given the least amount of overlap in stages of fusion, the closure of the hypoglossal canal provides the narrowest estimated age with the highest probability of age.     

Mediolateral oversizing influences pain, function, and flexion after TKA

Purpose

Manufacturers of total knee arthroplasty (TKA) have introduced narrower femurs to improve bone-implant fit. However, few studies have reported the clinical consequences of mediolateral oversizing. Our hypothesis was that component oversizing negatively influences the results after TKA.

Methods

One hundred and twelve prospectively followed patients with 114 consecutive TKA (64 females and 50 males) were retrospectively assessed. The mean age of the patients was 72 years (range, 56 to 85 years). The dimensions of the femur and tibia were measured on a preoperative CT-scan and were compared with those of the implanted TKA. The influence of size variation on the clinical outcomes 1 year after surgery was assessed.

Results

Mediolateral overhang was observed in at least one area in 66 % of the femurs (84 % in females and 54 % in males) and 61 % of the tibia (81 % in females and 40 % in males). Twenty-two patients presented no overhang in any area and 16 had overhang in all studied zones. The increase in the Pain and KOOS scores were 43 ± 21 and 36 ± 18 in the patients without overhang and 31 ± 19 and 25 ± 13 in patients with overhang (p = 0.033; p = 0.032). Knee flexion was 127° ± 7 and 121° ± 11, respectively. Regression and latent class analysis showed a significant negative correlation between overall oversizing and overall outcome.

Conclusions

This study confirms that oversizing may lead to worse clinical results in TKA. The clinical consequences are that surgeons should pay attention not to oversize implants during implantation nd that oversizing should be ruled out in case of so called unexplained pain.

Level of evidence

IV.     

Validity of different dental age estimation methods in Pakistani orthodontic patients

This research aims to evaluate the validity of Demirjian’s (1973), Nolla’s (1960) and Willem’s (2001) methods of dental age (DA) estimation in Pakistani orthodontic patients (8–16.9 years). It also addresses the validity of these methods in determining dental maturity across the gender and compares the difference between original Demirjian tables (based on French-Canadian standards) and Pakistani tables formulated by Sukhia et al. (2012). Orthopantomograms of 403 subjects (males?=?176, females?=?227) were examined for DA assessment by different methods. Paired t-test and Wilcoxon signed-ranked tests were used to determine significant differences between mean dental and chronological age among different age groups. Correlation between DA and CA were assessed by the Spearman’s correlation (p?=?≤0.05). Nolla’s method under-estimated the DA by 1.00 ± 1.54 in males and over-estimated by 0.21 ± 1.64 in females. DA was significantly advanced using Pakistani tables (males?=?0.32 ± 1.17, females?=?0.38 ± 1.33 years) and Willem’s method (males?=?0.31 ± 1.09, females?=?0.29 ± 0.48 years). DA correlated better with CA using Pakistani tables compared with the French-Canadian standards. Earlier dental maturation was reported in females compared with males using Demirjian’s and Nolla’s methods. Strong correlations were found between CA and DA according to all methods (p < 0.001). Overall, Willem’s method was identified as the most valid method for DA estimation in the Pakistani sample.